darwin_stop_world.c

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#include "private/pthread_support.h"

/* This probably needs more porting work to ppc64. */

# if defined(GC_DARWIN_THREADS)

/* From "Inside Mac OS X - Mach-O Runtime Architecture" published by Apple
   Page 49:
   "The space beneath the stack pointer, where a new stack frame would normally
   be allocated, is called the red zone. This area as shown in Figure 3-2 may
   be used for any purpose as long as a new stack frame does not need to be
   added to the stack."

   Page 50: "If a leaf procedure's red zone usage would exceed 224 bytes, then
   it must set up a stack frame just like routines that call other routines."
*/
#ifdef POWERPC
# if CPP_WORDSZ == 32
#   define PPC_RED_ZONE_SIZE 224
# elif CPP_WORDSZ == 64
#   define PPC_RED_ZONE_SIZE 320
# endif
#endif

typedef struct StackFrame {
  unsigned long	savedSP;
  unsigned long	savedCR;
  unsigned long	savedLR;
  unsigned long	reserved[2];
  unsigned long	savedRTOC;
} StackFrame;

unsigned long FindTopOfStack(unsigned long stack_start)
{
  StackFrame	*frame;

  if (stack_start == 0) {
# ifdef POWERPC
#   if CPP_WORDSZ == 32
      __asm__ volatile("lwz	%0,0(r1)" : "=r" (frame));
#   else
      __asm__ volatile("ld	%0,0(r1)" : "=r" (frame));
#   endif
# endif
  } else {
    frame = (StackFrame *)stack_start;
  }

# ifdef DEBUG_THREADS
    /* GC_printf("FindTopOfStack start at sp = %p\n", frame); */
# endif
  do {
    if (frame->savedSP == 0)
      break;
    /* if there are no more stack frames, stop */

    frame = (StackFrame*)frame->savedSP;

    /* we do these next two checks after going to the next frame
       because the LR for the first stack frame in the loop
       is not set up on purpose, so we shouldn't check it. */
    if ((frame->savedLR & ~3) == 0)
      break; /* if the next LR is bogus, stop */
    if ((~(frame->savedLR) & ~3) == 0)
      break; /* ditto */
  } while (1);

# ifdef DEBUG_THREADS
    /* GC_printf("FindTopOfStack finish at sp = %p\n", frame); */
# endif

  return (unsigned long)frame;
}

#ifdef DARWIN_DONT_PARSE_STACK
void GC_push_all_stacks()
{
  int i;
  kern_return_t r;
  GC_thread p;
  pthread_t me;
  ptr_t lo, hi;
  GC_THREAD_STATE_T state;
  /* MACHINE_THREAD_STATE_COUNT doesn't seem to be defined everywhere.	*/
  /* Hence we use our own version.					*/
  mach_msg_type_number_t thread_state_count = GC_MACH_THREAD_STATE_COUNT;

  me = pthread_self();
  if (!GC_thr_initialized)
    GC_thr_init();

  for(i = 0; i < THREAD_TABLE_SZ; i++) {
    for(p = GC_threads[i]; p != 0; p = p->next) {
      if(p->flags & FINISHED) continue;
      if(pthread_equal(p->id, me)) {
	lo = GC_approx_sp();
      } else {
	/* Get the thread state (registers, etc) */
	r = thread_get_state(p->stop_info.mach_thread, GC_MACH_THREAD_STATE,
			     (natural_t*)&state, &thread_state_count);

#       ifdef DEBUG_THREADS
	  GC_printf("thread_get_state return value = %d\n", r);
#	endif

	if(r != KERN_SUCCESS)
	  ABORT("thread_get_state failed");

#       if defined(I386)
	  lo = (void*)state . THREAD_FLD (esp);
	  GC_push_one(state . THREAD_FLD (eax));
	  GC_push_one(state . THREAD_FLD (ebx));
	  GC_push_one(state . THREAD_FLD (ecx));
	  GC_push_one(state . THREAD_FLD (edx));
	  GC_push_one(state . THREAD_FLD (edi));
	  GC_push_one(state . THREAD_FLD (esi));
	  GC_push_one(state . THREAD_FLD (ebp));

