libgc/darwin_stop_world.c

   1 #include "private/pthread_support.h"
   2
   3 # if defined(GC_DARWIN_THREADS)
   4
   5 #include <AvailabilityMacros.h>
   6 #include "mono/utils/mono-compiler.h"
   7
   8 #ifdef MONO_DEBUGGER_SUPPORTED
   9 #include "include/libgc-mono-debugger.h"
  10 #endif
  11
  12 /* From "Inside Mac OS X - Mach-O Runtime Architecture" published by Apple
  13    Page 49:
  14    "The space beneath the stack pointer, where a new stack frame would normally
  15    be allocated, is called the red zone. This area as shown in Figure 3-2 may
  16    be used for any purpose as long as a new stack frame does not need to be
  17    added to the stack."
  18
  19    Page 50: "If a leaf procedure's red zone usage would exceed 224 bytes, then
  20    it must set up a stack frame just like routines that call other routines."
  21 */
  22 #ifdef POWERPC
  23 # if CPP_WORDSZ == 32
  24 #   define PPC_RED_ZONE_SIZE 224
  25 # elif CPP_WORDSZ == 64
  26 #   define PPC_RED_ZONE_SIZE 320
  27 # endif
  28 #endif
  29
  30 typedef struct StackFrame {
  31   unsigned long savedSP;
  32   unsigned long savedCR;
  33   unsigned long savedLR;
  34   unsigned long reserved[2];
  35   unsigned long savedRTOC;
  36 } StackFrame;
  37
  38 unsigned long FindTopOfStack(unsigned int stack_start) {
  39   StackFrame    *frame;
  40
  41   if (stack_start == 0) {
  42 # ifdef POWERPC
  43 #   if CPP_WORDSZ == 32
  44       __asm__ volatile("lwz     %0,0(r1)" : "=r" (frame));
  45 #   else
  46       __asm__ volatile("ldz     %0,0(r1)" : "=r" (frame));
  47 #   endif
  48 # endif
  49   } else {
  50     frame = (StackFrame *)stack_start;
  51   }
  52
  53 # ifdef DEBUG_THREADS
  54     /* GC_printf1("FindTopOfStack start at sp = %p\n", frame); */
  55 # endif
  56   do {
  57     if (frame->savedSP == 0) break;
  58                 /* if there are no more stack frames, stop */
  59
  60     frame = (StackFrame*)frame->savedSP;
  61
  62     /* we do these next two checks after going to the next frame
  63        because the LR for the first stack frame in the loop
  64        is not set up on purpose, so we shouldn't check it. */
  65     if ((frame->savedLR & ~3) == 0) break; /* if the next LR is bogus, stop */
  66     if ((~(frame->savedLR) & ~3) == 0) break; /* ditto */
  67   } while (1);
  68
  69 # ifdef DEBUG_THREADS
  70     /* GC_printf1("FindTopOfStack finish at sp = %p\n", frame); */
  71 # endif
  72
  73   return (unsigned long)frame;
  74 }
  75
  76 #ifdef DARWIN_DONT_PARSE_STACK
  77 void GC_push_all_stacks() {
  78   int i;
  79   kern_return_t r;
  80   GC_thread p;
  81   pthread_t me;
  82   ptr_t lo, hi;
  83 #if defined(POWERPC)
  84   ppc_thread_state_t state;
  85   mach_msg_type_number_t thread_state_count = PPC_THREAD_STATE_COUNT;
  86 #elif defined(I386)
  87   i386_thread_state_t state;
  88   mach_msg_type_number_t thread_state_count = i386_THREAD_STATE_COUNT;
  89 #elif defined(ARM)
  90   arm_thread_state_t state;
  91   mach_msg_type_number_t thread_state_count = ARM_THREAD_STATE_COUNT;
  92 #elif defined(X86_64)
  93   x86_thread_state64_t state;
  94   mach_msg_type_number_t thread_state_count = x86_THREAD_STATE64_COUNT;
  95 #else
  96 # error FIXME for non-x86 || ppc architectures
  97   mach_msg_type_number_t thread_state_count = MACHINE_THREAD_STATE_COUNT;
  98 #endif
  99
 100   me = pthread_self();
 101   if (!GC_thr_initialized) GC_thr_init();
 102
 103   for(i=0;i<THREAD_TABLE_SZ;i++) {
 104     for(p=GC_threads[i];p!=0;p=p->next) {
 105       if(p -> flags & FINISHED) continue;
 106       if(pthread_equal(p->id,me)) {
 107         lo = GC_approx_sp();
