1 /* 2 SDL - Simple DirectMedia Layer 3 Copyright (C) 1997-2006 Sam Lantinga 4 5 This library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 This library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with this library; if not, write to the Free Software 17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 18 19 Sam Lantinga 20 slouken (at) libsdl.org 21 */ 22 #include "SDL_config.h" 23 24 /* This file contains portable memory management functions for SDL */ 25 26 #include "SDL_stdinc.h" 27 28 #ifndef HAVE_MALLOC 29 30 #define LACKS_SYS_TYPES_H 31 #define LACKS_STDIO_H 32 #define LACKS_STRINGS_H 33 #define LACKS_STRING_H 34 #define LACKS_STDLIB_H 35 #define ABORT 36 37 /* 38 This is a version (aka dlmalloc) of malloc/free/realloc written by 39 Doug Lea and released to the public domain, as explained at 40 http://creativecommons.org/licenses/publicdomain. Send questions, 41 comments, complaints, performance data, etc to dl (at) cs.oswego.edu 42 43 * Version 2.8.3 Thu Sep 22 11:16:15 2005 Doug Lea (dl at gee) 44 45 Note: There may be an updated version of this malloc obtainable at 46 ftp://gee.cs.oswego.edu/pub/misc/malloc.c 47 Check before installing! 48 49 * Quickstart 50 51 This library is all in one file to simplify the most common usage: 52 ftp it, compile it (-O3), and link it into another program. All of 53 the compile-time options default to reasonable values for use on 54 most platforms. You might later want to step through various 55 compile-time and dynamic tuning options. 56 57 For convenience, an include file for code using this malloc is at: 58 ftp://gee.cs.oswego.edu/pub/misc/malloc-2.8.3.h 59 You don't really need this .h file unless you call functions not 60 defined in your system include files. The .h file contains only the 61 excerpts from this file needed for using this malloc on ANSI C/C++ 62 systems, so long as you haven't changed compile-time options about 63 naming and tuning parameters. If you do, then you can create your 64 own malloc.h that does include all settings by cutting at the point 65 indicated below. Note that you may already by default be using a C 66 library containing a malloc that is based on some version of this 67 malloc (for example in linux). You might still want to use the one 68 in this file to customize settings or to avoid overheads associated 69 with library versions. 70 71 * Vital statistics: 72 73 Supported pointer/size_t representation: 4 or 8 bytes 74 size_t MUST be an unsigned type of the same width as 75 pointers. (If you are using an ancient system that declares 76 size_t as a signed type, or need it to be a different width 77 than pointers, you can use a previous release of this malloc 78 (e.g. 2.7.2) supporting these.) 79 80 Alignment: 8 bytes (default) 81 This suffices for nearly all current machines and C compilers. 82 However, you can define MALLOC_ALIGNMENT to be wider than this 83 if necessary (up to 128bytes), at the expense of using more space. 84 85 Minimum overhead per allocated chunk: 4 or 8 bytes (if 4byte sizes) 86 8 or 16 bytes (if 8byte sizes) 87 Each malloced chunk has a hidden word of overhead holding size 88 and status information, and additional cross-check word 89 if FOOTERS is defined. 90 91 Minimum allocated size: 4-byte ptrs: 16 bytes (including overhead) 92 8-byte ptrs: 32 bytes (including overhead) 93 94 Even a request for zero bytes (i.e., malloc(0)) returns a 95 pointer to something of the minimum allocatable size. 96 The maximum overhead wastage (i.e., number of extra bytes 97 allocated than were requested in malloc) is less than or equal 98 to the minimum size, except for requests >= mmap_threshold that 99 are serviced via mmap(), where the worst case wastage is about 100 32 bytes plus the remainder from a system page (the minimal 101 mmap unit); typically 4096 or 8192 bytes. 102 103 Security: static-safe; optionally more or less 104 The "security" of malloc refers to the ability of malicious 105 code to accentuate the effects of errors (for example, freeing 106 space that is not currently malloc'ed or overwriting past the 107 ends of chunks) in code that calls malloc. This malloc 108 guarantees not to modify any memory locations below the base of 109 heap, i.e., static variables, even in the presence of usage 110 errors. The routines additionally detect most improper frees 111 and reallocs. All this holds as long as the static bookkeeping 112 for malloc itself is not corrupted by some other means. This 113 is only one aspect of security -- these checks do not, and 114 cannot, detect all possible programming errors. 115 116 If FOOTERS is defined nonzero, then each allocated chunk 117 carries an additional check word to verify that it was malloced 118 from its space. These check words are the same within each 119 execution of a program using malloc, but differ across 120 executions, so externally crafted fake chunks cannot be 121 freed. This improves security by rejecting frees/reallocs that 122 could corrupt heap memory, in addition to the checks preventing 123 writes to statics that are always on. This may further improve 124 security at the expense of time and space overhead. (Note that 125 FOOTERS may also be worth using with MSPACES.) 126 127 By default detected errors cause the program to abort (calling 128 "abort()"). You can override this to instead proceed past 129 errors by defining PROCEED_ON_ERROR. In this case, a bad free 130 has no effect, and a malloc that encounters a bad address 131 caused by user overwrites will ignore the bad address by 132 dropping pointers and indices to all known memory. This may 133 be appropriate for programs that should continue if at all 134 possible in the face of programming errors, although they may 135 run out of memory because dropped memory is never reclaimed. 136 137 If you don't like either of these options, you can define 138 CORRUPTION_ERROR_ACTION and USAGE_ERROR_ACTION to do anything 139 else. And if if you are sure that your program using malloc has 140 no errors or vulnerabilities, you can define INSECURE to 1, 141 which might (or might not) provide a small performance improvement. 142 143 Thread-safety: NOT thread-safe unless USE_LOCKS defined 144 When USE_LOCKS is defined, each public call to malloc, free, 145 etc is surrounded with either a pthread mutex or a win32 146 spinlock (depending on WIN32). This is not especially fast, and 147 can be a major bottleneck. It is designed only to provide 148 minimal protection in concurrent environments, and to provide a 149 basis for extensions. If you are using malloc in a concurrent 150 program, consider instead using ptmalloc, which is derived from 151 a version of this malloc. (See http://www.malloc.de). 152 153 System requirements: Any combination of MORECORE and/or MMAP/MUNMAP 154 This malloc can use unix sbrk or any emulation (invoked using 155 the CALL_MORECORE macro) and/or mmap/munmap or any emulation 156 (invoked using CALL_MMAP/CALL_MUNMAP) to get and release system 157 memory. On most unix systems, it tends to work best if both 158 MORECORE and MMAP are enabled. On Win32, it uses emulations 159 based on VirtualAlloc. It also uses common C library functions 160 like memset. 161 162 Compliance: I believe it is compliant with the Single Unix Specification 163 (See http://www.unix.org). Also SVID/XPG, ANSI C, and probably 164 others as well. 165 166 * Overview of algorithms 167 168 This is not the fastest, most space-conserving, most portable, or 169 most tunable malloc ever written. However it is among the fastest 170 while also being among the most space-conserving, portable and 171 tunable. Consistent balance across these factors results in a good 172 general-purpose allocator for malloc-intensive programs. 173 174 In most ways, this malloc is a best-fit allocator. Generally, it 175 chooses the best-fitting existing chunk for a request, with ties 176 broken in approximately least-recently-used order. (This strategy 177 normally maintains low fragmentation.) However, for requests less 178 than 256bytes, it deviates from best-fit when there is not an 179 exactly fitting available chunk by preferring to use space adjacent 180 to that used for the previous small request, as well as by breaking 181 ties in approximately most-recently-used order. (These enhance 182 locality of series of small allocations.) And for very large requests 183 (>= 256Kb by default), it relies on system memory mapping 184 facilities, if supported. (This helps avoid carrying around and 185 possibly fragmenting memory used only for large chunks.) 186 187 All operations (except malloc_stats and mallinfo) have execution 188 times that are bounded by a constant factor of the number of bits in 189 a size_t, not counting any clearing in calloc or copying in realloc, 190 or actions surrounding MORECORE and MMAP that have times 191 proportional to the number of non-contiguous regions returned by 192 system allocation routines, which is often just 1. 193 194 The implementation is not very modular and seriously overuses 195 macros. Perhaps someday all C compilers will do as good a job 196 inlining modular code as can now be done by brute-force expansion, 197 but now, enough of them seem not to. 198 199 Some compilers issue a lot of warnings about code that is 200 dead/unreachable only on some platforms, and also about intentional 201 uses of negation on unsigned types. All known cases of each can be 202 ignored. 203 204 For a longer but out of date high-level description, see 205 http://gee.cs.oswego.edu/dl/html/malloc.html 206 207 * MSPACES 208 If MSPACES is defined, then in addition to malloc, free, etc., 209 this file also defines mspace_malloc, mspace_free, etc. These 210 are versions of malloc routines that take an "mspace" argument 211 obtained using create_mspace, to control all internal bookkeeping. 212 If ONLY_MSPACES is defined, only these versions are compiled. 213 So if you would like to use this allocator for only some allocations, 214 and your system malloc for others, you can compile with 215 ONLY_MSPACES and then do something like... 216 static mspace mymspace = create_mspace(0,0); // for example 217 #define mymalloc(bytes) mspace_malloc(mymspace, bytes) 218 219 (Note: If you only need one instance of an mspace, you can instead 220 use "USE_DL_PREFIX" to relabel the global malloc.) 221 222 You can similarly create thread-local allocators by storing 223 mspaces as thread-locals. For example: 224 static __thread mspace tlms = 0; 225 void* tlmalloc(size_t bytes) { 226 if (tlms == 0) tlms = create_mspace(0, 0); 227 return mspace_malloc(tlms, bytes); 228 } 229 void tlfree(void* mem) { mspace_free(tlms, mem); } 230 231 Unless FOOTERS is defined, each mspace is completely independent. 232 You cannot allocate from one and free to another (although 233 conformance is only weakly checked, so usage errors are not always 234 caught). If FOOTERS is defined, then each chunk carries around a tag 235 indicating its originating mspace, and frees are directed to their 236 originating spaces. 237 238 ------------------------- Compile-time options --------------------------- 239 240 Be careful in setting #define values for numerical constants of type 241 size_t. On some systems, literal values are not automatically extended 242 to size_t precision unless they are explicitly casted. 243 244 WIN32 default: defined if _WIN32 defined 245 Defining WIN32 sets up defaults for MS environment and compilers. 246 Otherwise defaults are for unix. 247 248 MALLOC_ALIGNMENT default: (size_t)8 249 Controls the minimum alignment for malloc'ed chunks. It must be a 250 power of two and at least 8, even on machines for which smaller 251 alignments would suffice. It may be defined as larger than this 252 though. Note however that code and data structures are optimized for 253 the case of 8-byte alignment. 254 255 MSPACES default: 0 (false) 256 If true, compile in support for independent allocation spaces. 257 This is only supported if HAVE_MMAP is true. 258 259 ONLY_MSPACES default: 0 (false) 260 If true, only compile in mspace versions, not regular versions. 261 262 USE_LOCKS default: 0 (false) 263 Causes each call to each public routine to be surrounded with 264 pthread or WIN32 mutex lock/unlock. (If set true, this can be 265 overridden on a per-mspace basis for mspace versions.) 266 267 FOOTERS default: 0 268 If true, provide extra checking and dispatching by placing 269 information in the footers of allocated chunks. This adds 270 space and time overhead. 271 272 INSECURE default: 0 273 If true, omit checks for usage errors and heap space overwrites. 274 275 USE_DL_PREFIX default: NOT defined 276 Causes compiler to prefix all public routines with the string 'dl'. 277 This can be useful when you only want to use this malloc in one part 278 of a program, using your regular system malloc elsewhere. 279 280 ABORT default: defined as abort() 281 Defines how to abort on failed checks. On most systems, a failed 282 check cannot die with an "assert" or even print an informative 283 message, because the underlying print routines in turn call malloc, 284 which will fail again. Generally, the best policy is to simply call 285 abort(). It's not very useful to do more than this because many 286 errors due to overwriting will show up as address faults (null, odd 287 addresses etc) rather than malloc-triggered checks, so will also 288 abort. Also, most compilers know that abort() does not return, so 289 can better optimize code conditionally calling it. 290 291 PROCEED_ON_ERROR default: defined as 0 (false) 292 Controls whether detected bad addresses cause them to bypassed 293 rather than aborting. If set, detected bad arguments to free and 294 realloc are ignored. And all bookkeeping information is zeroed out 295 upon a detected overwrite of freed heap space, thus losing the 296 ability to ever return it from malloc again, but enabling the 297 application to proceed. If PROCEED_ON_ERROR is defined, the 298 static variable malloc_corruption_error_count is compiled in 299 and can be examined to see if errors have occurred. This option 300 generates slower code than the default abort policy. 301 302 DEBUG default: NOT defined 303 The DEBUG setting is mainly intended for people trying to modify 304 this code or diagnose problems when porting to new platforms. 305 However, it may also be able to better isolate user errors than just 306 using runtime checks. The assertions in the check routines spell 307 out in more detail the assumptions and invariants underlying the 308 algorithms. The checking is fairly extensive, and will slow down 309 execution noticeably. Calling malloc_stats or mallinfo with DEBUG 310 set will attempt to check every non-mmapped allocated and free chunk 311 in the course of computing the summaries. 312 313 ABORT_ON_ASSERT_FAILURE default: defined as 1 (true) 314 Debugging assertion failures can be nearly impossible if your 315 version of the assert macro causes malloc to be called, which will 316 lead to a cascade of further failures, blowing the runtime stack. 317 ABORT_ON_ASSERT_FAILURE cause assertions failures to call abort(), 318 which will usually make debugging easier. 319 320 MALLOC_FAILURE_ACTION default: sets errno to ENOMEM, or no-op on win32 321 The action to take before "return 0" when malloc fails to be able to 322 return memory because there is none available. 323 324 HAVE_MORECORE default: 1 (true) unless win32 or ONLY_MSPACES 325 True if this system supports sbrk or an emulation of it. 326 327 MORECORE default: sbrk 328 The name of the sbrk-style system routine to call to obtain more 329 memory. See below for guidance on writing custom MORECORE 330 functions. The type of the argument to sbrk/MORECORE varies across 331 systems. It cannot be size_t, because it supports negative 332 arguments, so it is normally the signed type of the same width as 333 size_t (sometimes declared as "intptr_t"). It doesn't much matter 334 though. Internally, we only call it with arguments less than half 335 the max value of a size_t, which should work across all reasonable 336 possibilities, although sometimes generating compiler warnings. See 337 near the end of this file for guidelines for creating a custom 338 version of MORECORE. 339 340 MORECORE_CONTIGUOUS default: 1 (true) 341 If true, take advantage of fact that consecutive calls to MORECORE 342 with positive arguments always return contiguous increasing 343 addresses. This is true of unix sbrk. It does not hurt too much to 344 set it true anyway, since malloc copes with non-contiguities. 345 Setting it false when definitely non-contiguous saves time 346 and possibly wasted space it would take to discover this though. 347 348 MORECORE_CANNOT_TRIM default: NOT defined 349 True if MORECORE cannot release space back to the system when given 350 negative arguments. This is generally necessary only if you are 351 using a hand-crafted MORECORE function that cannot handle negative 352 arguments. 353 354 HAVE_MMAP default: 1 (true) 355 True if this system supports mmap or an emulation of it. If so, and 356 HAVE_MORECORE is not true, MMAP is used for all system 357 allocation. If set and HAVE_MORECORE is true as well, MMAP is 358 primarily used to directly allocate very large blocks. It is also 359 used as a backup strategy in cases where MORECORE fails to provide 360 space from system. Note: A single call to MUNMAP is assumed to be 361 able to unmap memory that may have be allocated using multiple calls 362 to MMAP, so long as they are adjacent. 363 364 HAVE_MREMAP default: 1 on linux, else 0 365 If true realloc() uses mremap() to re-allocate large blocks and 366 extend or shrink allocation spaces. 367 368 MMAP_CLEARS default: 1 on unix 369 True if mmap clears memory so calloc doesn't need to. This is true 370 for standard unix mmap using /dev/zero. 371 372 USE_BUILTIN_FFS default: 0 (i.e., not used) 373 Causes malloc to use the builtin ffs() function to compute indices. 374 Some compilers may recognize and intrinsify ffs to be faster than the 375 supplied C version. Also, the case of x86 using gcc is special-cased 376 to an asm instruction, so is already as fast as it can be, and so 377 this setting has no effect. (On most x86s, the asm version is only 378 slightly faster than the C version.) 379 380 malloc_getpagesize default: derive from system includes, or 4096. 381 The system page size. To the extent possible, this malloc manages 382 memory from the system in page-size units. This may be (and 383 usually is) a function rather than a constant. This is ignored 384 if WIN32, where page size is determined using getSystemInfo during 385 initialization. 386 387 USE_DEV_RANDOM default: 0 (i.e., not used) 388 Causes malloc to use /dev/random to initialize secure magic seed for 389 stamping footers. Otherwise, the current time is used. 390 391 NO_MALLINFO default: 0 392 If defined, don't compile "mallinfo". This can be a simple way 393 of dealing with mismatches between system declarations and 394 those in this file. 395 396 MALLINFO_FIELD_TYPE default: size_t 397 The type of the fields in the mallinfo struct. This was originally 398 defined as "int" in SVID etc, but is more usefully defined as 399 size_t. The value is used only if HAVE_USR_INCLUDE_MALLOC_H is not set 400 401 REALLOC_ZERO_BYTES_FREES default: not defined 402 This should be set if a call to realloc with zero bytes should 403 be the same as a call to free. Some people think it should. Otherwise, 404 since this malloc returns a unique pointer for malloc(0), so does 405 realloc(p, 0). 406 407 LACKS_UNISTD_H, LACKS_FCNTL_H, LACKS_SYS_PARAM_H, LACKS_SYS_MMAN_H 408 LACKS_STRINGS_H, LACKS_STRING_H, LACKS_SYS_TYPES_H, LACKS_ERRNO_H 409 LACKS_STDLIB_H default: NOT defined unless on WIN32 410 Define these if your system does not have these header files. 411 You might need to manually insert some of the declarations they provide. 412 413 DEFAULT_GRANULARITY default: page size if MORECORE_CONTIGUOUS, 414 system_info.dwAllocationGranularity in WIN32, 415 otherwise 64K. 416 Also settable using mallopt(M_GRANULARITY, x) 417 The unit for allocating and deallocating memory from the system. On 418 most systems with contiguous MORECORE, there is no reason to 419 make this more than a page. However, systems with MMAP tend to 420 either require or encourage larger granularities. You can increase 421 this value to prevent system allocation functions to be called so 422 often, especially if they are slow. The value must be at least one 423 page and must be a power of two. Setting to 0 causes initialization 424 to either page size or win32 region size. (Note: In previous 425 versions of malloc, the equivalent of this option was called 426 "TOP_PAD") 427 428 DEFAULT_TRIM_THRESHOLD default: 2MB 429 Also settable using mallopt(M_TRIM_THRESHOLD, x) 430 The maximum amount of unused top-most memory to keep before 431 releasing via malloc_trim in free(). Automatic trimming is mainly 432 useful in long-lived programs using contiguous MORECORE. Because 433 trimming via sbrk can be slow on some systems, and can sometimes be 434 wasteful (in cases where programs immediately afterward allocate 435 more large chunks) the value should be high enough so that your 436 overall system performance would improve by releasing this much 437 memory. As a rough guide, you might set to a value close to the 438 average size of a process (program) running on your system. 439 Releasing this much memory would allow such a process to run in 440 memory. Generally, it is worth tuning trim thresholds when a 441 program undergoes phases where several large chunks are allocated 442 and released in ways that can reuse each other's storage, perhaps 443 mixed with phases where there are no such chunks at all. The trim 444 value must be greater than page size to have any useful effect. To 445 disable trimming completely, you can set to MAX_SIZE_T. Note that the trick 446 some people use of mallocing a huge space and then freeing it at 447 program startup, in an attempt to reserve system memory, doesn't 448 have the intended effect under automatic trimming, since that memory 449 will immediately be returned to the system. 