1 /******************************************************************************/ 2 #ifdef JEMALLOC_H_TYPES 3 4 typedef struct tcache_bin_info_s tcache_bin_info_t; 5 typedef struct tcache_bin_s tcache_bin_t; 6 typedef struct tcache_s tcache_t; 7 typedef struct tcaches_s tcaches_t; 8 9 /* 10 * tcache pointers close to NULL are used to encode state information that is 11 * used for two purposes: preventing thread caching on a per thread basis and 12 * cleaning up during thread shutdown. 13 */ 14 #define TCACHE_STATE_DISABLED ((tcache_t *)(uintptr_t)1) 15 #define TCACHE_STATE_REINCARNATED ((tcache_t *)(uintptr_t)2) 16 #define TCACHE_STATE_PURGATORY ((tcache_t *)(uintptr_t)3) 17 #define TCACHE_STATE_MAX TCACHE_STATE_PURGATORY 18 19 /* 20 * Absolute minimum number of cache slots for each small bin. 21 */ 22 #define TCACHE_NSLOTS_SMALL_MIN 20 23 24 /* 25 * Absolute maximum number of cache slots for each small bin in the thread 26 * cache. This is an additional constraint beyond that imposed as: twice the 27 * number of regions per run for this size class. 28 * 29 * This constant must be an even number. 30 */ 31 #if defined(ANDROID_TCACHE_NSLOTS_SMALL_MAX) 32 #define TCACHE_NSLOTS_SMALL_MAX ANDROID_TCACHE_NSLOTS_SMALL_MAX 33 #else 34 #define TCACHE_NSLOTS_SMALL_MAX 200 35 #endif 36 37 /* Number of cache slots for large size classes. */ 38 #if defined(ANDROID_TCACHE_NSLOTS_LARGE) 39 #define TCACHE_NSLOTS_LARGE ANDROID_TCACHE_NSLOTS_LARGE 40 #else 41 #define TCACHE_NSLOTS_LARGE 20 42 #endif 43 44 /* (1U << opt_lg_tcache_max) is used to compute tcache_maxclass. */ 45 #if defined(ANDROID_LG_TCACHE_MAXCLASS_DEFAULT) 46 #define LG_TCACHE_MAXCLASS_DEFAULT ANDROID_LG_TCACHE_MAXCLASS_DEFAULT 47 #else 48 #define LG_TCACHE_MAXCLASS_DEFAULT 15 49 #endif 50 51 /* 52 * TCACHE_GC_SWEEP is the approximate number of allocation events between 53 * full GC sweeps. Integer rounding may cause the actual number to be 54 * slightly higher, since GC is performed incrementally. 55 */ 56 #define TCACHE_GC_SWEEP 8192 57 58 /* Number of tcache allocation/deallocation events between incremental GCs. */ 59 #define TCACHE_GC_INCR \ 60 ((TCACHE_GC_SWEEP / NBINS) + ((TCACHE_GC_SWEEP / NBINS == 0) ? 0 : 1)) 61 62 #endif /* JEMALLOC_H_TYPES */ 63 /******************************************************************************/ 64 #ifdef JEMALLOC_H_STRUCTS 65 66 typedef enum { 67 tcache_enabled_false = 0, /* Enable cast to/from bool. */ 68 tcache_enabled_true = 1, 69 tcache_enabled_default = 2 70 } tcache_enabled_t; 71 72 /* 73 * Read-only information associated with each element of tcache_t's tbins array 74 * is stored separately, mainly to reduce memory usage. 75 */ 76 struct tcache_bin_info_s { 77 unsigned ncached_max; /* Upper limit on ncached. */ 78 }; 79 80 struct tcache_bin_s { 81 tcache_bin_stats_t tstats; 82 int low_water; /* Min # cached since last GC. */ 83 unsigned lg_fill_div; /* Fill (ncached_max >> lg_fill_div). */ 84 unsigned ncached; /* # of cached objects. */ 85 /* 86 * To make use of adjacent cacheline prefetch, the items in the avail 87 * stack goes to higher address for newer allocations. avail points 88 * just above the available space, which means that 89 * avail[-ncached, ... -1] are available items and the lowest item will 90 * be allocated first. 