 108       } else {
 109         /* Get the thread state (registers, etc) */
 110         r = thread_get_state(
 111                              p->stop_info.mach_thread,
 112                              GC_MACH_THREAD_STATE_FLAVOR,
 113                              (natural_t*)&state,
 114                              &thread_state_count);
 115         if(r != KERN_SUCCESS) continue;
 116
 117 #if defined(I386)
 118 #if MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_5
 119
 120         lo = state.__esp;
 121
 122         GC_push_one(state.__eax);
 123         GC_push_one(state.__ebx);
 124         GC_push_one(state.__ecx);
 125         GC_push_one(state.__edx);
 126         GC_push_one(state.__edi);
 127         GC_push_one(state.__esi);
 128         GC_push_one(state.__ebp);
 129 #else
 130         lo = state.esp;
 131
 132         GC_push_one(state.eax);
 133         GC_push_one(state.ebx);
 134         GC_push_one(state.ecx);
 135         GC_push_one(state.edx);
 136         GC_push_one(state.edi);
 137         GC_push_one(state.esi);
 138         GC_push_one(state.ebp);
 139 #endif
 140 #elif defined(X86_64)
 141           lo = state.__rsp;
 142           GC_push_one(state.__rax);
 143           GC_push_one(state.__rbx);
 144           GC_push_one(state.__rcx);
 145           GC_push_one(state.__rdx);
 146           GC_push_one(state.__rdi);
 147           GC_push_one(state.__rsi);
 148           GC_push_one(state.__rbp);
 149           GC_push_one(state.__r8);
 150           GC_push_one(state.__r9);
 151           GC_push_one(state.__r10);
 152           GC_push_one(state.__r11);
 153           GC_push_one(state.__r12);
 154           GC_push_one(state.__r13);
 155           GC_push_one(state.__r14);
 156           GC_push_one(state.__r15);
 157 #elif defined(POWERPC)
 158 #if defined(_STRUCT_PPC_EXCEPTION_STATE) && defined(__DARWIN_UNIX03)
 159         lo = (void*)(state.__r1 - PPC_RED_ZONE_SIZE);
 160
 161         GC_push_one(state.__r0);
 162         GC_push_one(state.__r2);
 163         GC_push_one(state.__r3);
 164         GC_push_one(state.__r4);
 165         GC_push_one(state.__r5);
 166         GC_push_one(state.__r6);
 167         GC_push_one(state.__r7);
 168         GC_push_one(state.__r8);
 169         GC_push_one(state.__r9);
 170         GC_push_one(state.__r10);
 171         GC_push_one(state.__r11);
 172         GC_push_one(state.__r12);
 173         GC_push_one(state.__r13);
 174         GC_push_one(state.__r14);
 175         GC_push_one(state.__r15);
 176         GC_push_one(state.__r16);
 177         GC_push_one(state.__r17);
 178         GC_push_one(state.__r18);
 179         GC_push_one(state.__r19);
 180         GC_push_one(state.__r20);
 181         GC_push_one(state.__r21);
 182         GC_push_one(state.__r22);
 183         GC_push_one(state.__r23);
 184         GC_push_one(state.__r24);
 185         GC_push_one(state.__r25);
 186         GC_push_one(state.__r26);
 187         GC_push_one(state.__r27);
 188         GC_push_one(state.__r28);
 189         GC_push_one(state.__r29);
 190         GC_push_one(state.__r30);
 191         GC_push_one(state.__r31);
 192 #else
 193         lo = (void*)(state.r1 - PPC_RED_ZONE_SIZE);
 194
 195         GC_push_one(state.r0);
 196         GC_push_one(state.r2);
 197         GC_push_one(state.r3);
 198         GC_push_one(state.r4);
 199         GC_push_one(state.r5);
 200         GC_push_one(state.r6);
 201         GC_push_one(state.r7);
 202         GC_push_one(state.r8);
 203         GC_push_one(state.r9);
 204         GC_push_one(state.r10);
 205         GC_push_one(state.r11);
 206         GC_push_one(state.r12);
