1 /*--------------------------------------------------------------------*/ 2 /*--- Callgrind ---*/ 3 /*--- ct_threads.c ---*/ 4 /*--------------------------------------------------------------------*/ 5 6 /* 7 This file is part of Callgrind, a Valgrind tool for call tracing. 8 9 Copyright (C) 2002-2012, Josef Weidendorfer (Josef.Weidendorfer (at) gmx.de) 10 11 This program is free software; you can redistribute it and/or 12 modify it under the terms of the GNU General Public License as 13 published by the Free Software Foundation; either version 2 of the 14 License, or (at your option) any later version. 15 16 This program is distributed in the hope that it will be useful, but 17 WITHOUT ANY WARRANTY; without even the implied warranty of 18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 19 General Public License for more details. 20 21 You should have received a copy of the GNU General Public License 22 along with this program; if not, write to the Free Software 23 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 24 02111-1307, USA. 25 26 The GNU General Public License is contained in the file COPYING. 27 */ 28 29 #include "global.h" 30 31 #include "pub_tool_threadstate.h" 32 33 /* forward decls */ 34 static exec_state* exec_state_save(void); 35 static exec_state* exec_state_restore(void); 36 static exec_state* push_exec_state(int); 37 static exec_state* top_exec_state(void); 38 39 static exec_stack current_states; 40 41 42 /*------------------------------------------------------------*/ 43 /*--- Support for multi-threading ---*/ 44 /*------------------------------------------------------------*/ 45 46 47 /* 48 * For Valgrind, MT is cooperative (no preemting in our code), 49 * so we don't need locks... 50 * 51 * Per-thread data: 52 * - BBCCs 53 * - call stack 54 * - call hash 55 * - event counters: last, current 56 * 57 * Even when ignoring MT, we need this functions to set up some 58 * datastructures for the process (= Thread 1). 59 */ 60 61 /* current running thread */ 62 ThreadId CLG_(current_tid); 63 64 static thread_info* thread[VG_N_THREADS]; 65 66 thread_info** CLG_(get_threads)() 67 { 68 return thread; 69 } 70 71 thread_info* CLG_(get_current_thread)() 72 { 73 return thread[CLG_(current_tid)]; 74 } 75 76 void CLG_(init_threads)() 77 { 78 Int i; 79 for(i=0;i<VG_N_THREADS;i++) 80 thread[i] = 0; 81 CLG_(current_tid) = VG_INVALID_THREADID; 82 } 83 84 /* switches through all threads and calls func */ 85 void CLG_(forall_threads)(void (*func)(thread_info*)) 86 { 87 Int t, orig_tid = CLG_(current_tid); 88 89 for(t=1;t<VG_N_THREADS;t++) { 90 if (!thread[t]) continue; 91 CLG_(switch_thread)(t); 92 (*func)(thread[t]); 93 } 94 CLG_(switch_thread)(orig_tid); 95 } 96 97 98 static 99 thread_info* new_thread(void) 100 { 101 thread_info* t; 102 103 t = (thread_info*) CLG_MALLOC("cl.threads.nt.1", 104 sizeof(thread_info)); 105 106 /* init state */ 107 CLG_(init_exec_stack)( &(t->states) ); 108 CLG_(init_call_stack)( &(t->calls) ); 109 CLG_(init_fn_stack) ( &(t->fns) ); 110 /* t->states.entry[0]->cxt = CLG_(get_cxt)(t->fns.bottom); */ 111 112 /* event counters */ 113 t->lastdump_cost = CLG_(get_eventset_cost)( CLG_(sets).full ); 114 t->sighandler_cost = CLG_(get_eventset_cost)( CLG_(sets).full ); 115 CLG_(init_cost)( CLG_(sets).full, t->lastdump_cost ); 116 