450 451 DEFAULT_MMAP_THRESHOLD default: 256K 452 Also settable using mallopt(M_MMAP_THRESHOLD, x) 453 The request size threshold for using MMAP to directly service a 454 request. Requests of at least this size that cannot be allocated 455 using already-existing space will be serviced via mmap. (If enough 456 normal freed space already exists it is used instead.) Using mmap 457 segregates relatively large chunks of memory so that they can be 458 individually obtained and released from the host system. A request 459 serviced through mmap is never reused by any other request (at least 460 not directly; the system may just so happen to remap successive 461 requests to the same locations). Segregating space in this way has 462 the benefits that: Mmapped space can always be individually released 463 back to the system, which helps keep the system level memory demands 464 of a long-lived program low. Also, mapped memory doesn't become 465 `locked' between other chunks, as can happen with normally allocated 466 chunks, which means that even trimming via malloc_trim would not 467 release them. However, it has the disadvantage that the space 468 cannot be reclaimed, consolidated, and then used to service later 469 requests, as happens with normal chunks. The advantages of mmap 470 nearly always outweigh disadvantages for "large" chunks, but the 471 value of "large" may vary across systems. The default is an 472 empirically derived value that works well in most systems. You can 473 disable mmap by setting to MAX_SIZE_T. 474 475 */ 476 477 #ifndef WIN32 478 #ifdef _WIN32 479 #define WIN32 1 480 #endif /* _WIN32 */ 481 #endif /* WIN32 */ 482 #ifdef WIN32 483 #define WIN32_LEAN_AND_MEAN 484 #include <windows.h> 485 #define HAVE_MMAP 1 486 #define HAVE_MORECORE 0 487 #define LACKS_UNISTD_H 488 #define LACKS_SYS_PARAM_H 489 #define LACKS_SYS_MMAN_H 490 #define LACKS_STRING_H 491 #define LACKS_STRINGS_H 492 #define LACKS_SYS_TYPES_H 493 #define LACKS_ERRNO_H 494 #define LACKS_FCNTL_H 495 #define MALLOC_FAILURE_ACTION 496 #define MMAP_CLEARS 0 /* WINCE and some others apparently don't clear */ 497 #endif /* WIN32 */ 498 499 #if defined(DARWIN) || defined(_DARWIN) 500 /* Mac OSX docs advise not to use sbrk; it seems better to use mmap */ 501 #ifndef HAVE_MORECORE 502 #define HAVE_MORECORE 0 503 #define HAVE_MMAP 1 504 #endif /* HAVE_MORECORE */ 505 #endif /* DARWIN */ 506 507 #ifndef LACKS_SYS_TYPES_H 508 #include <sys/types.h> /* For size_t */ 509 #endif /* LACKS_SYS_TYPES_H */ 510 511 /* The maximum possible size_t value has all bits set */ 512 #define MAX_SIZE_T (~(size_t)0) 513 514 #ifndef ONLY_MSPACES 515 #define ONLY_MSPACES 0 516 #endif /* ONLY_MSPACES */ 517 #ifndef MSPACES 518 #if ONLY_MSPACES 519 #define MSPACES 1 520 #else /* ONLY_MSPACES */ 521 #define MSPACES 0 522 #endif /* ONLY_MSPACES */ 523 #endif /* MSPACES */ 524 #ifndef MALLOC_ALIGNMENT 525 #define MALLOC_ALIGNMENT ((size_t)8U) 526 #endif /* MALLOC_ALIGNMENT */ 527 #ifndef FOOTERS 528 #define FOOTERS 0 529 #endif /* FOOTERS */ 530 #ifndef ABORT 531 #define ABORT abort() 532 #endif /* ABORT */ 533 #ifndef ABORT_ON_ASSERT_FAILURE 534 #define ABORT_ON_ASSERT_FAILURE 1 535 #endif /* ABORT_ON_ASSERT_FAILURE */ 536 #ifndef PROCEED_ON_ERROR 537 #define PROCEED_ON_ERROR 0 538 #endif /* PROCEED_ON_ERROR */ 539 #ifndef USE_LOCKS 540 #define USE_LOCKS 0 541 #endif /* USE_LOCKS */ 542 #ifndef INSECURE 543 #define INSECURE 0 544 #endif /* INSECURE */ 545 #ifndef HAVE_MMAP 546 #define HAVE_MMAP 1 547 #endif /* HAVE_MMAP */ 548 #ifndef MMAP_CLEARS 549 #define MMAP_CLEARS 1 550 #endif /* MMAP_CLEARS */ 551 #ifndef HAVE_MREMAP 552 #ifdef linux 553 #define HAVE_MREMAP 1 554 #else /* linux */ 555 #define HAVE_MREMAP 0 556 #endif /* linux */ 557 #endif /* HAVE_MREMAP */ 558 #ifndef MALLOC_FAILURE_ACTION 559 #define MALLOC_FAILURE_ACTION errno = ENOMEM; 560 #endif /* MALLOC_FAILURE_ACTION */ 561 #ifndef HAVE_MORECORE 562 #if ONLY_MSPACES 563 #define HAVE_MORECORE 0 564 #else /* ONLY_MSPACES */ 565 #define HAVE_MORECORE 1 566 #endif /* ONLY_MSPACES */ 567 #endif /* HAVE_MORECORE */ 568 #if !HAVE_MORECORE 569 #define MORECORE_CONTIGUOUS 0 570 #else /* !HAVE_MORECORE */ 571 #ifndef MORECORE 572 #define MORECORE sbrk 573 #endif /* MORECORE */ 574 #ifndef MORECORE_CONTIGUOUS 575 #define MORECORE_CONTIGUOUS 1 576 #endif /* MORECORE_CONTIGUOUS */ 577 #endif /* HAVE_MORECORE */ 578 #ifndef DEFAULT_GRANULARITY 579 #if MORECORE_CONTIGUOUS 580 #define DEFAULT_GRANULARITY (0) /* 0 means to compute in init_mparams */ 581 #else /* MORECORE_CONTIGUOUS */ 582 #define DEFAULT_GRANULARITY ((size_t)64U * (size_t)1024U) 583 #endif /* MORECORE_CONTIGUOUS */ 584 #endif /* DEFAULT_GRANULARITY */ 585 #ifndef DEFAULT_TRIM_THRESHOLD 586 #ifndef MORECORE_CANNOT_TRIM 587 #define DEFAULT_TRIM_THRESHOLD ((size_t)2U * (size_t)1024U * (size_t)1024U) 588 #else /* MORECORE_CANNOT_TRIM */ 589 #define DEFAULT_TRIM_THRESHOLD MAX_SIZE_T 590 #endif /* MORECORE_CANNOT_TRIM */ 591 #endif /* DEFAULT_TRIM_THRESHOLD */ 592 #ifndef DEFAULT_MMAP_THRESHOLD 593 #if HAVE_MMAP 594 #define DEFAULT_MMAP_THRESHOLD ((size_t)256U * (size_t)1024U) 595 #else /* HAVE_MMAP */ 596 #define DEFAULT_MMAP_THRESHOLD MAX_SIZE_T 597 #endif /* HAVE_MMAP */ 598 #endif /* DEFAULT_MMAP_THRESHOLD */ 599 #ifndef USE_BUILTIN_FFS 600 #define USE_BUILTIN_FFS 0 601 #endif /* USE_BUILTIN_FFS */ 602 #ifndef USE_DEV_RANDOM 603 #define USE_DEV_RANDOM 0 604 #endif /* USE_DEV_RANDOM */ 605 #ifndef NO_MALLINFO 606 #define NO_MALLINFO 0 607 #endif /* NO_MALLINFO */ 608 #ifndef MALLINFO_FIELD_TYPE 609 #define MALLINFO_FIELD_TYPE size_t 610 #endif /* MALLINFO_FIELD_TYPE */ 611 612 #define memset SDL_memset 613 #define memcpy SDL_memcpy 614 #define malloc SDL_malloc 615 #define calloc SDL_calloc 616 #define realloc SDL_realloc 617 #define free SDL_free 618 619 /* 620 mallopt tuning options. SVID/XPG defines four standard parameter 621 numbers for mallopt, normally defined in malloc.h. None of these 622 are used in this malloc, so setting them has no effect. But this 623 malloc does support the following options. 624 */ 625 626 #define M_TRIM_THRESHOLD (-1) 627 #define M_GRANULARITY (-2) 628 #define M_MMAP_THRESHOLD (-3) 629 630 /* ------------------------ Mallinfo declarations ------------------------ */ 631 632 #if !NO_MALLINFO 633 /* 634 This version of malloc supports the standard SVID/XPG mallinfo 635 routine that returns a struct containing usage properties and 636 statistics. It should work on any system that has a 637 /usr/include/malloc.h defining struct mallinfo. The main 638 declaration needed is the mallinfo struct that is returned (by-copy) 639 by mallinfo(). The malloinfo struct contains a bunch of fields that 640 are not even meaningful in this version of malloc. These fields are 641 are instead filled by mallinfo() with other numbers that might be of 642 interest. 643 644 HAVE_USR_INCLUDE_MALLOC_H should be set if you have a 645 /usr/include/malloc.h file that includes a declaration of struct 646 mallinfo. If so, it is included; else a compliant version is 647 declared below. These must be precisely the same for mallinfo() to 648 work. The original SVID version of this struct, defined on most 649 systems with mallinfo, declares all fields as ints. But some others 650 define as unsigned long. If your system defines the fields using a 651 type of different width than listed here, you MUST #include your 652 system version and #define HAVE_USR_INCLUDE_MALLOC_H. 653 */ 654 655 /* #define HAVE_USR_INCLUDE_MALLOC_H */ 656 657 #ifdef HAVE_USR_INCLUDE_MALLOC_H 658 #include "/usr/include/malloc.h" 659 #else /* HAVE_USR_INCLUDE_MALLOC_H */ 660 661 struct mallinfo { 662 MALLINFO_FIELD_TYPE arena; /* non-mmapped space allocated from system */ 663 MALLINFO_FIELD_TYPE ordblks; /* number of free chunks */ 664 MALLINFO_FIELD_TYPE smblks; /* always 0 */ 665 MALLINFO_FIELD_TYPE hblks; /* always 0 */ 666 MALLINFO_FIELD_TYPE hblkhd; /* space in mmapped regions */ 667 MALLINFO_FIELD_TYPE usmblks; /* maximum total allocated space */ 668 MALLINFO_FIELD_TYPE fsmblks; /* always 0 */ 669 MALLINFO_FIELD_TYPE uordblks; /* total allocated space */ 670 MALLINFO_FIELD_TYPE fordblks; /* total free space */ 671 MALLINFO_FIELD_TYPE keepcost; /* releasable (via malloc_trim) space */ 672 }; 673 674 #endif /* HAVE_USR_INCLUDE_MALLOC_H */ 675 #endif /* NO_MALLINFO */ 676 677 #ifdef __cplusplus 678 extern "C" { 679 #endif /* __cplusplus */ 680 681 #if !ONLY_MSPACES 682 683 /* ------------------- Declarations of public routines ------------------- */ 684 685 #ifndef USE_DL_PREFIX 686 #define dlcalloc calloc 687 #define dlfree free 688 #define dlmalloc malloc 689 #define dlmemalign memalign 690 #define dlrealloc realloc 691 #define dlvalloc valloc 692 #define dlpvalloc pvalloc 693 #define dlmallinfo mallinfo 694 #define dlmallopt mallopt 695 #define dlmalloc_trim malloc_trim 696 #define dlmalloc_stats malloc_stats 697 #define dlmalloc_usable_size malloc_usable_size 698 #define dlmalloc_footprint malloc_footprint 699 #define dlmalloc_max_footprint malloc_max_footprint 700 #define dlindependent_calloc independent_calloc 701 #define dlindependent_comalloc independent_comalloc 702 #endif /* USE_DL_PREFIX */ 703 704 705 /* 706 malloc(size_t n) 707 Returns a pointer to a newly allocated chunk of at least n bytes, or 708 null if no space is available, in which case errno is set to ENOMEM 709 on ANSI C systems. 710 711 If n is zero, malloc returns a minimum-sized chunk. (The minimum 712 size is 16 bytes on most 32bit systems, and 32 bytes on 64bit 713 systems.) Note that size_t is an unsigned type, so calls with 714 arguments that would be negative if signed are interpreted as 715 requests for huge amounts of space, which will often fail. The 716 maximum supported value of n differs across systems, but is in all 717 cases less than the maximum representable value of a size_t. 718 */ 719 void* dlmalloc(size_t); 720 721 /* 722 free(void* p) 723 Releases the chunk of memory pointed to by p, that had been previously 724 allocated using malloc or a related routine such as realloc. 725 It has no effect if p is null. If p was not malloced or already 726 freed, free(p) will by default cause the current program to abort. 727 */ 728 void dlfree(void*); 729 730 /* 731 calloc(size_t n_elements, size_t element_size); 732 Returns a pointer to n_elements * element_size bytes, with all locations 733 set to zero. 734 */ 735 void* dlcalloc(size_t, size_t); 736 737 /* 738 realloc(void* p, size_t n) 739 Returns a pointer to a chunk of size n that contains the same data 740 as does chunk p up to the minimum of (n, p's size) bytes, or null 741 if no space is available. 742 743 The returned pointer may or may not be the same as p. The algorithm 744 prefers extending p in most cases when possible, otherwise it 745 employs the equivalent of a malloc-copy-free sequence. 746 747 If p is null, realloc is equivalent to malloc. 748 749 If space is not available, realloc returns null, errno is set (if on 750 ANSI) and p is NOT freed. 751 752 if n is for fewer bytes than already held by p, the newly unused 753 space is lopped off and freed if possible. realloc with a size 754 argument of zero (re)allocates a minimum-sized chunk. 755 756 The old unix realloc convention of allowing the last-free'd chunk 757 to be used as an argument to realloc is not supported. 758 */ 759 760 void* dlrealloc(void*, size_t); 761 762 /* 763 memalign(size_t alignment, size_t n); 764 Returns a pointer to a newly allocated chunk of n bytes, aligned 765 in accord with the alignment argument. 766 767 The alignment argument should be a power of two. If the argument is 768 not a power of two, the nearest greater power is used. 769 8-byte alignment is guaranteed by normal malloc calls, so don't 770 bother calling memalign with an argument of 8 or less. 771 772 Overreliance on memalign is a sure way to fragment space. 773 */ 774 void* dlmemalign(size_t, size_t); 775 776 /* 777 valloc(size_t n); 778 Equivalent to memalign(pagesize, n), where pagesize is the page 779 size of the system. If the pagesize is unknown, 4096 is used. 780 */ 781 void* dlvalloc(size_t); 782 783 /* 784 mallopt(int parameter_number, int parameter_value) 785 Sets tunable parameters The format is to provide a 786 (parameter-number, parameter-value) pair. mallopt then sets the 787 corresponding parameter to the argument value if it can (i.e., so 788 long as the value is meaningful), and returns 1 if successful else 789 0. SVID/XPG/ANSI defines four standard param numbers for mallopt, 790 normally defined in malloc.h. None of these are use in this malloc, 791 so setting them has no effect. But this malloc also supports other 792 options in mallopt. See below for details. Briefly, supported 793 parameters are as follows (listed defaults are for "typical" 794 configurations). 795 796 Symbol param # default allowed param values 797 M_TRIM_THRESHOLD -1 2*1024*1024 any (MAX_SIZE_T disables) 798 M_GRANULARITY -2 page size any power of 2 >= page size 799 M_MMAP_THRESHOLD -3 256*1024 any (or 0 if no MMAP support) 800 */ 801 int dlmallopt(int, int); 802 803 /* 804 malloc_footprint(); 805 Returns the number of bytes obtained from the system. The total 806 number of bytes allocated by malloc, realloc etc., is less than this 807 value. Unlike mallinfo, this function returns only a precomputed 808 result, so can be called frequently to monitor memory consumption. 809 Even if locks are otherwise defined, this function does not use them, 810 so results might not be up to date. 811 */ 812 size_t dlmalloc_footprint(void); 813 814 /* 815 malloc_max_footprint(); 816 Returns the maximum number of bytes obtained from the system. This 817 value will be greater than current footprint if deallocated space 818 has been reclaimed by the system. The peak number of bytes allocated 819 by malloc, realloc etc., is less than this value. Unlike mallinfo, 820 this function returns only a precomputed result, so can be called 821 frequently to monitor memory consumption. Even if locks are 822 otherwise defined, this function does not use them, so results might 823 not be up to date. 824 */ 825 size_t dlmalloc_max_footprint(void); 826 827 #if !NO_MALLINFO 828 /* 829 mallinfo() 830 Returns (by copy) a struct containing various summary statistics: 831 832 arena: current total non-mmapped bytes allocated from system 833 ordblks: the number of free chunks 834 smblks: always zero. 835 hblks: current number of mmapped regions 836 hblkhd: total bytes held in mmapped regions 837 usmblks: the maximum total allocated space. This will be greater 838 than current total if trimming has occurred. 839 fsmblks: always zero 840 uordblks: current total allocated space (normal or mmapped) 841 fordblks: total free space 842 keepcost: the maximum number of bytes that could ideally be released 843 back to system via malloc_trim. ("ideally" means that 844 it ignores page restrictions etc.) 845 846 Because these fields are ints, but internal bookkeeping may 847 be kept as longs, the reported values may wrap around zero and 848 thus be inaccurate. 849 */ 850 struct mallinfo dlmallinfo(void); 851 #endif /* NO_MALLINFO */ 852 853 /* 854 independent_calloc(size_t n_elements, size_t element_size, void* chunks[]); 855 856 independent_calloc is similar to calloc, but instead of returning a 857 single cleared space, it returns an array of pointers to n_elements 858 independent elements that can hold contents of size elem_size, each 859 of which starts out cleared, and can be independently freed, 860 realloc'ed etc. The elements are guaranteed to be adjacently 861 allocated (this is not guaranteed to occur with multiple callocs or 862 mallocs), which may also improve cache locality in some 863 applications. 864 865 The "chunks" argument is optional (i.e., may be null, which is 866 probably the most typical usage). If it is null, the returned array 867 is itself dynamically allocated and should also be freed when it is 868 no longer needed. Otherwise, the chunks array must be of at least 869 n_elements in length. It is filled in with the pointers to the 870 chunks. 871 872 In either case, independent_calloc returns this pointer array, or 873 null if the allocation failed. If n_elements is zero and "chunks" 874 is null, it returns a chunk representing an array with zero elements 875 (which should be freed if not wanted). 876 877 Each element must be individually freed when it is no longer 878 needed. If you'd like to instead be able to free all at once, you 879 should instead use regular calloc and assign pointers into this 880 space to represent elements. (In this case though, you cannot 881 independently free elements.) 882 883 independent_calloc simplifies and speeds up implementations of many 884 kinds of pools. It may also be useful when constructing large data 885 structures that initially have a fixed number of fixed-sized nodes, 886 but the number is not known at compile time, and some of the nodes 887 may later need to be freed. For example: 888 889 struct Node { int item; struct Node* next; }; 890 891 struct Node* build_list() { 892 struct Node** pool; 893 int n = read_number_of_nodes_needed(); 894 if (n <= 0) return 0; 895 pool = (struct Node**)(independent_calloc(n, sizeof(struct Node), 0); 896 if (pool == 0) die(); 897 // organize into a linked list... 898 struct Node* first = pool[0]; 899 for (i = 0; i < n-1; ++i) 900 pool[i]->next = pool[i+1]; 901 free(pool); // Can now free the array (or not, if it is needed later) 902 return first; 903 } 904 */ 905 void** dlindependent_calloc(size_t, size_t, void**); 906 907 /* 908 independent_comalloc(size_t n_elements, size_t sizes[], void* chunks[]); 909 910 independent_comalloc allocates, all at once, a set of n_elements 911 chunks with sizes indicated in the "sizes" array. It returns 912 an array of pointers to these elements, each of which can be 913 independently freed, realloc'ed etc. The elements are guaranteed to 914 be adjacently allocated (this is not guaranteed to occur with 915 multiple callocs or mallocs), which may also improve cache locality 916 in some applications. 917 918 The "chunks" argument is optional (i.e., may be null). If it is null 919 the returned array is itself dynamically allocated and should also 920 be freed when it is no longer needed. Otherwise, the chunks array 921 must be of at least n_elements in length. It is filled in with the 922 pointers to the chunks. 923 924 In either case, independent_comalloc returns this pointer array, or 925 null if the allocation failed. If n_elements is zero and chunks is 926 null, it returns a chunk representing an array with zero elements 927 (which should be freed if not wanted). 928 929 Each element must be individually freed when it is no longer 930 needed. If you'd like to instead be able to free all at once, you 931 should instead use a single regular malloc, and assign pointers at 932 particular offsets in the aggregate space. (In this case though, you 933 cannot independently free elements.) 934 935 independent_comallac differs from independent_calloc in that each 936 element may have a different size, and also that it does not 937 automatically clear elements. 938 939 independent_comalloc can be used to speed up allocation in cases 940 where several structs or objects must always be allocated at the 941 same time. For example: 942 943 struct Head { ... } 944 struct Foot { ... } 945 946 void send_message(char* msg) { 947 int msglen = strlen(msg); 948 size_t sizes[3] = { sizeof(struct Head), msglen, sizeof(struct Foot) }; 949 void* chunks[3]; 950 if (independent_comalloc(3, sizes, chunks) == 0) 951 die(); 952 struct Head* head = (struct Head*)(chunks[0]); 953 char* body = (char*)(chunks[1]); 954 struct Foot* foot = (struct Foot*)(chunks[2]); 955 // ... 956 } 957 958 In general though, independent_comalloc is worth using only for 959 larger values of n_elements. For small values, you probably won't 960 detect enough difference from series of malloc calls to bother. 961 962 Overuse of independent_comalloc can increase overall memory usage, 963 since it cannot reuse existing noncontiguous small chunks that 964 might be available for some of the elements. 965 */ 966 void** dlindependent_comalloc(size_t, size_t*, void**); 967 968 969 /* 970 pvalloc(size_t n); 971 Equivalent to valloc(minimum-page-that-holds(n)), that is, 972 round up n to nearest pagesize. 973 */ 974 void* dlpvalloc(size_t); 975 976 /* 977 malloc_trim(size_t pad); 978 979 If possible, gives memory back to the system (via negative arguments 980 to sbrk) if there is unused memory at the `high' end of the malloc 981 pool or in unused MMAP segments. You can call this after freeing 982 large blocks of memory to potentially reduce the system-level memory 983 requirements of a program. However, it cannot guarantee to reduce 984 memory. Under some allocation patterns, some large free blocks of 985 memory will be locked between two used chunks, so they cannot be 986 given back to the system. 987 988 The `pad' argument to malloc_trim represents the amount of free 989 trailing space to leave untrimmed. If this argument is zero, only 990 the minimum amount of memory to maintain internal data structures 991 will be left. Non-zero arguments can be supplied to maintain enough 992 trailing space to service future expected allocations without having 993 to re-obtain memory from the system. 994 995 Malloc_trim returns 1 if it actually released any memory, else 0. 996 */ 997 int dlmalloc_trim(size_t); 998 999 /* 1000 malloc_usable_size(void* p); 1001 1002 Returns the number of bytes you can actually use in 1003 an allocated chunk, which may be more than you requested (although 1004 often not) due to alignment and minimum size constraints. 1005 You can use this many bytes without worrying about 1006 overwriting other allocated objects. This is not a particularly great 1007 programming practice. malloc_usable_size can be more useful in 1008 debugging and assertions, for example: 1009 1010 p = malloc(n); 1011 assert(malloc_usable_size(p) >= 256); 1012 */ 1013 size_t dlmalloc_usable_size(void*); 1014 1015 /* 1016 malloc_stats(); 1017 Prints on stderr the amount of space obtained from the system (both 1018 via sbrk and mmap), the maximum amount (which may be more than 1019 current if malloc_trim and/or munmap got called), and the current 1020 number of bytes allocated via malloc (or realloc, etc) but not yet 1021 freed. Note that this is the number of bytes allocated, not the 1022 number requested. It will be larger than the number requested 1023 because of alignment and bookkeeping overhead. Because it includes 1024 alignment wastage as being in use, this figure may be greater than 1025 zero even when no user-level chunks are allocated. 1026 1027 The reported current and maximum system memory can be inaccurate if 1028 a program makes other calls to system memory allocation functions 1029 (normally sbrk) outside of malloc. 1030 1031 malloc_stats prints only the most commonly interesting statistics. 1032 More information can be obtained by calling mallinfo. 1033 */ 1034 void dlmalloc_stats(void); 1035 1036 #endif /* ONLY_MSPACES */ 1037 1038 #if MSPACES 1039 1040 /* 1041 mspace is an opaque type representing an independent 1042 region of space that supports mspace_malloc, etc. 1043 */ 1044 typedef void* mspace; 1045 1046 /* 1047 create_mspace creates and returns a new independent space with the 1048 given initial capacity, or, if 0, the default granularity size. It 1049 returns null if there is no system memory available to create the 1050 space. If argument locked is non-zero, the space uses a separate 1051 lock to control access. The capacity of the space will grow 1052 dynamically as needed to service mspace_malloc requests. You can 1053 control the sizes of incremental increases of this space by 1054 compiling with a different DEFAULT_GRANULARITY or dynamically 1055 setting with mallopt(M_GRANULARITY, value). 