 207         GC_push_one(state.r13);
 208         GC_push_one(state.r14);
 209         GC_push_one(state.r15);
 210         GC_push_one(state.r16);
 211         GC_push_one(state.r17);
 212         GC_push_one(state.r18);
 213         GC_push_one(state.r19);
 214         GC_push_one(state.r20);
 215         GC_push_one(state.r21);
 216         GC_push_one(state.r22);
 217         GC_push_one(state.r23);
 218         GC_push_one(state.r24);
 219         GC_push_one(state.r25);
 220         GC_push_one(state.r26);
 221         GC_push_one(state.r27);
 222         GC_push_one(state.r28);
 223         GC_push_one(state.r29);
 224         GC_push_one(state.r30);
 225         GC_push_one(state.r31);
 226 #endif
 227 #elif defined(ARM)
 228         lo = (void*)state.__sp;
 229
 230         GC_push_one(state.__r[0]);
 231         GC_push_one(state.__r[1]);
 232         GC_push_one(state.__r[2]);
 233         GC_push_one(state.__r[3]);
 234         GC_push_one(state.__r[4]);
 235         GC_push_one(state.__r[5]);
 236         GC_push_one(state.__r[6]);
 237         GC_push_one(state.__r[7]);
 238         GC_push_one(state.__r[8]);
 239         GC_push_one(state.__r[9]);
 240         GC_push_one(state.__r[10]);
 241         GC_push_one(state.__r[11]);
 242         GC_push_one(state.__r[12]);
 243         /* GC_push_one(state.__sp);  */
 244         GC_push_one(state.__lr);
 245         GC_push_one(state.__pc);
 246         GC_push_one(state.__cpsr);
 247 #else
 248 # error FIXME for non-x86 || ppc architectures
 249 #endif
 250       } /* p != me */
 251       if(p->flags & MAIN_THREAD)
 252         hi = GC_stackbottom;
 253       else
 254         hi = p->stack_end;
 255 #if DEBUG_THREADS
 256       GC_printf3("Darwin: Stack for thread 0x%lx = [%lx,%lx)\n",
 257                  (unsigned long) p -> id,
 258                  (unsigned long) lo,
 259                  (unsigned long) hi
 260                  );
 261 #endif
 262       GC_push_all_stack(lo,hi);
 263     } /* for(p=GC_threads[i]...) */
 264   } /* for(i=0;i<THREAD_TABLE_SZ...) */
 265 }
 266
 267 #else /* !DARWIN_DONT_PARSE_STACK; Use FindTopOfStack() */
 268
 269 void GC_push_all_stacks() {
 270     int i;
 271         task_t my_task;
 272     kern_return_t r;
 273     mach_port_t me;
 274     ptr_t lo, hi;
 275     thread_act_array_t act_list = 0;
 276     mach_msg_type_number_t listcount = 0;
 277
 278     me = mach_thread_self();
 279     if (!GC_thr_initialized) GC_thr_init();
 280
 281         my_task = current_task();
 282     r = task_threads(my_task, &act_list, &listcount);
 283     if(r != KERN_SUCCESS) ABORT("task_threads failed");
 284     for(i = 0; i < listcount; i++) {
 285       thread_act_t thread = act_list[i];
 286       if (thread == me) {
 287         lo = GC_approx_sp();
 288         hi = (ptr_t)FindTopOfStack(0);
 289       } else {
 290 #     if defined(POWERPC)
 291 #      if CPP_WORDSZ == 32
 292         ppc_thread_state_t info;
 293 #      else
 294         ppc_thread_state64_t info;
 295 #      endif
 296         mach_msg_type_number_t outCount = THREAD_STATE_MAX;
 297         r = thread_get_state(thread, GC_MACH_THREAD_STATE_FLAVOR,
 298                              (natural_t *)&info, &outCount);
 299         if(r != KERN_SUCCESS) continue;
 300
 301 #if defined(_STRUCT_PPC_EXCEPTION_STATE)
 302         lo = (void*)(info.__r1 - PPC_RED_ZONE_SIZE);
 303         hi = (ptr_t)FindTopOfStack(info.__r1);
 304
 305         GC_push_one(info.__r0);
 306         GC_push_one(info.__r2);
 307         GC_push_one(info.__r3);
 308         GC_push_one(info.__r4);
 309         GC_push_one(info.__r5);
