diff options
Diffstat (limited to 'include/zix/sem.h')
| -rw-r--r-- | include/zix/sem.h | 67 |
1 files changed, 66 insertions, 1 deletions
diff --git a/include/zix/sem.h b/include/zix/sem.h index b782761..fd85aab 100644 --- a/include/zix/sem.h +++ b/include/zix/sem.h @@ -22,6 +22,8 @@ extern "C" { #endif #include <stdbool.h> +#include <stdint.h> +#include <time.h> /** @addtogroup zix @@ -35,7 +37,7 @@ struct ZixSemImpl; /** A counting semaphore. - This is an integer that is always positive, and has two main operations: + This is an integer that is never negative, and has two main operations: increment (post) and decrement (wait). If a decrement can not be performed (i.e. the value is 0) the caller will be blocked until another thread posts and the operation can succeed. @@ -100,6 +102,20 @@ static inline ZixStatus zix_sem_try_wait(ZixSem* ZIX_NONNULL sem); /** + Wait for an amount of time until count is > 0, then decrement if possible. + + Obviously not realtime safe. + + @return #ZIX_STATUS_SUCCESS if `sem` was decremented, #ZIX_STATUS_TIMEOUT if + it was still zero when the timeout was reached, or #ZIX_STATUS_BAD_ARG if + `sem` is invalid. +*/ +static inline ZixStatus +zix_sem_timed_wait(ZixSem* ZIX_NONNULL sem, + uint32_t seconds, + uint32_t nanoseconds); + +/** @cond */ @@ -153,6 +169,19 @@ zix_sem_try_wait(ZixSem* ZIX_NONNULL sem) : ZIX_STATUS_ERROR; } +static inline ZixStatus +zix_sem_timed_wait(ZixSem* ZIX_NONNULL sem, + const uint32_t seconds, + const uint32_t nanoseconds) +{ + const mach_timespec_t interval = {seconds, (clock_res_t)nanoseconds}; + const kern_return_t r = semaphore_timedwait(sem->sem, interval); + + return (r == KERN_SUCCESS) ? ZIX_STATUS_SUCCESS + : (r == KERN_OPERATION_TIMED_OUT) ? ZIX_STATUS_TIMEOUT + : ZIX_STATUS_ERROR; +} + #elif defined(_WIN32) struct ZixSemImpl { @@ -197,6 +226,19 @@ zix_sem_try_wait(ZixSem* ZIX_NONNULL sem) : ZIX_STATUS_ERROR; } +static inline ZixStatus +zix_sem_timed_wait(ZixSem* ZIX_NONNULL sem, + const uint32_t seconds, + const uint32_t nanoseconds) +{ + const uint32_t milliseconds = seconds * 1000U + nanoseconds / 1000000U; + const DWORD r = WaitForSingleObject(sem->sem, milliseconds); + + return (r == WAIT_OBJECT_0) ? ZIX_STATUS_SUCCESS + : (r == WAIT_TIMEOUT) ? ZIX_STATUS_TIMEOUT + : ZIX_STATUS_ERROR; +} + #else /* !defined(__APPLE__) && !defined(_WIN32) */ struct ZixSemImpl { @@ -245,6 +287,29 @@ zix_sem_try_wait(ZixSem* ZIX_NONNULL sem) : ZIX_STATUS_SUCCESS; } +static inline ZixStatus +zix_sem_timed_wait(ZixSem* ZIX_NONNULL sem, + const uint32_t seconds, + const uint32_t nanoseconds) +{ + struct timespec ts = {0, 0}; + + if (clock_gettime(CLOCK_REALTIME, &ts)) { + return ZIX_STATUS_ERROR; + } + + ts.tv_sec += seconds; + ts.tv_nsec += nanoseconds; + + int r = 0; + while ((r = sem_timedwait(&sem->sem, &ts)) && errno == EINTR) { + // Interrupted, try again + } + + return r ? (errno == ETIMEDOUT ? ZIX_STATUS_TIMEOUT : zix_errno_status(errno)) + : ZIX_STATUS_SUCCESS; +} + #endif /** |