boehm-gc/darwin_stop_world.c

   1 #include "private/pthread_support.h"
   2
   3 /* This probably needs more porting work to ppc64. */
   4
   5 # if defined(GC_DARWIN_THREADS)
   6
   7 /* From "Inside Mac OS X - Mach-O Runtime Architecture" published by Apple
   8    Page 49:
   9    "The space beneath the stack pointer, where a new stack frame would normally
  10    be allocated, is called the red zone. This area as shown in Figure 3-2 may
  11    be used for any purpose as long as a new stack frame does not need to be
  12    added to the stack."
  13
  14    Page 50: "If a leaf procedure's red zone usage would exceed 224 bytes, then
  15    it must set up a stack frame just like routines that call other routines."
  16 */
  17 #if defined(__ppc__)
  18 # define PPC_RED_ZONE_SIZE 224
  19 #elif defined(__ppc64__)
  20 # define PPC_RED_ZONE_SIZE 320
  21 #endif
  22
  23 typedef struct StackFrame {
  24   unsigned long savedSP;
  25   unsigned long savedCR;
  26   unsigned long savedLR;
  27   unsigned long reserved[2];
  28   unsigned long savedRTOC;
  29 } StackFrame;
  30
  31 unsigned long FindTopOfStack(unsigned long stack_start) {
  32   StackFrame    *frame;
  33
  34   if (stack_start == 0) {
  35 # ifdef POWERPC
  36 #   if CPP_WORDSZ == 32
  37       __asm__ volatile("lwz     %0,0(r1)" : "=r" (frame));
  38 #   else
  39       __asm__ volatile("ld      %0,0(r1)" : "=r" (frame));
  40 #   endif
  41 # endif
  42   } else {
  43     frame = (StackFrame *)stack_start;
  44   }
  45
  46 # ifdef DEBUG_THREADS
  47     /* GC_printf1("FindTopOfStack start at sp = %p\n", frame); */
  48 # endif
  49   do {
  50     if (frame->savedSP == 0) break;
  51                 /* if there are no more stack frames, stop */
  52
  53     frame = (StackFrame*)frame->savedSP;
  54
  55     /* we do these next two checks after going to the next frame
  56        because the LR for the first stack frame in the loop
  57        is not set up on purpose, so we shouldn't check it. */
  58     if ((frame->savedLR & ~3) == 0) break; /* if the next LR is bogus, stop */
  59     if ((~(frame->savedLR) & ~3) == 0) break; /* ditto */
  60   } while (1);
  61
  62 # ifdef DEBUG_THREADS
  63     /* GC_printf1("FindTopOfStack finish at sp = %p\n", frame); */
  64 # endif
  65
  66   return (unsigned long)frame;
  67 }
  68
  69 #ifdef DARWIN_DONT_PARSE_STACK
  70 void GC_push_all_stacks() {
  71   int i;
  72   kern_return_t r;
  73   GC_thread p;
  74   pthread_t me;
  75   ptr_t lo, hi;
  76   GC_THREAD_STATE_T state;
  77   mach_msg_type_number_t thread_state_count = GC_MACH_THREAD_STATE_COUNT;
  78
  79   me = pthread_self();
  80   if (!GC_thr_initialized) GC_thr_init();
  81
  82   for(i=0;i<THREAD_TABLE_SZ;i++) {
  83     for(p=GC_threads[i];p!=0;p=p->next) {
  84       if(p -> flags & FINISHED) continue;
  85       if(pthread_equal(p->id,me)) {
  86         lo = GC_approx_sp();
  87       } else {
  88         /* Get the thread state (registers, etc) */
  89         r = thread_get_state(p->stop_info.mach_thread, GC_MACH_THREAD_STATE,
  90                              (natural_t*)&state, &thread_state_count);
  91         if(r != KERN_SUCCESS) ABORT("thread_get_state failed");
  92
  93 #if defined(I386)
  94         lo = (void*)state . THREAD_FLD (esp);
  95
  96         GC_push_one(state . THREAD_FLD (eax));
