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re PR target/24071 (__gthread_active_p vs __gthread_once)

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PR target/24071
	* gthr-posix.h (__gthread_active_p): New implementation on Solaris.
	* gthr-posix95.h (__gthread_active_p): Likewise.

From-SVN: r118259
This commit is contained in:
Eric Botcazou 2006-10-31 18:54:58 +01:00 committed by Eric Botcazou
parent 9e5ac75fe2
commit efd6ef80ca
3 changed files with 116 additions and 0 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2006-10-31 Eric Botcazou <ebotcazou@libertysurf.fr>
PR target/24071
* gthr-posix.h (__gthread_active_p): New implementation on Solaris.
* gthr-posix95.h (__gthread_active_p): Likewise.
2006-10-31 Richard Guenther <rguenther@suse.de>
* config/i386/i386.md (asindf2, asinsf2, asinxf2, acosdf2,

55
gcc/gthr-posix.h
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@ -142,6 +142,59 @@ __gthrw(pthread_setschedparam)
#if SUPPORTS_WEAK && GTHREAD_USE_WEAK
/* On Solaris 2.6 up to 9, the libc exposes a POSIX threads interface even if
-pthreads is not specified. The functions are dummies and most return an
error value. However pthread_once returns 0 without invoking the routine
it is passed so we cannot pretend that the interface is active if -pthreads
is not specified. On Solaris 2.5.1, the interface is not exposed at all so
we need to play the usual game with weak symbols. On Solaris 10 and up, a
working interface is always exposed. */
#if defined(__sun) && defined(__svr4__)
static volatile int __gthread_active = -1;
static void
__gthread_trigger (void)
{
__gthread_active = 1;
}
static inline int
__gthread_active_p (void)
{
static pthread_mutex_t __gthread_active_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_once_t __gthread_active_once = PTHREAD_ONCE_INIT;
/* Avoid reading __gthread_active twice on the main code path. */
int __gthread_active_latest_value = __gthread_active;
/* 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))
{
if (__gthrw_(pthread_once))
{
/* If this really is a threaded program, then we must ensure that
__gthread_active has been set to 1 before exiting this block. */
__gthrw_(pthread_mutex_lock) (&__gthread_active_mutex);
__gthrw_(pthread_once) (&__gthread_active_once, __gthread_trigger);
__gthrw_(pthread_mutex_unlock) (&__gthread_active_mutex);
}
/* Make sure we'll never enter this block again. */
if (__gthread_active < 0)
__gthread_active = 0;
__gthread_active_latest_value = __gthread_active;
}
return __gthread_active_latest_value != 0;
}
#else /* not Solaris */
static inline int
__gthread_active_p (void)
{
@ -150,6 +203,8 @@ __gthread_active_p (void)
return __gthread_active_ptr != 0;
}
#endif /* Solaris */
#else /* not SUPPORTS_WEAK */
static inline int

55
gcc/gthr-posix95.h
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@ -109,6 +109,59 @@ __gthrw(pthread_setschedparam)
#if SUPPORTS_WEAK && GTHREAD_USE_WEAK
/* On Solaris 2.6 up to 9, the libc exposes a POSIX threads interface even if
-pthreads is not specified. The functions are dummies and most return an
error value. However pthread_once returns 0 without invoking the routine
it is passed so we cannot pretend that the interface is active if -pthreads
is not specified. On Solaris 2.5.1, the interface is not exposed at all so
we need to play the usual game with weak symbols. On Solaris 10 and up, a
working interface is always exposed. */
#if defined(__sun) && defined(__svr4__)
static volatile int __gthread_active = -1;
static void
__gthread_trigger (void)
{
__gthread_active = 1;
}
static inline int
__gthread_active_p (void)
{
static pthread_mutex_t __gthread_active_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_once_t __gthread_active_once = PTHREAD_ONCE_INIT;
/* Avoid reading __gthread_active twice on the main code path. */
int __gthread_active_latest_value = __gthread_active;
/* 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))
{
if (__gthrw_(pthread_once))
{
/* If this really is a threaded program, then we must ensure that
__gthread_active has been set to 1 before exiting this block. */
__gthrw_(pthread_mutex_lock) (&__gthread_active_mutex);
__gthrw_(pthread_once) (&__gthread_active_once, __gthread_trigger);
__gthrw_(pthread_mutex_unlock) (&__gthread_active_mutex);
}
/* Make sure we'll never enter this block again. */
if (__gthread_active < 0)
__gthread_active = 0;
__gthread_active_latest_value = __gthread_active;
}
return __gthread_active_latest_value != 0;
}
#else /* not Solaris */
static inline int
__gthread_active_p (void)
{
@ -117,6 +170,8 @@ __gthread_active_p (void)
return __gthread_active_ptr != 0;
}
#endif /* Solaris */
#else /* not SUPPORTS_WEAK */
static inline int