From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:51440) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TUITR-0001GO-5B for qemu-devel@nongnu.org; Fri, 02 Nov 2012 10:43:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TUITI-000541-Un for qemu-devel@nongnu.org; Fri, 02 Nov 2012 10:43:53 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:49132) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TUITI-00052C-OQ for qemu-devel@nongnu.org; Fri, 02 Nov 2012 10:43:44 -0400 Received: by mail-pb0-f45.google.com with SMTP id rp2so2443187pbb.4 for ; Fri, 02 Nov 2012 07:43:44 -0700 (PDT) Sender: Paolo Bonzini From: Paolo Bonzini Date: Fri, 2 Nov 2012 15:43:21 +0100 Message-Id: <1351867404-25510-3-git-send-email-pbonzini@redhat.com> In-Reply-To: <1351867404-25510-1-git-send-email-pbonzini@redhat.com> References: <1351867404-25510-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH v2 2/5] semaphore: implement fallback counting semaphores with mutex+condvar List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: blauwirbel@gmail.com, jan.kiszka@siemens.com, peter.maydell@linaro.org OpenBSD and Darwin do not have sem_timedwait. Implement a fallback for them. Signed-off-by: Paolo Bonzini --- v1->v2: extract compute_abs_deadline and use it qemu-thread-posix.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++------ qemu-thread-posix.h | 6 ++++ 2 file modificati, 88 inserzioni(+), 10 rimozioni(-) diff --git a/qemu-thread-posix.c b/qemu-thread-posix.c index 6a3d3a1..4ef9c7b 100644 --- a/qemu-thread-posix.c +++ b/qemu-thread-posix.c @@ -122,36 +122,106 @@ void qemu_sem_init(QemuSemaphore *sem, int init) { int rc; +#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) + rc = pthread_mutex_init(&sem->lock, NULL); + if (rc != 0) { + error_exit(rc, __func__); + } + rc = pthread_cond_init(&sem->cond, NULL); + if (rc != 0) { + error_exit(rc, __func__); + } + if (init < 0) { + error_exit(EINVAL, __func__); + } + sem->count = init; +#else rc = sem_init(&sem->sem, 0, init); if (rc < 0) { error_exit(errno, __func__); } +#endif } void qemu_sem_destroy(QemuSemaphore *sem) { int rc; +#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) + rc = pthread_cond_destroy(&sem->cond); + if (rc < 0) { + error_exit(rc, __func__); + } + rc = pthread_mutex_destroy(&sem->lock); + if (rc < 0) { + error_exit(rc, __func__); + } +#else rc = sem_destroy(&sem->sem); if (rc < 0) { error_exit(errno, __func__); } +#endif } void qemu_sem_post(QemuSemaphore *sem) { int rc; +#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) + pthread_mutex_lock(&sem->lock); + if (sem->count == INT_MAX) { + rc = EINVAL; + } else if (sem->count++ < 0) { + rc = pthread_cond_signal(&sem->cond); + } else { + rc = 0; + } + pthread_mutex_unlock(&sem->lock); + if (rc != 0) { + error_exit(rc, __func__); + } +#else rc = sem_post(&sem->sem); if (rc < 0) { error_exit(errno, __func__); } +#endif +} + +static void compute_abs_deadline(struct timespec *ts, int ms) +{ + struct timeval tv; + gettimeofday(&tv, NULL); + ts->tv_nsec = tv.tv_usec * 1000 + (ms % 1000) * 1000000; + ts->tv_sec = tv.tv_sec + ms / 1000; + if (ts->tv_nsec >= 1000000000) { + ts->tv_sec++; + ts->tv_nsec -= 1000000000; + } } int qemu_sem_timedwait(QemuSemaphore *sem, int ms) { int rc; - + struct timespec ts; + +#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) + compute_abs_deadline(&ts, ms); + pthread_mutex_lock(&sem->lock); + --sem->count; + while (sem->count < 0) { + rc = pthread_cond_timedwait(&sem->cond, &sem->lock, &ts); + if (rc == ETIMEDOUT) { + break; + } + if (rc != 0) { + error_exit(rc, __func__); + } + } + pthread_mutex_unlock(&sem->lock); + return (rc == ETIMEDOUT ? -1 : 0); +#else if (ms <= 0) { /* This is cheaper than sem_timedwait. */ do { @@ -161,15 +231,7 @@ int qemu_sem_timedwait(QemuSemaphore *sem, int ms) return -1; } } else { - struct timeval tv; - struct timespec ts; - gettimeofday(&tv, NULL); - ts.tv_nsec = tv.tv_usec * 1000 + (ms % 1000) * 1000000; - ts.tv_sec = tv.tv_sec + ms / 1000; - if (ts.tv_nsec >= 1000000000) { - ts.tv_sec++; - ts.tv_nsec -= 1000000000; - } + compute_abs_deadline(&ts, ms); do { rc = sem_timedwait(&sem->sem, &ts); } while (rc == -1 && errno == EINTR); @@ -181,10 +243,19 @@ int qemu_sem_timedwait(QemuSemaphore *sem, int ms) error_exit(errno, __func__); } return 0; +#endif } void qemu_sem_wait(QemuSemaphore *sem) { +#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) + pthread_mutex_lock(&sem->lock); + --sem->count; + while (sem->count < 0) { + pthread_cond_wait(&sem->cond, &sem->lock); + } + pthread_mutex_unlock(&sem->lock); +#else int rc; do { @@ -193,6 +264,7 @@ void qemu_sem_wait(QemuSemaphore *sem) if (rc < 0) { error_exit(errno, __func__); } +#endif } void qemu_thread_create(QemuThread *thread, diff --git a/qemu-thread-posix.h b/qemu-thread-posix.h index 2542c15..380bae2 100644 --- a/qemu-thread-posix.h +++ b/qemu-thread-posix.h @@ -12,7 +12,13 @@ struct QemuCond { }; struct QemuSemaphore { +#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) + pthread_mutex_t lock; + pthread_cond_t cond; + int count; +#else sem_t sem; +#endif }; struct QemuThread { -- 1.7.12.1