diff options
Diffstat (limited to 'nptl/sem_wait.c')
-rw-r--r-- | nptl/sem_wait.c | 101 |
1 files changed, 35 insertions, 66 deletions
diff --git a/nptl/sem_wait.c b/nptl/sem_wait.c index df11933b69..c1fd10c9d0 100644 --- a/nptl/sem_wait.c +++ b/nptl/sem_wait.c @@ -17,80 +17,18 @@ License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ -#include <errno.h> -#include <sysdep.h> -#include <lowlevellock.h> -#include <internaltypes.h> -#include <semaphore.h> - -#include <pthreadP.h> -#include <shlib-compat.h> -#include <atomic.h> - - -void -attribute_hidden -__sem_wait_cleanup (void *arg) -{ - struct new_sem *isem = (struct new_sem *) arg; - - atomic_decrement (&isem->nwaiters); -} - -/* This is in a seperate function in order to make sure gcc - puts the call site into an exception region, and thus the - cleanups get properly run. */ -static int -__attribute__ ((noinline)) -do_futex_wait (struct new_sem *isem) -{ - int err, oldtype = __pthread_enable_asynccancel (); - - err = lll_futex_wait (&isem->value, 0, isem->private ^ FUTEX_PRIVATE_FLAG); - - __pthread_disable_asynccancel (oldtype); - return err; -} +#include "sem_waitcommon.c" int __new_sem_wait (sem_t *sem) { - struct new_sem *isem = (struct new_sem *) sem; - int err; - - if (atomic_decrement_if_positive (&isem->value) > 0) + if (__new_sem_wait_fast ((struct new_sem *) sem, 0) == 0) return 0; - - atomic_increment (&isem->nwaiters); - - pthread_cleanup_push (__sem_wait_cleanup, isem); - - while (1) - { - err = do_futex_wait(isem); - if (err != 0 && err != -EWOULDBLOCK) - { - __set_errno (-err); - err = -1; - break; - } - - if (atomic_decrement_if_positive (&isem->value) > 0) - { - err = 0; - break; - } - } - - pthread_cleanup_pop (0); - - atomic_decrement (&isem->nwaiters); - - return err; + else + return __new_sem_wait_slow((struct new_sem *) sem, NULL); } versioned_symbol (libpthread, __new_sem_wait, sem_wait, GLIBC_2_1); - #if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1) int attribute_compat_text_section @@ -121,3 +59,34 @@ __old_sem_wait (sem_t *sem) compat_symbol (libpthread, __old_sem_wait, sem_wait, GLIBC_2_0); #endif + +int +__new_sem_trywait (sem_t *sem) +{ + /* We must not fail spuriously, so require a definitive result even if this + may lead to a long execution time. */ + if (__new_sem_wait_fast ((struct new_sem *) sem, 1) == 0) + return 0; + __set_errno (EAGAIN); + return -1; +} +versioned_symbol (libpthread, __new_sem_trywait, sem_trywait, GLIBC_2_1); +#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1) +int +__old_sem_trywait (sem_t *sem) +{ + int *futex = (int *) sem; + int val; + + if (*futex > 0) + { + val = atomic_decrement_if_positive (futex); + if (val > 0) + return 0; + } + + __set_errno (EAGAIN); + return -1; +} +compat_symbol (libpthread, __old_sem_trywait, sem_trywait, GLIBC_2_0); +#endif |