  97         GC_push_one(state . THREAD_FLD (ebx));
  98         GC_push_one(state . THREAD_FLD (ecx));
  99         GC_push_one(state . THREAD_FLD (edx));
 100         GC_push_one(state . THREAD_FLD (edi));
 101         GC_push_one(state . THREAD_FLD (esi));
 102         GC_push_one(state . THREAD_FLD (ebp));
 103
 104 #elif defined(X86_64)
 105         lo = (void*)state . THREAD_FLD (rsp);
 106
 107         GC_push_one(state . THREAD_FLD (rax));
 108         GC_push_one(state . THREAD_FLD (rbx));
 109         GC_push_one(state . THREAD_FLD (rcx));
 110         GC_push_one(state . THREAD_FLD (rdx));
 111         GC_push_one(state . THREAD_FLD (rdi));
 112         GC_push_one(state . THREAD_FLD (rsi));
 113         GC_push_one(state . THREAD_FLD (rbp));
 114         GC_push_one(state . THREAD_FLD (rsp));
 115         GC_push_one(state . THREAD_FLD (r8));
 116         GC_push_one(state . THREAD_FLD (r9));
 117         GC_push_one(state . THREAD_FLD (r10));
 118         GC_push_one(state . THREAD_FLD (r11));
 119         GC_push_one(state . THREAD_FLD (r12));
 120         GC_push_one(state . THREAD_FLD (r13));
 121         GC_push_one(state . THREAD_FLD (r14));
 122         GC_push_one(state . THREAD_FLD (r15));
 123         GC_push_one(state . THREAD_FLD (rip));
 124         GC_push_one(state . THREAD_FLD (rflags));
 125         GC_push_one(state . THREAD_FLD (cs));
 126         GC_push_one(state . THREAD_FLD (fs));
 127         GC_push_one(state . THREAD_FLD (gs));
 128
 129 #elif defined(POWERPC)
 130         lo = (void*)(state . THREAD_FLD (r1) - PPC_RED_ZONE_SIZE);
 131
 132         GC_push_one(state . THREAD_FLD (r0));
 133         GC_push_one(state . THREAD_FLD (r2));
 134         GC_push_one(state . THREAD_FLD (r3));
 135         GC_push_one(state . THREAD_FLD (r4));
 136         GC_push_one(state . THREAD_FLD (r5));
 137         GC_push_one(state . THREAD_FLD (r6));
 138         GC_push_one(state . THREAD_FLD (r7));
 139         GC_push_one(state . THREAD_FLD (r8));
 140         GC_push_one(state . THREAD_FLD (r9));
 141         GC_push_one(state . THREAD_FLD (r10));
 142         GC_push_one(state . THREAD_FLD (r11));
 143         GC_push_one(state . THREAD_FLD (r12));
 144         GC_push_one(state . THREAD_FLD (r13));
 145         GC_push_one(state . THREAD_FLD (r14));
 146         GC_push_one(state . THREAD_FLD (r15));
 147         GC_push_one(state . THREAD_FLD (r16));
 148         GC_push_one(state . THREAD_FLD (r17));
 149         GC_push_one(state . THREAD_FLD (r18));
 150         GC_push_one(state . THREAD_FLD (r19));
 151         GC_push_one(state . THREAD_FLD (r20));
 152         GC_push_one(state . THREAD_FLD (r21));
 153         GC_push_one(state . THREAD_FLD (r22));
 154         GC_push_one(state . THREAD_FLD (r23));
 155         GC_push_one(state . THREAD_FLD (r24));
 156         GC_push_one(state . THREAD_FLD (r25));
 157         GC_push_one(state . THREAD_FLD (r26));
 158         GC_push_one(state . THREAD_FLD (r27));
 159         GC_push_one(state . THREAD_FLD (r28));
 160         GC_push_one(state . THREAD_FLD (r29));
 161         GC_push_one(state . THREAD_FLD (r30));
 162         GC_push_one(state . THREAD_FLD (r31));
 163 #else
 164 # error FIXME for non-x86 || ppc architectures
 165 #endif
 166       } /* p != me */
 167       if(p->flags & MAIN_THREAD)