1056 */ 1057 mspace create_mspace(size_t capacity, int locked); 1058 1059 /* 1060 destroy_mspace destroys the given space, and attempts to return all 1061 of its memory back to the system, returning the total number of 1062 bytes freed. After destruction, the results of access to all memory 1063 used by the space become undefined. 1064 */ 1065 size_t destroy_mspace(mspace msp); 1066 1067 /* 1068 create_mspace_with_base uses the memory supplied as the initial base 1069 of a new mspace. Part (less than 128*sizeof(size_t) bytes) of this 1070 space is used for bookkeeping, so the capacity must be at least this 1071 large. (Otherwise 0 is returned.) When this initial space is 1072 exhausted, additional memory will be obtained from the system. 1073 Destroying this space will deallocate all additionally allocated 1074 space (if possible) but not the initial base. 1075 */ 1076 mspace create_mspace_with_base(void* base, size_t capacity, int locked); 1077 1078 /* 1079 mspace_malloc behaves as malloc, but operates within 1080 the given space. 1081 */ 1082 void* mspace_malloc(mspace msp, size_t bytes); 1083 1084 /* 1085 mspace_free behaves as free, but operates within 1086 the given space. 1087 1088 If compiled with FOOTERS==1, mspace_free is not actually needed. 1089 free may be called instead of mspace_free because freed chunks from 1090 any space are handled by their originating spaces. 1091 */ 1092 void mspace_free(mspace msp, void* mem); 1093 1094 /* 1095 mspace_realloc behaves as realloc, but operates within 1096 the given space. 1097 1098 If compiled with FOOTERS==1, mspace_realloc is not actually 1099 needed. realloc may be called instead of mspace_realloc because 1100 realloced chunks from any space are handled by their originating 1101 spaces. 1102 */ 1103 void* mspace_realloc(mspace msp, void* mem, size_t newsize); 1104 1105 /* 1106 mspace_calloc behaves as calloc, but operates within 1107 the given space. 1108 */ 1109 void* mspace_calloc(mspace msp, size_t n_elements, size_t elem_size); 1110 1111 /* 1112 mspace_memalign behaves as memalign, but operates within 1113 the given space. 1114 */ 1115 void* mspace_memalign(mspace msp, size_t alignment, size_t bytes); 1116 1117 /* 1118 mspace_independent_calloc behaves as independent_calloc, but 1119 operates within the given space. 1120 */ 1121 void** mspace_independent_calloc(mspace msp, size_t n_elements, 1122 size_t elem_size, void* chunks[]); 1123 1124 /* 1125 mspace_independent_comalloc behaves as independent_comalloc, but 1126 operates within the given space. 1127 */ 1128 void** mspace_independent_comalloc(mspace msp, size_t n_elements, 1129 size_t sizes[], void* chunks[]); 1130 1131 /* 1132 mspace_footprint() returns the number of bytes obtained from the 1133 system for this space. 1134 */ 1135 size_t mspace_footprint(mspace msp); 1136 1137 /* 1138 mspace_max_footprint() returns the peak number of bytes obtained from the 1139 system for this space. 1140 */ 1141 size_t mspace_max_footprint(mspace msp); 1142 1143 1144 #if !NO_MALLINFO 1145 /* 1146 mspace_mallinfo behaves as mallinfo, but reports properties of 1147 the given space. 1148 */ 1149 struct mallinfo mspace_mallinfo(mspace msp); 1150 #endif /* NO_MALLINFO */ 1151 1152 /* 1153 mspace_malloc_stats behaves as malloc_stats, but reports 1154 properties of the given space. 1155 */ 1156 void mspace_malloc_stats(mspace msp); 1157 1158 /* 1159 mspace_trim behaves as malloc_trim, but 1160 operates within the given space. 1161 */ 1162 int mspace_trim(mspace msp, size_t pad); 1163 1164 /* 1165 An alias for mallopt. 1166 */ 1167 int mspace_mallopt(int, int); 1168 1169 #endif /* MSPACES */ 1170 1171 #ifdef __cplusplus 1172 }; /* end of extern "C" */ 1173 #endif /* __cplusplus */ 1174 1175 /* 1176 ======================================================================== 1177 To make a fully customizable malloc.h header file, cut everything 1178 above this line, put into file malloc.h, edit to suit, and #include it 1179 on the next line, as well as in programs that use this malloc. 1180 ======================================================================== 1181 */ 1182 1183 /* #include "malloc.h" */ 1184 1185 /*------------------------------ internal #includes ---------------------- */ 1186 1187 #ifdef _MSC_VER 1188 #pragma warning( disable : 4146 ) /* no "unsigned" warnings */ 1189 #endif /* _MSC_VER */ 1190 1191 #ifndef LACKS_STDIO_H 1192 #include <stdio.h> /* for printing in malloc_stats */ 1193 #endif 1194 1195 #ifndef LACKS_ERRNO_H 1196 #include <errno.h> /* for MALLOC_FAILURE_ACTION */ 1197 #endif /* LACKS_ERRNO_H */ 1198 #if FOOTERS 1199 #include <time.h> /* for magic initialization */ 1200 #endif /* FOOTERS */ 1201 #ifndef LACKS_STDLIB_H 1202 #include <stdlib.h> /* for abort() */ 1203 #endif /* LACKS_STDLIB_H */ 1204 #ifdef DEBUG 1205 #if ABORT_ON_ASSERT_FAILURE 1206 #define assert(x) if(!(x)) ABORT 1207 #else /* ABORT_ON_ASSERT_FAILURE */ 1208 #include <assert.h> 1209 #endif /* ABORT_ON_ASSERT_FAILURE */ 1210 #else /* DEBUG */ 1211 #define assert(x) 1212 #endif /* DEBUG */ 1213 #ifndef LACKS_STRING_H 1214 #include <string.h> /* for memset etc */ 1215 #endif /* LACKS_STRING_H */ 1216 #if USE_BUILTIN_FFS 1217 #ifndef LACKS_STRINGS_H 1218 #include <strings.h> /* for ffs */ 1219 #endif /* LACKS_STRINGS_H */ 1220 #endif /* USE_BUILTIN_FFS */ 1221 #if HAVE_MMAP 1222 #ifndef LACKS_SYS_MMAN_H 1223 #include <sys/mman.h> /* for mmap */ 1224 #endif /* LACKS_SYS_MMAN_H */ 1225 #ifndef LACKS_FCNTL_H 1226 #include <fcntl.h> 1227 #endif /* LACKS_FCNTL_H */ 1228 #endif /* HAVE_MMAP */ 1229 #if HAVE_MORECORE 1230 #ifndef LACKS_UNISTD_H 1231 #include <unistd.h> /* for sbrk */ 1232 #else /* LACKS_UNISTD_H */ 1233 #if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) 1234 extern void* sbrk(ptrdiff_t); 1235 #endif /* FreeBSD etc */ 1236 #endif /* LACKS_UNISTD_H */ 1237 #endif /* HAVE_MMAP */ 1238 1239 #ifndef WIN32 1240 #ifndef malloc_getpagesize 1241 # ifdef _SC_PAGESIZE /* some SVR4 systems omit an underscore */ 1242 # ifndef _SC_PAGE_SIZE 1243 # define _SC_PAGE_SIZE _SC_PAGESIZE 1244 # endif 1245 # endif 1246 # ifdef _SC_PAGE_SIZE 1247 # define malloc_getpagesize sysconf(_SC_PAGE_SIZE) 1248 # else 1249 # if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE) 1250 extern size_t getpagesize(); 1251 # define malloc_getpagesize getpagesize() 1252 # else 1253 # ifdef WIN32 /* use supplied emulation of getpagesize */ 1254 # define malloc_getpagesize getpagesize() 1255 # else 1256 # ifndef LACKS_SYS_PARAM_H 1257 # include <sys/param.h> 1258 # endif 1259 # ifdef EXEC_PAGESIZE 1260 # define malloc_getpagesize EXEC_PAGESIZE 1261 # else 1262 # ifdef NBPG 1263 # ifndef CLSIZE 1264 # define malloc_getpagesize NBPG 1265 # else 1266 # define malloc_getpagesize (NBPG * CLSIZE) 1267 # endif 1268 # else 1269 # ifdef NBPC 1270 # define malloc_getpagesize NBPC 1271 # else 1272 # ifdef PAGESIZE 1273 # define malloc_getpagesize PAGESIZE 1274 # else /* just guess */ 1275 # define malloc_getpagesize ((size_t)4096U) 1276 # endif 1277 # endif 1278 # endif 1279 # endif 1280 # endif 1281 # endif 1282 # endif 1283 #endif 1284 #endif 1285 1286 /* ------------------- size_t and alignment properties -------------------- */ 1287 1288 /* The byte and bit size of a size_t */ 1289 #define SIZE_T_SIZE (sizeof(size_t)) 1290 #define SIZE_T_BITSIZE (sizeof(size_t) << 3) 1291 1292 /* Some constants coerced to size_t */ 1293 /* Annoying but necessary to avoid errors on some plaftorms */ 1294 #define SIZE_T_ZERO ((size_t)0) 1295 #define SIZE_T_ONE ((size_t)1) 1296 #define SIZE_T_TWO ((size_t)2) 1297 #define TWO_SIZE_T_SIZES (SIZE_T_SIZE<<1) 1298 #define FOUR_SIZE_T_SIZES (SIZE_T_SIZE<<2) 1299 #define SIX_SIZE_T_SIZES (FOUR_SIZE_T_SIZES+TWO_SIZE_T_SIZES) 1300 #define HALF_MAX_SIZE_T (MAX_SIZE_T / 2U) 1301 1302 /* The bit mask value corresponding to MALLOC_ALIGNMENT */ 1303 #define CHUNK_ALIGN_MASK (MALLOC_ALIGNMENT - SIZE_T_ONE) 1304 1305 /* True if address a has acceptable alignment */ 1306 #define is_aligned(A) (((size_t)((A)) & (CHUNK_ALIGN_MASK)) == 0) 1307 1308 /* the number of bytes to offset an address to align it */ 1309 #define align_offset(A)\ 1310 ((((size_t)(A) & CHUNK_ALIGN_MASK) == 0)? 0 :\ 1311 ((MALLOC_ALIGNMENT - ((size_t)(A) & CHUNK_ALIGN_MASK)) & CHUNK_ALIGN_MASK)) 1312 1313 /* -------------------------- MMAP preliminaries ------------------------- */ 1314 1315 /* 1316 If HAVE_MORECORE or HAVE_MMAP are false, we just define calls and 1317 checks to fail so compiler optimizer can delete code rather than 1318 using so many "#if"s. 1319 */ 1320 1321 1322 /* MORECORE and MMAP must return MFAIL on failure */ 1323 #define MFAIL ((void*)(MAX_SIZE_T)) 1324 #define CMFAIL ((char*)(MFAIL)) /* defined for convenience */ 1325 1326 #if !HAVE_MMAP 1327 #define IS_MMAPPED_BIT (SIZE_T_ZERO) 1328 #define USE_MMAP_BIT (SIZE_T_ZERO) 1329 #define CALL_MMAP(s) MFAIL 1330 #define CALL_MUNMAP(a, s) (-1) 1331 #define DIRECT_MMAP(s) MFAIL 1332 1333 #else /* HAVE_MMAP */ 1334 #define IS_MMAPPED_BIT (SIZE_T_ONE) 1335 #define USE_MMAP_BIT (SIZE_T_ONE) 1336 1337 #ifndef WIN32 1338 #define CALL_MUNMAP(a, s) munmap((a), (s)) 1339 #define MMAP_PROT (PROT_READ|PROT_WRITE) 1340 #if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) 1341 #define MAP_ANONYMOUS MAP_ANON 1342 #endif /* MAP_ANON */ 1343 #ifdef MAP_ANONYMOUS 1344 #define MMAP_FLAGS (MAP_PRIVATE|MAP_ANONYMOUS) 1345 #define CALL_MMAP(s) mmap(0, (s), MMAP_PROT, MMAP_FLAGS, -1, 0) 1346 #else /* MAP_ANONYMOUS */ 1347 /* 1348 Nearly all versions of mmap support MAP_ANONYMOUS, so the following 1349 is unlikely to be needed, but is supplied just in case. 1350 */ 1351 #define MMAP_FLAGS (MAP_PRIVATE) 1352 static int dev_zero_fd = -1; /* Cached file descriptor for /dev/zero. */ 1353 #define CALL_MMAP(s) ((dev_zero_fd < 0) ? \ 1354 (dev_zero_fd = open("/dev/zero", O_RDWR), \ 1355 mmap(0, (s), MMAP_PROT, MMAP_FLAGS, dev_zero_fd, 0)) : \ 1356 mmap(0, (s), MMAP_PROT, MMAP_FLAGS, dev_zero_fd, 0)) 1357 #endif /* MAP_ANONYMOUS */ 1358 1359 #define DIRECT_MMAP(s) CALL_MMAP(s) 1360 #else /* WIN32 */ 1361 1362 /* Win32 MMAP via VirtualAlloc */ 1363 static void* win32mmap(size_t size) { 1364 void* ptr = VirtualAlloc(0, size, MEM_RESERVE|MEM_COMMIT, PAGE_READWRITE); 1365 return (ptr != 0)? ptr: MFAIL; 1366 } 1367 1368 /* For direct MMAP, use MEM_TOP_DOWN to minimize interference */ 1369 static void* win32direct_mmap(size_t size) { 1370 void* ptr = VirtualAlloc(0, size, MEM_RESERVE|MEM_COMMIT|MEM_TOP_DOWN, 1371 PAGE_READWRITE); 1372 return (ptr != 0)? ptr: MFAIL; 1373 } 1374 1375 /* This function supports releasing coalesed segments */ 1376 static int win32munmap(void* ptr, size_t size) { 1377 MEMORY_BASIC_INFORMATION minfo; 1378 char* cptr = ptr; 1379 while (size) { 1380 if (VirtualQuery(cptr, &minfo, sizeof(minfo)) == 0) 1381 return -1; 1382 if (minfo.BaseAddress != cptr || minfo.AllocationBase != cptr || 1383 minfo.State != MEM_COMMIT || minfo.RegionSize > size) 1384 return -1; 1385 if (VirtualFree(cptr, 0, MEM_RELEASE) == 0) 1386 return -1; 1387 cptr += minfo.RegionSize; 1388 size -= minfo.RegionSize; 1389 } 1390 return 0; 1391 } 1392 1393 #define CALL_MMAP(s) win32mmap(s) 1394 #define CALL_MUNMAP(a, s) win32munmap((a), (s)) 1395 #define DIRECT_MMAP(s) win32direct_mmap(s) 1396 #endif /* WIN32 */ 1397 #endif /* HAVE_MMAP */ 1398 1399 #if HAVE_MMAP && HAVE_MREMAP 1400 #define CALL_MREMAP(addr, osz, nsz, mv) mremap((addr), (osz), (nsz), (mv)) 1401 #else /* HAVE_MMAP && HAVE_MREMAP */ 1402 #define CALL_MREMAP(addr, osz, nsz, mv) MFAIL 1403 #endif /* HAVE_MMAP && HAVE_MREMAP */ 1404 1405 #if HAVE_MORECORE 1406 #define CALL_MORECORE(S) MORECORE(S) 1407 #else /* HAVE_MORECORE */ 1408 #define CALL_MORECORE(S) MFAIL 1409 #endif /* HAVE_MORECORE */ 1410 1411 /* mstate bit set if continguous morecore disabled or failed */ 1412 #define USE_NONCONTIGUOUS_BIT (4U) 1413 1414 /* segment bit set in create_mspace_with_base */ 1415 #define EXTERN_BIT (8U) 1416 1417 1418 /* --------------------------- Lock preliminaries ------------------------ */ 1419 1420 #if USE_LOCKS 1421 1422 /* 1423 When locks are defined, there are up to two global locks: 1424 1425 * If HAVE_MORECORE, morecore_mutex protects sequences of calls to 1426 MORECORE. In many cases sys_alloc requires two calls, that should 1427 not be interleaved with calls by other threads. This does not 1428 protect against direct calls to MORECORE by other threads not 1429 using this lock, so there is still code to cope the best we can on 1430 interference. 1431 1432 * magic_init_mutex ensures that mparams.magic and other 1433 unique mparams values are initialized only once. 1434 */ 1435 1436 #ifndef WIN32 1437 /* By default use posix locks */ 1438 #include <pthread.h> 1439 #define MLOCK_T pthread_mutex_t 1440 #define INITIAL_LOCK(l) pthread_mutex_init(l, NULL) 1441 #define ACQUIRE_LOCK(l) pthread_mutex_lock(l) 1442 #define RELEASE_LOCK(l) pthread_mutex_unlock(l) 1443 1444 #if HAVE_MORECORE 1445 static MLOCK_T morecore_mutex = PTHREAD_MUTEX_INITIALIZER; 1446 #endif /* HAVE_MORECORE */ 1447 1448 static MLOCK_T magic_init_mutex = PTHREAD_MUTEX_INITIALIZER; 1449 1450 #else /* WIN32 */ 1451 /* 1452 Because lock-protected regions have bounded times, and there 1453 are no recursive lock calls, we can use simple spinlocks. 1454 */ 1455 1456 #define MLOCK_T long 1457 static int win32_acquire_lock (MLOCK_T *sl) { 1458 for (;;) { 1459 #ifdef InterlockedCompareExchangePointer 1460 if (!InterlockedCompareExchange(sl, 1, 0)) 1461 return 0; 1462 #else /* Use older void* version */ 1463 if (!InterlockedCompareExchange((void**)sl, (void*)1, (void*)0)) 1464 return 0; 1465 #endif /* InterlockedCompareExchangePointer */ 1466 Sleep (0); 1467 } 1468 } 1469 1470 static void win32_release_lock (MLOCK_T *sl) { 1471 InterlockedExchange (sl, 0); 1472 } 1473 1474 #define INITIAL_LOCK(l) *(l)=0 1475 #define ACQUIRE_LOCK(l) win32_acquire_lock(l) 1476 #define RELEASE_LOCK(l) win32_release_lock(l) 1477 #if HAVE_MORECORE 1478 static MLOCK_T morecore_mutex; 1479 #endif /* HAVE_MORECORE */ 1480 static MLOCK_T magic_init_mutex; 1481 #endif /* WIN32 */ 1482 1483 #define USE_LOCK_BIT (2U) 1484 #else /* USE_LOCKS */ 1485 #define USE_LOCK_BIT (0U) 1486 #define INITIAL_LOCK(l) 1487 #endif /* USE_LOCKS */ 1488 1489 #if USE_LOCKS && HAVE_MORECORE 1490 #define ACQUIRE_MORECORE_LOCK() ACQUIRE_LOCK(&morecore_mutex); 1491 #define RELEASE_MORECORE_LOCK() RELEASE_LOCK(&morecore_mutex); 1492 #else /* USE_LOCKS && HAVE_MORECORE */ 1493 #define ACQUIRE_MORECORE_LOCK() 1494 #define RELEASE_MORECORE_LOCK() 1495 #endif /* USE_LOCKS && HAVE_MORECORE */ 1496 1497 #if USE_LOCKS 1498 #define ACQUIRE_MAGIC_INIT_LOCK() ACQUIRE_LOCK(&magic_init_mutex); 1499 #define RELEASE_MAGIC_INIT_LOCK() RELEASE_LOCK(&magic_init_mutex); 1500 #else /* USE_LOCKS */ 1501 #define ACQUIRE_MAGIC_INIT_LOCK() 1502 #define RELEASE_MAGIC_INIT_LOCK() 1503 #endif /* USE_LOCKS */ 1504 1505 1506 /* ----------------------- Chunk representations ------------------------ */ 1507 1508 /* 1509 (The following includes lightly edited explanations by Colin Plumb.) 1510 1511 The malloc_chunk declaration below is misleading (but accurate and 1512 necessary). It declares a "view" into memory allowing access to 1513 necessary fields at known offsets from a given base. 1514 1515 Chunks of memory are maintained using a `boundary tag' method as 1516 originally described by Knuth. (See the paper by Paul Wilson 1517 ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a survey of such 1518 techniques.) Sizes of free chunks are stored both in the front of 1519 each chunk and at the end. This makes consolidating fragmented 1520 chunks into bigger chunks fast. The head fields also hold bits 1521 representing whether chunks are free or in use. 1522 1523 Here are some pictures to make it clearer. They are "exploded" to 1524 show that the state of a chunk can be thought of as extending from 1525 the high 31 bits of the head field of its header through the 1526 prev_foot and PINUSE_BIT bit of the following chunk header. 1527 1528 A chunk that's in use looks like: 1529 1530 chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1531 | Size of previous chunk (if P = 1) | 1532 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1533 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| 1534 | Size of this chunk 1| +-+ 1535 mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1536 | | 1537 +- -+ 1538 | | 1539 +- -+ 1540 | : 1541 +- size - sizeof(size_t) available payload bytes -+ 1542 : | 1543 chunk-> +- -+ 1544 | | 1545 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1546 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1| 1547 | Size of next chunk (may or may not be in use) | +-+ 1548 mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1549 1550 And if it's free, it looks like this: 1551 1552 chunk-> +- -+ 1553 | User payload (must be in use, or we would have merged!) | 1554 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1555 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| 1556 | Size of this chunk 0| +-+ 1557 mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1558 | Next pointer | 1559 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1560 | Prev pointer | 1561 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1562 | : 1563 +- size - sizeof(struct chunk) unused bytes -+ 1564 : | 1565 chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1566 | Size of this chunk | 1567 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1568 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| 1569 | Size of next chunk (must be in use, or we would have merged)| +-+ 1570 mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1571 | : 1572 +- User payload -+ 1573 : | 1574 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1575 |0| 1576 +-+ 1577 Note that since we always merge adjacent free chunks, the chunks 1578 adjacent to a free chunk must be in use. 1579 1580 Given a pointer to a chunk (which can be derived trivially from the 1581 payload pointer) we can, in O(1) time, find out whether the adjacent 1582 chunks are free, and if so, unlink them from the lists that they 1583 are on and merge them with the current chunk. 1584 1585 Chunks always begin on even word boundaries, so the mem portion 1586 (which is returned to the user) is also on an even word boundary, and 1587 thus at least double-word aligned. 1588 1589 The P (PINUSE_BIT) bit, stored in the unused low-order bit of the 1590 chunk size (which is always a multiple of two words), is an in-use 1591 bit for the *previous* chunk. If that bit is *clear*, then the 1592 word before the current chunk size contains the previous chunk 1593 size, and can be used to find the front of the previous chunk. 1594 The very first chunk allocated always has this bit set, preventing 1595 access to non-existent (or non-owned) memory. If pinuse is set for 1596 any given chunk, then you CANNOT determine the size of the 1597 previous chunk, and might even get a memory addressing fault when 1598 trying to do so. 1599 1600 The C (CINUSE_BIT) bit, stored in the unused second-lowest bit of 1601 the chunk size redundantly records whether the current chunk is 1602 inuse. This redundancy enables usage checks within free and realloc, 1603 and reduces indirection when freeing and consolidating chunks. 1604 1605 Each freshly allocated chunk must have both cinuse and pinuse set. 1606 That is, each allocated chunk borders either a previously allocated 1607 and still in-use chunk, or the base of its memory arena. This is 1608 ensured by making all allocations from the the `lowest' part of any 1609 found chunk. Further, no free chunk physically borders another one, 1610 so each free chunk is known to be preceded and followed by either 1611 inuse chunks or the ends of memory. 1612 1613 Note that the `foot' of the current chunk is actually represented 1614 as the prev_foot of the NEXT chunk. This makes it easier to 1615 deal with alignments etc but can be very confusing when trying 1616 to extend or adapt this code. 1617 1618 The exceptions to all this are 1619 1620 1. The special chunk `top' is the top-most available chunk (i.e., 1621 the one bordering the end of available memory). It is treated 1622 specially. Top is never included in any bin, is used only if 1623 no other chunk is available, and is released back to the 1624 system if it is very large (see M_TRIM_THRESHOLD). In effect, 1625 the top chunk is treated as larger (and thus less well 1626 fitting) than any other available chunk. The top chunk 1627 doesn't update its trailing size field since there is no next 1628 contiguous chunk that would have to index off it. However, 1629 space is still allocated for it (TOP_FOOT_SIZE) to enable 1630 separation or merging when space is extended. 1631 1632 3. Chunks allocated via mmap, which have the lowest-order bit 1633 (IS_MMAPPED_BIT) set in their prev_foot fields, and do not set 1634 PINUSE_BIT in their head fields. Because they are allocated 1635 one-by-one, each must carry its own prev_foot field, which is 1636 also used to hold the offset this chunk has within its mmapped 1637 region, which is needed to preserve alignment. Each mmapped 1638 chunk is trailed by the first two fields of a fake next-chunk 1639 for sake of usage checks. 