CLG_(init_cost)( CLG_(sets).full, t->sighandler_cost ); 117 118 /* init data containers */ 119 CLG_(init_fn_array)( &(t->fn_active) ); 120 CLG_(init_bbcc_hash)( &(t->bbccs) ); 121 CLG_(init_jcc_hash)( &(t->jccs) ); 122 123 return t; 124 } 125 126 127 void CLG_(switch_thread)(ThreadId tid) 128 { 129 if (tid == CLG_(current_tid)) return; 130 131 CLG_DEBUG(0, ">> thread %d (was %d)\n", tid, CLG_(current_tid)); 132 133 if (CLG_(current_tid) != VG_INVALID_THREADID) { 134 /* save thread state */ 135 thread_info* t = thread[CLG_(current_tid)]; 136 137 CLG_ASSERT(t != 0); 138 139 /* current context (including signal handler contexts) */ 140 exec_state_save(); 141 CLG_(copy_current_exec_stack)( &(t->states) ); 142 CLG_(copy_current_call_stack)( &(t->calls) ); 143 CLG_(copy_current_fn_stack) ( &(t->fns) ); 144 145 CLG_(copy_current_fn_array) ( &(t->fn_active) ); 146 /* If we cumulate costs of threads, use TID 1 for all jccs/bccs */ 147 if (!CLG_(clo).separate_threads) t = thread[1]; 148 CLG_(copy_current_bbcc_hash)( &(t->bbccs) ); 149 CLG_(copy_current_jcc_hash) ( &(t->jccs) ); 150 } 151 152 CLG_(current_tid) = tid; 153 CLG_ASSERT(tid < VG_N_THREADS); 154 155 if (tid != VG_INVALID_THREADID) { 156 thread_info* t; 157 158 /* load thread state */ 159 160 if (thread[tid] == 0) thread[tid] = new_thread(); 161 t = thread[tid]; 162 163 /* current context (including signal handler contexts) */ 164 CLG_(set_current_exec_stack)( &(t->states) ); 165 exec_state_restore(); 166 CLG_(set_current_call_stack)( &(t->calls) ); 167 CLG_(set_current_fn_stack) ( &(t->fns) ); 168 169 CLG_(set_current_fn_array) ( &(t->fn_active) ); 170 /* If we cumulate costs of threads, use TID 1 for all jccs/bccs */ 171 if (!CLG_(clo).separate_threads) t = thread[1]; 172 CLG_(set_current_bbcc_hash) ( &(t->bbccs) ); 173 CLG_(set_current_jcc_hash) ( &(t->jccs) ); 174 } 175 } 176 177 178 void CLG_(run_thread)(ThreadId tid) 179 { 180 /* check for dumps needed */ 181 static ULong bbs_done = 0; 182 static Char buf[512]; 183 184 if (CLG_(clo).dump_every_bb >0) { 185 if (CLG_(stat).bb_executions - bbs_done > CLG_(clo).dump_every_bb) { 186 VG_(sprintf)(buf, "--dump-every-bb=%llu", CLG_(clo).dump_every_bb); 187 CLG_(dump_profile)(buf, False); 188 bbs_done = CLG_(stat).bb_executions; 189 } 190 } 191 192 /* now check for thread switch */ 193 CLG_(switch_thread)(tid); 194 } 195 196 void CLG_(pre_signal)(ThreadId tid, Int sigNum, Bool alt_stack) 197 { 198 exec_state *es; 199 200 CLG_DEBUG(0, ">> pre_signal(TID %d, sig %d, alt_st %s)\n", 201 tid, sigNum, alt_stack ? "yes":"no"); 202 203 /* switch to the thread the handler runs in */ 204 CLG_(switch_thread)(tid); 205 206 /* save current execution state */ 207 exec_state_save(); 208 209 /* setup new cxtinfo struct for this signal handler */ 210 es = push_exec_state(sigNum); 211 CLG_(zero_cost)( CLG_(sets).full, es->cost ); 212 CLG_(current_state).cost = es->cost; 213 es->call_stack_bottom = CLG_(current_call_stack).sp; 214 215 /* setup current state for a spontaneous call */ 216 CLG_(init_exec_state)( &CLG_(current_state) ); 217 CLG_(current_state).sig = sigNum; 218 CLG_(push_cxt)(0); 219 } 220 221 /* Run post-signal if the stackpointer for call stack is at 222 * the bottom in current exec state (e.g. a signal handler) 223 * 224 * Called from CLG_(pop_call_stack) 225 */ 226 void CLG_(run_post_signal_on_call_stack_bottom)() 