 168         hi = GC_stackbottom;
 169       else
 170         hi = p->stack_end;
 171 #if DEBUG_THREADS
 172       GC_printf3("Darwin: Stack for thread 0x%lx = [%lx,%lx)\n",
 173                  (unsigned long) p -> id,
 174                  (unsigned long) lo,
 175                  (unsigned long) hi
 176                  );
 177 #endif
 178       GC_push_all_stack(lo,hi);
 179     } /* for(p=GC_threads[i]...) */
 180   } /* for(i=0;i<THREAD_TABLE_SZ...) */
 181 }
 182
 183 #else /* !DARWIN_DONT_PARSE_STACK; Use FindTopOfStack() */
 184
 185 void GC_push_all_stacks() {
 186     int i;
 187     kern_return_t r;
 188     mach_port_t me;
 189     ptr_t lo, hi;
 190     thread_act_array_t act_list = 0;
 191     mach_msg_type_number_t listcount = 0;
 192
 193     me = mach_thread_self();
 194     if (!GC_thr_initialized) GC_thr_init();
 195
 196     r = task_threads(current_task(), &act_list, &listcount);
 197     if(r != KERN_SUCCESS) ABORT("task_threads failed");
 198     for(i = 0; i < listcount; i++) {
 199       thread_act_t thread = act_list[i];
 200       if (thread == me) {
 201         lo = GC_approx_sp();
 202         hi = (ptr_t)FindTopOfStack(0);
 203       } else {
 204 #     if defined(__ppc__) || defined(__ppc64__)
 205         GC_THREAD_STATE_T info;
 206         mach_msg_type_number_t outCount = THREAD_STATE_MAX;
 207         r = thread_get_state(thread, GC_MACH_THREAD_STATE,
 208                              (natural_t *)&info, &outCount);
 209         if(r != KERN_SUCCESS) ABORT("task_get_state failed");
 210
 211         lo = (void*)(info . THREAD_FLD (r1) - PPC_RED_ZONE_SIZE);
 212         hi = (ptr_t)FindTopOfStack(info . THREAD_FLD (r1));
 213
 214         GC_push_one(info . THREAD_FLD (r0));
 215         GC_push_one(info . THREAD_FLD (r2));
 216         GC_push_one(info . THREAD_FLD (r3));
 217         GC_push_one(info . THREAD_FLD (r4));
 218         GC_push_one(info . THREAD_FLD (r5));
 219         GC_push_one(info . THREAD_FLD (r6));
 220         GC_push_one(info . THREAD_FLD (r7));
 221         GC_push_one(info . THREAD_FLD (r8));
 222         GC_push_one(info . THREAD_FLD (r9));
 223         GC_push_one(info . THREAD_FLD (r10));
 224         GC_push_one(info . THREAD_FLD (r11));
 225         GC_push_one(info . THREAD_FLD (r12));
 226         GC_push_one(info . THREAD_FLD (r13));
 227         GC_push_one(info . THREAD_FLD (r14));
 228         GC_push_one(info . THREAD_FLD (r15));
 229         GC_push_one(info . THREAD_FLD (r16));
 230         GC_push_one(info . THREAD_FLD (r17));
 231         GC_push_one(info . THREAD_FLD (r18));
 232         GC_push_one(info . THREAD_FLD (r19));
 233         GC_push_one(info . THREAD_FLD (r20));
 234         GC_push_one(info . THREAD_FLD (r21));
 235         GC_push_one(info . THREAD_FLD (r22));
 236         GC_push_one(info . THREAD_FLD (r23));
 237         GC_push_one(info . THREAD_FLD (r24));
 238         GC_push_one(info . THREAD_FLD (r25));
 239         GC_push_one(info . THREAD_FLD (r26));
 240         GC_push_one(info . THREAD_FLD (r27));
 241         GC_push_one(info . THREAD_FLD (r28));
 242         GC_push_one(info . THREAD_FLD (r29));
 243         GC_push_one(info . THREAD_FLD (r30));
 244         GC_push_one(info . THREAD_FLD (r31));
 245 #      else
 246         /* FIXME: Remove after testing: */