91 */ 92 void **avail; /* Stack of available objects. */ 93 }; 94 95 struct tcache_s { 96 ql_elm(tcache_t) link; /* Used for aggregating stats. */ 97 uint64_t prof_accumbytes;/* Cleared after arena_prof_accum(). */ 98 ticker_t gc_ticker; /* Drives incremental GC. */ 99 szind_t next_gc_bin; /* Next bin to GC. */ 100 tcache_bin_t tbins[1]; /* Dynamically sized. */ 101 /* 102 * The pointer stacks associated with tbins follow as a contiguous 103 * array. During tcache initialization, the avail pointer in each 104 * element of tbins is initialized to point to the proper offset within 105 * this array. 106 */ 107 }; 108 109 /* Linkage for list of available (previously used) explicit tcache IDs. */ 110 struct tcaches_s { 111 union { 112 tcache_t *tcache; 113 tcaches_t *next; 114 }; 115 }; 116 117 #endif /* JEMALLOC_H_STRUCTS */ 118 /******************************************************************************/ 119 #ifdef JEMALLOC_H_EXTERNS 120 121 extern bool opt_tcache; 122 extern ssize_t opt_lg_tcache_max; 123 124 extern tcache_bin_info_t *tcache_bin_info; 125 126 /* 127 * Number of tcache bins. There are NBINS small-object bins, plus 0 or more 128 * large-object bins. 129 */ 130 extern unsigned nhbins; 131 132 /* Maximum cached size class. */ 133 extern size_t tcache_maxclass; 134 135 /* 136 * Explicit tcaches, managed via the tcache.{create,flush,destroy} mallctls and 137 * usable via the MALLOCX_TCACHE() flag. The automatic per thread tcaches are 138 * completely disjoint from this data structure. tcaches starts off as a sparse 139 * array, so it has no physical memory footprint until individual pages are 140 * touched. This allows the entire array to be allocated the first time an 141 * explicit tcache is created without a disproportionate impact on memory usage. 142 */ 143 extern tcaches_t *tcaches; 144 145 size_t tcache_salloc(const void *ptr); 146 void tcache_event_hard(tsd_t *tsd, tcache_t *tcache); 147 void *tcache_alloc_small_hard(tsd_t *tsd, arena_t *arena, tcache_t *tcache, 148 tcache_bin_t *tbin, szind_t binind, bool *tcache_success); 149 void tcache_bin_flush_small(tsd_t *tsd, tcache_t *tcache, tcache_bin_t *tbin, 150 szind_t binind, unsigned rem); 151 void tcache_bin_flush_large(tsd_t *tsd, tcache_bin_t *tbin, szind_t binind, 152 unsigned rem, tcache_t *tcache); 153 void tcache_arena_associate(tcache_t *tcache, arena_t *arena); 154 void tcache_arena_reassociate(tcache_t *tcache, arena_t *oldarena, 155 arena_t *newarena); 156 void tcache_arena_dissociate(tcache_t *tcache, arena_t *arena); 157 tcache_t *tcache_get_hard(tsd_t *tsd); 158 tcache_t *tcache_create(tsd_t *tsd, arena_t *arena); 159 void tcache_cleanup(tsd_t *tsd); 160 void tcache_enabled_cleanup(tsd_t *tsd); 161 void tcache_stats_merge(tcache_t *tcache, arena_t *arena); 162 bool tcaches_create(tsd_t *tsd, unsigned *r_ind); 163 void tcaches_flush(tsd_t *tsd, unsigned ind); 164 void tcaches_destroy(tsd_t *tsd, unsigned ind); 165 bool tcache_boot(void); 166 167 #endif /* JEMALLOC_H_EXTERNS */ 168 /******************************************************************************/ 169 #ifdef JEMALLOC_H_INLINES 170 171 #ifndef JEMALLOC_ENABLE_INLINE 172 void tcache_event(tsd_t *tsd, tcache_t *tcache); 173 void tcache_flush(void); 174 bool tcache_enabled_get(void); 175 tcache_t *tcache_get(tsd_t *tsd, bool create); 176 void tcache_enabled_set(bool enabled); 177 void *tcache_alloc_easy(tcache_bin_t *tbin, bool *tcache_success); 178 void *tcache_alloc_small(tsd_t *tsd, arena_t *arena, tcache_t *tcache, 179 size_t size, szind_t ind, bool zero, bool slow_path); 180 void *tcache_alloc_large(tsd_t *tsd, arena_t *arena, tcache_t *tcache, 181 size_t size, szind_t ind, bool zero, bool slow_path); 182 void tcache_dalloc_small(tsd_t *tsd, tcache_t *tcache, void *ptr, 183 szind_t binind, bool slow_path); 184 void tcache_dalloc_large(tsd_t *tsd, tcache_t *tcache, void *ptr, 185 size_t size, bool slow_path); 186 tcache_t *tcaches_get(tsd_t *tsd, unsigned ind); 187 #endif 188 189 #if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_TCACHE_C_)) 190 JEMALLOC_INLINE void 191 tcache_flush(void) 192 { 193 tsd_t *tsd; 194 195 cassert(config_tcache); 196 197 tsd = tsd_fetch(); 198 tcache_cleanup(tsd); 199 } 200 201 JEMALLOC_INLINE bool 202 tcache_enabled_get(void) 203 { 204 tsd_t *tsd; 205 tcache_enabled_t tcache_enabled; 206 207 cassert(config_tcache); 208 209 tsd = tsd_fetch(); 210 tcache_enabled = tsd_tcache_enabled_get(tsd); 211 if (tcache_enabled == tcache_enabled_default) { 212 tcache_enabled = (tcache_enabled_t)opt_tcache; 213 tsd_tcache_enabled_set(tsd, tcache_enabled); 214 } 215 216 return ((bool)tcache_enabled); 217 } 218 219 JEMALLOC_INLINE void 220 tcache_enabled_set(bool enabled) 221 { 222 tsd_t *tsd; 223 tcache_enabled_t tcache_enabled; 224 225 cassert(config_tcache); 226 227 tsd = tsd_fetch(); 228 229 tcache_enabled = (tcache_enabled_t)enabled; 230 tsd_tcache_enabled_set(tsd, tcache_enabled); 231 232 if (!enabled) 233 tcache_cleanup(tsd); 234 } 235 236 JEMALLOC_ALWAYS_INLINE tcache_t * 237 tcache_get(tsd_t *tsd, bool create) 238 { 239 tcache_t *tcache; 240 241 if (!config_tcache) 242 return (NULL); 243 244 tcache = tsd_tcache_get(tsd); 245 if (!create) 246 return (tcache); 247 if (unlikely(tcache == NULL) && tsd_nominal(tsd)) { 248 tcache = tcache_get_hard(tsd); 249 tsd_tcache_set(tsd, tcache); 250 } 251 252 return (tcache); 253 } 254 255 JEMALLOC_ALWAYS_INLINE void 256 tcache_event(tsd_t *tsd, tcache_t *tcache) 257 { 258 259 if (TCACHE_GC_INCR == 0) 260 return; 261 262 if (unlikely(ticker_tick(&tcache->gc_ticker))) 263 tcache_event_hard(tsd, tcache); 264 } 265 266 JEMALLOC_ALWAYS_INLINE void * 267 tcache_alloc_easy(tcache_bin_t *tbin, bool *tcache_success) 268 { 269 void *ret; 270 271 if (unlikely(tbin->ncached == 0)) { 272 tbin->low_water = -1; 273 *tcache_success = false; 274 return (NULL); 275 } 276 /* 277 * tcache_success (instead of ret) should be checked upon the return of 278 * this function. We avoid checking (ret == NULL) because there is 279 * never a null stored on the avail stack (which is unknown to the 280 * compiler), and eagerly checking ret would cause pipeline stall 281 * (waiting for the cacheline). 