227 { 228 exec_state* es = top_exec_state(); 229 CLG_ASSERT(es != 0); 230 CLG_ASSERT(CLG_(current_state).sig >0); 231 232 if (CLG_(current_call_stack).sp == es->call_stack_bottom) 233 CLG_(post_signal)( CLG_(current_tid), CLG_(current_state).sig ); 234 } 235 236 void CLG_(post_signal)(ThreadId tid, Int sigNum) 237 { 238 exec_state* es; 239 UInt fn_number, *pactive; 240 241 CLG_DEBUG(0, ">> post_signal(TID %d, sig %d)\n", 242 tid, sigNum); 243 244 /* thread switching potentially needed, eg. with instrumentation off */ 245 CLG_(switch_thread)(tid); 246 CLG_ASSERT(sigNum == CLG_(current_state).sig); 247 248 /* Unwind call stack of this signal handler. 249 * This should only be needed at finalisation time 250 */ 251 es = top_exec_state(); 252 CLG_ASSERT(es != 0); 253 while(CLG_(current_call_stack).sp > es->call_stack_bottom) 254 CLG_(pop_call_stack)(); 255 256 if (CLG_(current_state).cxt) { 257 /* correct active counts */ 258 fn_number = CLG_(current_state).cxt->fn[0]->number; 259 pactive = CLG_(get_fn_entry)(fn_number); 260 (*pactive)--; 261 CLG_DEBUG(0, " set active count of %s back to %d\n", 262 CLG_(current_state).cxt->fn[0]->name, *pactive); 263 } 264 265 if (CLG_(current_fn_stack).top > CLG_(current_fn_stack).bottom) { 266 /* set fn_stack_top back. 267 * top can point to 0 if nothing was executed in the signal handler; 268 * this is possible at end on unwinding handlers. 269 */ 270 if (*(CLG_(current_fn_stack).top) != 0) { 271 CLG_(current_fn_stack).top--; 272 CLG_ASSERT(*(CLG_(current_fn_stack).top) == 0); 273 } 274 if (CLG_(current_fn_stack).top > CLG_(current_fn_stack).bottom) 275 CLG_(current_fn_stack).top--; 276 } 277 278 /* sum up costs */ 279 CLG_ASSERT(CLG_(current_state).cost == es->cost); 280 CLG_(add_and_zero_cost)( CLG_(sets).full, 281 thread[CLG_(current_tid)]->sighandler_cost, 282 CLG_(current_state).cost ); 283 284 /* restore previous context */ 285 es->sig = -1; 286 current_states.sp--; 287 es = top_exec_state(); 288 CLG_(current_state).sig = es->sig; 289 exec_state_restore(); 290 291 /* There is no way to reliable get the thread ID we are switching to 292 * after this handler returns. So we sync with actual TID at start of 293 * CLG_(setup_bb)(), which should be the next for callgrind. 294 */ 295 } 296 297 298 299 /*------------------------------------------------------------*/ 300 /*--- Execution states in a thread & signal handlers ---*/ 301 /*------------------------------------------------------------*/ 302 303 /* Each thread can be interrupted by a signal handler, and they 304 * themselves again. But as there's no scheduling among handlers 305 * of the same thread, we don't need additional stacks. 306 * So storing execution contexts and 307 * adding separators in the callstack(needed to not intermix normal/handler 308 * functions in contexts) should be enough. 309 */ 310 311 /* not initialized: call_stack_bottom, sig */ 312 void CLG_(init_exec_state)(exec_state* es) 313 { 314 es->collect = CLG_(clo).collect_atstart; 315 es->cxt = 0; 316 es->jmps_passed = 0; 317 es->bbcc = 0; 318 es->nonskipped = 0; 319 } 320 321 322 static exec_state* new_exec_state(Int sigNum) 323 { 324 exec_state* es; 325 es = (exec_state*) CLG_MALLOC("cl.threads.nes.1", 326 sizeof(exec_state)); 327 328 /* allocate real cost space: needed as incremented by 329 * simulation functions */ 