1640 1641 */ 1642 1643 struct malloc_chunk { 1644 size_t prev_foot; /* Size of previous chunk (if free). */ 1645 size_t head; /* Size and inuse bits. */ 1646 struct malloc_chunk* fd; /* double links -- used only if free. */ 1647 struct malloc_chunk* bk; 1648 }; 1649 1650 typedef struct malloc_chunk mchunk; 1651 typedef struct malloc_chunk* mchunkptr; 1652 typedef struct malloc_chunk* sbinptr; /* The type of bins of chunks */ 1653 typedef size_t bindex_t; /* Described below */ 1654 typedef unsigned int binmap_t; /* Described below */ 1655 typedef unsigned int flag_t; /* The type of various bit flag sets */ 1656 1657 /* ------------------- Chunks sizes and alignments ----------------------- */ 1658 1659 #define MCHUNK_SIZE (sizeof(mchunk)) 1660 1661 #if FOOTERS 1662 #define CHUNK_OVERHEAD (TWO_SIZE_T_SIZES) 1663 #else /* FOOTERS */ 1664 #define CHUNK_OVERHEAD (SIZE_T_SIZE) 1665 #endif /* FOOTERS */ 1666 1667 /* MMapped chunks need a second word of overhead ... */ 1668 #define MMAP_CHUNK_OVERHEAD (TWO_SIZE_T_SIZES) 1669 /* ... and additional padding for fake next-chunk at foot */ 1670 #define MMAP_FOOT_PAD (FOUR_SIZE_T_SIZES) 1671 1672 /* The smallest size we can malloc is an aligned minimal chunk */ 1673 #define MIN_CHUNK_SIZE\ 1674 ((MCHUNK_SIZE + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK) 1675 1676 /* conversion from malloc headers to user pointers, and back */ 1677 #define chunk2mem(p) ((void*)((char*)(p) + TWO_SIZE_T_SIZES)) 1678 #define mem2chunk(mem) ((mchunkptr)((char*)(mem) - TWO_SIZE_T_SIZES)) 1679 /* chunk associated with aligned address A */ 1680 #define align_as_chunk(A) (mchunkptr)((A) + align_offset(chunk2mem(A))) 1681 1682 /* Bounds on request (not chunk) sizes. */ 1683 #define MAX_REQUEST ((-MIN_CHUNK_SIZE) << 2) 1684 #define MIN_REQUEST (MIN_CHUNK_SIZE - CHUNK_OVERHEAD - SIZE_T_ONE) 1685 1686 /* pad request bytes into a usable size */ 1687 #define pad_request(req) \ 1688 (((req) + CHUNK_OVERHEAD + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK) 1689 1690 /* pad request, checking for minimum (but not maximum) */ 1691 #define request2size(req) \ 1692 (((req) < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(req)) 1693 1694 1695 /* ------------------ Operations on head and foot fields ----------------- */ 1696 1697 /* 1698 The head field of a chunk is or'ed with PINUSE_BIT when previous 1699 adjacent chunk in use, and or'ed with CINUSE_BIT if this chunk is in 1700 use. If the chunk was obtained with mmap, the prev_foot field has 1701 IS_MMAPPED_BIT set, otherwise holding the offset of the base of the 1702 mmapped region to the base of the chunk. 1703 */ 1704 1705 #define PINUSE_BIT (SIZE_T_ONE) 1706 #define CINUSE_BIT (SIZE_T_TWO) 1707 #define INUSE_BITS (PINUSE_BIT|CINUSE_BIT) 1708 1709 /* Head value for fenceposts */ 1710 #define FENCEPOST_HEAD (INUSE_BITS|SIZE_T_SIZE) 1711 1712 /* extraction of fields from head words */ 1713 #define cinuse(p) ((p)->head & CINUSE_BIT) 1714 #define pinuse(p) ((p)->head & PINUSE_BIT) 1715 #define chunksize(p) ((p)->head & ~(INUSE_BITS)) 1716 1717 #define clear_pinuse(p) ((p)->head &= ~PINUSE_BIT) 1718 #define clear_cinuse(p) ((p)->head &= ~CINUSE_BIT) 1719 1720 /* Treat space at ptr +/- offset as a chunk */ 1721 #define chunk_plus_offset(p, s) ((mchunkptr)(((char*)(p)) + (s))) 1722 #define chunk_minus_offset(p, s) ((mchunkptr)(((char*)(p)) - (s))) 1723 1724 /* Ptr to next or previous physical malloc_chunk. */ 1725 #define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->head & ~INUSE_BITS))) 1726 #define prev_chunk(p) ((mchunkptr)( ((char*)(p)) - ((p)->prev_foot) )) 1727 1728 /* extract next chunk's pinuse bit */ 1729 #define next_pinuse(p) ((next_chunk(p)->head) & PINUSE_BIT) 1730 1731 /* Get/set size at footer */ 1732 #define get_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot) 1733 #define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot = (s)) 1734 1735 /* Set size, pinuse bit, and foot */ 1736 #define set_size_and_pinuse_of_free_chunk(p, s)\ 1737 ((p)->head = (s|PINUSE_BIT), set_foot(p, s)) 1738 1739 /* Set size, pinuse bit, foot, and clear next pinuse */ 1740 #define set_free_with_pinuse(p, s, n)\ 1741 (clear_pinuse(n), set_size_and_pinuse_of_free_chunk(p, s)) 1742 1743 #define is_mmapped(p)\ 1744 (!((p)->head & PINUSE_BIT) && ((p)->prev_foot & IS_MMAPPED_BIT)) 1745 1746 /* Get the internal overhead associated with chunk p */ 1747 #define overhead_for(p)\ 1748 (is_mmapped(p)? MMAP_CHUNK_OVERHEAD : CHUNK_OVERHEAD) 1749 1750 /* Return true if malloced space is not necessarily cleared */ 1751 #if MMAP_CLEARS 1752 #define calloc_must_clear(p) (!is_mmapped(p)) 1753 #else /* MMAP_CLEARS */ 1754 #define calloc_must_clear(p) (1) 1755 #endif /* MMAP_CLEARS */ 1756 1757 /* ---------------------- Overlaid data structures ----------------------- */ 1758 1759 /* 1760 When chunks are not in use, they are treated as nodes of either 1761 lists or trees. 1762 1763 "Small" chunks are stored in circular doubly-linked lists, and look 1764 like this: 1765 1766 chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1767 | Size of previous chunk | 1768 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1769 `head:' | Size of chunk, in bytes |P| 1770 mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1771 | Forward pointer to next chunk in list | 1772 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1773 | Back pointer to previous chunk in list | 1774 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1775 | Unused space (may be 0 bytes long) . 1776 . . 1777 . | 1778 nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1779 `foot:' | Size of chunk, in bytes | 1780 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1781 1782 Larger chunks are kept in a form of bitwise digital trees (aka 1783 tries) keyed on chunksizes. Because malloc_tree_chunks are only for 1784 free chunks greater than 256 bytes, their size doesn't impose any 1785 constraints on user chunk sizes. Each node looks like: 1786 1787 chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1788 | Size of previous chunk | 1789 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1790 `head:' | Size of chunk, in bytes |P| 1791 mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1792 | Forward pointer to next chunk of same size | 1793 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1794 | Back pointer to previous chunk of same size | 1795 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1796 | Pointer to left child (child[0]) | 1797 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1798 | Pointer to right child (child[1]) | 1799 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1800 | Pointer to parent | 1801 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1802 | bin index of this chunk | 1803 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1804 | Unused space . 1805 . | 1806 nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1807 `foot:' | Size of chunk, in bytes | 1808 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1809 1810 Each tree holding treenodes is a tree of unique chunk sizes. Chunks 1811 of the same size are arranged in a circularly-linked list, with only 1812 the oldest chunk (the next to be used, in our FIFO ordering) 1813 actually in the tree. (Tree members are distinguished by a non-null 1814 parent pointer.) If a chunk with the same size an an existing node 1815 is inserted, it is linked off the existing node using pointers that 1816 work in the same way as fd/bk pointers of small chunks. 1817 1818 Each tree contains a power of 2 sized range of chunk sizes (the 1819 smallest is 0x100 <= x < 0x180), which is is divided in half at each 1820 tree level, with the chunks in the smaller half of the range (0x100 1821 <= x < 0x140 for the top nose) in the left subtree and the larger 1822 half (0x140 <= x < 0x180) in the right subtree. This is, of course, 1823 done by inspecting individual bits. 1824 1825 Using these rules, each node's left subtree contains all smaller 1826 sizes than its right subtree. However, the node at the root of each 1827 subtree has no particular ordering relationship to either. (The 1828 dividing line between the subtree sizes is based on trie relation.) 1829 If we remove the last chunk of a given size from the interior of the 1830 tree, we need to replace it with a leaf node. The tree ordering 1831 rules permit a node to be replaced by any leaf below it. 1832 1833 The smallest chunk in a tree (a common operation in a best-fit 1834 allocator) can be found by walking a path to the leftmost leaf in 1835 the tree. Unlike a usual binary tree, where we follow left child 1836 pointers until we reach a null, here we follow the right child 1837 pointer any time the left one is null, until we reach a leaf with 1838 both child pointers null. The smallest chunk in the tree will be 1839 somewhere along that path. 1840 1841 The worst case number of steps to add, find, or remove a node is 1842 bounded by the number of bits differentiating chunks within 1843 bins. Under current bin calculations, this ranges from 6 up to 21 1844 (for 32 bit sizes) or up to 53 (for 64 bit sizes). The typical case 1845 is of course much better. 1846 */ 1847 1848 struct malloc_tree_chunk { 1849 /* The first four fields must be compatible with malloc_chunk */ 1850 size_t prev_foot; 1851 size_t head; 1852 struct malloc_tree_chunk* fd; 1853 struct malloc_tree_chunk* bk; 1854 1855 struct malloc_tree_chunk* child[2]; 1856 struct malloc_tree_chunk* parent; 1857 bindex_t index; 1858 }; 1859 1860 typedef struct malloc_tree_chunk tchunk; 1861 typedef struct malloc_tree_chunk* tchunkptr; 1862 typedef struct malloc_tree_chunk* tbinptr; /* The type of bins of trees */ 1863 1864 /* A little helper macro for trees */ 1865 #define leftmost_child(t) ((t)->child[0] != 0? (t)->child[0] : (t)->child[1]) 1866 1867 /* ----------------------------- Segments -------------------------------- */ 1868 1869 /* 1870 Each malloc space may include non-contiguous segments, held in a 1871 list headed by an embedded malloc_segment record representing the 1872 top-most space. Segments also include flags holding properties of 1873 the space. Large chunks that are directly allocated by mmap are not 1874 included in this list. They are instead independently created and 1875 destroyed without otherwise keeping track of them. 1876 1877 Segment management mainly comes into play for spaces allocated by 1878 MMAP. Any call to MMAP might or might not return memory that is 1879 adjacent to an existing segment. MORECORE normally contiguously 1880 extends the current space, so this space is almost always adjacent, 1881 which is simpler and faster to deal with. (This is why MORECORE is 1882 used preferentially to MMAP when both are available -- see 1883 sys_alloc.) When allocating using MMAP, we don't use any of the 1884 hinting mechanisms (inconsistently) supported in various 1885 implementations of unix mmap, or distinguish reserving from 1886 committing memory. Instead, we just ask for space, and exploit 1887 contiguity when we get it. It is probably possible to do 1888 better than this on some systems, but no general scheme seems 1889 to be significantly better. 1890 1891 Management entails a simpler variant of the consolidation scheme 1892 used for chunks to reduce fragmentation -- new adjacent memory is 1893 normally prepended or appended to an existing segment. However, 1894 there are limitations compared to chunk consolidation that mostly 1895 reflect the fact that segment processing is relatively infrequent 1896 (occurring only when getting memory from system) and that we 1897 don't expect to have huge numbers of segments: 1898 1899 * Segments are not indexed, so traversal requires linear scans. (It 1900 would be possible to index these, but is not worth the extra 1901 overhead and complexity for most programs on most platforms.) 1902 * New segments are only appended to old ones when holding top-most 1903 memory; if they cannot be prepended to others, they are held in 1904 different segments. 1905 1906 Except for the top-most segment of an mstate, each segment record 1907 is kept at the tail of its segment. Segments are added by pushing 1908 segment records onto the list headed by &mstate.seg for the 1909 containing mstate. 1910 1911 Segment flags control allocation/merge/deallocation policies: 1912 * If EXTERN_BIT set, then we did not allocate this segment, 1913 and so should not try to deallocate or merge with others. 1914 (This currently holds only for the initial segment passed 1915 into create_mspace_with_base.) 1916 * If IS_MMAPPED_BIT set, the segment may be merged with 1917 other surrounding mmapped segments and trimmed/de-allocated 1918 using munmap. 1919 * If neither bit is set, then the segment was obtained using 1920 MORECORE so can be merged with surrounding MORECORE'd segments 1921 and deallocated/trimmed using MORECORE with negative arguments. 1922 */ 1923 1924 struct malloc_segment { 1925 char* base; /* base address */ 1926 size_t size; /* allocated size */ 1927 struct malloc_segment* next; /* ptr to next segment */ 1928 flag_t sflags; /* mmap and extern flag */ 1929 }; 1930 1931 #define is_mmapped_segment(S) ((S)->sflags & IS_MMAPPED_BIT) 1932 #define is_extern_segment(S) ((S)->sflags & EXTERN_BIT) 1933 1934 typedef struct malloc_segment msegment; 1935 typedef struct malloc_segment* msegmentptr; 1936 1937 /* ---------------------------- malloc_state ----------------------------- */ 1938 1939 /* 1940 A malloc_state holds all of the bookkeeping for a space. 1941 The main fields are: 1942 1943 Top 1944 The topmost chunk of the currently active segment. Its size is 1945 cached in topsize. The actual size of topmost space is 1946 topsize+TOP_FOOT_SIZE, which includes space reserved for adding 1947 fenceposts and segment records if necessary when getting more 1948 space from the system. The size at which to autotrim top is 1949 cached from mparams in trim_check, except that it is disabled if 1950 an autotrim fails. 1951 1952 Designated victim (dv) 1953 This is the preferred chunk for servicing small requests that 1954 don't have exact fits. It is normally the chunk split off most 1955 recently to service another small request. Its size is cached in 1956 dvsize. The link fields of this chunk are not maintained since it 1957 is not kept in a bin. 1958 1959 SmallBins 1960 An array of bin headers for free chunks. These bins hold chunks 1961 with sizes less than MIN_LARGE_SIZE bytes. Each bin contains 1962 chunks of all the same size, spaced 8 bytes apart. To simplify 1963 use in double-linked lists, each bin header acts as a malloc_chunk 1964 pointing to the real first node, if it exists (else pointing to 1965 itself). This avoids special-casing for headers. But to avoid 1966 waste, we allocate only the fd/bk pointers of bins, and then use 1967 repositioning tricks to treat these as the fields of a chunk. 1968 1969 TreeBins 1970 Treebins are pointers to the roots of trees holding a range of 1971 sizes. There are 2 equally spaced treebins for each power of two 1972 from TREE_SHIFT to TREE_SHIFT+16. The last bin holds anything 1973 larger. 1974 1975 Bin maps 1976 There is one bit map for small bins ("smallmap") and one for 1977 treebins ("treemap). Each bin sets its bit when non-empty, and 1978 clears the bit when empty. Bit operations are then used to avoid 1979 bin-by-bin searching -- nearly all "search" is done without ever 1980 looking at bins that won't be selected. The bit maps 1981 conservatively use 32 bits per map word, even if on 64bit system. 1982 For a good description of some of the bit-based techniques used 1983 here, see Henry S. Warren Jr's book "Hacker's Delight" (and 1984 supplement at http://hackersdelight.org/). Many of these are 1985 intended to reduce the branchiness of paths through malloc etc, as 1986 well as to reduce the number of memory locations read or written. 1987 1988 Segments 1989 A list of segments headed by an embedded malloc_segment record 1990 representing the initial space. 1991 1992 Address check support 1993 The least_addr field is the least address ever obtained from 1994 MORECORE or MMAP. Attempted frees and reallocs of any address less 1995 than this are trapped (unless INSECURE is defined). 1996 1997 Magic tag 1998 A cross-check field that should always hold same value as mparams.magic. 1999 2000 Flags 2001 Bits recording whether to use MMAP, locks, or contiguous MORECORE 2002 2003 Statistics 2004 Each space keeps track of current and maximum system memory 2005 obtained via MORECORE or MMAP. 2006 2007 Locking 2008 If USE_LOCKS is defined, the "mutex" lock is acquired and released 2009 around every public call using this mspace. 2010 */ 2011 2012 /* Bin types, widths and sizes */ 2013 #define NSMALLBINS (32U) 2014 #define NTREEBINS (32U) 2015 #define SMALLBIN_SHIFT (3U) 2016 #define SMALLBIN_WIDTH (SIZE_T_ONE << SMALLBIN_SHIFT) 2017 #define TREEBIN_SHIFT (8U) 2018 #define MIN_LARGE_SIZE (SIZE_T_ONE << TREEBIN_SHIFT) 2019 #define MAX_SMALL_SIZE (MIN_LARGE_SIZE - SIZE_T_ONE) 2020 #define MAX_SMALL_REQUEST (MAX_SMALL_SIZE - CHUNK_ALIGN_MASK - CHUNK_OVERHEAD) 2021 2022 struct malloc_state { 2023 binmap_t smallmap; 2024 binmap_t treemap; 2025 size_t dvsize; 2026 size_t topsize; 2027 char* least_addr; 2028 mchunkptr dv; 2029 mchunkptr top; 2030 size_t trim_check; 2031 size_t magic; 2032 mchunkptr smallbins[(NSMALLBINS+1)*2]; 2033 tbinptr treebins[NTREEBINS]; 2034 size_t footprint; 2035 size_t max_footprint; 2036 flag_t mflags; 2037 #if USE_LOCKS 2038 MLOCK_T mutex; /* locate lock among fields that rarely change */ 2039 #endif /* USE_LOCKS */ 2040 msegment seg; 2041 }; 2042 2043 typedef struct malloc_state* mstate; 2044 2045 /* ------------- Global malloc_state and malloc_params ------------------- */ 2046 2047 /* 2048 malloc_params holds global properties, including those that can be 2049 dynamically set using mallopt. There is a single instance, mparams, 2050 initialized in init_mparams. 2051 */ 2052 2053 struct malloc_params { 2054 size_t magic; 2055 size_t page_size; 2056 size_t granularity; 2057 size_t mmap_threshold; 2058 size_t trim_threshold; 2059 flag_t default_mflags; 2060 }; 2061 2062 static struct malloc_params mparams; 2063 2064 /* The global malloc_state used for all non-"mspace" calls */ 2065 static struct malloc_state _gm_; 2066 #define gm (&_gm_) 2067 #define is_global(M) ((M) == &_gm_) 2068 #define is_initialized(M) ((M)->top != 0) 2069 2070 /* -------------------------- system alloc setup ------------------------- */ 2071 2072 /* Operations on mflags */ 2073 2074 #define use_lock(M) ((M)->mflags & USE_LOCK_BIT) 2075 #define enable_lock(M) ((M)->mflags |= USE_LOCK_BIT) 2076 #define disable_lock(M) ((M)->mflags &= ~USE_LOCK_BIT) 2077 2078 #define use_mmap(M) ((M)->mflags & USE_MMAP_BIT) 2079 #define enable_mmap(M) ((M)->mflags |= USE_MMAP_BIT) 2080 #define disable_mmap(M) ((M)->mflags &= ~USE_MMAP_BIT) 2081 2082 #define use_noncontiguous(M) ((M)->mflags & USE_NONCONTIGUOUS_BIT) 2083 #define disable_contiguous(M) ((M)->mflags |= USE_NONCONTIGUOUS_BIT) 2084 2085 #define set_lock(M,L)\ 2086 ((M)->mflags = (L)?\ 2087 ((M)->mflags | USE_LOCK_BIT) :\ 2088 ((M)->mflags & ~USE_LOCK_BIT)) 2089 2090 /* page-align a size */ 2091 #define page_align(S)\ 2092 (((S) + (mparams.page_size)) & ~(mparams.page_size - SIZE_T_ONE)) 2093 2094 /* granularity-align a size */ 2095 #define granularity_align(S)\ 2096 (((S) + (mparams.granularity)) & ~(mparams.granularity - SIZE_T_ONE)) 2097 2098 #define is_page_aligned(S)\ 2099 (((size_t)(S) & (mparams.page_size - SIZE_T_ONE)) == 0) 2100 #define is_granularity_aligned(S)\ 2101 (((size_t)(S) & (mparams.granularity - SIZE_T_ONE)) == 0) 2102 2103 /* True if segment S holds address A */ 2104 #define segment_holds(S, A)\ 2105 ((char*)(A) >= S->base && (char*)(A) < S->base + S->size) 2106 2107 /* Return segment holding given address */ 2108 static msegmentptr segment_holding(mstate m, char* addr) { 2109 msegmentptr sp = &m->seg; 2110 for (;;) { 2111 if (addr >= sp->base && addr < sp->base + sp->size) 2112 return sp; 2113 if ((sp = sp->next) == 0) 2114 return 0; 2115 } 2116 } 2117 2118 /* Return true if segment contains a segment link */ 2119 static int has_segment_link(mstate m, msegmentptr ss) { 2120 msegmentptr sp = &m->seg; 2121 for (;;) { 2122 if ((char*)sp >= ss->base && (char*)sp < ss->base + ss->size) 2123 return 1; 2124 if ((sp = sp->next) == 0) 2125 return 0; 2126 } 2127 } 2128 2129 #ifndef MORECORE_CANNOT_TRIM 2130 #define should_trim(M,s) ((s) > (M)->trim_check) 2131 #else /* MORECORE_CANNOT_TRIM */ 2132 #define should_trim(M,s) (0) 2133 #endif /* MORECORE_CANNOT_TRIM */ 2134 2135 /* 2136 TOP_FOOT_SIZE is padding at the end of a segment, including space 2137 that may be needed to place segment records and fenceposts when new 2138 noncontiguous segments are added. 2139 */ 2140 #define TOP_FOOT_SIZE\ 2141 (align_offset(chunk2mem(0))+pad_request(sizeof(struct malloc_segment))+MIN_CHUNK_SIZE) 2142 2143 2144 /* ------------------------------- Hooks -------------------------------- */ 2145 2146 /* 2147 PREACTION should be defined to return 0 on success, and nonzero on 2148 failure. If you are not using locking, you can redefine these to do 2149 anything you like. 2150 */ 2151 2152 #if USE_LOCKS 2153 2154 /* Ensure locks are initialized */ 2155 #define GLOBALLY_INITIALIZE() (mparams.page_size == 0 && init_mparams()) 2156 2157 #define PREACTION(M) ((GLOBALLY_INITIALIZE() || use_lock(M))? ACQUIRE_LOCK(&(M)->mutex) : 0) 2158 #define POSTACTION(M) { if (use_lock(M)) RELEASE_LOCK(&(M)->mutex); } 2159 #else /* USE_LOCKS */ 2160 2161 #ifndef PREACTION 2162 #define PREACTION(M) (0) 2163 #endif /* PREACTION */ 2164 2165 #ifndef POSTACTION 2166 #define POSTACTION(M) 2167 #endif /* POSTACTION */ 2168 2169 #endif /* USE_LOCKS */ 2170 2171 /* 2172 CORRUPTION_ERROR_ACTION is triggered upon detected bad addresses. 2173 USAGE_ERROR_ACTION is triggered on detected bad frees and 2174 reallocs. The argument p is an address that might have triggered the 2175 fault. It is ignored by the two predefined actions, but might be 2176 useful in custom actions that try to help diagnose errors. 2177 */ 2178 2179 #if PROCEED_ON_ERROR 2180 2181 /* A count of the number of corruption errors causing resets */ 2182 int malloc_corruption_error_count; 2183 2184 /* default corruption action */ 2185 static void reset_on_error(mstate m); 2186 2187 #define CORRUPTION_ERROR_ACTION(m) reset_on_error(m) 2188 #define USAGE_ERROR_ACTION(m, p) 2189 2190 #else /* PROCEED_ON_ERROR */ 2191 2192 #ifndef CORRUPTION_ERROR_ACTION 2193 #define CORRUPTION_ERROR_ACTION(m) ABORT 2194 #endif /* CORRUPTION_ERROR_ACTION */ 2195 2196 #ifndef USAGE_ERROR_ACTION 2197 #define USAGE_ERROR_ACTION(m,p) ABORT 2198 #endif /* USAGE_ERROR_ACTION */ 2199 2200 #endif /* PROCEED_ON_ERROR */ 2201 2202 /* -------------------------- Debugging setup ---------------------------- */ 2203 2204 #if ! DEBUG 2205 2206 #define check_free_chunk(M,P) 2207 #define check_inuse_chunk(M,P) 2208 #define check_malloced_chunk(M,P,N) 2209 #define check_mmapped_chunk(M,P) 2210 #define check_malloc_state(M) 2211 #define check_top_chunk(M,P) 2212 2213 #else /* DEBUG */ 2214 #define check_free_chunk(M,P) do_check_free_chunk(M,P) 2215 #define check_inuse_chunk(M,P) do_check_inuse_chunk(M,P) 2216 #define check_top_chunk(M,P) do_check_top_chunk(M,P) 2217 #define check_malloced_chunk(M,P,N) do_check_malloced_chunk(M,P,N) 2218 #define check_mmapped_chunk(M,P) do_check_mmapped_chunk(M,P) 2219 #define check_malloc_state(M) do_check_malloc_state(M) 2220 2221 static void do_check_any_chunk(mstate m, mchunkptr p); 2222 static void do_check_top_chunk(mstate m, mchunkptr p); 2223 static void do_check_mmapped_chunk(mstate m, mchunkptr p); 2224 static void do_check_inuse_chunk(mstate m, mchunkptr p); 2225 static void do_check_free_chunk(mstate m, mchunkptr p); 2226 static void do_check_malloced_chunk(mstate m, void* mem, size_t s); 2227 static void do_check_tree(mstate m, tchunkptr t); 2228 static void do_check_treebin(mstate m, bindex_t i); 2229 static void do_check_smallbin(mstate m, bindex_t i); 2230 static void do_check_malloc_state(mstate m); 2231 static int bin_find(mstate m, mchunkptr x); 2232 static size_t traverse_and_check(mstate m); 2233 #endif /* DEBUG */ 2234 2235 /* ---------------------------- Indexing Bins ---------------------------- */ 2236 2237 #define is_small(s) (((s) >> SMALLBIN_SHIFT) < NSMALLBINS) 2238 #define small_index(s) ((s) >> SMALLBIN_SHIFT) 2239 #define small_index2size(i) ((i) << SMALLBIN_SHIFT) 2240 #define MIN_SMALL_INDEX (small_index(MIN_CHUNK_SIZE)) 2241 2242 /* addressing by index. See above about smallbin repositioning */ 2243 #define smallbin_at(M, i) ((sbinptr)((char*)&((M)->smallbins[(i)<<1]))) 2244 #define treebin_at(M,i) (&((M)->treebins[i])) 2245 2246 /* assign tree index for size S to variable I */ 2247 #if defined(__GNUC__) && defined(i386) 2248 #define compute_tree_index(S, I)\ 2249 {\ 2250 size_t X = S >> TREEBIN_SHIFT;\ 2251 if (X == 0)\ 2252 I = 0;\ 2253 else if (X > 0xFFFF)\ 2254 I = NTREEBINS-1;\ 2255 else {\ 2256 unsigned int K;\ 2257 __asm__("bsrl %1,%0\n\t" : "=r" (K) : "rm" (X));\ 2258 I = (bindex_t)((K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1)));\ 2259 }\ 2260 } 2261 #else /* GNUC */ 2262 #define compute_tree_index(S, I)\ 2263 {\ 2264 size_t X = S >> TREEBIN_SHIFT;\ 2265 if (X == 0)\ 2266 I = 0;\ 2267 else if (X > 0xFFFF)\ 2268 I = NTREEBINS-1;\ 2269 else {\ 2270 unsigned int Y = (unsigned int)X;\ 2271 unsigned int N = ((Y - 0x100) >> 16) & 8;\ 2272 unsigned int K = (((Y <<= N) - 0x1000) >> 16) & 4;\ 2273 N += K;\ 2274 N += K = (((Y <<= K) - 0x4000) >> 16) & 2;\ 2275 K = 14 - N + ((Y <<= K) >> 15);\ 2276 I = (K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1));\ 2277 }\ 2278 } 2279 #endif /* GNUC */ 2280 2281 /* Bit representing maximum resolved size in a treebin at i */ 2282 #define bit_for_tree_index(i) \ 2283 (i == NTREEBINS-1)? (SIZE_T_BITSIZE-1) : (((i) >> 1) + TREEBIN_SHIFT - 2) 2284 2285 /* Shift placing maximum resolved bit in a treebin at i as sign bit */ 2286 #define leftshift_for_tree_index(i) \ 2287 ((i == NTREEBINS-1)? 