282 */ 283 *tcache_success = true; 284 ret = *(tbin->avail - tbin->ncached); 285 tbin->ncached--; 286 287 if (unlikely((int)tbin->ncached < tbin->low_water)) 288 tbin->low_water = tbin->ncached; 289 290 return (ret); 291 } 292 293 JEMALLOC_ALWAYS_INLINE void * 294 tcache_alloc_small(tsd_t *tsd, arena_t *arena, tcache_t *tcache, size_t size, 295 szind_t binind, bool zero, bool slow_path) 296 { 297 void *ret; 298 tcache_bin_t *tbin; 299 bool tcache_success; 300 size_t usize JEMALLOC_CC_SILENCE_INIT(0); 301 302 assert(binind < NBINS); 303 tbin = &tcache->tbins[binind]; 304 ret = tcache_alloc_easy(tbin, &tcache_success); 305 assert(tcache_success == (ret != NULL)); 306 if (unlikely(!tcache_success)) { 307 bool tcache_hard_success; 308 arena = arena_choose(tsd, arena); 309 if (unlikely(arena == NULL)) 310 return (NULL); 311 312 ret = tcache_alloc_small_hard(tsd, arena, tcache, tbin, binind, 313 &tcache_hard_success); 314 if (tcache_hard_success == false) 315 return (NULL); 316 } 317 318 assert(ret); 319 /* 320 * Only compute usize if required. The checks in the following if 321 * statement are all static. 322 */ 323 if (config_prof || (slow_path && config_fill) || unlikely(zero)) { 324 usize = index2size(binind); 325 assert(tcache_salloc(ret) == usize); 326 } 327 328 if (likely(!zero)) { 329 if (slow_path && config_fill) { 330 if (unlikely(opt_junk_alloc)) { 331 arena_alloc_junk_small(ret, 332 &arena_bin_info[binind], false); 333 } else if (unlikely(opt_zero)) 334 memset(ret, 0, usize); 335 } 336 } else { 337 if (slow_path && config_fill && unlikely(opt_junk_alloc)) { 338 arena_alloc_junk_small(ret, &arena_bin_info[binind], 339 true); 340 } 341 memset(ret, 0, usize); 342 } 343 344 if (config_stats) 345 tbin->tstats.nrequests++; 346 if (config_prof) 347 tcache->prof_accumbytes += usize; 348 tcache_event(tsd, tcache); 349 return (ret); 350 } 351 352 JEMALLOC_ALWAYS_INLINE void * 353 tcache_alloc_large(tsd_t *tsd, arena_t *arena, tcache_t *tcache, size_t size, 354 szind_t binind, bool zero, bool slow_path) 355 { 356 void *ret; 357 tcache_bin_t *tbin; 358 bool tcache_success; 359 360 assert(binind < nhbins); 361 tbin = &tcache->tbins[binind]; 362 ret = tcache_alloc_easy(tbin, &tcache_success); 363 assert(tcache_success == (ret != NULL)); 364 if (unlikely(!tcache_success)) { 365 /* 366 * Only allocate one large object at a time, because it's quite 367 * expensive to create one and not use it. 368 */ 369 arena = arena_choose(tsd, arena); 370 if (unlikely(arena == NULL)) 371 return (NULL); 372 373 ret = arena_malloc_large(tsd, arena, binind, zero); 374 if (ret == NULL) 