 310         GC_push_one(info.__r6);
 311         GC_push_one(info.__r7);
 312         GC_push_one(info.__r8);
 313         GC_push_one(info.__r9);
 314         GC_push_one(info.__r10);
 315         GC_push_one(info.__r11);
 316         GC_push_one(info.__r12);
 317         GC_push_one(info.__r13);
 318         GC_push_one(info.__r14);
 319         GC_push_one(info.__r15);
 320         GC_push_one(info.__r16);
 321         GC_push_one(info.__r17);
 322         GC_push_one(info.__r18);
 323         GC_push_one(info.__r19);
 324         GC_push_one(info.__r20);
 325         GC_push_one(info.__r21);
 326         GC_push_one(info.__r22);
 327         GC_push_one(info.__r23);
 328         GC_push_one(info.__r24);
 329         GC_push_one(info.__r25);
 330         GC_push_one(info.__r26);
 331         GC_push_one(info.__r27);
 332         GC_push_one(info.__r28);
 333         GC_push_one(info.__r29);
 334         GC_push_one(info.__r30);
 335         GC_push_one(info.__r31);
 336 #else
 337         lo = (void*)(info.r1 - PPC_RED_ZONE_SIZE);
 338         hi = (ptr_t)FindTopOfStack(info.r1);
 339
 340         GC_push_one(info.r0);
 341         GC_push_one(info.r2);
 342         GC_push_one(info.r3);
 343         GC_push_one(info.r4);
 344         GC_push_one(info.r5);
 345         GC_push_one(info.r6);
 346         GC_push_one(info.r7);
 347         GC_push_one(info.r8);
 348         GC_push_one(info.r9);
 349         GC_push_one(info.r10);
 350         GC_push_one(info.r11);
 351         GC_push_one(info.r12);
 352         GC_push_one(info.r13);
 353         GC_push_one(info.r14);
 354         GC_push_one(info.r15);
 355         GC_push_one(info.r16);
 356         GC_push_one(info.r17);
 357         GC_push_one(info.r18);
 358         GC_push_one(info.r19);
 359         GC_push_one(info.r20);
 360         GC_push_one(info.r21);
 361         GC_push_one(info.r22);
 362         GC_push_one(info.r23);
 363         GC_push_one(info.r24);
 364         GC_push_one(info.r25);
 365         GC_push_one(info.r26);
 366         GC_push_one(info.r27);
 367         GC_push_one(info.r28);
 368         GC_push_one(info.r29);
 369         GC_push_one(info.r30);
 370         GC_push_one(info.r31);
 371 #endif
 372 #      elif defined(I386) /* !POWERPC */
 373         /* FIXME: Remove after testing: */
 374         WARN("This is completely untested and likely will not work\n", 0);
 375         i386_thread_state_t info;
 376         mach_msg_type_number_t outCount = THREAD_STATE_MAX;
 377         r = thread_get_state(thread, GC_MACH_THREAD_STATE_FLAVOR,
 378                              (natural_t *)&info, &outCount);
 379         if(r != KERN_SUCCESS) continue;
 380
 381 #if MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_5
 382         lo = (void*)info.__esp;
 383         hi = (ptr_t)FindTopOfStack(info.__esp);
 384
 385         GC_push_one(info.__eax);
 386         GC_push_one(info.__ebx);
 387         GC_push_one(info.__ecx);
 388         GC_push_one(info.__edx);
 389         GC_push_one(info.__edi);
 390         GC_push_one(info.__esi);
 391         GC_push_one(info.__ebp);
 392         /* GC_push_one(info.__esp);  */
 393         GC_push_one(info.__ss);
 394         GC_push_one(info.__eip);
 395         GC_push_one(info.__cs);
 396         GC_push_one(info.__ds);
 397         GC_push_one(info.__es);
 398         GC_push_one(info.__fs);
 399         GC_push_one(info.__gs);
 400 #else
 401         lo = (void*)info.esp;
 402         hi = (ptr_t)FindTopOfStack(info.esp);
 403
 404         GC_push_one(info.eax);
 405         GC_push_one(info.ebx);
 406         GC_push_one(info.ecx);
 407         GC_push_one(info.edx);
