Пример #1
0
int
GC_pthread_create(pthread_t *new_thread,
          const pthread_attr_t *attr_in,
          void * (*thread_execp)(void *), void *arg)
{
    int result;
    GC_thread t;
    pthread_t my_new_thread;
    pthread_attr_t  attr;
    word my_flags = 0;
    int  flag;
    void * stack = 0;
    size_t stack_size = 0;
    int    n;
    struct sched_param schedparam;
   
    (void)pthread_attr_init(&attr);
    if (attr_in != 0) {
	(void)pthread_attr_getstacksize(attr_in, &stack_size);
	(void)pthread_attr_getstackaddr(attr_in, &stack);
    }

    LOCK();
    if (!GC_is_initialized) {
	    GC_init_inner();
    }
    GC_multithreaded++;
	    
    if (stack == 0) {
     	if (stack_size == 0)
		stack_size = 1048576;
			  /* ^-- 1 MB (this was GC_min_stack_sz, but that
			   * violates the pthread_create documentation which
			   * says the default value if none is supplied is
			   * 1MB) */
	else
		stack_size += thr_min_stack();

     	stack = (void *)GC_stack_alloc(&stack_size);
     	if (stack == 0) {
	    GC_multithreaded--;
     	    UNLOCK();
	    errno = ENOMEM;
     	    return -1;
     	}
    } else {
    	my_flags |= CLIENT_OWNS_STACK;
    }
    (void)pthread_attr_setstacksize(&attr, stack_size);
    (void)pthread_attr_setstackaddr(&attr, stack);
    if (attr_in != 0) {
	(void)pthread_attr_getscope(attr_in, &n);
	(void)pthread_attr_setscope(&attr, n);
	(void)pthread_attr_getschedparam(attr_in, &schedparam);
	(void)pthread_attr_setschedparam(&attr, &schedparam);
	(void)pthread_attr_getschedpolicy(attr_in, &n);
	(void)pthread_attr_setschedpolicy(&attr, n);
	(void)pthread_attr_getinheritsched(attr_in, &n);
	(void)pthread_attr_setinheritsched(&attr, n);

	(void)pthread_attr_getdetachstate(attr_in, &flag);
	if (flag == PTHREAD_CREATE_DETACHED) {
		my_flags |= DETACHED;
	}
	(void)pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
    }
    /*
     * thr_create can call malloc(), which if redirected will
     * attempt to acquire the allocation lock.
     * Unlock here to prevent deadlock.
     */


#if 0
#ifdef I386
    UNLOCK();
#endif
#endif
    result = 
	    pthread_create(&my_new_thread, &attr, thread_execp, arg);
#if 0
#ifdef I386
    LOCK();
#endif
#endif
    if (result == 0) {
        t = GC_new_thread(my_new_thread);
        t -> flags = my_flags;
        if (!(my_flags & DETACHED)) cond_init(&(t->join_cv), USYNC_THREAD, 0);
        t -> stack = stack;
        t -> stack_size = stack_size;
        if (new_thread != 0) *new_thread = my_new_thread;
        pthread_cond_signal(&GC_create_cv);
    } else {
	    if (!(my_flags & CLIENT_OWNS_STACK)) {
		    GC_stack_free(stack, stack_size);
	    }        
	    GC_multithreaded--;
    }
    UNLOCK();
    pthread_attr_destroy(&attr);
    return(result);
}
Пример #2
0
/* We hold the allocation lock.	*/
void GC_thr_init(void)
{
#   ifndef GC_DARWIN_THREADS
        int dummy;
#   endif
    GC_thread t;

    if (GC_thr_initialized) return;
    GC_thr_initialized = TRUE;
    
#   ifdef HANDLE_FORK
      /* Prepare for a possible fork.	*/
        pthread_atfork(GC_fork_prepare_proc, GC_fork_parent_proc,
	  	       GC_fork_child_proc);
#   endif /* HANDLE_FORK */
#   if defined(INCLUDE_LINUX_THREAD_DESCR)
      /* Explicitly register the region including the address 		*/
      /* of a thread local variable.  This should include thread	*/
      /* locals for the main thread, except for those allocated		*/
      /* in response to dlopen calls.					*/  
	{
	  ptr_t thread_local_addr = (ptr_t)(&dummy_thread_local);
	  ptr_t main_thread_start, main_thread_end;
          if (!GC_enclosing_mapping(thread_local_addr, &main_thread_start,
				    &main_thread_end)) {
	    ABORT("Failed to find mapping for main thread thread locals");
	  }
	  GC_add_roots_inner(main_thread_start, main_thread_end, FALSE);
	}
#   endif
    /* Add the initial thread, so we can stop it.	*/
      t = GC_new_thread(pthread_self());
#     ifdef GC_DARWIN_THREADS
         t -> stop_info.mach_thread = mach_thread_self();
#     else
         t -> stop_info.stack_ptr = (ptr_t)(&dummy);
#     endif
      t -> flags = DETACHED | MAIN_THREAD;

    GC_stop_init();

