boehm-gc/darwin_stop_world.c

   1 #include "private/pthread_support.h"
   2
   3 # if defined(GC_DARWIN_THREADS)
   4
   5 #define DEBUG_THREADS 0
   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 #define PPC_RED_ZONE_SIZE 224
  18
  19 void GC_push_all_stacks() {
  20     int i;
  21     kern_return_t r;
  22     GC_thread p;
  23     pthread_t me;
  24     ptr_t lo, hi;
  25 #       if defined(POWERPC)
  26         ppc_thread_state_t state;
  27 #       else
  28 #               error FIXME for non-ppc OS X
  29 #       endif
  30     mach_msg_type_number_t thread_state_count = MACHINE_THREAD_STATE_COUNT;
  31
  32     me = pthread_self();
  33     if (!GC_thr_initialized) GC_thr_init();
  34
  35     for(i=0;i<THREAD_TABLE_SZ;i++) {
  36         for(p=GC_threads[i];p!=0;p=p->next) {
  37             if(p -> flags & FINISHED) continue;
  38             if(pthread_equal(p->id,me)) {
  39                 lo = GC_approx_sp();
  40             } else {
  41                 /* Get the thread state (registers, etc) */
  42                 r = thread_get_state(
  43                     p->stop_info.mach_thread,
  44                     MACHINE_THREAD_STATE,
  45                     (natural_t*)&state,
  46                     &thread_state_count);
  47                 if(r != KERN_SUCCESS) ABORT("thread_get_state failed");
  48
  49                 #ifdef POWERPC
  50                     lo = (void*)(state.r1 - PPC_RED_ZONE_SIZE);
  51
  52                     GC_push_one(state.r0);
  53                     GC_push_one(state.r2);
  54                     GC_push_one(state.r3);
  55                     GC_push_one(state.r4);
  56                     GC_push_one(state.r5);
  57                     GC_push_one(state.r6);
  58                     GC_push_one(state.r7);
  59                     GC_push_one(state.r8);
  60                     GC_push_one(state.r9);
  61                     GC_push_one(state.r10);
  62                     GC_push_one(state.r11);
  63                     GC_push_one(state.r12);
  64                     GC_push_one(state.r13);
  65                     GC_push_one(state.r14);
  66                     GC_push_one(state.r15);
  67                     GC_push_one(state.r16);
  68                     GC_push_one(state.r17);
  69                     GC_push_one(state.r18);
  70                     GC_push_one(state.r19);
  71                     GC_push_one(state.r20);
  72                     GC_push_one(state.r21);
  73                     GC_push_one(state.r22);
  74                     GC_push_one(state.r23);
  75                     GC_push_one(state.r24);
  76                     GC_push_one(state.r25);
  77                     GC_push_one(state.r26);
  78                     GC_push_one(state.r27);
  79                     GC_push_one(state.r28);
  80                     GC_push_one(state.r29);
  81                     GC_push_one(state.r30);
  82                     GC_push_one(state.r31);
  83                 #else
  84                 #       error FIXME for non-PPC darwin
  85                 #endif /* !POWERPC */
  86             } /* p != me */
  87             if(p->flags & MAIN_THREAD)
  88                 hi = GC_stackbottom;
  89             else
  90                 hi = p->stack_end;
  91             #if DEBUG_THREADS
  92                 GC_printf3("Darwin: Stack for thread 0x%lx = [%lx,%lx)\n",
  93                     (unsigned long) p -> id,
  94                     (unsigned long) lo,
  95                     (unsigned long) hi
  96                 );
  97             #endif
  98             GC_push_all_stack(lo,hi);
  99         } /* for(p=GC_threads[i]...) */
 100     } /* for(i=0;i<THREAD_TABLE_SZ...) */
 101 }
 102
 103 /* Caller holds allocation lock.        */
 104 void GC_stop_world()
 105 {
 106     int i;
 107     GC_thread p;
 108     pthread_t my_thread = pthread_self();
 109     kern_return_t kern_result;
 110
 111     #if DEBUG_THREADS
 112     GC_printf1("Stopping the world from 0x%lx\n", pthread_self());
 113     #endif
 114
 115     /* Make sure all free list construction has stopped before we start. */
 116     /* No new construction can start, since free list construction is   */
 117     /* required to acquire and release the GC lock before it starts,    */
 118     /* and we have the lock.                                            */
 119 #   ifdef PARALLEL_MARK
 120       GC_acquire_mark_lock();
 121       GC_ASSERT(GC_fl_builder_count == 0);
 122       /* We should have previously waited for it to become zero. */
 123 #   endif /* PARALLEL_MARK */
 124
 125     for (i = 0; i < THREAD_TABLE_SZ; i++) {
 126         for (p = GC_threads[i]; p != 0; p = p -> next) {
 127             if (p -> id == my_thread) continue;
 128             if (p -> flags & FINISHED) continue;
 129             if (p -> thread_blocked) /* Will wait */ continue;
 130
 131             #if DEBUG_THREADS
 132             GC_printf1("Suspending thread 0x%lx\n", p -> id);
 133             #endif
 134
 135             /* Suspend the thread */
 136             kern_result = thread_suspend(p->stop_info.mach_thread);
 137             if(kern_result != KERN_SUCCESS) ABORT("thread_suspend failed");
 138
 139             /* This is only needed if we are modifying the threads
 140                state. thread_abort_safely should also be used
 141                if this code is ever added in again.
 142
 143                kern_result = thread_abort(p->stop_info.mach_thread);
 144                if(kern_result != KERN_SUCCESS)
 145                    ABORT("thread_abort failed (%ul)",kern_result);
 146             */
 147         }
 148     }
 149
 150 #   ifdef MPROTECT_VDB
 151     if(GC_incremental) {
 152         extern void GC_mprotect_stop();
 153         GC_mprotect_stop();
 154     }
 155 #   endif
 156
 157 #   ifdef PARALLEL_MARK
 158       GC_release_mark_lock();
 159 #   endif
 160     #if DEBUG_THREADS
 161       GC_printf1("World stopped from 0x%lx\n", pthread_self());
 162     #endif
 163 }
 164
 165 /* Caller holds allocation lock, and has held it continuously since     */
 166 /* the world stopped.                                                   */
 167 void GC_start_world()
 168 {
 169     pthread_t my_thread = pthread_self();
 170     int i;
 171     GC_thread p;
 172     kern_return_t kern_result;
 173
 174 #   if DEBUG_THREADS
 175       GC_printf0("World starting\n");
 176 #   endif
 177
 178 #   ifdef MPROTECT_VDB
 179     if(GC_incremental) {
 180         extern void GC_mprotect_resume();
 181         GC_mprotect_resume();
 182     }
 183 #   endif
 184
 185     for (i = 0; i < THREAD_TABLE_SZ; i++) {
 186         for (p = GC_threads[i]; p != 0; p = p -> next) {
 187             if (p -> id == my_thread) continue;
 188             if (p -> flags & FINISHED) continue;
 189             if (p -> thread_blocked) continue;
 190
 191             #if DEBUG_THREADS
 192             GC_printf1("Resuming 0x%lx\n", p -> id);
 193             #endif
 194
 195             /* Resume the thread */
 196             kern_result = thread_resume(p->stop_info.mach_thread);
 197             if(kern_result != KERN_SUCCESS) ABORT("thread_resume failed");
 198         }
 199     }
 200     #if DEBUG_THREADS
 201       GC_printf0("World started\n");
 202     #endif
 203 }
 204
 205 void GC_stop_init() {
 206
 207 }
 208
 209 #endif