0 : \ 2288 ((SIZE_T_BITSIZE-SIZE_T_ONE) - (((i) >> 1) + TREEBIN_SHIFT - 2))) 2289 2290 /* The size of the smallest chunk held in bin with index i */ 2291 #define minsize_for_tree_index(i) \ 2292 ((SIZE_T_ONE << (((i) >> 1) + TREEBIN_SHIFT)) | \ 2293 (((size_t)((i) & SIZE_T_ONE)) << (((i) >> 1) + TREEBIN_SHIFT - 1))) 2294 2295 2296 /* ------------------------ Operations on bin maps ----------------------- */ 2297 2298 /* bit corresponding to given index */ 2299 #define idx2bit(i) ((binmap_t)(1) << (i)) 2300 2301 /* Mark/Clear bits with given index */ 2302 #define mark_smallmap(M,i) ((M)->smallmap |= idx2bit(i)) 2303 #define clear_smallmap(M,i) ((M)->smallmap &= ~idx2bit(i)) 2304 #define smallmap_is_marked(M,i) ((M)->smallmap & idx2bit(i)) 2305 2306 #define mark_treemap(M,i) ((M)->treemap |= idx2bit(i)) 2307 #define clear_treemap(M,i) ((M)->treemap &= ~idx2bit(i)) 2308 #define treemap_is_marked(M,i) ((M)->treemap & idx2bit(i)) 2309 2310 /* index corresponding to given bit */ 2311 2312 #if defined(__GNUC__) && defined(i386) 2313 #define compute_bit2idx(X, I)\ 2314 {\ 2315 unsigned int J;\ 2316 __asm__("bsfl %1,%0\n\t" : "=r" (J) : "rm" (X));\ 2317 I = (bindex_t)J;\ 2318 } 2319 2320 #else /* GNUC */ 2321 #if USE_BUILTIN_FFS 2322 #define compute_bit2idx(X, I) I = ffs(X)-1 2323 2324 #else /* USE_BUILTIN_FFS */ 2325 #define compute_bit2idx(X, I)\ 2326 {\ 2327 unsigned int Y = X - 1;\ 2328 unsigned int K = Y >> (16-4) & 16;\ 2329 unsigned int N = K; Y >>= K;\ 2330 N += K = Y >> (8-3) & 8; Y >>= K;\ 2331 N += K = Y >> (4-2) & 4; Y >>= K;\ 2332 N += K = Y >> (2-1) & 2; Y >>= K;\ 2333 N += K = Y >> (1-0) & 1; Y >>= K;\ 2334 I = (bindex_t)(N + Y);\ 2335 } 2336 #endif /* USE_BUILTIN_FFS */ 2337 #endif /* GNUC */ 2338 2339 /* isolate the least set bit of a bitmap */ 2340 #define least_bit(x) ((x) & -(x)) 2341 2342 /* mask with all bits to left of least bit of x on */ 2343 #define left_bits(x) ((x<<1) | -(x<<1)) 2344 2345 /* mask with all bits to left of or equal to least bit of x on */ 2346 #define same_or_left_bits(x) ((x) | -(x)) 2347 2348 2349 /* ----------------------- Runtime Check Support ------------------------- */ 2350 2351 /* 2352 For security, the main invariant is that malloc/free/etc never 2353 writes to a static address other than malloc_state, unless static 2354 malloc_state itself has been corrupted, which cannot occur via 2355 malloc (because of these checks). In essence this means that we 2356 believe all pointers, sizes, maps etc held in malloc_state, but 2357 check all of those linked or offsetted from other embedded data 2358 structures. These checks are interspersed with main code in a way 2359 that tends to minimize their run-time cost. 2360 2361 When FOOTERS is defined, in addition to range checking, we also 2362 verify footer fields of inuse chunks, which can be used guarantee 2363 that the mstate controlling malloc/free is intact. This is a 2364 streamlined version of the approach described by William Robertson 2365 et al in "Run-time Detection of Heap-based Overflows" LISA'03 2366 http://www.usenix.org/events/lisa03/tech/robertson.html The footer 2367 of an inuse chunk holds the xor of its mstate and a random seed, 2368 that is checked upon calls to free() and realloc(). This is 2369 (probablistically) unguessable from outside the program, but can be 2370 computed by any code successfully malloc'ing any chunk, so does not 2371 itself provide protection against code that has already broken 2372 security through some other means. Unlike Robertson et al, we 2373 always dynamically check addresses of all offset chunks (previous, 2374 next, etc). This turns out to be cheaper than relying on hashes. 2375 */ 2376 2377 #if !INSECURE 2378 /* Check if address a is at least as high as any from MORECORE or MMAP */ 2379 #define ok_address(M, a) ((char*)(a) >= (M)->least_addr) 2380 /* Check if address of next chunk n is higher than base chunk p */ 2381 #define ok_next(p, n) ((char*)(p) < (char*)(n)) 2382 /* Check if p has its cinuse bit on */ 2383 #define ok_cinuse(p) cinuse(p) 2384 /* Check if p has its pinuse bit on */ 2385 #define ok_pinuse(p) pinuse(p) 2386 2387 #else /* !INSECURE */ 2388 #define ok_address(M, a) (1) 2389 #define ok_next(b, n) (1) 2390 #define ok_cinuse(p) (1) 2391 #define ok_pinuse(p) (1) 2392 #endif /* !INSECURE */ 2393 2394 #if (FOOTERS && !INSECURE) 2395 /* Check if (alleged) mstate m has expected magic field */ 2396 #define ok_magic(M) ((M)->magic == mparams.magic) 2397 #else /* (FOOTERS && !INSECURE) */ 2398 #define ok_magic(M) (1) 2399 #endif /* (FOOTERS && !INSECURE) */ 2400 2401 2402 /* In gcc, use __builtin_expect to minimize impact of checks */ 2403 #if !INSECURE 2404 #if defined(__GNUC__) && __GNUC__ >= 3 2405 #define RTCHECK(e) __builtin_expect(e, 1) 2406 #else /* GNUC */ 2407 #define RTCHECK(e) (e) 2408 #endif /* GNUC */ 2409 #else /* !INSECURE */ 2410 #define RTCHECK(e) (1) 2411 #endif /* !INSECURE */ 2412 2413 /* macros to set up inuse chunks with or without footers */ 2414 2415 #if !FOOTERS 2416 2417 #define mark_inuse_foot(M,p,s) 2418 2419 /* Set cinuse bit and pinuse bit of next chunk */ 2420 #define set_inuse(M,p,s)\ 2421 ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\ 2422 ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT) 2423 2424 /* Set cinuse and pinuse of this chunk and pinuse of next chunk */ 2425 #define set_inuse_and_pinuse(M,p,s)\ 2426 ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ 2427 ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT) 2428 2429 /* Set size, cinuse and pinuse bit of this chunk */ 2430 #define set_size_and_pinuse_of_inuse_chunk(M, p, s)\ 2431 ((p)->head = (s|PINUSE_BIT|CINUSE_BIT)) 2432 2433 #else /* FOOTERS */ 2434 2435 /* Set foot of inuse chunk to be xor of mstate and seed */ 2436 #define mark_inuse_foot(M,p,s)\ 2437 (((mchunkptr)((char*)(p) + (s)))->prev_foot = ((size_t)(M) ^ mparams.magic)) 2438 2439 #define get_mstate_for(p)\ 2440 ((mstate)(((mchunkptr)((char*)(p) +\ 2441 (chunksize(p))))->prev_foot ^ mparams.magic)) 2442 2443 #define set_inuse(M,p,s)\ 2444 ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\ 2445 (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT), \ 2446 mark_inuse_foot(M,p,s)) 2447 2448 #define set_inuse_and_pinuse(M,p,s)\ 2449 ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ 2450 (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT),\ 2451 mark_inuse_foot(M,p,s)) 2452 2453 #define set_size_and_pinuse_of_inuse_chunk(M, p, s)\ 2454 ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ 2455 mark_inuse_foot(M, p, s)) 2456 2457 #endif /* !FOOTERS */ 2458 2459 /* ---------------------------- setting mparams -------------------------- */ 2460 2461 /* Initialize mparams */ 2462 static int init_mparams(void) { 2463 if (mparams.page_size == 0) { 2464 size_t s; 2465 2466 mparams.mmap_threshold = DEFAULT_MMAP_THRESHOLD; 2467 mparams.trim_threshold = DEFAULT_TRIM_THRESHOLD; 2468 #if MORECORE_CONTIGUOUS 2469 mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT; 2470 #else /* MORECORE_CONTIGUOUS */ 2471 mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT|USE_NONCONTIGUOUS_BIT; 2472 #endif /* MORECORE_CONTIGUOUS */ 2473 2474 #if (FOOTERS && !INSECURE) 2475 { 2476 #if USE_DEV_RANDOM 2477 int fd; 2478 unsigned char buf[sizeof(size_t)]; 2479 /* Try to use /dev/urandom, else fall back on using time */ 2480 if ((fd = open("/dev/urandom", O_RDONLY)) >= 0 && 2481 read(fd, buf, sizeof(buf)) == sizeof(buf)) { 2482 s = *((size_t *) buf); 2483 close(fd); 2484 } 2485 else 2486 #endif /* USE_DEV_RANDOM */ 2487 s = (size_t)(time(0) ^ (size_t)0x55555555U); 2488 2489 s |= (size_t)8U; /* ensure nonzero */ 2490 s &= ~(size_t)7U; /* improve chances of fault for bad values */ 2491 2492 } 2493 #else /* (FOOTERS && !INSECURE) */ 2494 s = (size_t)0x58585858U; 2495 #endif /* (FOOTERS && !INSECURE) */ 2496 ACQUIRE_MAGIC_INIT_LOCK(); 2497 if (mparams.magic == 0) { 2498 mparams.magic = s; 2499 /* Set up lock for main malloc area */ 2500 INITIAL_LOCK(&gm->mutex); 2501 gm->mflags = mparams.default_mflags; 2502 } 2503 RELEASE_MAGIC_INIT_LOCK(); 2504 2505 #ifndef WIN32 2506 mparams.page_size = malloc_getpagesize; 2507 mparams.granularity = ((DEFAULT_GRANULARITY != 0)? 2508 DEFAULT_GRANULARITY : mparams.page_size); 2509 #else /* WIN32 */ 2510 { 2511 SYSTEM_INFO system_info; 2512 GetSystemInfo(&system_info); 2513 mparams.page_size = system_info.dwPageSize; 2514 mparams.granularity = system_info.dwAllocationGranularity; 2515 } 2516 #endif /* WIN32 */ 2517 2518 /* Sanity-check configuration: 2519 size_t must be unsigned and as wide as pointer type. 2520 ints must be at least 4 bytes. 2521 alignment must be at least 8. 2522 Alignment, min chunk size, and page size must all be powers of 2. 2523 */ 2524 if ((sizeof(size_t) != sizeof(char*)) || 2525 (MAX_SIZE_T < MIN_CHUNK_SIZE) || 2526 (sizeof(int) < 4) || 2527 (MALLOC_ALIGNMENT < (size_t)8U) || 2528 ((MALLOC_ALIGNMENT & (MALLOC_ALIGNMENT-SIZE_T_ONE)) != 0) || 2529 ((MCHUNK_SIZE & (MCHUNK_SIZE-SIZE_T_ONE)) != 0) || 2530 ((mparams.granularity & (mparams.granularity-SIZE_T_ONE)) != 0) || 2531 ((mparams.page_size & (mparams.page_size-SIZE_T_ONE)) != 0)) 2532 ABORT; 2533 } 2534 return 0; 2535 } 2536 2537 /* support for mallopt */ 2538 static int change_mparam(int param_number, int value) { 2539 size_t val = (size_t)value; 2540 init_mparams(); 2541 switch(param_number) { 2542 case M_TRIM_THRESHOLD: 2543 mparams.trim_threshold = val; 2544 return 1; 2545 case M_GRANULARITY: 2546 if (val >= mparams.page_size && ((val & (val-1)) == 0)) { 2547 mparams.granularity = val; 2548 return 1; 2549 } 2550 else 2551 return 0; 2552 case M_MMAP_THRESHOLD: 2553 mparams.mmap_threshold = val; 2554 return 1; 2555 default: 2556 return 0; 2557 } 2558 } 2559 2560 #if DEBUG 2561 /* ------------------------- Debugging Support --------------------------- */ 2562 2563 /* Check properties of any chunk, whether free, inuse, mmapped etc */ 2564 static void do_check_any_chunk(mstate m, mchunkptr p) { 2565 assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); 2566 assert(ok_address(m, p)); 2567 } 2568 2569 /* Check properties of top chunk */ 2570 static void do_check_top_chunk(mstate m, mchunkptr p) { 2571 msegmentptr sp = segment_holding(m, (char*)p); 2572 size_t sz = chunksize(p); 2573 assert(sp != 0); 2574 assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); 2575 assert(ok_address(m, p)); 2576 assert(sz == m->topsize); 2577 assert(sz > 0); 2578 assert(sz == ((sp->base + sp->size) - (char*)p) - TOP_FOOT_SIZE); 2579 assert(pinuse(p)); 2580 assert(!next_pinuse(p)); 2581 } 2582 2583 /* Check properties of (inuse) mmapped chunks */ 2584 static void do_check_mmapped_chunk(mstate m, mchunkptr p) { 2585 size_t sz = chunksize(p); 2586 size_t len = (sz + (p->prev_foot & ~IS_MMAPPED_BIT) + MMAP_FOOT_PAD); 2587 assert(is_mmapped(p)); 2588 assert(use_mmap(m)); 2589 assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); 2590 assert(ok_address(m, p)); 2591 assert(!is_small(sz)); 2592 assert((len & (mparams.page_size-SIZE_T_ONE)) == 0); 2593 assert(chunk_plus_offset(p, sz)->head == FENCEPOST_HEAD); 2594 assert(chunk_plus_offset(p, sz+SIZE_T_SIZE)->head == 0); 2595 } 2596 2597 /* Check properties of inuse chunks */ 2598 static void do_check_inuse_chunk(mstate m, mchunkptr p) { 2599 do_check_any_chunk(m, p); 2600 assert(cinuse(p)); 2601 assert(next_pinuse(p)); 2602 /* If not pinuse and not mmapped, previous chunk has OK offset */ 2603 assert(is_mmapped(p) || pinuse(p) || next_chunk(prev_chunk(p)) == p); 2604 if (is_mmapped(p)) 2605 do_check_mmapped_chunk(m, p); 2606 } 2607 2608 /* Check properties of free chunks */ 2609 static void do_check_free_chunk(mstate m, mchunkptr p) { 2610 size_t sz = p->head & ~(PINUSE_BIT|CINUSE_BIT); 2611 mchunkptr next = chunk_plus_offset(p, sz); 2612 do_check_any_chunk(m, p); 2613 assert(!cinuse(p)); 2614 assert(!next_pinuse(p)); 2615 assert (!is_mmapped(p)); 2616 if (p != m->dv && p != m->top) { 2617 if (sz >= MIN_CHUNK_SIZE) { 2618 assert((sz & CHUNK_ALIGN_MASK) == 0); 2619 assert(is_aligned(chunk2mem(p))); 2620 assert(next->prev_foot == sz); 2621 assert(pinuse(p)); 2622 assert (next == m->top || cinuse(next)); 2623 assert(p->fd->bk == p); 2624 assert(p->bk->fd == p); 2625 } 2626 else /* markers are always of size SIZE_T_SIZE */ 2627 assert(sz == SIZE_T_SIZE); 2628 } 2629 } 2630 2631 /* Check properties of malloced chunks at the point they are malloced */ 2632 static void do_check_malloced_chunk(mstate m, void* mem, size_t s) { 2633 if (mem != 0) { 2634 mchunkptr p = mem2chunk(mem); 2635 size_t sz = p->head & ~(PINUSE_BIT|CINUSE_BIT); 2636 do_check_inuse_chunk(m, p); 2637 assert((sz & CHUNK_ALIGN_MASK) == 0); 2638 assert(sz >= MIN_CHUNK_SIZE); 2639 assert(sz >= s); 2640 /* unless mmapped, size is less than MIN_CHUNK_SIZE more than request */ 2641 assert(is_mmapped(p) || sz < (s + MIN_CHUNK_SIZE)); 2642 } 2643 } 2644 2645 /* Check a tree and its subtrees. */ 2646 static void do_check_tree(mstate m, tchunkptr t) { 2647 tchunkptr head = 0; 2648 tchunkptr u = t; 2649 bindex_t tindex = t->index; 2650 size_t tsize = chunksize(t); 2651 bindex_t idx; 2652 compute_tree_index(tsize, idx); 2653 assert(tindex == idx); 2654 assert(tsize >= MIN_LARGE_SIZE); 2655 assert(tsize >= minsize_for_tree_index(idx)); 2656 assert((idx == NTREEBINS-1) || (tsize < minsize_for_tree_index((idx+1)))); 2657 2658 do { /* traverse through chain of same-sized nodes */ 2659 do_check_any_chunk(m, ((mchunkptr)u)); 2660 assert(u->index == tindex); 2661 assert(chunksize(u) == tsize); 2662 assert(!cinuse(u)); 2663 assert(!next_pinuse(u)); 2664 assert(u->fd->bk == u); 2665 assert(u->bk->fd == u); 2666 if (u->parent == 0) { 2667 assert(u->child[0] == 0); 2668 assert(u->child[1] == 0); 2669 } 2670 else { 2671 assert(head == 0); /* only one node on chain has parent */ 2672 head = u; 2673 assert(u->parent != u); 2674 assert (u->parent->child[0] == u || 2675 u->parent->child[1] == u || 2676 *((tbinptr*)(u->parent)) == u); 2677 if (u->child[0] != 0) { 2678 assert(u->child[0]->parent == u); 2679 assert(u->child[0] != u); 2680 do_check_tree(m, u->child[0]); 2681 } 2682 if (u->child[1] != 0) { 2683 assert(u->child[1]->parent == u); 2684 assert(u->child[1] != u); 2685 do_check_tree(m, u->child[1]); 2686 } 2687 if (u->child[0] != 0 && u->child[1] != 0) { 2688 assert(chunksize(u->child[0]) < chunksize(u->child[1])); 2689 } 2690 } 2691 u = u->fd; 2692 } while (u != t); 2693 assert(head != 0); 2694 } 2695 2696 /* Check all the chunks in a treebin. */ 2697 static void do_check_treebin(mstate m, bindex_t i) { 2698 tbinptr* tb = treebin_at(m, i); 2699 tchunkptr t = *tb; 2700 int empty = (m->treemap & (1U << i)) == 0; 2701 if (t == 0) 2702 assert(empty); 2703 if (!empty) 2704 do_check_tree(m, t); 2705 } 2706 2707 /* Check all the chunks in a smallbin. */ 2708 static void do_check_smallbin(mstate m, bindex_t i) { 2709 sbinptr b = smallbin_at(m, i); 2710 mchunkptr p = b->bk; 2711 unsigned int empty = (m->smallmap & (1U << i)) == 0; 2712 if (p == b) 2713 assert(empty); 2714 if (!empty) { 2715 for (; p != b; p = p->bk) { 2716 size_t size = chunksize(p); 2717 mchunkptr q; 2718 /* each chunk claims to be free */ 2719 do_check_free_chunk(m, p); 2720 /* chunk belongs in bin */ 2721 assert(small_index(size) == i); 2722 assert(p->bk == b || chunksize(p->bk) == chunksize(p)); 2723 /* chunk is followed by an inuse chunk */ 2724 q = next_chunk(p); 2725 if (q->head != FENCEPOST_HEAD) 2726 do_check_inuse_chunk(m, q); 2727 } 2728 } 2729 } 2730 2731 /* Find x in a bin. Used in other check functions. */ 2732 static int bin_find(mstate m, mchunkptr x) { 2733 size_t size = chunksize(x); 2734 if (is_small(size)) { 2735 bindex_t sidx = small_index(size); 2736 sbinptr b = smallbin_at(m, sidx); 2737 if (smallmap_is_marked(m, sidx)) { 2738 mchunkptr p = b; 2739 do { 2740 if (p == x) 2741 return 1; 2742 } while ((p = p->fd) != b); 2743 } 2744 } 2745 else { 2746 bindex_t tidx; 2747 compute_tree_index(size, tidx); 2748 if (treemap_is_marked(m, tidx)) { 2749 tchunkptr t = *treebin_at(m, tidx); 2750 size_t sizebits = size << leftshift_for_tree_index(tidx); 2751 while (t != 0 && chunksize(t) != size) { 2752 t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]; 2753 sizebits <<= 1; 2754 } 2755 if (t != 0) { 2756 tchunkptr u = t; 2757 do { 2758 if (u == (tchunkptr)x) 2759 return 1; 2760 } while ((u = u->fd) != t); 2761 } 2762 } 2763 } 2764 return 0; 2765 } 2766 2767 /* Traverse each chunk and check it; return total */ 2768 static size_t traverse_and_check(mstate m) { 2769 size_t sum = 0; 2770 if (is_initialized(m)) { 2771 msegmentptr s = &m->seg; 2772 sum += m->topsize + TOP_FOOT_SIZE; 2773 while (s != 0) { 2774 mchunkptr q = align_as_chunk(s->base); 2775 mchunkptr lastq = 0; 2776 assert(pinuse(q)); 2777 while (segment_holds(s, q) && 2778 q != m->top && q->head != FENCEPOST_HEAD) { 2779 sum += chunksize(q); 2780 if (cinuse(q)) { 2781 assert(!bin_find(m, q)); 2782 do_check_inuse_chunk(m, q); 2783 } 2784 else { 2785 assert(q == m->dv || bin_find(m, q)); 2786 assert(lastq == 0 || cinuse(lastq)); /* Not 2 consecutive free */ 2787 do_check_free_chunk(m, q); 2788 } 2789 lastq = q; 2790 q = next_chunk(q); 2791 } 2792 s = s->next; 2793 } 2794 } 2795 return sum; 2796 } 2797 2798 /* Check all properties of malloc_state. */ 2799 static void do_check_malloc_state(mstate m) { 2800 bindex_t i; 2801 size_t total; 2802 /* check bins */ 2803 for (i = 0; i < NSMALLBINS; ++i) 2804 do_check_smallbin(m, i); 2805 for (i = 0; i < NTREEBINS; ++i) 2806 do_check_treebin(m, i); 2807 2808 if (m->dvsize != 0) { /* check dv chunk */ 2809 do_check_any_chunk(m, m->dv); 2810 assert(m->dvsize == chunksize(m->dv)); 2811 assert(m->dvsize >= MIN_CHUNK_SIZE); 2812 assert(bin_find(m, m->dv) == 0); 2813 } 2814 2815 if (m->top != 0) { /* check top chunk */ 2816 do_check_top_chunk(m, m->top); 2817 assert(m->topsize == chunksize(m->top)); 2818 assert(m->topsize > 0); 2819 assert(bin_find(m, m->top) == 0); 2820 } 2821 2822 total = traverse_and_check(m); 2823 assert(total <= m->footprint); 2824 assert(m->footprint <= m->max_footprint); 2825 } 2826 #endif /* DEBUG */ 2827 2828 /* ----------------------------- statistics ------------------------------ */ 2829 2830 #if !NO_MALLINFO 2831 static struct mallinfo internal_mallinfo(mstate m) { 2832 struct mallinfo nm = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; 2833 if (!PREACTION(m)) { 2834 check_malloc_state(m); 2835 if (is_initialized(m)) { 2836 size_t nfree = SIZE_T_ONE; /* top always free */ 2837 size_t mfree = m->topsize + TOP_FOOT_SIZE; 2838 size_t sum = mfree; 2839 msegmentptr s = &m->seg; 2840 while (s != 0) { 2841 mchunkptr q = align_as_chunk(s->base); 2842 while (segment_holds(s, q) && 2843 q != m->top && q->head != FENCEPOST_HEAD) { 2844 size_t sz = chunksize(q); 2845 sum += sz; 2846 if (!cinuse(q)) { 2847 mfree += sz; 2848 ++nfree; 2849 } 2850 q = next_chunk(q); 2851 } 2852 s = s->next; 2853 } 2854 2855 nm.arena = sum; 2856 nm.ordblks = nfree; 2857 nm.hblkhd = m->footprint - sum; 2858 nm.usmblks = m->max_footprint; 2859 nm.uordblks = m->footprint - mfree; 2860 nm.fordblks = mfree; 2861 nm.keepcost = m->topsize; 2862 } 2863 2864 POSTACTION(m); 2865 } 2866 return nm; 2867 } 2868 #endif /* !NO_MALLINFO */ 2869 2870 static void internal_malloc_stats(mstate m) { 2871 if (!PREACTION(m)) { 2872 size_t maxfp = 0; 2873 size_t fp = 0; 2874 size_t used = 0; 2875 check_malloc_state(m); 2876 if (is_initialized(m)) { 2877 msegmentptr s = &m->seg; 2878 maxfp = m->max_footprint; 2879 fp = m->footprint; 2880 used = fp - (m->topsize + TOP_FOOT_SIZE); 2881 2882 while (s != 0) { 2883 mchunkptr q = align_as_chunk(s->base); 2884 while (segment_holds(s, q) && 2885 q != m->top && q->head != FENCEPOST_HEAD) { 2886 if (!cinuse(q)) 2887 used -= chunksize(q); 2888 q = next_chunk(q); 2889 } 2890 s = s->next; 2891 } 2892 } 2893 2894 #ifndef LACKS_STDIO_H 2895 fprintf(stderr, "max system bytes = %10lu\n", (unsigned long)(maxfp)); 2896 fprintf(stderr, "system bytes = %10lu\n", (unsigned long)(fp)); 2897 fprintf(stderr, "in use bytes = %10lu\n", (unsigned long)(used)); 2898 #endif 2899 2900 POSTACTION(m); 2901 } 2902 } 2903 2904 /* ----------------------- Operations on smallbins ----------------------- */ 2905 2906 /* 2907 Various forms of linking and unlinking are defined as macros. Even 2908 the ones for trees, which are very long but have very short typical 2909 paths. This is ugly but reduces reliance on inlining support of 2910 compilers. 