375 return (NULL); 376 } else { 377 size_t usize JEMALLOC_CC_SILENCE_INIT(0); 378 379 /* Only compute usize on demand */ 380 if (config_prof || (slow_path && config_fill) || 381 unlikely(zero)) { 382 usize = index2size(binind); 383 assert(usize <= tcache_maxclass); 384 } 385 386 if (config_prof && usize == LARGE_MINCLASS) { 387 arena_chunk_t *chunk = 388 (arena_chunk_t *)CHUNK_ADDR2BASE(ret); 389 size_t pageind = (((uintptr_t)ret - (uintptr_t)chunk) >> 390 LG_PAGE); 391 arena_mapbits_large_binind_set(chunk, pageind, 392 BININD_INVALID); 393 } 394 if (likely(!zero)) { 395 if (slow_path && config_fill) { 396 if (unlikely(opt_junk_alloc)) 397 memset(ret, 0xa5, usize); 398 else if (unlikely(opt_zero)) 399 memset(ret, 0, usize); 400 } 401 } else 402 memset(ret, 0, usize); 403 404 if (config_stats) 405 tbin->tstats.nrequests++; 406 if (config_prof) 407 tcache->prof_accumbytes += usize; 408 } 409 410 tcache_event(tsd, tcache); 411 return (ret); 412 } 413 414 JEMALLOC_ALWAYS_INLINE void 415 tcache_dalloc_small(tsd_t *tsd, tcache_t *tcache, void *ptr, szind_t binind, 416 bool slow_path) 417 { 418 tcache_bin_t *tbin; 419 tcache_bin_info_t *tbin_info; 420 421 assert(tcache_salloc(ptr) <= SMALL_MAXCLASS); 422 423 if (slow_path && config_fill && unlikely(opt_junk_free)) 424 arena_dalloc_junk_small(ptr, &arena_bin_info[binind]); 425 426 tbin = &tcache->tbins[binind]; 427 tbin_info = &tcache_bin_info[binind]; 428 if (unlikely(tbin->ncached == tbin_info->ncached_max)) { 429 tcache_bin_flush_small(tsd, tcache, tbin, binind, 430 (tbin_info->ncached_max >> 1)); 431 } 432 assert(tbin->ncached < tbin_info->ncached_max); 433 tbin->ncached++; 434 *(tbin->avail - tbin->ncached) = ptr; 435 436 tcache_event(tsd, tcache); 437 } 438 439 JEMALLOC_ALWAYS_INLINE void 440 tcache_dalloc_large(tsd_t *tsd, tcache_t *tcache, void *ptr, size_t size, 441 bool slow_path) 442 { 443 szind_t binind; 444 tcache_bin_t *tbin; 445 tcache_bin_info_t *tbin_info; 446 447 assert((size & PAGE_MASK) == 0); 448 assert(tcache_salloc(ptr) > SMALL_MAXCLASS); 449 assert(tcache_salloc(ptr) <= tcache_maxclass); 450 451 binind = size2index(size); 452 453 if (slow_path && config_fill && unlikely(opt_junk_free)) 454 arena_dalloc_junk_large(ptr, size); 455 456 tbin = &tcache->tbins[binind]; 457 tbin_info = &tcache_bin_info[binind]; 458 if (unlikely(tbin->ncached == tbin_info->ncached_max)) { 459 tcache_bin_flush_large(tsd, tbin, binind, 460 (tbin_info->ncached_max >> 1), tcache); 461 } 462 assert(tbin->ncached < tbin_info->ncached_max); 463 tbin->ncached++; 464 *(tbin->avail - tbin->ncached) = ptr; 465 466 tcache_event(tsd, tcache); 467 } 468 469 JEMALLOC_ALWAYS_INLINE tcache_t * 470 tcaches_get(tsd_t *tsd, unsigned ind) 471 { 472 tcaches_t *elm = &tcaches[ind]; 473 if (unlikely(elm->tcache == NULL)) 474 elm->tcache = tcache_create(tsd, arena_choose(tsd, NULL)); 475 return (elm->tcache); 476 } 477 #endif 478 479 #endif /* JEMALLOC_H_INLINES */ 480 /******************************************************************************/ 481