 247         WARN("This is completely untested and likely will not work\n", 0);
 248         GC_THREAD_STATE_T info;
 249         mach_msg_type_number_t outCount = THREAD_STATE_MAX;
 250         r = thread_get_state(thread, GC_MACH_THREAD_STATE, (natural_t *)&info,
 251                              &outCount);
 252         if(r != KERN_SUCCESS) ABORT("task_get_state failed");
 253
 254         lo = (void*)info . THREAD_FLD (esp);
 255         hi = (ptr_t)FindTopOfStack(info . THREAD_FLD (esp));
 256
 257         GC_push_one(info . THREAD_FLD (eax));
 258         GC_push_one(info . THREAD_FLD (ebx));
 259         GC_push_one(info . THREAD_FLD (ecx));
 260         GC_push_one(info . THREAD_FLD (edx));
 261         GC_push_one(info . THREAD_FLD (edi));
 262         GC_push_one(info . THREAD_FLD (esi));
 263         /* GC_push_one(info . THREAD_FLD (ebp));  */
 264         /* GC_push_one(info . THREAD_FLD (esp));  */
 265         GC_push_one(info . THREAD_FLD (ss));
 266         GC_push_one(info . THREAD_FLD (eip));
 267         GC_push_one(info . THREAD_FLD (cs));
 268         GC_push_one(info . THREAD_FLD (ds));
 269         GC_push_one(info . THREAD_FLD (es));
 270         GC_push_one(info . THREAD_FLD (fs));
 271         GC_push_one(info . THREAD_FLD (gs));
 272 #      endif /* !POWERPC */
 273       }
 274 #     if DEBUG_THREADS
 275        GC_printf3("Darwin: Stack for thread 0x%lx = [%lx,%lx)\n",
 276                   (unsigned long) thread,
 277                   (unsigned long) lo,
 278                   (unsigned long) hi
 279                  );
 280 #     endif
 281       GC_push_all_stack(lo, hi);
 282     } /* for(p=GC_threads[i]...) */
 283     vm_deallocate(current_task(), (vm_address_t)act_list, sizeof(thread_t) * listcount);
 284 }
 285 #endif /* !DARWIN_DONT_PARSE_STACK */
 286
 287 static mach_port_t GC_mach_handler_thread;
 288 static int GC_use_mach_handler_thread = 0;
 289
 290 static struct GC_mach_thread GC_mach_threads[THREAD_TABLE_SZ];
 291 static int GC_mach_threads_count;
 292
 293 void GC_stop_init() {
 294   int i;
 295
 296   for (i = 0; i < THREAD_TABLE_SZ; i++) {
 297     GC_mach_threads[i].thread = 0;
 298     GC_mach_threads[i].already_suspended = 0;
 299   }
 300   GC_mach_threads_count = 0;
 301 }
 302
 303 /* returns true if there's a thread in act_list that wasn't in old_list */
 304 int GC_suspend_thread_list(thread_act_array_t act_list, int count,
 305                            thread_act_array_t old_list, int old_count) {
 306   mach_port_t my_thread = mach_thread_self();
 307   int i, j;
 308
 309   int changed = 0;
 310
 311   for(i = 0; i < count; i++) {
 312     thread_act_t thread = act_list[i];
 313 #   if DEBUG_THREADS
 314       GC_printf1("Attempting to suspend thread %p\n", thread);
 315 #   endif
 316     /* find the current thread in the old list */
 317     int found = 0;
 318     for(j = 0; j < old_count; j++) {
 319       thread_act_t old_thread = old_list[j];
 320       if (old_thread == thread) {
 321         found = 1;
 322         break;
 323       }
 324     }
 325     if (!found) {
 326       /* add it to the GC_mach_threads list */
 327       GC_mach_threads[GC_mach_threads_count].thread = thread;
 328       /* default is not suspended */
 329       GC_mach_threads[GC_mach_threads_count].already_suspended = 0;
 330       changed = 1;
 331     }
 332
