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| author | Justin King <jcking@google.com> | 2024-01-11 18:51:23 +0000 |
|---|---|---|
| committer | Pranav Kant <prka@google.com> | 2024-01-12 23:20:06 +0000 |
| commit | be3c0fe888d69cdfda53a8065c5f486d01f7096e (patch) | |
| tree | 895caa0dfb2d0fa35d613d33022fb82531ca040c | |
| parent | 5643a977d0e2cca3877775f27a41df08e98d833a (diff) | |
| download | glibc-be3c0fe888d69cdfda53a8065c5f486d01f7096e.tar.gz glibc-be3c0fe888d69cdfda53a8065c5f486d01f7096e.tar.xz glibc-be3c0fe888d69cdfda53a8065c5f486d01f7096e.zip | |
Optimize pthread_cond_timedwait to avoid unnecessary call to clock_gettime for CLOCK_MONOTONIC
| -rw-r--r-- | nptl/pthread_cond_wait.c | 29 | ||||
| -rw-r--r-- | nptl/sem_waitcommon.c | 4 | ||||
| -rw-r--r-- | sysdeps/nptl/futex-internal.h | 2 | ||||
| -rw-r--r-- | sysdeps/sparc/sparc32/sem_waitcommon.c | 2 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/futex-internal.h | 4 |
5 files changed, 10 insertions, 31 deletions
diff --git a/nptl/pthread_cond_wait.c b/nptl/pthread_cond_wait.c index 3e11054182..0dbab42148 100644 --- a/nptl/pthread_cond_wait.c +++ b/nptl/pthread_cond_wait.c @@ -510,34 +510,13 @@ __pthread_cond_wait_common (pthread_cond_t *cond, pthread_mutex_t *mutex, if (__glibc_unlikely (abstime->tv_sec < 0)) err = ETIMEDOUT; - else if ((flags & __PTHREAD_COND_CLOCK_MONOTONIC_MASK) != 0) - { - /* CLOCK_MONOTONIC is requested. */ - struct timespec rt; - if (__clock_gettime (CLOCK_MONOTONIC, &rt) != 0) - __libc_fatal ("clock_gettime does not support " - "CLOCK_MONOTONIC"); - /* Convert the absolute timeout value to a relative - timeout. */ - rt.tv_sec = abstime->tv_sec - rt.tv_sec; - rt.tv_nsec = abstime->tv_nsec - rt.tv_nsec; - if (rt.tv_nsec < 0) - { - rt.tv_nsec += 1000000000; - --rt.tv_sec; - } - /* Did we already time out? */ - if (__glibc_unlikely (rt.tv_sec < 0)) - err = ETIMEDOUT; - else - err = futex_reltimed_wait_cancelable - (cond->__data.__g_signals + g, 0, &rt, private); - } else { - /* Use CLOCK_REALTIME. */ err = futex_abstimed_wait_cancelable - (cond->__data.__g_signals + g, 0, abstime, private); + (cond->__data.__g_signals + g, 0, abstime, + (flags & __PTHREAD_COND_CLOCK_MONOTONIC_MASK) != 0 + ? 0 + : FUTEX_CLOCK_REALTIME, private); } } diff --git a/nptl/sem_waitcommon.c b/nptl/sem_waitcommon.c index 30984be2d0..7d2a5b2121 100644 --- a/nptl/sem_waitcommon.c +++ b/nptl/sem_waitcommon.c @@ -110,10 +110,10 @@ do_futex_wait (struct new_sem *sem, const struct timespec *abstime) #if __HAVE_64B_ATOMICS err = futex_abstimed_wait_cancelable ( (unsigned int *) &sem->data + SEM_VALUE_OFFSET, 0, abstime, - sem->private); + FUTEX_CLOCK_REALTIME, sem->private); #else err = futex_abstimed_wait_cancelable (&sem->value, SEM_NWAITERS_MASK, - abstime, sem->private); + abstime, FUTEX_CLOCK_REALTIME, sem->private); #endif return err; diff --git a/sysdeps/nptl/futex-internal.h b/sysdeps/nptl/futex-internal.h index 1a5624789d..a0ed961def 100644 --- a/sysdeps/nptl/futex-internal.h +++ b/sysdeps/nptl/futex-internal.h @@ -169,7 +169,7 @@ futex_abstimed_wait (unsigned int* futex_word, unsigned int expected, static __always_inline int futex_abstimed_wait_cancelable (unsigned int* futex_word, unsigned int expected, - const struct timespec* abstime, int private); + const struct timespec* abstime, int clockbit, int private); /* Atomically wrt other futex operations on the same futex, this unblocks the specified number of processes, or all processes blocked on this futex if diff --git a/sysdeps/sparc/sparc32/sem_waitcommon.c b/sysdeps/sparc/sparc32/sem_waitcommon.c index 1ddd65f745..5e45d0c3af 100644 --- a/sysdeps/sparc/sparc32/sem_waitcommon.c +++ b/sysdeps/sparc/sparc32/sem_waitcommon.c @@ -52,7 +52,7 @@ do_futex_wait (struct new_sem *sem, const struct timespec *abstime) int err; err = futex_abstimed_wait_cancelable (&sem->value, SEM_NWAITERS_MASK, - abstime, sem->private); + abstime, FUTEX_CLOCK_REALTIME, sem->private); return err; } diff --git a/sysdeps/unix/sysv/linux/futex-internal.h b/sysdeps/unix/sysv/linux/futex-internal.h index 96a07b05b9..7ccd40ac08 100644 --- a/sysdeps/unix/sysv/linux/futex-internal.h +++ b/sysdeps/unix/sysv/linux/futex-internal.h @@ -194,7 +194,7 @@ futex_abstimed_wait (unsigned int *futex_word, unsigned int expected, static __always_inline int futex_abstimed_wait_cancelable (unsigned int *futex_word, unsigned int expected, - const struct timespec *abstime, int private) + const struct timespec *abstime, int clockbit, int private) { /* Work around the fact that the kernel rejects negative timeout values despite them being valid. */ @@ -203,7 +203,7 @@ futex_abstimed_wait_cancelable (unsigned int *futex_word, int oldtype; oldtype = __pthread_enable_asynccancel (); int err = lll_futex_timed_wait_bitset (futex_word, expected, abstime, - FUTEX_CLOCK_REALTIME, private); + clockbit, private); __pthread_disable_asynccancel (oldtype); switch (err) { |