2911 */ 2912 2913 /* Link a free chunk into a smallbin */ 2914 #define insert_small_chunk(M, P, S) {\ 2915 bindex_t I = small_index(S);\ 2916 mchunkptr B = smallbin_at(M, I);\ 2917 mchunkptr F = B;\ 2918 assert(S >= MIN_CHUNK_SIZE);\ 2919 if (!smallmap_is_marked(M, I))\ 2920 mark_smallmap(M, I);\ 2921 else if (RTCHECK(ok_address(M, B->fd)))\ 2922 F = B->fd;\ 2923 else {\ 2924 CORRUPTION_ERROR_ACTION(M);\ 2925 }\ 2926 B->fd = P;\ 2927 F->bk = P;\ 2928 P->fd = F;\ 2929 P->bk = B;\ 2930 } 2931 2932 /* Unlink a chunk from a smallbin */ 2933 #define unlink_small_chunk(M, P, S) {\ 2934 mchunkptr F = P->fd;\ 2935 mchunkptr B = P->bk;\ 2936 bindex_t I = small_index(S);\ 2937 assert(P != B);\ 2938 assert(P != F);\ 2939 assert(chunksize(P) == small_index2size(I));\ 2940 if (F == B)\ 2941 clear_smallmap(M, I);\ 2942 else if (RTCHECK((F == smallbin_at(M,I) || ok_address(M, F)) &&\ 2943 (B == smallbin_at(M,I) || ok_address(M, B)))) {\ 2944 F->bk = B;\ 2945 B->fd = F;\ 2946 }\ 2947 else {\ 2948 CORRUPTION_ERROR_ACTION(M);\ 2949 }\ 2950 } 2951 2952 /* Unlink the first chunk from a smallbin */ 2953 #define unlink_first_small_chunk(M, B, P, I) {\ 2954 mchunkptr F = P->fd;\ 2955 assert(P != B);\ 2956 assert(P != F);\ 2957 assert(chunksize(P) == small_index2size(I));\ 2958 if (B == F)\ 2959 clear_smallmap(M, I);\ 2960 else if (RTCHECK(ok_address(M, F))) {\ 2961 B->fd = F;\ 2962 F->bk = B;\ 2963 }\ 2964 else {\ 2965 CORRUPTION_ERROR_ACTION(M);\ 2966 }\ 2967 } 2968 2969 /* Replace dv node, binning the old one */ 2970 /* Used only when dvsize known to be small */ 2971 #define replace_dv(M, P, S) {\ 2972 size_t DVS = M->dvsize;\ 2973 if (DVS != 0) {\ 2974 mchunkptr DV = M->dv;\ 2975 assert(is_small(DVS));\ 2976 insert_small_chunk(M, DV, DVS);\ 2977 }\ 2978 M->dvsize = S;\ 2979 M->dv = P;\ 2980 } 2981 2982 /* ------------------------- Operations on trees ------------------------- */ 2983 2984 /* Insert chunk into tree */ 2985 #define insert_large_chunk(M, X, S) {\ 2986 tbinptr* H;\ 2987 bindex_t I;\ 2988 compute_tree_index(S, I);\ 2989 H = treebin_at(M, I);\ 2990 X->index = I;\ 2991 X->child[0] = X->child[1] = 0;\ 2992 if (!treemap_is_marked(M, I)) {\ 2993 mark_treemap(M, I);\ 2994 *H = X;\ 2995 X->parent = (tchunkptr)H;\ 2996 X->fd = X->bk = X;\ 2997 }\ 2998 else {\ 2999 tchunkptr T = *H;\ 3000 size_t K = S << leftshift_for_tree_index(I);\ 3001 for (;;) {\ 3002 if (chunksize(T) != S) {\ 3003 tchunkptr* C = &(T->child[(K >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]);\ 3004 K <<= 1;\ 3005 if (*C != 0)\ 3006 T = *C;\ 3007 else if (RTCHECK(ok_address(M, C))) {\ 3008 *C = X;\ 3009 X->parent = T;\ 3010 X->fd = X->bk = X;\ 3011 break;\ 3012 }\ 3013 else {\ 3014 CORRUPTION_ERROR_ACTION(M);\ 3015 break;\ 3016 }\ 3017 }\ 3018 else {\ 3019 tchunkptr F = T->fd;\ 3020 if (RTCHECK(ok_address(M, T) && ok_address(M, F))) {\ 3021 T->fd = F->bk = X;\ 3022 X->fd = F;\ 3023 X->bk = T;\ 3024 X->parent = 0;\ 3025 break;\ 3026 }\ 3027 else {\ 3028 CORRUPTION_ERROR_ACTION(M);\ 3029 break;\ 3030 }\ 3031 }\ 3032 }\ 3033 }\ 3034 } 3035 3036 /* 3037 Unlink steps: 3038 3039 1. If x is a chained node, unlink it from its same-sized fd/bk links 3040 and choose its bk node as its replacement. 3041 2. If x was the last node of its size, but not a leaf node, it must 3042 be replaced with a leaf node (not merely one with an open left or 3043 right), to make sure that lefts and rights of descendents 3044 correspond properly to bit masks. We use the rightmost descendent 3045 of x. We could use any other leaf, but this is easy to locate and 3046 tends to counteract removal of leftmosts elsewhere, and so keeps 3047 paths shorter than minimally guaranteed. This doesn't loop much 3048 because on average a node in a tree is near the bottom. 3049 3. If x is the base of a chain (i.e., has parent links) relink 3050 x's parent and children to x's replacement (or null if none). 3051 */ 3052 3053 #define unlink_large_chunk(M, X) {\ 3054 tchunkptr XP = X->parent;\ 3055 tchunkptr R;\ 3056 if (X->bk != X) {\ 3057 tchunkptr F = X->fd;\ 3058 R = X->bk;\ 3059 if (RTCHECK(ok_address(M, F))) {\ 3060 F->bk = R;\ 3061 R->fd = F;\ 3062 }\ 3063 else {\ 3064 CORRUPTION_ERROR_ACTION(M);\ 3065 }\ 3066 }\ 3067 else {\ 3068 tchunkptr* RP;\ 3069 if (((R = *(RP = &(X->child[1]))) != 0) ||\ 3070 ((R = *(RP = &(X->child[0]))) != 0)) {\ 3071 tchunkptr* CP;\ 3072 while ((*(CP = &(R->child[1])) != 0) ||\ 3073 (*(CP = &(R->child[0])) != 0)) {\ 3074 R = *(RP = CP);\ 3075 }\ 3076 if (RTCHECK(ok_address(M, RP)))\ 3077 *RP = 0;\ 3078 else {\ 3079 CORRUPTION_ERROR_ACTION(M);\ 3080 }\ 3081 }\ 3082 }\ 3083 if (XP != 0) {\ 3084 tbinptr* H = treebin_at(M, X->index);\ 3085 if (X == *H) {\ 3086 if ((*H = R) == 0) \ 3087 clear_treemap(M, X->index);\ 3088 }\ 3089 else if (RTCHECK(ok_address(M, XP))) {\ 3090 if (XP->child[0] == X) \ 3091 XP->child[0] = R;\ 3092 else \ 3093 XP->child[1] = R;\ 3094 }\ 3095 else\ 3096 CORRUPTION_ERROR_ACTION(M);\ 3097 if (R != 0) {\ 3098 if (RTCHECK(ok_address(M, R))) {\ 3099 tchunkptr C0, C1;\ 3100 R->parent = XP;\ 3101 if ((C0 = X->child[0]) != 0) {\ 3102 if (RTCHECK(ok_address(M, C0))) {\ 3103 R->child[0] = C0;\ 3104 C0->parent = R;\ 3105 }\ 3106 else\ 3107 CORRUPTION_ERROR_ACTION(M);\ 3108 }\ 3109 if ((C1 = X->child[1]) != 0) {\ 3110 if (RTCHECK(ok_address(M, C1))) {\ 3111 R->child[1] = C1;\ 3112 C1->parent = R;\ 3113 }\ 3114 else\ 3115 CORRUPTION_ERROR_ACTION(M);\ 3116 }\ 3117 }\ 3118 else\ 3119 CORRUPTION_ERROR_ACTION(M);\ 3120 }\ 3121 }\ 3122 } 3123 3124 /* Relays to large vs small bin operations */ 3125 3126 #define insert_chunk(M, P, S)\ 3127 if (is_small(S)) insert_small_chunk(M, P, S)\ 3128 else { tchunkptr TP = (tchunkptr)(P); insert_large_chunk(M, TP, S); } 3129 3130 #define unlink_chunk(M, P, S)\ 3131 if (is_small(S)) unlink_small_chunk(M, P, S)\ 3132 else { tchunkptr TP = (tchunkptr)(P); unlink_large_chunk(M, TP); } 3133 3134 3135 /* Relays to internal calls to malloc/free from realloc, memalign etc */ 3136 3137 #if ONLY_MSPACES 3138 #define internal_malloc(m, b) mspace_malloc(m, b) 3139 #define internal_free(m, mem) mspace_free(m,mem); 3140 #else /* ONLY_MSPACES */ 3141 #if MSPACES 3142 #define internal_malloc(m, b)\ 3143 (m == gm)? dlmalloc(b) : mspace_malloc(m, b) 3144 #define internal_free(m, mem)\ 3145 if (m == gm) dlfree(mem); else mspace_free(m,mem); 3146 #else /* MSPACES */ 3147 #define internal_malloc(m, b) dlmalloc(b) 3148 #define internal_free(m, mem) dlfree(mem) 3149 #endif /* MSPACES */ 3150 #endif /* ONLY_MSPACES */ 3151 3152 /* ----------------------- Direct-mmapping chunks ----------------------- */ 3153 3154 /* 3155 Directly mmapped chunks are set up with an offset to the start of 3156 the mmapped region stored in the prev_foot field of the chunk. This 3157 allows reconstruction of the required argument to MUNMAP when freed, 3158 and also allows adjustment of the returned chunk to meet alignment 3159 requirements (especially in memalign). There is also enough space 3160 allocated to hold a fake next chunk of size SIZE_T_SIZE to maintain 3161 the PINUSE bit so frees can be checked. 3162 */ 3163 3164 /* Malloc using mmap */ 3165 static void* mmap_alloc(mstate m, size_t nb) { 3166 size_t mmsize = granularity_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK); 3167 if (mmsize > nb) { /* Check for wrap around 0 */ 3168 char* mm = (char*)(DIRECT_MMAP(mmsize)); 3169 if (mm != CMFAIL) { 3170 size_t offset = align_offset(chunk2mem(mm)); 3171 size_t psize = mmsize - offset - MMAP_FOOT_PAD; 3172 mchunkptr p = (mchunkptr)(mm + offset); 3173 p->prev_foot = offset | IS_MMAPPED_BIT; 3174 (p)->head = (psize|CINUSE_BIT); 3175 mark_inuse_foot(m, p, psize); 3176 chunk_plus_offset(p, psize)->head = FENCEPOST_HEAD; 3177 chunk_plus_offset(p, psize+SIZE_T_SIZE)->head = 0; 3178 3179 if (mm < m->least_addr) 3180 m->least_addr = mm; 3181 if ((m->footprint += mmsize) > m->max_footprint) 3182 m->max_footprint = m->footprint; 3183 assert(is_aligned(chunk2mem(p))); 3184 check_mmapped_chunk(m, p); 3185 return chunk2mem(p); 3186 } 3187 } 3188 return 0; 3189 } 3190 3191 /* Realloc using mmap */ 3192 static mchunkptr mmap_resize(mstate m, mchunkptr oldp, size_t nb) { 3193 size_t oldsize = chunksize(oldp); 3194 if (is_small(nb)) /* Can't shrink mmap regions below small size */ 3195 return 0; 3196 /* Keep old chunk if big enough but not too big */ 3197 if (oldsize >= nb + SIZE_T_SIZE && 3198 (oldsize - nb) <= (mparams.granularity << 1)) 3199 return oldp; 3200 else { 3201 size_t offset = oldp->prev_foot & ~IS_MMAPPED_BIT; 3202 size_t oldmmsize = oldsize + offset + MMAP_FOOT_PAD; 3203 size_t newmmsize = granularity_align(nb + SIX_SIZE_T_SIZES + 3204 CHUNK_ALIGN_MASK); 3205 char* cp = (char*)CALL_MREMAP((char*)oldp - offset, 3206 oldmmsize, newmmsize, 1); 3207 if (cp != CMFAIL) { 3208 mchunkptr newp = (mchunkptr)(cp + offset); 3209 size_t psize = newmmsize - offset - MMAP_FOOT_PAD; 3210 newp->head = (psize|CINUSE_BIT); 3211 mark_inuse_foot(m, newp, psize); 3212 chunk_plus_offset(newp, psize)->head = FENCEPOST_HEAD; 3213 chunk_plus_offset(newp, psize+SIZE_T_SIZE)->head = 0; 3214 3215 if (cp < m->least_addr) 3216 m->least_addr = cp; 3217 if ((m->footprint += newmmsize - oldmmsize) > m->max_footprint) 3218 m->max_footprint = m->footprint; 3219 check_mmapped_chunk(m, newp); 3220 return newp; 3221 } 3222 } 3223 return 0; 3224 } 3225 3226 /* -------------------------- mspace management -------------------------- */ 3227 3228 /* Initialize top chunk and its size */ 3229 static void init_top(mstate m, mchunkptr p, size_t psize) { 3230 /* Ensure alignment */ 3231 size_t offset = align_offset(chunk2mem(p)); 3232 p = (mchunkptr)((char*)p + offset); 3233 psize -= offset; 3234 3235 m->top = p; 3236 m->topsize = psize; 3237 p->head = psize | PINUSE_BIT; 3238 /* set size of fake trailing chunk holding overhead space only once */ 3239 chunk_plus_offset(p, psize)->head = TOP_FOOT_SIZE; 3240 m->trim_check = mparams.trim_threshold; /* reset on each update */ 3241 } 3242 3243 /* Initialize bins for a new mstate that is otherwise zeroed out */ 3244 static void init_bins(mstate m) { 3245 /* Establish circular links for smallbins */ 3246 bindex_t i; 3247 for (i = 0; i < NSMALLBINS; ++i) { 3248 sbinptr bin = smallbin_at(m,i); 3249 bin->fd = bin->bk = bin; 3250 } 3251 } 3252 3253 #if PROCEED_ON_ERROR 3254 3255 /* default corruption action */ 3256 static void reset_on_error(mstate m) { 3257 int i; 3258 ++malloc_corruption_error_count; 3259 /* Reinitialize fields to forget about all memory */ 3260 m->smallbins = m->treebins = 0; 3261 m->dvsize = m->topsize = 0; 3262 m->seg.base = 0; 3263 m->seg.size = 0; 3264 m->seg.next = 0; 3265 m->top = m->dv = 0; 3266 for (i = 0; i < NTREEBINS; ++i) 3267 *treebin_at(m, i) = 0; 3268 init_bins(m); 3269 } 3270 #endif /* PROCEED_ON_ERROR */ 3271 3272 /* Allocate chunk and prepend remainder with chunk in successor base. */ 3273 static void* prepend_alloc(mstate m, char* newbase, char* oldbase, 3274 size_t nb) { 3275 mchunkptr p = align_as_chunk(newbase); 3276 mchunkptr oldfirst = align_as_chunk(oldbase); 3277 size_t psize = (char*)oldfirst - (char*)p; 3278 mchunkptr q = chunk_plus_offset(p, nb); 3279 size_t qsize = psize - nb; 3280 set_size_and_pinuse_of_inuse_chunk(m, p, nb); 3281 3282 assert((char*)oldfirst > (char*)q); 3283 assert(pinuse(oldfirst)); 3284 assert(qsize >= MIN_CHUNK_SIZE); 3285 3286 /* consolidate remainder with first chunk of old base */ 3287 if (oldfirst == m->top) { 3288 size_t tsize = m->topsize += qsize; 3289 m->top = q; 3290 q->head = tsize | PINUSE_BIT; 3291 check_top_chunk(m, q); 3292 } 3293 else if (oldfirst == m->dv) { 3294 size_t dsize = m->dvsize += qsize; 3295 m->dv = q; 3296 set_size_and_pinuse_of_free_chunk(q, dsize); 3297 } 3298 else { 3299 if (!cinuse(oldfirst)) { 3300 size_t nsize = chunksize(oldfirst); 3301 unlink_chunk(m, oldfirst, nsize); 3302 oldfirst = chunk_plus_offset(oldfirst, nsize); 3303 qsize += nsize; 3304 } 3305 set_free_with_pinuse(q, qsize, oldfirst); 3306 insert_chunk(m, q, qsize); 3307 check_free_chunk(m, q); 3308 } 3309 3310 check_malloced_chunk(m, chunk2mem(p), nb); 3311 return chunk2mem(p); 3312 } 3313 3314 3315 /* Add a segment to hold a new noncontiguous region */ 3316 static void add_segment(mstate m, char* tbase, size_t tsize, flag_t mmapped) { 3317 /* Determine locations and sizes of segment, fenceposts, old top */ 3318 char* old_top = (char*)m->top; 3319 msegmentptr oldsp = segment_holding(m, old_top); 3320 char* old_end = oldsp->base + oldsp->size; 3321 size_t ssize = pad_request(sizeof(struct malloc_segment)); 3322 char* rawsp = old_end - (ssize + FOUR_SIZE_T_SIZES + CHUNK_ALIGN_MASK); 3323 size_t offset = align_offset(chunk2mem(rawsp)); 3324 char* asp = rawsp + offset; 3325 char* csp = (asp < (old_top + MIN_CHUNK_SIZE))? old_top : asp; 3326 mchunkptr sp = (mchunkptr)csp; 3327 msegmentptr ss = (msegmentptr)(chunk2mem(sp)); 3328 mchunkptr tnext = chunk_plus_offset(sp, ssize); 3329 mchunkptr p = tnext; 3330 int nfences = 0; 3331 3332 /* reset top to new space */ 3333 init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE); 3334 3335 /* Set up segment record */ 3336 assert(is_aligned(ss)); 3337 set_size_and_pinuse_of_inuse_chunk(m, sp, ssize); 3338 *ss = m->seg; /* Push current record */ 3339 m->seg.base = tbase; 3340 m->seg.size = tsize; 3341 m->seg.sflags = mmapped; 3342 m->seg.next = ss; 3343 3344 /* Insert trailing fenceposts */ 3345 for (;;) { 3346 mchunkptr nextp = chunk_plus_offset(p, SIZE_T_SIZE); 3347 p->head = FENCEPOST_HEAD; 3348 ++nfences; 3349 if ((char*)(&(nextp->head)) < old_end) 3350 p = nextp; 3351 else 3352 break; 3353 } 3354 assert(nfences >= 2); 3355 3356 /* Insert the rest of old top into a bin as an ordinary free chunk */ 3357 if (csp != old_top) { 3358 mchunkptr q = (mchunkptr)old_top; 3359 size_t psize = csp - old_top; 3360 mchunkptr tn = chunk_plus_offset(q, psize); 3361 set_free_with_pinuse(q, psize, tn); 3362 insert_chunk(m, q, psize); 3363 } 3364 3365 check_top_chunk(m, m->top); 3366 } 3367 3368 /* -------------------------- System allocation -------------------------- */ 3369 3370 /* Get memory from system using MORECORE or MMAP */ 3371 static void* sys_alloc(mstate m, size_t nb) { 3372 char* tbase = CMFAIL; 3373 size_t tsize = 0; 3374 flag_t mmap_flag = 0; 3375 3376 init_mparams(); 3377 3378 /* Directly map large chunks */ 3379 if (use_mmap(m) && nb >= mparams.mmap_threshold) { 3380 void* mem = mmap_alloc(m, nb); 3381 if (mem != 0) 3382 return mem; 3383 } 3384 3385 /* 3386 Try getting memory in any of three ways (in most-preferred to 3387 least-preferred order): 3388 1. A call to MORECORE that can normally contiguously extend memory. 3389 (disabled if not MORECORE_CONTIGUOUS or not HAVE_MORECORE or 3390 or main space is mmapped or a previous contiguous call failed) 3391 2. A call to MMAP new space (disabled if not HAVE_MMAP). 3392 Note that under the default settings, if MORECORE is unable to 3393 fulfill a request, and HAVE_MMAP is true, then mmap is 3394 used as a noncontiguous system allocator. This is a useful backup 3395 strategy for systems with holes in address spaces -- in this case 3396 sbrk cannot contiguously expand the heap, but mmap may be able to 3397 find space. 3398 3. A call to MORECORE that cannot usually contiguously extend memory. 3399 (disabled if not HAVE_MORECORE) 3400 */ 3401 3402 if (MORECORE_CONTIGUOUS && !use_noncontiguous(m)) { 3403 char* br = CMFAIL; 3404 msegmentptr ss = (m->top == 0)? 0 : segment_holding(m, (char*)m->top); 3405 size_t asize = 0; 3406 ACQUIRE_MORECORE_LOCK(); 3407 3408 if (ss == 0) { /* First time through or recovery */ 3409 char* base = (char*)CALL_MORECORE(0); 3410 if (base != CMFAIL) { 3411 asize = granularity_align(nb + TOP_FOOT_SIZE + MALLOC_ALIGNMENT + SIZE_T_ONE); 3412 /* Adjust to end on a page boundary */ 3413 if (!is_page_aligned(base)) 3414 asize += (page_align((size_t)base) - (size_t)base); 3415 /* Can't call MORECORE if size is negative when treated as signed */ 3416 if (asize < HALF_MAX_SIZE_T && 3417 (br = (char*)(CALL_MORECORE(asize))) == base) { 3418 tbase = base; 3419 tsize = asize; 3420 } 3421 } 3422 } 3423 else { 3424 /* Subtract out existing available top space from MORECORE request. */ 3425 asize = granularity_align(nb - m->topsize + TOP_FOOT_SIZE + MALLOC_ALIGNMENT + SIZE_T_ONE); 3426 /* Use mem here only if it did continuously extend old space */ 3427 if (asize < HALF_MAX_SIZE_T && 3428 (br = (char*)(CALL_MORECORE(asize))) == ss->base+ss->size) { 3429 tbase = br; 3430 tsize = asize; 3431 } 3432 } 3433 3434 if (tbase == CMFAIL) { /* Cope with partial failure */ 3435 if (br != CMFAIL) { /* Try to use/extend the space we did get */ 3436 if (asize < HALF_MAX_SIZE_T && 3437 asize < nb + TOP_FOOT_SIZE + SIZE_T_ONE) { 3438 size_t esize = granularity_align(nb + TOP_FOOT_SIZE + MALLOC_ALIGNMENT + SIZE_T_ONE - asize); 3439 if (esize < HALF_MAX_SIZE_T) { 3440 char* end = (char*)CALL_MORECORE(esize); 3441 if (end != CMFAIL) 3442 asize += esize; 3443 else { /* Can't use; try to release */ 3444 end = (char*)CALL_MORECORE(-asize); 3445 br = CMFAIL; 3446 } 3447 } 3448 } 3449 } 3450 if (br != CMFAIL) { /* Use the space we did get */ 3451 tbase = br; 3452 tsize = asize; 3453 } 3454 else 3455 disable_contiguous(m); /* Don't try contiguous path in the future */ 3456 } 3457 3458 RELEASE_MORECORE_LOCK(); 3459 } 3460 3461 if (HAVE_MMAP && tbase == CMFAIL) { /* Try MMAP */ 3462 size_t req = nb + TOP_FOOT_SIZE + MALLOC_ALIGNMENT + SIZE_T_ONE; 3463 size_t rsize = granularity_align(req); 3464 if (rsize > nb) { /* Fail if wraps around zero */ 3465 char* mp = (char*)(CALL_MMAP(rsize)); 3466 if (mp != CMFAIL) { 3467 tbase = mp; 3468 tsize = rsize; 3469 mmap_flag = IS_MMAPPED_BIT; 3470 } 3471 } 3472 } 3473 3474 if (HAVE_MORECORE && tbase == CMFAIL) { /* Try noncontiguous MORECORE */ 3475 size_t asize = granularity_align(nb + TOP_FOOT_SIZE + MALLOC_ALIGNMENT + SIZE_T_ONE); 3476 if (asize < HALF_MAX_SIZE_T) { 3477 char* br = CMFAIL; 3478 char* end = CMFAIL; 3479 ACQUIRE_MORECORE_LOCK(); 3480 br = (char*)(CALL_MORECORE(asize)); 3481 end = (char*)(CALL_MORECORE(0)); 3482 RELEASE_MORECORE_LOCK(); 3483 if (br != CMFAIL && end != CMFAIL && br < end) { 3484 size_t ssize = end - br; 3485 if (ssize > nb + TOP_FOOT_SIZE) { 3486 tbase = br; 3487 tsize = ssize; 3488 } 3489 } 3490 } 3491 } 3492 3493 if (tbase != CMFAIL) { 3494 3495 if ((m->footprint += tsize) > m->max_footprint) 3496 m->max_footprint = m->footprint; 3497 3498 if (!is_initialized(m)) { /* first-time initialization */ 3499 m->seg.base = m->least_addr = tbase; 3500 m->seg.size = tsize; 3501 m->seg.sflags = mmap_flag; 3502 m->magic = mparams.magic; 3503 init_bins(m); 3504 if (is_global(m)) 3505 init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE); 3506 else { 3507 /* Offset top by embedded malloc_state */ 3508 mchunkptr mn = next_chunk(mem2chunk(m)); 3509 init_top(m, mn, (size_t)((tbase + tsize) - (char*)mn) -TOP_FOOT_SIZE); 3510 } 3511 } 3512 3513 else { 3514 /* Try to merge with an existing segment */ 3515 msegmentptr sp = &m->seg; 3516 while (sp != 0 && tbase != sp->base + sp->size) 3517 sp = sp->next; 3518 if (sp != 0 && 3519 !is_extern_segment(sp) && 3520 (sp->sflags & IS_MMAPPED_BIT) == mmap_flag && 3521 segment_holds(sp, m->top)) { /* append */ 3522 sp->size += tsize; 3523 init_top(m, m->top, m->topsize + tsize); 3524 } 3525 else { 3526 if (tbase < m->least_addr) 3527 m->least_addr = tbase; 3528 sp = &m->seg; 3529 while (sp != 0 && sp->base != tbase + tsize) 3530 sp = sp->next; 3531 if (sp != 0 && 3532 !is_extern_segment(sp) && 3533 (sp->sflags & IS_MMAPPED_BIT) == mmap_flag) { 3534 char* oldbase = sp->base; 3535 sp->base = tbase; 3536 sp->size += tsize; 3537 return prepend_alloc(m, tbase, oldbase, nb); 3538 } 3539 else 3540 add_segment(m, tbase, tsize, mmap_flag); 3541 } 3542 } 3543 3544 if (nb < m->topsize) { /* Allocate from new or extended top space */ 3545 size_t rsize = m->topsize -= nb; 3546 mchunkptr p = m->top; 3547 mchunkptr r = m->top = chunk_plus_offset(p, nb); 3548 r->head = rsize | PINUSE_BIT; 3549 set_size_and_pinuse_of_inuse_chunk(m, p, nb); 3550 check_top_chunk(m, m->top); 3551 check_malloced_chunk(m, chunk2mem(p), nb); 3552 return chunk2mem(p); 3553 } 3554 } 3555 3556 MALLOC_FAILURE_ACTION; 3557 return 0; 3558 } 3559 3560 /* ----------------------- system deallocation -------------------------- */ 3561 3562 /* Unmap and unlink any mmapped segments that don't contain used chunks */ 3563 static size_t release_unused_segments(mstate m) { 3564 size_t released = 0; 3565 msegmentptr pred = &m->seg; 3566 msegmentptr sp = pred->next; 3567 while (sp != 0) { 3568 char* base = sp->base; 3569 size_t size = sp->size; 3570 msegmentptr next = sp->next; 3571 if (is_mmapped_segment(sp) && !is_extern_segment(sp)) { 3572 mchunkptr p = align_as_chunk(base); 3573 size_t psize = chunksize(p); 3574 /* Can unmap if first chunk holds entire segment and not pinned */ 3575 if (!cinuse(p) && (char*)p + psize >= base + size - TOP_FOOT_SIZE) { 3576 tchunkptr tp = (tchunkptr)p; 3577 assert(segment_holds(sp, (char*)sp)); 3578 if (p == m->dv) { 3579 m->dv = 0; 3580 m->dvsize = 0; 3581 } 3582 else { 3583 unlink_large_chunk(m, tp); 3584 } 3585 if (CALL_MUNMAP(base, size) == 0) { 3586 released += size; 3587 m->footprint -= size; 3588 /* unlink obsoleted record */ 3589 sp = pred; 3590 sp->next = next; 3591 } 3592 else { /* back out if cannot unmap */ 3593 insert_large_chunk(m, tp, psize); 3594 } 3595 } 3596 } 3597 pred = sp; 3598 sp = next; 3599 } 3600 return released; 3601 } 3602 3603 static int sys_trim(mstate m, size_t pad) { 3604 size_t released = 0; 3605 if (pad < MAX_REQUEST && is_initialized(m)) { 3606 pad += TOP_FOOT_SIZE; /* ensure enough room for segment overhead */ 3607 3608 if (m->topsize > pad) { 3609 /* Shrink top space in granularity-size units, keeping at least one */ 3610 size_t unit = mparams.granularity; 3611 size_t extra = ((m->topsize - pad + (unit - SIZE_T_ONE)) / unit - 3612 SIZE_T_ONE) * unit; 3613 msegmentptr sp = segment_holding(m, (char*)m->top); 3614 3615 if (!is_extern_segment(sp)) { 3616 if (is_mmapped_segment(sp)) { 3617 if (HAVE_MMAP && 3618 sp->size >= extra && 3619 !has_segment_link(m, sp)) { /* can't shrink if pinned */ 3620 size_t newsize = sp->size - extra; 3621 /* Prefer mremap, fall back to munmap */ 3622 if ((CALL_MREMAP(sp->base, sp->size, newsize, 0) != MFAIL) || 3623 (CALL_MUNMAP(sp->base + newsize, extra) == 0)) { 3624 released = extra; 3625 } 3626 } 3627 } 3628 else if (HAVE_MORECORE) { 3629 if (extra >= HALF_MAX_SIZE_T) /* Avoid wrapping negative */ 3630 extra = (HALF_MAX_SIZE_T) + SIZE_T_ONE - unit; 3631 ACQUIRE_MORECORE_LOCK(); 3632 { 3633 /* Make sure end of memory is where we last set it. */ 3634 char* old_br = (char*)(CALL_MORECORE(0)); 3635 if (old_br == sp->base + sp->size) { 3636 char* rel_br = (char*)(CALL_MORECORE(-extra)); 3637 char* new_br = (char*)(CALL_MORECORE(0)); 3638 if (rel_br != CMFAIL && new_br < old_br) 3639 released = old_br - new_br; 3640 } 3641 } 3642 RELEASE_MORECORE_LOCK(); 3643 } 3644 } 3645 3646 if (released != 0) { 3647 sp->size -= released; 3648 m->footprint -= released; 3649 init_top(m, m->top, m->topsize - released); 3650 check_top_chunk(m, m->top); 3651 } 3652 } 3653 3654 /* Unmap any unused mmapped segments */ 3655 if (HAVE_MMAP) 3656 released += release_unused_segments(m); 3657 3658 /* On failure, disable autotrim to avoid repeated failed future calls */ 3659 if (released == 0) 3660 m->trim_check = MAX_SIZE_T; 3661 } 3662 3663 return (released != 0)? 