#       elif defined(X86_64)
	  lo = (void*)state . THREAD_FLD (rsp);
	  GC_push_one(state . THREAD_FLD (rax));
	  GC_push_one(state . THREAD_FLD (rbx));
	  GC_push_one(state . THREAD_FLD (rcx));
	  GC_push_one(state . THREAD_FLD (rdx));
	  GC_push_one(state . THREAD_FLD (rdi));
	  GC_push_one(state . THREAD_FLD (rsi));
	  GC_push_one(state . THREAD_FLD (rbp));
	  GC_push_one(state . THREAD_FLD (rsp));
	  GC_push_one(state . THREAD_FLD (r8));
	  GC_push_one(state . THREAD_FLD (r9));
	  GC_push_one(state . THREAD_FLD (r10));
	  GC_push_one(state . THREAD_FLD (r11));
	  GC_push_one(state . THREAD_FLD (r12));
	  GC_push_one(state . THREAD_FLD (r13));
	  GC_push_one(state . THREAD_FLD (r14));
	  GC_push_one(state . THREAD_FLD (r15));
	  GC_push_one(state . THREAD_FLD (rip));
	  GC_push_one(state . THREAD_FLD (rflags));
	  GC_push_one(state . THREAD_FLD (cs));
	  GC_push_one(state . THREAD_FLD (fs));
	  GC_push_one(state . THREAD_FLD (gs));

#       elif defined(POWERPC)
	  lo = (void*)(state . THREAD_FLD (r1) - PPC_RED_ZONE_SIZE);

	  GC_push_one(state . THREAD_FLD (r0));
	  GC_push_one(state . THREAD_FLD (r2));
	  GC_push_one(state . THREAD_FLD (r3));
	  GC_push_one(state . THREAD_FLD (r4));
	  GC_push_one(state . THREAD_FLD (r5));
	  GC_push_one(state . THREAD_FLD (r6));
	  GC_push_one(state . THREAD_FLD (r7));
	  GC_push_one(state . THREAD_FLD (r8));
	  GC_push_one(state . THREAD_FLD (r9));
	  GC_push_one(state . THREAD_FLD (r10));
	  GC_push_one(state . THREAD_FLD (r11));
	  GC_push_one(state . THREAD_FLD (r12));
	  GC_push_one(state . THREAD_FLD (r13));
	  GC_push_one(state . THREAD_FLD (r14));
	  GC_push_one(state . THREAD_FLD (r15));
	  GC_push_one(state . THREAD_FLD (r16));
	  GC_push_one(state . THREAD_FLD (r17));
	  GC_push_one(state . THREAD_FLD (r18));
	  GC_push_one(state . THREAD_FLD (r19));
	  GC_push_one(state . THREAD_FLD (r20));
	  GC_push_one(state . THREAD_FLD (r21));
	  GC_push_one(state . THREAD_FLD (r22));
	  GC_push_one(state . THREAD_FLD (r23));
	  GC_push_one(state . THREAD_FLD (r24));
	  GC_push_one(state . THREAD_FLD (r25));
	  GC_push_one(state . THREAD_FLD (r26));
	  GC_push_one(state . THREAD_FLD (r27));
	  GC_push_one(state . THREAD_FLD (r28));
	  GC_push_one(state . THREAD_FLD (r29));
	  GC_push_one(state . THREAD_FLD (r30));
	  GC_push_one(state . THREAD_FLD (r31));
#	else
#	  error FIXME for non-x86 || ppc architectures
#	endif
      } /* p != me */
      if(p->flags & MAIN_THREAD)
	hi = GC_stackbottom;
      else
	hi = p->stack_end;
#     if DEBUG_THREADS
        GC_printf("Darwin: Stack for thread 0x%lx = [%lx,%lx)\n",
		  (unsigned long) p -> id, (unsigned long) lo,
		  (unsigned long) hi);
#     endif
      GC_push_all_stack(lo, hi);
    } /* for(p=GC_threads[i]...) */
  } /* for(i=0;i<THREAD_TABLE_SZ...) */
}

