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| author | Rich Felker <dalias@aerifal.cx> | 2011-03-04 00:45:59 -0500 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2011-03-04 00:45:59 -0500 |
| commit | 6fc5fdbdc70dd17ea8e681a361fb4dae541ee953 (patch) | |
| tree | eee28ceddc2de85e528e50340e045a875e6a8e60 /src/thread/sem_trywait.c | |
| parent | 03dcc3417ce4388a652bdd053cb2b6af860daf00 (diff) | |
| download | musl-6fc5fdbdc70dd17ea8e681a361fb4dae541ee953.tar.gz | |
implement POSIX semaphores
Diffstat (limited to 'src/thread/sem_trywait.c')
| -rw-r--r-- | src/thread/sem_trywait.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/thread/sem_trywait.c b/src/thread/sem_trywait.c new file mode 100644 index 00000000..d0e928ef --- /dev/null +++ b/src/thread/sem_trywait.c @@ -0,0 +1,11 @@ +#include <semaphore.h> +#include "pthread_impl.h" + +int sem_trywait(sem_t *sem) +{ + int val = a_fetch_add(sem->__val, -1); + if (val > 0) return 0; + a_inc(sem->__val); + errno = EAGAIN; + return -1; +} |