1 : 0; 3664 } 3665 3666 /* ---------------------------- malloc support --------------------------- */ 3667 3668 /* allocate a large request from the best fitting chunk in a treebin */ 3669 static void* tmalloc_large(mstate m, size_t nb) { 3670 tchunkptr v = 0; 3671 size_t rsize = -nb; /* Unsigned negation */ 3672 tchunkptr t; 3673 bindex_t idx; 3674 compute_tree_index(nb, idx); 3675 3676 if ((t = *treebin_at(m, idx)) != 0) { 3677 /* Traverse tree for this bin looking for node with size == nb */ 3678 size_t sizebits = nb << leftshift_for_tree_index(idx); 3679 tchunkptr rst = 0; /* The deepest untaken right subtree */ 3680 for (;;) { 3681 tchunkptr rt; 3682 size_t trem = chunksize(t) - nb; 3683 if (trem < rsize) { 3684 v = t; 3685 if ((rsize = trem) == 0) 3686 break; 3687 } 3688 rt = t->child[1]; 3689 t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]; 3690 if (rt != 0 && rt != t) 3691 rst = rt; 3692 if (t == 0) { 3693 t = rst; /* set t to least subtree holding sizes > nb */ 3694 break; 3695 } 3696 sizebits <<= 1; 3697 } 3698 } 3699 3700 if (t == 0 && v == 0) { /* set t to root of next non-empty treebin */ 3701 binmap_t leftbits = left_bits(idx2bit(idx)) & m->treemap; 3702 if (leftbits != 0) { 3703 bindex_t i; 3704 binmap_t leastbit = least_bit(leftbits); 3705 compute_bit2idx(leastbit, i); 3706 t = *treebin_at(m, i); 3707 } 3708 } 3709 3710 while (t != 0) { /* find smallest of tree or subtree */ 3711 size_t trem = chunksize(t) - nb; 3712 if (trem < rsize) { 3713 rsize = trem; 3714 v = t; 3715 } 3716 t = leftmost_child(t); 3717 } 3718 3719 /* If dv is a better fit, return 0 so malloc will use it */ 3720 if (v != 0 && rsize < (size_t)(m->dvsize - nb)) { 3721 if (RTCHECK(ok_address(m, v))) { /* split */ 3722 mchunkptr r = chunk_plus_offset(v, nb); 3723 assert(chunksize(v) == rsize + nb); 3724 if (RTCHECK(ok_next(v, r))) { 3725 unlink_large_chunk(m, v); 3726 if (rsize < MIN_CHUNK_SIZE) 3727 set_inuse_and_pinuse(m, v, (rsize + nb)); 3728 else { 3729 set_size_and_pinuse_of_inuse_chunk(m, v, nb); 3730 set_size_and_pinuse_of_free_chunk(r, rsize); 3731 insert_chunk(m, r, rsize); 3732 } 3733 return chunk2mem(v); 3734 } 3735 } 3736 CORRUPTION_ERROR_ACTION(m); 3737 } 3738 return 0; 3739 } 3740 3741 /* allocate a small request from the best fitting chunk in a treebin */ 3742 static void* tmalloc_small(mstate m, size_t nb) { 3743 tchunkptr t, v; 3744 size_t rsize; 3745 bindex_t i; 3746 binmap_t leastbit = least_bit(m->treemap); 3747 compute_bit2idx(leastbit, i); 3748 3749 v = t = *treebin_at(m, i); 3750 rsize = chunksize(t) - nb; 3751 3752 while ((t = leftmost_child(t)) != 0) { 3753 size_t trem = chunksize(t) - nb; 3754 if (trem < rsize) { 3755 rsize = trem; 3756 v = t; 3757 } 3758 } 3759 3760 if (RTCHECK(ok_address(m, v))) { 3761 mchunkptr r = chunk_plus_offset(v, nb); 3762 assert(chunksize(v) == rsize + nb); 3763 if (RTCHECK(ok_next(v, r))) { 3764 unlink_large_chunk(m, v); 3765 if (rsize < MIN_CHUNK_SIZE) 3766 set_inuse_and_pinuse(m, v, (rsize + nb)); 3767 else { 3768 set_size_and_pinuse_of_inuse_chunk(m, v, nb); 3769 set_size_and_pinuse_of_free_chunk(r, rsize); 3770 replace_dv(m, r, rsize); 3771 } 3772 return chunk2mem(v); 3773 } 3774 } 3775 3776 CORRUPTION_ERROR_ACTION(m); 3777 return 0; 3778 } 3779 3780 /* --------------------------- realloc support --------------------------- */ 3781 3782 static void* internal_realloc(mstate m, void* oldmem, size_t bytes) { 3783 if (bytes >= MAX_REQUEST) { 3784 MALLOC_FAILURE_ACTION; 3785 return 0; 3786 } 3787 if (!PREACTION(m)) { 3788 mchunkptr oldp = mem2chunk(oldmem); 3789 size_t oldsize = chunksize(oldp); 3790 mchunkptr next = chunk_plus_offset(oldp, oldsize); 3791 mchunkptr newp = 0; 3792 void* extra = 0; 3793 3794 /* Try to either shrink or extend into top. Else malloc-copy-free */ 3795 3796 if (RTCHECK(ok_address(m, oldp) && ok_cinuse(oldp) && 3797 ok_next(oldp, next) && ok_pinuse(next))) { 3798 size_t nb = request2size(bytes); 3799 if (is_mmapped(oldp)) 3800 newp = mmap_resize(m, oldp, nb); 3801 else if (oldsize >= nb) { /* already big enough */ 3802 size_t rsize = oldsize - nb; 3803 newp = oldp; 3804 if (rsize >= MIN_CHUNK_SIZE) { 3805 mchunkptr remainder = chunk_plus_offset(newp, nb); 3806 set_inuse(m, newp, nb); 3807 set_inuse(m, remainder, rsize); 3808 extra = chunk2mem(remainder); 3809 } 3810 } 3811 else if (next == m->top && oldsize + m->topsize > nb) { 3812 /* Expand into top */ 3813 size_t newsize = oldsize + m->topsize; 3814 size_t newtopsize = newsize - nb; 3815 mchunkptr newtop = chunk_plus_offset(oldp, nb); 3816 set_inuse(m, oldp, nb); 3817 newtop->head = newtopsize |PINUSE_BIT; 3818 m->top = newtop; 3819 m->topsize = newtopsize; 3820 newp = oldp; 3821 } 3822 } 3823 else { 3824 USAGE_ERROR_ACTION(m, oldmem); 3825 POSTACTION(m); 3826 return 0; 3827 } 3828 3829 POSTACTION(m); 3830 3831 if (newp != 0) { 3832 if (extra != 0) { 3833 internal_free(m, extra); 3834 } 3835 check_inuse_chunk(m, newp); 3836 return chunk2mem(newp); 3837 } 3838 else { 3839 void* newmem = internal_malloc(m, bytes); 3840 if (newmem != 0) { 3841 size_t oc = oldsize - overhead_for(oldp); 3842 memcpy(newmem, oldmem, (oc < bytes)? oc : bytes); 3843 internal_free(m, oldmem); 3844 } 3845 return newmem; 3846 } 3847 } 3848 return 0; 3849 } 3850 3851 /* --------------------------- memalign support -------------------------- */ 3852 3853 static void* internal_memalign(mstate m, size_t alignment, size_t bytes) { 3854 if (alignment <= MALLOC_ALIGNMENT) /* Can just use malloc */ 3855 return internal_malloc(m, bytes); 3856 if (alignment < MIN_CHUNK_SIZE) /* must be at least a minimum chunk size */ 3857 alignment = MIN_CHUNK_SIZE; 3858 if ((alignment & (alignment-SIZE_T_ONE)) != 0) {/* Ensure a power of 2 */ 3859 size_t a = MALLOC_ALIGNMENT << 1; 3860 while (a < alignment) a <<= 1; 3861 alignment = a; 3862 } 3863 3864 if (bytes >= MAX_REQUEST - alignment) { 3865 if (m != 0) { /* Test isn't needed but avoids compiler warning */ 3866 MALLOC_FAILURE_ACTION; 3867 } 3868 } 3869 else { 3870 size_t nb = request2size(bytes); 3871 size_t req = nb + alignment + MIN_CHUNK_SIZE - CHUNK_OVERHEAD; 3872 char* mem = (char*)internal_malloc(m, req); 3873 if (mem != 0) { 3874 void* leader = 0; 3875 void* trailer = 0; 3876 mchunkptr p = mem2chunk(mem); 3877 3878 if (PREACTION(m)) return 0; 3879 if ((((size_t)(mem)) % alignment) != 0) { /* misaligned */ 3880 /* 3881 Find an aligned spot inside chunk. Since we need to give 3882 back leading space in a chunk of at least MIN_CHUNK_SIZE, if 3883 the first calculation places us at a spot with less than 3884 MIN_CHUNK_SIZE leader, we can move to the next aligned spot. 3885 We've allocated enough total room so that this is always 3886 possible. 3887 */ 3888 char* br = (char*)mem2chunk((size_t)(((size_t)(mem + 3889 alignment - 3890 SIZE_T_ONE)) & 3891 -alignment)); 3892 char* pos = ((size_t)(br - (char*)(p)) >= MIN_CHUNK_SIZE)? 3893 br : br+alignment; 3894 mchunkptr newp = (mchunkptr)pos; 3895 size_t leadsize = pos - (char*)(p); 3896 size_t newsize = chunksize(p) - leadsize; 3897 3898 if (is_mmapped(p)) { /* For mmapped chunks, just adjust offset */ 3899 newp->prev_foot = p->prev_foot + leadsize; 3900 newp->head = (newsize|CINUSE_BIT); 3901 } 3902 else { /* Otherwise, give back leader, use the rest */ 3903 set_inuse(m, newp, newsize); 3904 set_inuse(m, p, leadsize); 3905 leader = chunk2mem(p); 3906 } 3907 p = newp; 3908 } 3909 3910 /* Give back spare room at the end */ 3911 if (!is_mmapped(p)) { 3912 size_t size = chunksize(p); 3913 if (size > nb + MIN_CHUNK_SIZE) { 3914 size_t remainder_size = size - nb; 3915 mchunkptr remainder = chunk_plus_offset(p, nb); 3916 set_inuse(m, p, nb); 3917 set_inuse(m, remainder, remainder_size); 3918 trailer = chunk2mem(remainder); 3919 } 3920 } 3921 3922 assert (chunksize(p) >= nb); 3923 assert((((size_t)(chunk2mem(p))) % alignment) == 0); 3924 check_inuse_chunk(m, p); 3925 POSTACTION(m); 3926 if (leader != 0) { 3927 internal_free(m, leader); 3928 } 3929 if (trailer != 0) { 3930 internal_free(m, trailer); 3931 } 3932 return chunk2mem(p); 3933 } 3934 } 3935 return 0; 3936 } 3937 3938 /* ------------------------ comalloc/coalloc support --------------------- */ 3939 3940 static void** ialloc(mstate m, 3941 size_t n_elements, 3942 size_t* sizes, 3943 int opts, 3944 void* chunks[]) { 3945 /* 3946 This provides common support for independent_X routines, handling 3947 all of the combinations that can result. 3948 3949 The opts arg has: 3950 bit 0 set if all elements are same size (using sizes[0]) 3951 bit 1 set if elements should be zeroed 3952 */ 3953 3954 size_t element_size; /* chunksize of each element, if all same */ 3955 size_t contents_size; /* total size of elements */ 3956 size_t array_size; /* request size of pointer array */ 3957 void* mem; /* malloced aggregate space */ 3958 mchunkptr p; /* corresponding chunk */ 3959 size_t remainder_size; /* remaining bytes while splitting */ 3960 void** marray; /* either "chunks" or malloced ptr array */ 3961 mchunkptr array_chunk; /* chunk for malloced ptr array */ 3962 flag_t was_enabled; /* to disable mmap */ 3963 size_t size; 3964 size_t i; 3965 3966 /* compute array length, if needed */ 3967 if (chunks != 0) { 3968 if (n_elements == 0) 3969 return chunks; /* nothing to do */ 3970 marray = chunks; 3971 array_size = 0; 3972 } 3973 else { 3974 /* if empty req, must still return chunk representing empty array */ 3975 if (n_elements == 0) 3976 return (void**)internal_malloc(m, 0); 3977 marray = 0; 3978 array_size = request2size(n_elements * (sizeof(void*))); 3979 } 3980 3981 /* compute total element size */ 3982 if (opts & 0x1) { /* all-same-size */ 3983 element_size = request2size(*sizes); 3984 contents_size = n_elements * element_size; 3985 } 3986 else { /* add up all the sizes */ 3987 element_size = 0; 3988 contents_size = 0; 3989 for (i = 0; i != n_elements; ++i) 3990 contents_size += request2size(sizes[i]); 3991 } 3992 3993 size = contents_size + array_size; 3994 3995 /* 3996 Allocate the aggregate chunk. First disable direct-mmapping so 3997 malloc won't use it, since we would not be able to later 3998 free/realloc space internal to a segregated mmap region. 3999 */ 4000 was_enabled = use_mmap(m); 4001 disable_mmap(m); 4002 mem = internal_malloc(m, size - CHUNK_OVERHEAD); 4003 if (was_enabled) 4004 enable_mmap(m); 4005 if (mem == 0) 4006 return 0; 4007 4008 if (PREACTION(m)) return 0; 4009 p = mem2chunk(mem); 4010 remainder_size = chunksize(p); 4011 4012 assert(!is_mmapped(p)); 4013 4014 if (opts & 0x2) { /* optionally clear the elements */ 4015 memset((size_t*)mem, 0, remainder_size - SIZE_T_SIZE - array_size); 4016 } 4017 4018 /* If not provided, allocate the pointer array as final part of chunk */ 4019 if (marray == 0) { 4020 size_t array_chunk_size; 4021 array_chunk = chunk_plus_offset(p, contents_size); 4022 array_chunk_size = remainder_size - contents_size; 4023 marray = (void**) (chunk2mem(array_chunk)); 4024 set_size_and_pinuse_of_inuse_chunk(m, array_chunk, array_chunk_size); 4025 remainder_size = contents_size; 4026 } 4027 4028 /* split out elements */ 4029 for (i = 0; ; ++i) { 4030 marray[i] = chunk2mem(p); 4031 if (i != n_elements-1) { 4032 if (element_size != 0) 4033 size = element_size; 4034 else 4035 size = request2size(sizes[i]); 4036 remainder_size -= size; 4037 set_size_and_pinuse_of_inuse_chunk(m, p, size); 4038 p = chunk_plus_offset(p, size); 4039 } 4040 else { /* the final element absorbs any overallocation slop */ 4041 set_size_and_pinuse_of_inuse_chunk(m, p, remainder_size); 4042 break; 4043 } 4044 } 4045 4046 #if DEBUG 4047 if (marray != chunks) { 4048 /* final element must have exactly exhausted chunk */ 4049 if (element_size != 0) { 4050 assert(remainder_size == element_size); 4051 } 4052 else { 4053 assert(remainder_size == request2size(sizes[i])); 4054 } 4055 check_inuse_chunk(m, mem2chunk(marray)); 4056 } 4057 for (i = 0; i != n_elements; ++i) 4058 check_inuse_chunk(m, mem2chunk(marray[i])); 4059 4060 #endif /* DEBUG */ 4061 4062 POSTACTION(m); 4063 return marray; 4064 } 4065 4066 4067 /* -------------------------- public routines ---------------------------- */ 4068 4069 #if !ONLY_MSPACES 4070 4071 void* dlmalloc(size_t bytes) { 4072 /* 4073 Basic algorithm: 4074 If a small request (< 256 bytes minus per-chunk overhead): 4075 1. If one exists, use a remainderless chunk in associated smallbin. 4076 (Remainderless means that there are too few excess bytes to 4077 represent as a chunk.) 4078 2. If it is big enough, use the dv chunk, which is normally the 4079 chunk adjacent to the one used for the most recent small request. 4080 3. If one exists, split the smallest available chunk in a bin, 4081 saving remainder in dv. 4082 4. If it is big enough, use the top chunk. 4083 5. If available, get memory from system and use it 4084 Otherwise, for a large request: 4085 1. Find the smallest available binned chunk that fits, and use it 4086 if it is better fitting than dv chunk, splitting if necessary. 4087 2. If better fitting than any binned chunk, use the dv chunk. 4088 3. If it is big enough, use the top chunk. 4089 4. If request size >= mmap threshold, try to directly mmap this chunk. 4090 5. If available, get memory from system and use it 4091 4092 The ugly goto's here ensure that postaction occurs along all paths. 4093 */ 4094 4095 if (!PREACTION(gm)) { 4096 void* mem; 4097 size_t nb; 4098 if (bytes <= MAX_SMALL_REQUEST) { 4099 bindex_t idx; 4100 binmap_t smallbits; 4101 nb = (bytes < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(bytes); 4102 idx = small_index(nb); 4103 smallbits = gm->smallmap >> idx; 4104 4105 if ((smallbits & 0x3U) != 0) { /* Remainderless fit to a smallbin. */ 4106 mchunkptr b, p; 4107 idx += ~smallbits & 1; /* Uses next bin if idx empty */ 4108 b = smallbin_at(gm, idx); 4109 p = b->fd; 4110 assert(chunksize(p) == small_index2size(idx)); 4111 unlink_first_small_chunk(gm, b, p, idx); 4112 set_inuse_and_pinuse(gm, p, small_index2size(idx)); 4113 mem = chunk2mem(p); 4114 check_malloced_chunk(gm, mem, nb); 4115 goto postaction; 4116 } 4117 4118 else if (nb > gm->dvsize) { 4119 if (smallbits != 0) { /* Use chunk in next nonempty smallbin */ 4120 mchunkptr b, p, r; 4121 size_t rsize; 4122 bindex_t i; 4123 binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx)); 4124 binmap_t leastbit = least_bit(leftbits); 4125 compute_bit2idx(leastbit, i); 4126 b = smallbin_at(gm, i); 4127 p = b->fd; 4128 assert(chunksize(p) == small_index2size(i)); 4129 unlink_first_small_chunk(gm, b, p, i); 4130 rsize = small_index2size(i) - nb; 4131 /* Fit here cannot be remainderless if 4byte sizes */ 4132 if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE) 4133 set_inuse_and_pinuse(gm, p, small_index2size(i)); 4134 else { 4135 set_size_and_pinuse_of_inuse_chunk(gm, p, nb); 4136 r = chunk_plus_offset(p, nb); 4137 set_size_and_pinuse_of_free_chunk(r, rsize); 4138 replace_dv(gm, r, rsize); 4139 } 4140 mem = chunk2mem(p); 4141 check_malloced_chunk(gm, mem, nb); 4142 goto postaction; 4143 } 4144 4145 else if (gm->treemap != 0 && (mem = tmalloc_small(gm, nb)) != 0) { 4146 check_malloced_chunk(gm, mem, nb); 4147 goto postaction; 4148 } 4149 } 4150 } 4151 else if (bytes >= MAX_REQUEST) 4152 nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */ 4153 else { 4154 nb = pad_request(bytes); 4155 if (gm->treemap != 0 && (mem = tmalloc_large(gm, nb)) != 0) { 4156 check_malloced_chunk(gm, mem, nb); 4157 goto postaction; 4158 } 4159 } 4160 4161 if (nb <= gm->dvsize) { 4162 size_t rsize = gm->dvsize - nb; 4163 mchunkptr p = gm->dv; 4164 if (rsize >= MIN_CHUNK_SIZE) { /* split dv */ 4165 mchunkptr r = gm->dv = chunk_plus_offset(p, nb); 4166 gm->dvsize = rsize; 4167 set_size_and_pinuse_of_free_chunk(r, rsize); 4168 set_size_and_pinuse_of_inuse_chunk(gm, p, nb); 4169 } 4170 else { /* exhaust dv */ 4171 size_t dvs = gm->dvsize; 4172 gm->dvsize = 0; 4173 gm->dv = 0; 4174 set_inuse_and_pinuse(gm, p, dvs); 4175 } 4176 mem = chunk2mem(p); 4177 check_malloced_chunk(gm, mem, nb); 4178 goto postaction; 4179 } 4180 4181 else if (nb < gm->topsize) { /* Split top */ 4182 size_t rsize = gm->topsize -= nb; 4183 mchunkptr p = gm->top; 4184 mchunkptr r = gm->top = chunk_plus_offset(p, nb); 4185 r->head = rsize | PINUSE_BIT; 4186 set_size_and_pinuse_of_inuse_chunk(gm, p, nb); 4187 mem = chunk2mem(p); 4188 check_top_chunk(gm, gm->top); 4189 check_malloced_chunk(gm, mem, nb); 4190 goto postaction; 4191 } 4192 4193 mem = sys_alloc(gm, nb); 4194 4195 postaction: 4196 POSTACTION(gm); 4197 return mem; 4198 } 4199 4200 return 0; 4201 } 4202 4203 void dlfree(void* mem) { 4204 /* 4205 Consolidate freed chunks with preceeding or succeeding bordering 4206 free chunks, if they exist, and then place in a bin. Intermixed 4207 with special cases for top, dv, mmapped chunks, and usage errors. 4208 */ 4209 4210 if (mem != 0) { 4211 mchunkptr p = mem2chunk(mem); 4212 #if FOOTERS 4213 mstate fm = get_mstate_for(p); 4214 if (!ok_magic(fm)) { 4215 USAGE_ERROR_ACTION(fm, p); 4216 return; 4217 } 4218 #else /* FOOTERS */ 4219 #define fm gm 4220 #endif /* FOOTERS */ 4221 if (!PREACTION(fm)) { 4222 check_inuse_chunk(fm, p); 4223 if (RTCHECK(ok_address(fm, p) && ok_cinuse(p))) { 4224 size_t psize = chunksize(p); 4225 mchunkptr next = chunk_plus_offset(p, psize); 4226 if (!pinuse(p)) { 4227 size_t prevsize = p->prev_foot; 4228 if ((prevsize & IS_MMAPPED_BIT) != 0) { 4229 prevsize &= ~IS_MMAPPED_BIT; 4230 psize += prevsize + MMAP_FOOT_PAD; 4231 if (CALL_MUNMAP((char*)p - prevsize, psize) == 0) 4232 fm->footprint -= psize; 4233 goto postaction; 4234 } 4235 else { 4236 mchunkptr prev = chunk_minus_offset(p, prevsize); 4237 psize += prevsize; 4238 p = prev; 4239 if (RTCHECK(ok_address(fm, prev))) { /* consolidate backward */ 4240 if (p != fm->dv) { 4241 unlink_chunk(fm, p, prevsize); 4242 } 4243 else if ((next->head & INUSE_BITS) == INUSE_BITS) { 4244 fm->dvsize = psize; 4245 set_free_with_pinuse(p, psize, next); 4246 goto postaction; 4247 } 4248 } 4249 else 4250 goto erroraction; 4251 } 4252 } 4253 4254 if (RTCHECK(ok_next(p, next) && ok_pinuse(next))) { 4255 if (!cinuse(next)) { /* consolidate forward */ 4256 if (next == fm->top) { 4257 size_t tsize = fm->topsize += psize; 4258 fm->top = p; 4259 p->head = tsize | PINUSE_BIT; 4260 if (p == fm->dv) { 4261 fm->dv = 0; 4262 fm->dvsize = 0; 4263 } 4264 if (should_trim(fm, tsize)) 4265 sys_trim(fm, 0); 4266 goto postaction; 4267 } 4268 else if (next == fm->dv) { 4269 size_t dsize = fm->dvsize += psize; 4270 fm->dv = p; 4271 set_size_and_pinuse_of_free_chunk(p, dsize); 4272 goto postaction; 4273 } 4274 else { 4275 size_t nsize = chunksize(next); 4276 psize += nsize; 4277 unlink_chunk(fm, next, nsize); 4278 set_size_and_pinuse_of_free_chunk(p, psize); 4279 if (p == fm->dv) { 4280 fm->dvsize = psize; 4281 goto postaction; 4282 } 4283 } 4284 } 4285 else 4286 set_free_with_pinuse(p, psize, next); 4287 insert_chunk(fm, p, psize); 4288 check_free_chunk(fm, p); 4289 goto postaction; 4290 } 4291 } 4292 erroraction: 4293 USAGE_ERROR_ACTION(fm, p); 4294 postaction: 4295 POSTACTION(fm); 4296 } 4297 } 4298 #if !FOOTERS 4299 #undef fm 4300 #endif /* FOOTERS */ 4301 } 4302 4303 void* dlcalloc(size_t n_elements, size_t elem_size) { 4304 void* mem; 4305 size_t req = 0; 4306 if (n_elements != 0) { 4307 req = n_elements * elem_size; 4308 if (((n_elements | elem_size) & ~(size_t)0xffff) && 4309 (req / n_elements != elem_size)) 4310 req = MAX_SIZE_T; /* force downstream failure on overflow */ 4311 } 4312 mem = dlmalloc(req); 4313 if (mem != 0 && calloc_must_clear(mem2chunk(mem))) 4314 memset(mem, 0, req); 4315 return mem; 4316 } 4317 4318 void* dlrealloc(void* oldmem, size_t bytes) { 4319 if (oldmem == 0) 4320 return dlmalloc(bytes); 4321 #ifdef REALLOC_ZERO_BYTES_FREES 4322 if (bytes == 0) { 4323 dlfree(oldmem); 4324 return 0; 4325 } 4326 #endif /* REALLOC_ZERO_BYTES_FREES */ 4327 else { 4328 #if ! FOOTERS 4329 mstate m = gm; 4330 #else /* FOOTERS */ 4331 mstate m = get_mstate_for(mem2chunk(oldmem)); 4332 if (!ok_magic(m)) { 4333 USAGE_ERROR_ACTION(m, oldmem); 4334 return 0; 4335 } 4336 #endif /* FOOTERS */ 4337 return internal_realloc(m, oldmem, bytes); 4338 } 4339 } 4340 4341 void* dlmemalign(size_t alignment, size_t bytes) { 4342 return internal_memalign(gm, alignment, bytes); 4343 } 4344 4345 void** dlindependent_calloc(size_t n_elements, size_t elem_size, 4346 void* chunks[]) { 4347 size_t sz = elem_size; /* serves as 1-element array */ 4348 return ialloc(gm, n_elements, &sz, 3, chunks); 4349 } 4350 4351 void** dlindependent_comalloc(size_t n_elements, size_t sizes[], 4352 void* chunks[]) { 4353 return ialloc(gm, n_elements, sizes, 0, chunks); 4354 } 4355 4356 void* dlvalloc(size_t bytes) { 4357 size_t pagesz; 4358 init_mparams(); 4359 pagesz = mparams.page_size; 4360 return dlmemalign(pagesz, bytes); 4361 } 4362 4363 void* dlpvalloc(size_t bytes) { 4364 size_t pagesz; 4365 init_mparams(); 4366 pagesz = mparams.page_size; 4367 return dlmemalign(pagesz, (bytes + pagesz - SIZE_T_ONE) & ~(pagesz - SIZE_T_ONE)); 4368 } 4369 4370 int dlmalloc_trim(size_t pad) { 4371 int result = 0; 4372 if (!PREACTION(gm)) { 4373 result = sys_trim(gm, pad); 4374 POSTACTION(gm); 4375 } 4376 return result; 4377 } 4378 4379 size_t dlmalloc_footprint(void) { 4380 return gm->footprint; 4381 } 4382 4383 size_t dlmalloc_max_footprint(void) { 4384 return gm->max_footprint; 4385 } 4386 4387 #if !NO_MALLINFO 4388 struct mallinfo dlmallinfo(void) { 4389 return internal_mallinfo(gm); 4390 } 4391 #endif /* NO_MALLINFO */ 4392 4393 void dlmalloc_stats() { 4394 internal_malloc_stats(gm); 4395 } 4396 4397 size_t dlmalloc_usable_size(void* mem) { 4398 if (mem != 0) { 4399 mchunkptr p = mem2chunk(mem); 4400 if (cinuse(p)) 4401 return chunksize(p) - overhead_for(p); 4402 } 4403 return 0; 4404 } 4405 4406 int dlmallopt(int param_number, int value) { 4407 return change_mparam(param_number, value); 4408 } 4409 4410 #endif /* !ONLY_MSPACES */ 4411 4412 /* ----------------------------- user mspaces ---------------------------- */ 4413 4414 #if MSPACES 4415 4416 static mstate init_user_mstate(char* tbase, size_t tsize) { 4417 size_t msize = pad_request(sizeof(struct malloc_state)); 4418 mchunkptr mn; 4419 mchunkptr msp = align_as_chunk(tbase); 4420 mstate m = (mstate)(chunk2mem(msp)); 4421 memset(m, 0, msize); 4422 INITIAL_LOCK(&m->mutex); 4423 msp->head = (msize|PINUSE_BIT|CINUSE_BIT); 4424 m->seg.base = m->least_addr = tbase; 4425 m->seg.size = m->footprint = m->max_footprint = tsize; 4426 m->magic = mparams.magic; 4427 m->mflags = mparams.default_mflags; 4428 disable_contiguous(m); 4429 init_bins(m); 4430 mn = next_chunk(mem2chunk(m)); 4431 init_top(m, mn, (size_t)((tbase + tsize) - (char*)mn) - TOP_FOOT_SIZE); 4432 check_top_chunk(m, m->top); 4433 return m; 4434 } 4435 4436 mspace create_mspace(size_t capacity, int locked) { 4437 mstate m = 0; 4438 size_t msize = pad_request(sizeof(struct malloc_state)); 4439 init_mparams(); /* Ensure pagesize etc initialized */ 4440 4441 if (capacity < (size_t) -(msize + TOP_FOOT_SIZE + mparams.page_size)) { 4442 size_t rs = ((capacity == 0)? mparams.granularity : 4443 (capacity + TOP_FOOT_SIZE + msize)); 4444 size_t tsize = granularity_align(rs); 4445 char* tbase = (char*)(CALL_MMAP(tsize)); 4446 if (tbase != CMFAIL) { 4447 m = init_user_mstate(tbase, tsize); 4448 m->seg.sflags = IS_MMAPPED_BIT; 4449 set_lock(m, locked); 4450 } 4451 } 4452 return (mspace)m; 4453 } 4454 4455 mspace create_mspace_with_base(void* base, size_t capacity, int locked) { 4456 mstate m = 0; 4457 size_t msize = pad_request(sizeof(struct malloc_state)); 4458 init_mparams(); /* Ensure pagesize etc initialized */ 4459 4460 if (capacity > msize + TOP_FOOT_SIZE && 4461 capacity < (size_t) -(msize + TOP_FOOT_SIZE + mparams.page_size)) { 4462 m = init_user_mstate((char*)base, capacity); 4463 m->seg.sflags = EXTERN_BIT; 4464 set_lock(m, locked); 4465 } 4466 return (mspace)m; 4467 } 4468 4469 size_t destroy_mspace(mspace msp) { 4470 size_t freed = 0; 4471 mstate ms = (mstate)msp; 4472 if (ok_magic(ms)) { 4473 msegmentptr sp = &ms->seg; 4474 while (sp != 0) { 4475 char* base = sp->base; 4476 size_t size = sp->size; 4477 flag_t flag = sp->sflags; 4478 sp = sp->next; 4479 if ((flag & IS_MMAPPED_BIT) && !