calls in shared flavors of the HP-UX C library. Most of the stubs
have no functionality. The details are described in the "libc cumulative
patch" for each subversion of HP-UX 11. There are two special interfaces
- provided for checking whether an application is linked to a pthread
+ provided for checking whether an application is linked to a shared pthread
library or not. However, these interfaces aren't available in early
- libc versions. We also can't use pthread_once as some libc versions
- call the init function. So, we use pthread_create to check whether it
- is possible to create a thread or not. The stub implementation returns
- the error number ENOSYS. */
+ pthread libraries. We also need a test that works for archive
+ libraries. We can't use pthread_once as some libc versions call the
+ init function. We also can't use pthread_create or pthread_attr_init
+ as these create a thread and thereby prevent changing the default stack
+ size. The function pthread_default_stacksize_np is available in both
+ the archive and shared versions of libpthread. It can be used to
+ determine the default pthread stack size. There is a stub in some
+ shared libc versions which returns a zero size if pthreads are not
+ active. We provide an equivalent stub to handle cases where libc
+ doesn't provide one. */
#if defined(__hppa__) && defined(__hpux__)
-#include <errno.h>
-
static volatile int __gthread_active = -1;
-static void *
-__gthread_start (void *arg __attribute__((unused)))
-{
- return NULL;
-}
-
-static void __gthread_active_init (void) __attribute__((noinline));
-static void
-__gthread_active_init (void)
-{
- static pthread_mutex_t __gthread_active_mutex = PTHREAD_MUTEX_INITIALIZER;
- pthread_t t;
- pthread_attr_t a;
- int result;
-
- __gthrw_(pthread_mutex_lock) (&__gthread_active_mutex);
- if (__gthread_active < 0)
- {
- __gthrw_(pthread_attr_init) (&a);
- __gthrw_(pthread_attr_setdetachstate) (&a, PTHREAD_CREATE_DETACHED);
- result = __gthrw_(pthread_create) (&t, &a, __gthread_start, NULL);
- if (result != ENOSYS)
- __gthread_active = 1;
- else
- __gthread_active = 0;
- __gthrw_(pthread_attr_destroy) (&a);
- }
- __gthrw_(pthread_mutex_unlock) (&__gthread_active_mutex);
-}
-
static inline int
__gthread_active_p (void)
{
/* Avoid reading __gthread_active twice on the main code path. */
int __gthread_active_latest_value = __gthread_active;
+ size_t __s;
- /* This test is not protected to avoid taking a lock on the main code
- path so every update of __gthread_active in a threaded program must
- be atomic with regard to the result of the test. */
if (__builtin_expect (__gthread_active_latest_value < 0, 0))
{
- __gthread_active_init ();
+ pthread_default_stacksize_np (0, &__s);
+ __gthread_active = __s ? 1 : 0;
__gthread_active_latest_value = __gthread_active;
}