330 es->cost = CLG_(get_eventset_cost)(CLG_(sets).full); 331 CLG_(zero_cost)( CLG_(sets).full, es->cost ); 332 CLG_(init_exec_state)(es); 333 es->sig = sigNum; 334 es->call_stack_bottom = 0; 335 336 return es; 337 } 338 339 void CLG_(init_exec_stack)(exec_stack* es) 340 { 341 Int i; 342 343 /* The first element is for the main thread */ 344 es->entry[0] = new_exec_state(0); 345 for(i=1;i<MAX_SIGHANDLERS;i++) 346 es->entry[i] = 0; 347 es->sp = 0; 348 } 349 350 void CLG_(copy_current_exec_stack)(exec_stack* dst) 351 { 352 Int i; 353 354 dst->sp = current_states.sp; 355 for(i=0;i<MAX_SIGHANDLERS;i++) 356 dst->entry[i] = current_states.entry[i]; 357 } 358 359 void CLG_(set_current_exec_stack)(exec_stack* dst) 360 { 361 Int i; 362 363 current_states.sp = dst->sp; 364 for(i=0;i<MAX_SIGHANDLERS;i++) 365 current_states.entry[i] = dst->entry[i]; 366 } 367 368 369 /* Get top context info struct of current thread */ 370 static 371 exec_state* top_exec_state(void) 372 { 373 Int sp = current_states.sp; 374 exec_state* es; 375 376 CLG_ASSERT((sp >= 0) && (sp < MAX_SIGHANDLERS)); 377 es = current_states.entry[sp]; 378 CLG_ASSERT(es != 0); 379 return es; 380 } 381 382 /* Allocates a free context info structure for a new entered 383 * signal handler, putting it on the context stack. 384 * Returns a pointer to the structure. 385 */ 386 static exec_state* push_exec_state(int sigNum) 387 { 388 Int sp; 389 exec_state* es; 390 391 current_states.sp++; 392 sp = current_states.sp; 393 394 CLG_ASSERT((sigNum > 0) && (sigNum <= _VKI_NSIG)); 395 CLG_ASSERT((sp > 0) && (sp < MAX_SIGHANDLERS)); 396 es = current_states.entry[sp]; 397 if (!es) { 398 es = new_exec_state(sigNum); 399 current_states.entry[sp] = es; 400 } 401 else 402 es->sig = sigNum; 403 404 return es; 405 } 406 407 /* Save current context to top cxtinfo struct */ 408 static 409 exec_state* exec_state_save(void) 410 { 411 exec_state* es = top_exec_state(); 412 413 es->cxt = CLG_(current_state).cxt; 414 es->collect = CLG_(current_state).collect; 415 es->jmps_passed = CLG_(current_state).jmps_passed; 416 es->bbcc = CLG_(current_state).bbcc; 417 es->nonskipped = CLG_(current_state).nonskipped; 418 CLG_ASSERT(es->cost == CLG_(current_state).cost); 419 420 CLG_DEBUGIF(1) { 421 CLG_DEBUG(1, " cxtinfo_save(sig %d): collect %s, jmps_passed %d\n", 422 es->sig, es->collect ? "Yes": "No", es->jmps_passed); 423 CLG_(print_bbcc)(-9, es->bbcc); 424 CLG_(print_cost)(-9, CLG_(sets).full, es->cost); 425 } 426 427 /* signal number does not need to be saved */ 428 CLG_ASSERT(CLG_(current_state).sig == es->sig); 429 430 return es; 431 } 432 433 static 434 exec_state* exec_state_restore(void) 435 { 436 exec_state* es = top_exec_state(); 437 438 CLG_(current_state).cxt = es->cxt; 439 CLG_(current_state).collect = es->collect; 440 CLG_(current_state).jmps_passed = es->jmps_passed; 441 CLG_(current_state).bbcc = es->bbcc; 442 CLG_(current_state).nonskipped = es->nonskipped; 443 CLG_(current_state).cost = es->cost; 444 CLG_(current_state).sig = es->sig; 445 446 CLG_DEBUGIF(1) { 447 CLG_DEBUG(1, " exec_state_restore(sig %d): collect %s, jmps_passed %d\n", 448 es->sig, es->collect ? "Yes": "No", es->jmps_passed); 449 CLG_(print_bbcc)(-9, es->bbcc); 450 CLG_(print_cxt)(-9, es->cxt, 0); 451 CLG_(print_cost)(-9, CLG_(sets).full, es->cost); 452 } 453 454 return es; 455 } 456 457