    /* Set GC_nprocs.  */
      {
	char * nprocs_string = GETENV("GC_NPROCS");
	GC_nprocs = -1;
	if (nprocs_string != NULL) GC_nprocs = atoi(nprocs_string);
      }
      if (GC_nprocs <= 0) {
#       if defined(GC_HPUX_THREADS)
	  GC_nprocs = pthread_num_processors_np();
#       endif
#	if defined(GC_OSF1_THREADS) || defined(GC_AIX_THREADS) \
	   || defined(GC_SOLARIS_THREADS) || defined(GC_GNU_THREADS)
	  GC_nprocs = sysconf(_SC_NPROCESSORS_ONLN);
	  if (GC_nprocs <= 0) GC_nprocs = 1;
#	endif
#       if defined(GC_IRIX_THREADS)
	  GC_nprocs = sysconf(_SC_NPROC_ONLN);
	  if (GC_nprocs <= 0) GC_nprocs = 1;
#       endif
#       if defined(GC_NETBSD_THREADS)
	  GC_nprocs = get_ncpu();
#       endif
#       if defined(GC_OPENBSD_THREADS)
	  GC_nprocs = 1;
#       endif
#       if defined(GC_DARWIN_THREADS) || defined(GC_FREEBSD_THREADS)
	  int ncpus = 1;
	  size_t len = sizeof(ncpus);
	  sysctl((int[2]) {CTL_HW, HW_NCPU}, 2, &ncpus, &len, NULL, 0);
Пример #3
0
/*
 * This may be called from DllMain, and hence operates under unusual
 * constraints.  In particular, it must be lock-free if GC_win32_dll_threads
 * is set.  Always called from the thread being added.
 * If GC_win32_dll_threads is not set, we already hold the allocation lock,
 * except possibly during single-threaded start-up code.
 */
static GC_thread GC_register_my_thread_inner(struct GC_stack_base *sb,
					     DWORD thread_id)
{
  GC_vthread me;

  /* The following should be a noop according to the win32	*/
  /* documentation.  There is empirical evidence that it	*/
  /* isn't.		- HB					*/
# if defined(MPROTECT_VDB)
#   if defined(GWW_VDB)
      if (GC_incremental && !GC_gww_dirty_init())
	SetUnhandledExceptionFilter(GC_write_fault_handler);
#   else
      if (GC_incremental) SetUnhandledExceptionFilter(GC_write_fault_handler);
#   endif
# endif

  if (GC_win32_dll_threads) {
    int i;
    /* It appears to be unsafe to acquire a lock here, since this	*/
    /* code is apparently not preeemptible on some systems.		*/
    /* (This is based on complaints, not on Microsoft's official	*/
    /* documentation, which says this should perform "only simple	*/
    /* initialization tasks".)						*/
    /* Hence we make do with nonblocking synchronization.		*/
    /* It has been claimed that DllMain is really only executed with	*/
    /* a particular system lock held, and thus careful use of locking	*/
    /* around code that doesn't call back into the system libraries	*/
    /* might be OK.  But this hasn't been tested across all win32	*/
    /* variants.							*/
                /* cast away volatile qualifier */
    for (i = 0; InterlockedExchange((IE_t)&dll_thread_table[i].in_use,1) != 0;
	 i++) {
      /* Compare-and-swap would make this cleaner, but that's not 	*/
      /* supported before Windows 98 and NT 4.0.  In Windows 2000,	*/
      /* InterlockedExchange is supposed to be replaced by		*/
      /* InterlockedExchangePointer, but that's not really what I	*/
      /* want here.							*/
      /* FIXME: We should eventually declare Win95 dead and use AO_	*/
      /* primitives here.						*/
      if (i == MAX_THREADS - 1)
        ABORT("too many threads");
    }
    /* Update GC_max_thread_index if necessary.  The following is safe,	*/
    /* and unlike CompareExchange-based solutions seems to work on all	*/
    /* Windows95 and later platforms.					*/
    /* Unfortunately, GC_max_thread_index may be temporarily out of 	*/
    /* bounds, so readers have to compensate.				*/
    while (i > GC_max_thread_index) {
      InterlockedIncrement((IE_t)&GC_max_thread_index);
    }
    if (GC_max_thread_index >= MAX_THREADS) {
      /* We overshot due to simultaneous increments.	*/
      /* Setting it to MAX_THREADS-1 is always safe.	*/
      GC_max_thread_index = MAX_THREADS - 1;
    }
    me = dll_thread_table + i;
  } else /* Not using DllMain */ {
    GC_ASSERT(I_HOLD_LOCK());
    GC_in_thread_creation = TRUE; /* OK to collect from unknown thread. */
    me = GC_new_thread(thread_id);
    GC_in_thread_creation = FALSE;
  }
# ifdef GC_PTHREADS
    /* me can be NULL -> segfault */
    me -> pthread_id = pthread_self();
# endif

  if (!DuplicateHandle(GetCurrentProcess(),
                 	GetCurrentThread(),
		        GetCurrentProcess(),
		        (HANDLE*)&(me -> handle),
		        0,
		        0,
		        DUPLICATE_SAME_ACCESS)) {
	DWORD last_error = GetLastError();
	GC_err_printf("Last error code: %d\n", last_error);
	ABORT("DuplicateHandle failed");
  }
  me -> stack_base = sb -> mem_base;
  /* Up until this point, GC_push_all_stacks considers this thread	*/
  /* invalid.								*/
  /* Up until this point, this entry is viewed as reserved but invalid	*/
  /* by GC_delete_thread.						*/
  me -> id = thread_id;
# if defined(THREAD_LOCAL_ALLOC)
      GC_init_thread_local((GC_tlfs)(&(me->tlfs)));
# endif
  if (me -> stack_base == NULL) 
      ABORT("Bad stack base in GC_register_my_thread_inner");
  if (GC_win32_dll_threads) {
    if (GC_please_stop) {
      AO_store(&GC_attached_thread, TRUE);
      AO_nop_full();  // Later updates must become visible after this.
    }
    /* We'd like to wait here, but can't, since waiting in DllMain 	*/
    /* provokes deadlocks.						*/
    /* Thus we force marking to be restarted instead.			*/
  } else {
    GC_ASSERT(!GC_please_stop);
  	/* Otherwise both we and the thread stopping code would be	*/
  	/* holding the allocation lock.					*/
  }
  return (GC_thread)(me);
}