(flag & EXTERN_BIT) && 4480 CALL_MUNMAP(base, size) == 0) 4481 freed += size; 4482 } 4483 } 4484 else { 4485 USAGE_ERROR_ACTION(ms,ms); 4486 } 4487 return freed; 4488 } 4489 4490 /* 4491 mspace versions of routines are near-clones of the global 4492 versions. This is not so nice but better than the alternatives. 4493 */ 4494 4495 4496 void* mspace_malloc(mspace msp, size_t bytes) { 4497 mstate ms = (mstate)msp; 4498 if (!ok_magic(ms)) { 4499 USAGE_ERROR_ACTION(ms,ms); 4500 return 0; 4501 } 4502 if (!PREACTION(ms)) { 4503 void* mem; 4504 size_t nb; 4505 if (bytes <= MAX_SMALL_REQUEST) { 4506 bindex_t idx; 4507 binmap_t smallbits; 4508 nb = (bytes < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(bytes); 4509 idx = small_index(nb); 4510 smallbits = ms->smallmap >> idx; 4511 4512 if ((smallbits & 0x3U) != 0) { /* Remainderless fit to a smallbin. */ 4513 mchunkptr b, p; 4514 idx += ~smallbits & 1; /* Uses next bin if idx empty */ 4515 b = smallbin_at(ms, idx); 4516 p = b->fd; 4517 assert(chunksize(p) == small_index2size(idx)); 4518 unlink_first_small_chunk(ms, b, p, idx); 4519 set_inuse_and_pinuse(ms, p, small_index2size(idx)); 4520 mem = chunk2mem(p); 4521 check_malloced_chunk(ms, mem, nb); 4522 goto postaction; 4523 } 4524 4525 else if (nb > ms->dvsize) { 4526 if (smallbits != 0) { /* Use chunk in next nonempty smallbin */ 4527 mchunkptr b, p, r; 4528 size_t rsize; 4529 bindex_t i; 4530 binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx)); 4531 binmap_t leastbit = least_bit(leftbits); 4532 compute_bit2idx(leastbit, i); 4533 b = smallbin_at(ms, i); 4534 p = b->fd; 4535 assert(chunksize(p) == small_index2size(i)); 4536 unlink_first_small_chunk(ms, b, p, i); 4537 rsize = small_index2size(i) - nb; 4538 /* Fit here cannot be remainderless if 4byte sizes */ 4539 if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE) 4540 set_inuse_and_pinuse(ms, p, small_index2size(i)); 4541 else { 4542 set_size_and_pinuse_of_inuse_chunk(ms, p, nb); 4543 r = chunk_plus_offset(p, nb); 4544 set_size_and_pinuse_of_free_chunk(r, rsize); 4545 replace_dv(ms, r, rsize); 4546 } 4547 mem = chunk2mem(p); 4548 check_malloced_chunk(ms, mem, nb); 4549 goto postaction; 4550 } 4551 4552 else if (ms->treemap != 0 && (mem = tmalloc_small(ms, nb)) != 0) { 4553 check_malloced_chunk(ms, mem, nb); 4554 goto postaction; 4555 } 4556 } 4557 } 4558 else if (bytes >= MAX_REQUEST) 4559 nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */ 4560 else { 4561 nb = pad_request(bytes); 4562 if (ms->treemap != 0 && (mem = tmalloc_large(ms, nb)) != 0) { 4563 check_malloced_chunk(ms, mem, nb); 4564 goto postaction; 4565 } 4566 } 4567 4568 if (nb <= ms->dvsize) { 4569 size_t rsize = ms->dvsize - nb; 4570 mchunkptr p = ms->dv; 4571 if (rsize >= MIN_CHUNK_SIZE) { /* split dv */ 4572 mchunkptr r = ms->dv = chunk_plus_offset(p, nb); 4573 ms->dvsize = rsize; 4574 set_size_and_pinuse_of_free_chunk(r, rsize); 4575 set_size_and_pinuse_of_inuse_chunk(ms, p, nb); 4576 } 4577 else { /* exhaust dv */ 4578 size_t dvs = ms->dvsize; 4579 ms->dvsize = 0; 4580 ms->dv = 0; 4581 set_inuse_and_pinuse(ms, p, dvs); 4582 } 4583 mem = chunk2mem(p); 4584 check_malloced_chunk(ms, mem, nb); 4585 goto postaction; 4586 } 4587 4588 else if (nb < ms->topsize) { /* Split top */ 4589 size_t rsize = ms->topsize -= nb; 4590 mchunkptr p = ms->top; 4591 mchunkptr r = ms->top = chunk_plus_offset(p, nb); 4592 r->head = rsize | PINUSE_BIT; 4593 set_size_and_pinuse_of_inuse_chunk(ms, p, nb); 4594 mem = chunk2mem(p); 4595 check_top_chunk(ms, ms->top); 4596 check_malloced_chunk(ms, mem, nb); 4597 goto postaction; 4598 } 4599 4600 mem = sys_alloc(ms, nb); 4601 4602 postaction: 4603 POSTACTION(ms); 4604 return mem; 4605 } 4606 4607 return 0; 4608 } 4609 4610 void mspace_free(mspace msp, void* mem) { 4611 if (mem != 0) { 4612 mchunkptr p = mem2chunk(mem); 4613 #if FOOTERS 4614 mstate fm = get_mstate_for(p); 4615 #else /* FOOTERS */ 4616 mstate fm = (mstate)msp; 4617 #endif /* FOOTERS */ 4618 if (!ok_magic(fm)) { 4619 USAGE_ERROR_ACTION(fm, p); 4620 return; 4621 } 4622 if (!PREACTION(fm)) { 4623 check_inuse_chunk(fm, p); 4624 if (RTCHECK(ok_address(fm, p) && ok_cinuse(p))) { 4625 size_t psize = chunksize(p); 4626 mchunkptr next = chunk_plus_offset(p, psize); 4627 if (!pinuse(p)) { 4628 size_t prevsize = p->prev_foot; 4629 if ((prevsize & IS_MMAPPED_BIT) != 0) { 4630 prevsize &= ~IS_MMAPPED_BIT; 4631 psize += prevsize + MMAP_FOOT_PAD; 4632 if (CALL_MUNMAP((char*)p - prevsize, psize) == 0) 4633 fm->footprint -= psize; 4634 goto postaction; 4635 } 4636 else { 4637 mchunkptr prev = chunk_minus_offset(p, prevsize); 4638 psize += prevsize; 4639 p = prev; 4640 if (RTCHECK(ok_address(fm, prev))) { /* consolidate backward */ 4641 if (p != fm->dv) { 4642 unlink_chunk(fm, p, prevsize); 4643 } 4644 else if ((next->head & INUSE_BITS) == INUSE_BITS) { 4645 fm->dvsize = psize; 4646 set_free_with_pinuse(p, psize, next); 4647 goto postaction; 4648 } 4649 } 4650 else 4651 goto erroraction; 4652 } 4653 } 4654 4655 if (RTCHECK(ok_next(p, next) && ok_pinuse(next))) { 4656 if (!cinuse(next)) { /* consolidate forward */ 4657 if (next == fm->top) { 4658 size_t tsize = fm->topsize += psize; 4659 fm->top = p; 4660 p->head = tsize | PINUSE_BIT; 4661 if (p == fm->dv) { 4662 fm->dv = 0; 4663 fm->dvsize = 0; 4664 } 4665 if (should_trim(fm, tsize)) 4666 sys_trim(fm, 0); 4667 goto postaction; 4668 } 4669 else if (next == fm->dv) { 4670 size_t dsize = fm->dvsize += psize; 4671 fm->dv = p; 4672 set_size_and_pinuse_of_free_chunk(p, dsize); 4673 goto postaction; 4674 } 4675 else { 4676 size_t nsize = chunksize(next); 4677 psize += nsize; 4678 unlink_chunk(fm, next, nsize); 4679 set_size_and_pinuse_of_free_chunk(p, psize); 4680 if (p == fm->dv) { 4681 fm->dvsize = psize; 4682 goto postaction; 4683 } 4684 } 4685 } 4686 else 4687 set_free_with_pinuse(p, psize, next); 4688 insert_chunk(fm, p, psize); 4689 check_free_chunk(fm, p); 4690 goto postaction; 4691 } 4692 } 4693 erroraction: 4694 USAGE_ERROR_ACTION(fm, p); 4695 postaction: 4696 POSTACTION(fm); 4697 } 4698 } 4699 } 4700 4701 void* mspace_calloc(mspace msp, size_t n_elements, size_t elem_size) { 4702 void* mem; 4703 size_t req = 0; 4704 mstate ms = (mstate)msp; 4705 if (!ok_magic(ms)) { 4706 USAGE_ERROR_ACTION(ms,ms); 4707 return 0; 4708 } 4709 if (n_elements != 0) { 4710 req = n_elements * elem_size; 4711 if (((n_elements | elem_size) & ~(size_t)0xffff) && 4712 (req / n_elements != elem_size)) 4713 req = MAX_SIZE_T; /* force downstream failure on overflow */ 4714 } 4715 mem = internal_malloc(ms, req); 4716 if (mem != 0 && calloc_must_clear(mem2chunk(mem))) 4717 memset(mem, 0, req); 4718 return mem; 4719 } 4720 4721 void* mspace_realloc(mspace msp, void* oldmem, size_t bytes) { 4722 if (oldmem == 0) 4723 return mspace_malloc(msp, bytes); 4724 #ifdef REALLOC_ZERO_BYTES_FREES 4725 if (bytes == 0) { 4726 mspace_free(msp, oldmem); 4727 return 0; 4728 } 4729 #endif /* REALLOC_ZERO_BYTES_FREES */ 4730 else { 4731 #if FOOTERS 4732 mchunkptr p = mem2chunk(oldmem); 4733 mstate ms = get_mstate_for(p); 4734 #else /* FOOTERS */ 4735 mstate ms = (mstate)msp; 4736 #endif /* FOOTERS */ 4737 if (!ok_magic(ms)) { 4738 USAGE_ERROR_ACTION(ms,ms); 4739 return 0; 4740 } 4741 return internal_realloc(ms, oldmem, bytes); 4742 } 4743 } 4744 4745 void* mspace_memalign(mspace msp, size_t alignment, size_t bytes) { 4746 mstate ms = (mstate)msp; 4747 if (!ok_magic(ms)) { 4748 USAGE_ERROR_ACTION(ms,ms); 4749 return 0; 4750 } 4751 return internal_memalign(ms, alignment, bytes); 4752 } 4753 4754 void** mspace_independent_calloc(mspace msp, size_t n_elements, 4755 size_t elem_size, void* chunks[]) { 4756 size_t sz = elem_size; /* serves as 1-element array */ 4757 mstate ms = (mstate)msp; 4758 if (!ok_magic(ms)) { 4759 USAGE_ERROR_ACTION(ms,ms); 4760 return 0; 4761 } 4762 return ialloc(ms, n_elements, &sz, 3, chunks); 4763 } 4764 4765 void** mspace_independent_comalloc(mspace msp, size_t n_elements, 4766 size_t sizes[], void* chunks[]) { 4767 mstate ms = (mstate)msp; 4768 if (!ok_magic(ms)) { 4769 USAGE_ERROR_ACTION(ms,ms); 4770 return 0; 4771 } 4772 return ialloc(ms, n_elements, sizes, 0, chunks); 4773 } 4774 4775 int mspace_trim(mspace msp, size_t pad) { 4776 int result = 0; 4777 mstate ms = (mstate)msp; 4778 if (ok_magic(ms)) { 4779 if (!PREACTION(ms)) { 4780 result = sys_trim(ms, pad); 4781 POSTACTION(ms); 4782 } 4783 } 4784 else { 4785 USAGE_ERROR_ACTION(ms,ms); 4786 } 4787 return result; 4788 } 4789 4790 void mspace_malloc_stats(mspace msp) { 4791 mstate ms = (mstate)msp; 4792 if (ok_magic(ms)) { 4793 internal_malloc_stats(ms); 4794 } 4795 else { 4796 USAGE_ERROR_ACTION(ms,ms); 4797 } 4798 } 4799 4800 size_t mspace_footprint(mspace msp) { 4801 size_t result; 4802 mstate ms = (mstate)msp; 4803 if (ok_magic(ms)) { 4804 result = ms->footprint; 4805 } 4806 USAGE_ERROR_ACTION(ms,ms); 4807 return result; 4808 } 4809 4810 4811 size_t mspace_max_footprint(mspace msp) { 4812 size_t result; 4813 mstate ms = (mstate)msp; 4814 if (ok_magic(ms)) { 4815 result = ms->max_footprint; 4816 } 4817 USAGE_ERROR_ACTION(ms,ms); 4818 return result; 4819 } 4820 4821 4822 #if !NO_MALLINFO 4823 struct mallinfo mspace_mallinfo(mspace msp) { 4824 mstate ms = (mstate)msp; 4825 if (!ok_magic(ms)) { 4826 USAGE_ERROR_ACTION(ms,ms); 4827 } 4828 return internal_mallinfo(ms); 4829 } 4830 #endif /* NO_MALLINFO */ 4831 4832 int mspace_mallopt(int param_number, int value) { 4833 return change_mparam(param_number, value); 4834 } 4835 4836 #endif /* MSPACES */ 4837 4838 /* -------------------- Alternative MORECORE functions ------------------- */ 4839 4840 /* 4841 Guidelines for creating a custom version of MORECORE: 4842 4843 * For best performance, MORECORE should allocate in multiples of pagesize. 4844 * MORECORE may allocate more memory than requested. (Or even less, 4845 but this will usually result in a malloc failure.) 4846 * MORECORE must not allocate memory when given argument zero, but 4847 instead return one past the end address of memory from previous 4848 nonzero call. 4849 * For best performance, consecutive calls to MORECORE with positive 4850 arguments should return increasing addresses, indicating that 4851 space has been contiguously extended. 4852 * Even though consecutive calls to MORECORE need not return contiguous 4853 addresses, it must be OK for malloc'ed chunks to span multiple 4854 regions in those cases where they do happen to be contiguous. 4855 * MORECORE need not handle negative arguments -- it may instead 4856 just return MFAIL when given negative arguments. 4857 Negative arguments are always multiples of pagesize. MORECORE 4858 must not misinterpret negative args as large positive unsigned 4859 args. You can suppress all such calls from even occurring by defining 4860 MORECORE_CANNOT_TRIM, 4861 4862 As an example alternative MORECORE, here is a custom allocator 4863 kindly contributed for pre-OSX macOS. It uses virtually but not 4864 necessarily physically contiguous non-paged memory (locked in, 4865 present and won't get swapped out). You can use it by uncommenting 4866 this section, adding some #includes, and setting up the appropriate 4867 defines above: 4868 4869 #define MORECORE osMoreCore 4870 4871 There is also a shutdown routine that should somehow be called for 4872 cleanup upon program exit. 4873 4874 #define MAX_POOL_ENTRIES 100 4875 #define MINIMUM_MORECORE_SIZE (64 * 1024U) 4876 static int next_os_pool; 4877 void *our_os_pools[MAX_POOL_ENTRIES]; 4878 4879 void *osMoreCore(int size) 4880 { 4881 void *ptr = 0; 4882 static void *sbrk_top = 0; 4883 4884 if (size > 0) 4885 { 4886 if (size < MINIMUM_MORECORE_SIZE) 4887 size = MINIMUM_MORECORE_SIZE; 4888 if (CurrentExecutionLevel() == kTaskLevel) 4889 ptr = PoolAllocateResident(size + RM_PAGE_SIZE, 0); 4890 if (ptr == 0) 4891 { 4892 return (void *) MFAIL; 4893 } 4894 // save ptrs so they can be freed during cleanup 4895 our_os_pools[next_os_pool] = ptr; 4896 next_os_pool++; 4897 ptr = (void *) ((((size_t) ptr) + RM_PAGE_MASK) & ~RM_PAGE_MASK); 4898 sbrk_top = (char *) ptr + size; 4899 return ptr; 4900 } 4901 else if (size < 0) 4902 { 4903 // we don't currently support shrink behavior 4904 return (void *) MFAIL; 4905 } 4906 else 4907 { 4908 return sbrk_top; 4909 } 4910 } 4911 4912 // cleanup any allocated memory pools 4913 // called as last thing before shutting down driver 4914 4915 void osCleanupMem(void) 4916 { 4917 void **ptr; 4918 4919 for (ptr = our_os_pools; ptr < &our_os_pools[MAX_POOL_ENTRIES]; ptr++) 4920 if (*ptr) 4921 { 4922 PoolDeallocate(*ptr); 4923 *ptr = 0; 4924 } 4925 } 4926 4927 */ 4928 4929 4930 /* ----------------------------------------------------------------------- 4931 History: 4932 V2.8.3 Thu Sep 22 11:16:32 2005 Doug Lea (dl at gee) 4933 * Add max_footprint functions 4934 * Ensure all appropriate literals are size_t 4935 * Fix conditional compilation problem for some #define settings 4936 * Avoid concatenating segments with the one provided 4937 in create_mspace_with_base 4938 * Rename some variables to avoid compiler shadowing warnings 4939 * Use explicit lock initialization. 4940 * Better handling of sbrk interference. 4941 * Simplify and fix segment insertion, trimming and mspace_destroy 4942 * Reinstate REALLOC_ZERO_BYTES_FREES option from 2.7.x 4943 * Thanks especially to Dennis Flanagan for help on these. 4944 4945 V2.8.2 Sun Jun 12 16:01:10 2005 Doug Lea (dl at gee) 4946 * Fix memalign brace error. 4947 4948 V2.8.1 Wed Jun 8 16:11:46 2005 Doug Lea (dl at gee) 4949 * Fix improper #endif nesting in C++ 4950 * Add explicit casts needed for C++ 4951 4952 V2.8.0 Mon May 30 14:09:02 2005 Doug Lea (dl at gee) 4953 * Use trees for large bins 4954 * Support mspaces 4955 * Use segments to unify sbrk-based and mmap-based system allocation, 4956 removing need for emulation on most platforms without sbrk. 4957 * Default safety checks 4958 * Optional footer checks. Thanks to William Robertson for the idea. 4959 * Internal code refactoring 4960 * Incorporate suggestions and platform-specific changes. 4961 Thanks to Dennis Flanagan, Colin Plumb, Niall Douglas, 4962 Aaron Bachmann, Emery Berger, and others. 4963 * Speed up non-fastbin processing enough to remove fastbins. 4964 * Remove useless cfree() to avoid conflicts with other apps. 4965 * Remove internal memcpy, memset. Compilers handle builtins better. 4966 * Remove some options that no one ever used and rename others. 4967 4968 V2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee) 4969 * Fix malloc_state bitmap array misdeclaration 4970 4971 V2.7.1 Thu Jul 25 10:58:03 2002 Doug Lea (dl at gee) 4972 * Allow tuning of FIRST_SORTED_BIN_SIZE 4973 * Use PTR_UINT as type for all ptr->int casts. Thanks to John Belmonte. 4974 * Better detection and support for non-contiguousness of MORECORE. 4975 Thanks to Andreas Mueller, Conal Walsh, and Wolfram Gloger 4976 * Bypass most of malloc if no frees. Thanks To Emery Berger. 4977 * Fix freeing of old top non-contiguous chunk im sysmalloc. 4978 * Raised default trim and map thresholds to 256K. 4979 * Fix mmap-related #defines. Thanks to Lubos Lunak. 4980 * Fix copy macros; added LACKS_FCNTL_H. Thanks to Neal Walfield. 4981 * Branch-free bin calculation 4982 * Default trim and mmap thresholds now 256K. 4983 4984 V2.7.0 Sun Mar 11 14:14:06 2001 Doug Lea (dl at gee) 4985 * Introduce independent_comalloc and independent_calloc. 4986 Thanks to Michael Pachos for motivation and help. 4987 * Make optional .h file available 4988 * Allow > 2GB requests on 32bit systems. 4989 * new WIN32 sbrk, mmap, munmap, lock code from <Walter (at) GeNeSys-e.de>. 4990 Thanks also to Andreas Mueller <a.mueller at paradatec.de>, 4991 and Anonymous. 4992 * Allow override of MALLOC_ALIGNMENT (Thanks to Ruud Waij for 4993 helping test this.) 4994 * memalign: check alignment arg 4995 * realloc: don't try to shift chunks backwards, since this 4996 leads to more fragmentation in some programs and doesn't 4997 seem to help in any others. 4998 * Collect all cases in malloc requiring system memory into sysmalloc 4999 * Use mmap as backup to sbrk 5000 * Place all internal state in malloc_state 5001 * Introduce fastbins (although similar to 2.5.1) 5002 * Many minor tunings and cosmetic improvements 5003 * Introduce USE_PUBLIC_MALLOC_WRAPPERS, USE_MALLOC_LOCK 5004 * Introduce MALLOC_FAILURE_ACTION, MORECORE_CONTIGUOUS 5005 Thanks to Tony E. Bennett <tbennett (at) nvidia.com> and others. 5006 * Include errno.h to support default failure action. 5007 5008 V2.6.6 Sun Dec 5 07:42:19 1999 Doug Lea (dl at gee) 5009 * return null for negative arguments 5010 * Added Several WIN32 cleanups from Martin C. Fong <mcfong at yahoo.com> 5011 * Add 'LACKS_SYS_PARAM_H' for those systems without 'sys/param.h' 5012 (e.g. WIN32 platforms) 5013 * Cleanup header file inclusion for WIN32 platforms 5014 * Cleanup code to avoid Microsoft Visual C++ compiler complaints 5015 * Add 'USE_DL_PREFIX' to quickly allow co-existence with existing 5016 memory allocation routines 5017 * Set 'malloc_getpagesize' for WIN32 platforms (needs more work) 5018 * Use 'assert' rather than 'ASSERT' in WIN32 code to conform to 5019 usage of 'assert' in non-WIN32 code 5020 * Improve WIN32 'sbrk()' emulation's 'findRegion()' routine to 5021 avoid infinite loop 5022 * Always call 'fREe()' rather than 'free()' 5023 5024 V2.6.5 Wed Jun 17 15:57:31 1998 Doug Lea (dl at gee) 5025 * Fixed ordering problem with boundary-stamping 5026 5027 V2.6.3 Sun May 19 08:17:58 1996 Doug Lea (dl at gee) 5028 * Added pvalloc, as recommended by H.J. Liu 5029 * Added 64bit pointer support mainly from Wolfram Gloger 5030 * Added anonymously donated WIN32 sbrk emulation 5031 * Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen 5032 * malloc_extend_top: fix mask error that caused wastage after 5033 foreign sbrks 5034 * Add linux mremap support code from HJ Liu 5035 5036 V2.6.2 Tue Dec 5 06:52:55 1995 Doug Lea (dl at gee) 5037 * Integrated most documentation with the code. 5038 * Add support for mmap, with help from 5039 Wolfram Gloger (Gloger (at) lrz.uni-muenchen.de). 5040 * Use last_remainder in more cases. 5041 * Pack bins using idea from colin (at) nyx10.cs.du.edu 5042 * Use ordered bins instead of best-fit threshhold 5043 * Eliminate block-local decls to simplify tracing and debugging. 5044 * Support another case of realloc via move into top 5045 * Fix error occuring when initial sbrk_base not word-aligned. 5046 * Rely on page size for units instead of SBRK_UNIT to 5047 avoid surprises about sbrk alignment conventions. 5048 * Add mallinfo, mallopt. Thanks to Raymond Nijssen 5049 (raymond (at) es.ele.tue.nl) for the suggestion. 5050 * Add `pad' argument to malloc_trim and top_pad mallopt parameter. 5051 * More precautions for cases where other routines call sbrk, 5052 courtesy of Wolfram Gloger (Gloger (at) lrz.uni-muenchen.de). 5053 * Added macros etc., allowing use in linux libc from 5054 H.J. Lu (hjl (at) gnu.ai.mit.edu) 5055 * Inverted this history list 5056 5057 V2.6.1 Sat Dec 2 14:10:57 1995 Doug Lea (dl at gee) 5058 * Re-tuned and fixed to behave more nicely with V2.6.0 changes. 5059 * Removed all preallocation code since under current scheme 5060 the work required to undo bad preallocations exceeds 5061 the work saved in good cases for most test programs. 5062 * No longer use return list or unconsolidated bins since 5063 no scheme using them consistently outperforms those that don't 5064 given above changes. 5065 * Use best fit for very large chunks to prevent some worst-cases. 5066 * Added some support for debugging 5067 5068 V2.6.0 Sat Nov 4 07:05:23 1995 Doug Lea (dl at gee) 5069 * Removed footers when chunks are in use. Thanks to 5070 Paul Wilson (wilson (at) cs.texas.edu) for the suggestion. 5071 5072 V2.5.4 Wed Nov 1 07:54:51 1995 Doug Lea (dl at gee) 5073 * Added malloc_trim, with help from Wolfram Gloger 5074 (wmglo (at) Dent.MED.Uni-Muenchen.DE). 5075 5076 V2.5.3 Tue Apr 26 10:16:01 1994 Doug Lea (dl at g) 5077 5078 V2.5.2 Tue Apr 5 16:20:40 1994 Doug Lea (dl at g) 5079 * realloc: try to expand in both directions 5080 * malloc: swap order of clean-bin strategy; 5081 * realloc: only conditionally expand backwards 5082 * Try not to scavenge used bins 5083 * Use bin counts as a guide to preallocation 5084 * Occasionally bin return list chunks in first scan 5085 * Add a few optimizations from colin (at) nyx10.cs.du.edu 5086 5087 V2.5.1 Sat Aug 14 15:40:43 1993 Doug Lea (dl at g) 5088 * faster bin computation & slightly different binning 5089 * merged all consolidations to one part of malloc proper 5090 (eliminating old malloc_find_space & malloc_clean_bin) 5091 * Scan 2 returns chunks (not just 1) 5092 * Propagate failure in realloc if malloc returns 0 5093 * Add stuff to allow compilation on non-ANSI compilers 5094 from kpv (at) research.att.com 5095 5096 V2.5 Sat Aug 7 07:41:59 1993 Doug Lea (dl at g.oswego.edu) 5097 * removed potential for odd address access in prev_chunk 5098 * removed dependency on getpagesize.h 5099 * misc cosmetics and a bit more internal documentation 5100 * anticosmetics: mangled names in macros to evade debugger strangeness 5101 * tested on sparc, hp-700, dec-mips, rs6000 5102 with gcc & native cc (hp, dec only) allowing 5103 Detlefs & Zorn comparison study (in SIGPLAN Notices.) 5104 5105 Trial version Fri Aug 28 13:14:29 1992 Doug Lea (dl at g.oswego.edu) 5106 * Based loosely on libg++-1.2X malloc. (It retains some of the overall 5107 structure of old version, but most details differ.) 5108 5109 */ 5110 5111 #endif /* !HAVE_MALLOC */ 5112