 408         GC_push_one(info.edi);
 409         GC_push_one(info.esi);
 410         GC_push_one(info.ebp);
 411         /* GC_push_one(info.esp);  */
 412         GC_push_one(info.ss);
 413         GC_push_one(info.eip);
 414         GC_push_one(info.cs);
 415         GC_push_one(info.ds);
 416         GC_push_one(info.es);
 417         GC_push_one(info.fs);
 418         GC_push_one(info.gs);
 419 #endif
 420 #      elif defined(ARM) /* !I386 */
 421         arm_thread_state_t info;
 422         mach_msg_type_number_t outCount = THREAD_STATE_MAX;
 423         r = thread_get_state(thread, GC_MACH_THREAD_STATE_FLAVOR,
 424                              (natural_t *)&info, &outCount);
 425         if(r != KERN_SUCCESS) continue;
 426
 427         lo = (void*)info.__sp;
 428         hi = (ptr_t)FindTopOfStack(info.__sp);
 429
 430         GC_push_one(info.__r[0]);
 431         GC_push_one(info.__r[1]);
 432         GC_push_one(info.__r[2]);
 433         GC_push_one(info.__r[3]);
 434         GC_push_one(info.__r[4]);
 435         GC_push_one(info.__r[5]);
 436         GC_push_one(info.__r[6]);
 437         GC_push_one(info.__r[7]);
 438         GC_push_one(info.__r[8]);
 439         GC_push_one(info.__r[9]);
 440         GC_push_one(info.__r[10]);
 441         GC_push_one(info.__r[11]);
 442         GC_push_one(info.__r[12]);
 443         /* GC_push_one(info.__sp);  */
 444         GC_push_one(info.__lr);
 445         GC_push_one(info.__pc);
 446         GC_push_one(info.__cpsr);
 447 #      endif /* !ARM */
 448       }
 449 #     if DEBUG_THREADS
 450        GC_printf3("Darwin: Stack for thread 0x%lx = [%lx,%lx)\n",
 451                   (unsigned long) thread,
 452                   (unsigned long) lo,
 453                   (unsigned long) hi
 454                  );
 455 #     endif
 456       GC_push_all_stack(lo, hi);
 457           mach_port_deallocate(my_task, thread);
 458     } /* for(p=GC_threads[i]...) */
 459     vm_deallocate(my_task, (vm_address_t)act_list, sizeof(thread_t) * listcount);
 460         mach_port_deallocate(my_task, me);
 461 }
 462 #endif /* !DARWIN_DONT_PARSE_STACK */
 463
 464 static mach_port_t GC_mach_handler_thread;
 465 static int GC_use_mach_handler_thread = 0;
 466
 467 #define SUSPEND_THREADS_SIZE 2048
 468 static struct GC_mach_thread GC_mach_threads[SUSPEND_THREADS_SIZE];
 469 static int GC_mach_threads_count;
 470
 471 void GC_stop_init() {
 472   int i;
 473
 474   for (i = 0; i < SUSPEND_THREADS_SIZE; i++) {
 475     GC_mach_threads[i].thread = 0;
 476     GC_mach_threads[i].already_suspended = 0;
 477   }
 478   GC_mach_threads_count = 0;
 479 }
 480
 481 /* returns true if there's a thread in act_list that wasn't in old_list */
 482 int GC_suspend_thread_list(thread_act_array_t act_list, int count,
 483                            thread_act_array_t old_list, int old_count) {
 484   mach_port_t my_thread = mach_thread_self();
 485   int i, j;
 486
 487   int changed = 0;
 488
 489   for(i = 0; i < count; i++) {
 490     thread_act_t thread = act_list[i];
 491 #   if DEBUG_THREADS
 492       GC_printf1("Attempting to suspend thread %p\n", thread);
 493 #   endif
 494     /* find the current thread in the old list */
 495     int found = 0;
 496     for(j = 0; j < old_count; j++) {
 497       thread_act_t old_thread = old_list[j];
 498       if (old_thread == thread) {
 499         found = 1;
 500         break;
 501       }
 502     }
 503     if (!found) {
 504       /* add it to the GC_mach_threads list */
 505       GC_mach_threads[GC_mach_threads_count].thread = thread;
 506       /* default is not suspended */
