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);
}
/* 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);
/*
* 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);
}