 333     if (thread != my_thread &&
 334         (!GC_use_mach_handler_thread
 335          || (GC_use_mach_handler_thread
 336              && GC_mach_handler_thread != thread))) {
 337       struct thread_basic_info info;
 338       mach_msg_type_number_t outCount = THREAD_INFO_MAX;
 339       kern_return_t kern_result = thread_info(thread, THREAD_BASIC_INFO,
 340                                 (thread_info_t)&info, &outCount);
 341       if(kern_result != KERN_SUCCESS) {
 342         /* the thread may have quit since the thread_threads () call
 343          * we mark already_suspended so it's not dealt with anymore later
 344          */
 345         if (!found) {
 346           GC_mach_threads[GC_mach_threads_count].already_suspended = TRUE;
 347           GC_mach_threads_count++;
 348         }
 349         continue;
 350       }
 351 #     if DEBUG_THREADS
 352         GC_printf2("Thread state for 0x%lx = %d\n", thread, info.run_state);
 353 #     endif
 354       if (!found) {
 355         GC_mach_threads[GC_mach_threads_count].already_suspended = info.suspend_count;
 356       }
 357       if (info.suspend_count) continue;
 358
 359 #     if DEBUG_THREADS
 360         GC_printf1("Suspending 0x%lx\n", thread);
 361 #     endif
 362       /* Suspend the thread */
 363       kern_result = thread_suspend(thread);
 364       if(kern_result != KERN_SUCCESS) {
 365         /* the thread may have quit since the thread_threads () call
 366          * we mark already_suspended so it's not dealt with anymore later
 367          */
 368         if (!found) {
 369           GC_mach_threads[GC_mach_threads_count].already_suspended = TRUE;
 370           GC_mach_threads_count++;
 371         }
 372         continue;
 373       }
 374     }
 375     if (!found) GC_mach_threads_count++;
 376   }
 377   return changed;
 378 }
 379
 380
 381 /* Caller holds allocation lock.        */
 382 void GC_stop_world()
 383 {
 384   int i, changes;
 385     GC_thread p;
 386     mach_port_t my_thread = mach_thread_self();
 387     kern_return_t kern_result;
 388     thread_act_array_t act_list, prev_list;
 389     mach_msg_type_number_t listcount, prevcount;
 390
 391 #   if DEBUG_THREADS
 392       GC_printf1("Stopping the world from 0x%lx\n", mach_thread_self());
 393 #   endif
 394
 395     /* clear out the mach threads list table */
 396     GC_stop_init();
 397
 398     /* Make sure all free list construction has stopped before we start. */
 399     /* No new construction can start, since free list construction is   */
 400     /* required to acquire and release the GC lock before it starts,    */
 401     /* and we have the lock.                                            */
 402 #   ifdef PARALLEL_MARK
 403       GC_acquire_mark_lock();
 404       GC_ASSERT(GC_fl_builder_count == 0);
 405       /* We should have previously waited for it to become zero. */
 406 #   endif /* PARALLEL_MARK */
 407
 408       /* Loop stopping threads until you have gone over the whole list
 409          twice without a new one appearing. thread_create() won't
 410          return (and thus the thread stop) until the new thread
 411          exists, so there is no window whereby you could stop a
 412          thread, recognise it is stopped, but then have a new thread
 413          it created before stopping show up later.
