From 8ab3026489eafa9da07c09f1929593fe0db5e380 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 21 Feb 2022 12:46:32 +0100 Subject: [PATCH] thread-posix: optimize qemu_sem_timedwait with zero timeout In this case there is no need to call pthread_cond_timedwait; the function is just a trywait and waiting on the condition variable would always time out. Signed-off-by: Paolo Bonzini --- util/qemu-thread-posix.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c index 8505d8c60f..ac1d56e673 100644 --- a/util/qemu-thread-posix.c +++ b/util/qemu-thread-posix.c @@ -284,8 +284,12 @@ int qemu_sem_timedwait(QemuSemaphore *sem, int ms) compute_abs_deadline(&ts, ms); qemu_mutex_lock(&sem->mutex); while (sem->count == 0) { - rc = qemu_cond_timedwait_ts(&sem->cond, &sem->mutex, &ts, - __FILE__, __LINE__); + if (ms == 0) { + rc = false; + } else { + rc = qemu_cond_timedwait_ts(&sem->cond, &sem->mutex, &ts, + __FILE__, __LINE__); + } if (!rc) { /* timeout */ break; }