#else /* !DARWIN_DONT_PARSE_STACK; Use FindTopOfStack() */

void GC_push_all_stacks()
{
  unsigned int i;
  task_t my_task;
  kern_return_t r;
  mach_port_t me;
  ptr_t lo, hi;
  thread_act_array_t act_list = 0;
  mach_msg_type_number_t listcount = 0;

  me = mach_thread_self();
  if (!GC_thr_initialized)
    GC_thr_init();

  my_task = current_task();
  r = task_threads(my_task, &act_list, &listcount);
  if(r != KERN_SUCCESS)
    ABORT("task_threads failed");
  for(i = 0; i < listcount; i++) {
    thread_act_t thread = act_list[i];
    if (thread == me) {
      lo = GC_approx_sp();
      hi = (ptr_t)FindTopOfStack(0);
    } else {
#     if defined(POWERPC)
        GC_THREAD_STATE_T info;
	mach_msg_type_number_t outCount = THREAD_STATE_MAX;
	r = thread_get_state(thread, GC_MACH_THREAD_STATE, (natural_t *)&info,
			     &outCount);
	if(r != KERN_SUCCESS)
	  ABORT("task_get_state failed");

	lo = (void*)(info . THREAD_FLD (r1) - PPC_RED_ZONE_SIZE);
	hi = (ptr_t)FindTopOfStack(info . THREAD_FLD (r1));

	GC_push_one(info . THREAD_FLD (r0));
	GC_push_one(info . THREAD_FLD (r2));
	GC_push_one(info . THREAD_FLD (r3));
	GC_push_one(info . THREAD_FLD (r4));
	GC_push_one(info . THREAD_FLD (r5));
	GC_push_one(info . THREAD_FLD (r6));
	GC_push_one(info . THREAD_FLD (r7));
	GC_push_one(info . THREAD_FLD (r8));
	GC_push_one(info . THREAD_FLD (r9));
	GC_push_one(info . THREAD_FLD (r10));
	GC_push_one(info . THREAD_FLD (r11));
	GC_push_one(info . THREAD_FLD (r12));
	GC_push_one(info . THREAD_FLD (r13));
	GC_push_one(info . THREAD_FLD (r14));
	GC_push_one(info . THREAD_FLD (r15));
	GC_push_one(info . THREAD_FLD (r16));
	GC_push_one(info . THREAD_FLD (r17));
	GC_push_one(info . THREAD_FLD (r18));
	GC_push_one(info . THREAD_FLD (r19));
	GC_push_one(info . THREAD_FLD (r20));
	GC_push_one(info . THREAD_FLD (r21));
	GC_push_one(info . THREAD_FLD (r22));
	GC_push_one(info . THREAD_FLD (r23));
	GC_push_one(info . THREAD_FLD (r24));
	GC_push_one(info . THREAD_FLD (r25));
	GC_push_one(info . THREAD_FLD (r26));
	GC_push_one(info . THREAD_FLD (r27));
	GC_push_one(info . THREAD_FLD (r28));
	GC_push_one(info . THREAD_FLD (r29));
	GC_push_one(info . THREAD_FLD (r30));
	GC_push_one(info . THREAD_FLD (r31));

#     elif defined(I386)
	/* FIXME: Remove after testing:	*/
	WARN("This is completely untested and likely will not work\n", 0);
	GC_THREAD_STATE_T info;
	mach_msg_type_number_t outCount = THREAD_STATE_MAX;
	r = thread_get_state(thread, GC_MACH_THREAD_STATE, (natural_t *)&info,
			     &outCount);
	if(r != KERN_SUCCESS)
	  ABORT("task_get_state failed");

	lo = (void*)info . THREAD_FLD (esp);
	hi = (ptr_t)FindTopOfStack(info . THREAD_FLD (esp));

	GC_push_one(info . THREAD_FLD (eax));
	GC_push_one(info . THREAD_FLD (ebx));
	GC_push_one(info . THREAD_FLD (ecx));
	GC_push_one(info . THREAD_FLD (edx));
	GC_push_one(info . THREAD_FLD (edi));
	GC_push_one(info . THREAD_FLD (esi));
	/* GC_push_one(info . THREAD_FLD (ebp));  */
	/* GC_push_one(info . THREAD_FLD (esp));  */
	GC_push_one(info . THREAD_FLD (ss));
	GC_push_one(info . THREAD_FLD (eip));
	GC_push_one(info . THREAD_FLD (cs));
	GC_push_one(info . THREAD_FLD (ds));
	GC_push_one(info . THREAD_FLD (es));
	GC_push_one(info . THREAD_FLD (fs));
	GC_push_one(info . THREAD_FLD (gs));

#     elif defined(X86_64)
	GC_THREAD_STATE_T info;
	mach_msg_type_number_t outCount = THREAD_STATE_MAX;
	r = thread_get_state(thread, GC_MACH_THREAD_STATE, (natural_t *)&info,
			     &outCount);
	if(r != KERN_SUCCESS)
	  ABORT("task_get_state failed");