 414       */
 415
 416       changes = 1;
 417       prev_list = NULL;
 418       prevcount = 0;
 419       do {
 420         int result;
 421         kern_result = task_threads(current_task(), &act_list, &listcount);
 422         result = GC_suspend_thread_list(act_list, listcount,
 423                                         prev_list, prevcount);
 424         changes = result;
 425         prev_list = act_list;
 426         prevcount = listcount;
 427         vm_deallocate(current_task(), (vm_address_t)act_list, sizeof(thread_t) * listcount);
 428       } while (changes);
 429
 430
 431 #   ifdef MPROTECT_VDB
 432       if(GC_incremental) {
 433         extern void GC_mprotect_stop();
 434         GC_mprotect_stop();
 435       }
 436 #   endif
 437
 438 #   ifdef PARALLEL_MARK
 439       GC_release_mark_lock();
 440 #   endif
 441     #if DEBUG_THREADS
 442       GC_printf1("World stopped from 0x%lx\n", my_thread);
 443     #endif
 444 }
 445
 446 /* Caller holds allocation lock, and has held it continuously since     */
 447 /* the world stopped.                                                   */
 448 void GC_start_world()
 449 {
 450   mach_port_t my_thread = mach_thread_self();
 451   int i, j;
 452   GC_thread p;
 453   kern_return_t kern_result;
 454   thread_act_array_t act_list;
 455   mach_msg_type_number_t listcount;
 456   struct thread_basic_info info;
 457   mach_msg_type_number_t outCount = THREAD_INFO_MAX;
 458
 459 #   if DEBUG_THREADS
 460       GC_printf0("World starting\n");
 461 #   endif
 462
 463 #   ifdef MPROTECT_VDB
 464       if(GC_incremental) {
 465         extern void GC_mprotect_resume();
 466         GC_mprotect_resume();
 467       }
 468 #   endif
 469
 470     kern_result = task_threads(current_task(), &act_list, &listcount);
 471     for(i = 0; i < listcount; i++) {
 472       thread_act_t thread = act_list[i];
 473       if (thread != my_thread &&
 474           (!GC_use_mach_handler_thread ||
 475            (GC_use_mach_handler_thread && GC_mach_handler_thread != thread))) {
 476         for(j = 0; j < GC_mach_threads_count; j++) {
 477           if (thread == GC_mach_threads[j].thread) {
 478             if (GC_mach_threads[j].already_suspended) {
 479 #             if DEBUG_THREADS
 480                 GC_printf1("Not resuming already suspended thread %p\n", thread);
 481 #             endif
 482               continue;
 483             }
 484             kern_result = thread_info(thread, THREAD_BASIC_INFO,
 485                                       (thread_info_t)&info, &outCount);
 486             if(kern_result != KERN_SUCCESS) ABORT("thread_info failed");
 487 #           if DEBUG_THREADS
 488               GC_printf2("Thread state for 0x%lx = %d\n", thread,
 489                          info.run_state);
 490               GC_printf1("Resuming 0x%lx\n", thread);
 491 #           endif
 492             /* Resume the thread */
 493             kern_result = thread_resume(thread);
 494             if(kern_result != KERN_SUCCESS) ABORT("thread_resume failed");
 495           }
 496         }
 497       }
 498     }
 499     vm_deallocate(current_task(), (vm_address_t)act_list, sizeof(thread_t) * listcount);
 500 #   if DEBUG_THREADS
 501      GC_printf0("World started\n");
 502 #   endif
 503 }
 504
 505 void GC_darwin_register_mach_handler_thread(mach_port_t thread) {
 506   GC_mach_handler_thread = thread;
 507   GC_use_mach_handler_thread = 1;
 508 }
 509
 510 #endif