 507       GC_mach_threads[GC_mach_threads_count].already_suspended = 0;
 508       changed = 1;
 509     }
 510
 511     if (thread != my_thread &&
 512         (!GC_use_mach_handler_thread
 513          || (GC_use_mach_handler_thread
 514              && GC_mach_handler_thread != thread))) {
 515       struct thread_basic_info info;
 516       mach_msg_type_number_t outCount = THREAD_INFO_MAX;
 517       kern_return_t kern_result = thread_info(thread, THREAD_BASIC_INFO,
 518                                 (thread_info_t)&info, &outCount);
 519       if(kern_result != KERN_SUCCESS) {
 520         /* the thread may have quit since the thread_threads () call
 521          * we mark already_suspended so it's not dealt with anymore later
 522          */
 523         if (!found) {
 524           GC_mach_threads[GC_mach_threads_count].already_suspended = TRUE;
 525           GC_mach_threads_count++;
 526         }
 527         continue;
 528       }
 529 #     if DEBUG_THREADS
 530         GC_printf2("Thread state for 0x%lx = %d\n", thread, info.run_state);
 531 #     endif
 532       if (!found) {
 533         GC_mach_threads[GC_mach_threads_count].already_suspended = info.suspend_count;
 534       }
 535       if (info.suspend_count) continue;
 536
 537 #     if DEBUG_THREADS
 538         GC_printf1("Suspending 0x%lx\n", thread);
 539 #     endif
 540       /* Suspend the thread */
 541       kern_result = thread_suspend(thread);
 542       if(kern_result != KERN_SUCCESS) {
 543         /* the thread may have quit since the thread_threads () call
 544          * we mark already_suspended so it's not dealt with anymore later
 545          */
 546         if (!found) {
 547           GC_mach_threads[GC_mach_threads_count].already_suspended = TRUE;
 548           GC_mach_threads_count++;
 549         }
 550         continue;
 551       }
 552     }
 553     if (!found) GC_mach_threads_count++;
 554   }
 555
 556   mach_port_deallocate(current_task(), my_thread);
 557   return changed;
 558 }
 559
 560
 561 /* Caller holds allocation lock.        */
 562 void GC_stop_world()
 563 {
 564   int i, changes;
 565     GC_thread p;
 566         task_t my_task = current_task();
 567     mach_port_t my_thread = mach_thread_self();
 568     kern_return_t kern_result;
 569     thread_act_array_t act_list, prev_list;
 570     mach_msg_type_number_t listcount, prevcount;
 571
 572     if (GC_notify_event)
 573         GC_notify_event (GC_EVENT_PRE_STOP_WORLD);
 574
 575 #   if DEBUG_THREADS
 576       GC_printf1("Stopping the world from 0x%lx\n", mach_thread_self());
 577 #   endif
 578
 579     /* clear out the mach threads list table */
 580     GC_stop_init();
 581
 582     /* Make sure all free list construction has stopped before we start. */
 583     /* No new construction can start, since free list construction is   */
 584     /* required to acquire and release the GC lock before it starts,    */
 585     /* and we have the lock.                                            */
 586 #   ifdef PARALLEL_MARK
 587       GC_acquire_mark_lock();
 588       GC_ASSERT(GC_fl_builder_count == 0);
 589       /* We should have previously waited for it to become zero. */
 590 #   endif /* PARALLEL_MARK */
 591
 592       /* Loop stopping threads until you have gone over the whole list
 593          twice without a new one appearing. thread_create() won't
 594          return (and thus the thread stop) until the new thread
 595          exists, so there is no window whereby you could stop a
 596          thread, recognise it is stopped, but then have a new thread
 597          it created before stopping show up later.
 598       */
 599
 600       changes = 1;
 601       prev_list = NULL;
 602       prevcount = 0;
 603       do {
 604         int result;
 605         kern_result = task_threads(my_task, &act_list, &listcount);
 606
 607         if(kern_result == KERN_SUCCESS) {
 608                 result = GC_suspend_thread_list(act_list, listcount,
 609                                                                                 prev_list, prevcount);
 610                 changes = result;
 611
 612                 if(prev_list != NULL) {
 613                         for(i = 0; i < prevcount; i++)
 614                                 mach_port_deallocate(my_task, prev_list[i]);
 615
 616                         vm_deallocate(my_task, (vm_address_t)prev_list, sizeof(thread_t) * prevcount);
 617                 }
 618
 619                 prev_list = act_list;
 620                 prevcount = listcount;
 621         }
 622       } while (changes);
 623
 624           for(i = 0; i < listcount; i++)
 625                   mach_port_deallocate(my_task, act_list[i]);
 626
 627           vm_deallocate(my_task, (vm_address_t)act_list, sizeof(thread_t) * listcount);
 628
 629
 630 #   ifdef MPROTECT_VDB
 631       if(GC_incremental) {
 632         extern void GC_mprotect_stop();
 633         GC_mprotect_stop();
 634       }
 635 #   endif
 636
 637 #   ifdef PARALLEL_MARK
 638       GC_release_mark_lock();
 639 #   endif
 640     #if DEBUG_THREADS
 641       GC_printf1("World stopped from 0x%lx\n", my_thread);
 642     #endif
 643
 644           mach_port_deallocate(my_task, my_thread);
 645
 646     if (GC_notify_event)
 647         GC_notify_event (GC_EVENT_POST_STOP_WORLD);
 648 }
 649
 650 /* Caller holds allocation lock, and has held it continuously since     */
 651 /* the world stopped.                                                   */
 652 void GC_start_world()
 653 {
 654   task_t my_task = current_task();
 655   mach_port_t my_thread = mach_thread_self();
 656   int i, j;
 657   GC_thread p;
 658   kern_return_t kern_result;
 659   thread_act_array_t act_list;
 660   mach_msg_type_number_t listcount;
 661   struct thread_basic_info info;
 662   mach_msg_type_number_t outCount = THREAD_INFO_MAX;
 663
 664   if (GC_notify_event)
 665       GC_notify_event (GC_EVENT_PRE_START_WORLD);
 666
 667 #   if DEBUG_THREADS
 668       GC_printf0("World starting\n");
 669 #   endif
 670
 671 #   ifdef MPROTECT_VDB
 672       if(GC_incremental) {
 673         extern void GC_mprotect_resume();
 674         GC_mprotect_resume();
 675       }
 676 #   endif
 677
 678     kern_result = task_threads(my_task, &act_list, &listcount);
 679     for(i = 0; i < listcount; i++) {
 680       thread_act_t thread = act_list[i];
 681       if (thread != my_thread &&
 682           (!GC_use_mach_handler_thread ||
 683            (GC_use_mach_handler_thread && GC_mach_handler_thread != thread))) {
 684         for(j = 0; j < GC_mach_threads_count; j++) {
 685           if (thread == GC_mach_threads[j].thread) {
 686             if (GC_mach_threads[j].already_suspended) {
 687 #             if DEBUG_THREADS
 688                 GC_printf1("Not resuming already suspended thread %p\n", thread);
 689 #             endif
 690               continue;
 691             }
 692             kern_result = thread_info(thread, THREAD_BASIC_INFO,
 693                                       (thread_info_t)&info, &outCount);
 694             if(kern_result != KERN_SUCCESS) continue;
 695 #           if DEBUG_THREADS
 696               GC_printf2("Thread state for 0x%lx = %d\n", thread,
 697                          info.run_state);
 698               GC_printf1("Resuming 0x%lx\n", thread);
 699 #           endif
 700             /* Resume the thread */
 701             kern_result = thread_resume(thread);
 702             if(kern_result != KERN_SUCCESS) continue;
 703           }
 704         }
 705       }
 706
 707           mach_port_deallocate(my_task, thread);
 708     }
 709     vm_deallocate(my_task, (vm_address_t)act_list, sizeof(thread_t) * listcount);
 710
 711         mach_port_deallocate(my_task, my_thread);
 712
 713     if (GC_notify_event)
 714         GC_notify_event (GC_EVENT_POST_START_WORLD);
 715
 716 #   if DEBUG_THREADS
 717      GC_printf0("World started\n");
 718 #   endif
 719 }
 720
 721 void GC_darwin_register_mach_handler_thread(mach_port_t thread) {
 722   GC_mach_handler_thread = thread;
 723   GC_use_mach_handler_thread = 1;
 724 }
 725
 726 #ifdef MONO_DEBUGGER_SUPPORTED
 727 GCThreadFunctions *gc_thread_vtable = NULL;
 728
 729 void *
 730 GC_mono_debugger_get_stack_ptr (void)
 731 {
 732         GC_thread me;
 733
 734         me = GC_lookup_thread (pthread_self ());
 735         return &me->stop_info.stack_ptr;
 736 }
 737 #endif
 738
 739 #endif