Message ID | 1351862047-23172-3-git-send-email-pbonzini@redhat.com |
---|---|
State | New |
Headers | show |
On 2 November 2012 14:14, Paolo Bonzini <pbonzini@redhat.com> wrote: > +#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) > + struct timespec ts; > + clock_gettime(CLOCK_REALTIME, &ts); qemu-thread-posix.c:198:5: warning: implicit declaration of function 'clock_gettime' is invalid in C99 [-Wimplicit-function-declaration] clock_gettime(CLOCK_REALTIME, &ts); ^ qemu-thread-posix.c:198:19: error: use of undeclared identifier 'CLOCK_REALTIME' clock_gettime(CLOCK_REALTIME, &ts); ^ 1 warning and 1 error generated. make: *** [qemu-thread-posix.o] Error 1 MacOS doesn't implement clock_gettime()... -- PMM
On 11/02/12 09:14, Paolo Bonzini wrote: > OpenBSD and Darwin do not have sem_timedwait. Implement a fallback > for them. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > qemu-thread-posix.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > qemu-thread-posix.h | 6 +++++ > 2 file modificati, 80 inserzioni(+) > > diff --git a/qemu-thread-posix.c b/qemu-thread-posix.c > index 6a3d3a1..048db8f 100644 > --- a/qemu-thread-posix.c > +++ b/qemu-thread-posix.c > @@ -122,36 +122,100 @@ void qemu_sem_init(QemuSemaphore *sem, int init) > { > int rc; > > +#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) OpenBSD 5.2 & -current (libpthread) / NetBSD -current (librt) have supported sem_timedwait() for roughly 8 months now. Please change this to properly test for the presence of sem_timedwait() within the configure script.
Il 18/11/2012 10:09, Brad Smith ha scritto: > On 11/02/12 09:14, Paolo Bonzini wrote: >> OpenBSD and Darwin do not have sem_timedwait. Implement a fallback >> for them. >> >> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> >> --- >> qemu-thread-posix.c | 74 >> +++++++++++++++++++++++++++++++++++++++++++++++++++++ >> qemu-thread-posix.h | 6 +++++ >> 2 file modificati, 80 inserzioni(+) >> >> diff --git a/qemu-thread-posix.c b/qemu-thread-posix.c >> index 6a3d3a1..048db8f 100644 >> --- a/qemu-thread-posix.c >> +++ b/qemu-thread-posix.c >> @@ -122,36 +122,100 @@ void qemu_sem_init(QemuSemaphore *sem, int init) >> { >> int rc; >> >> +#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) > > OpenBSD 5.2 & -current (libpthread) / NetBSD -current (librt) have > supported sem_timedwait() for roughly 8 months now. Please change this > to properly test for the presence of sem_timedwait() within the > configure script. Please submit a patch. The patched code works, and it's not even suboptimal because *BSD use a mutex/condvar to implement semaphores. We end up executing the very same code. Paolo
On Sun, Nov 18, 2012 at 05:06:40PM +0100, Paolo Bonzini wrote: > Il 18/11/2012 10:09, Brad Smith ha scritto: > > On 11/02/12 09:14, Paolo Bonzini wrote: > >> OpenBSD and Darwin do not have sem_timedwait. Implement a fallback > >> for them. > >> > >> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > >> --- > >> qemu-thread-posix.c | 74 > >> +++++++++++++++++++++++++++++++++++++++++++++++++++++ > >> qemu-thread-posix.h | 6 +++++ > >> 2 file modificati, 80 inserzioni(+) > >> > >> diff --git a/qemu-thread-posix.c b/qemu-thread-posix.c > >> index 6a3d3a1..048db8f 100644 > >> --- a/qemu-thread-posix.c > >> +++ b/qemu-thread-posix.c > >> @@ -122,36 +122,100 @@ void qemu_sem_init(QemuSemaphore *sem, int init) > >> { > >> int rc; > >> > >> +#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) > > > > OpenBSD 5.2 & -current (libpthread) / NetBSD -current (librt) have > > supported sem_timedwait() for roughly 8 months now. Please change this > > to properly test for the presence of sem_timedwait() within the > > configure script. > > Please submit a patch. The patched code works, and it's not even > suboptimal because *BSD use a mutex/condvar to implement semaphores. We > end up executing the very same code. I understand what you mean. It's more so out of principle to try and remove workarounds wherever possible when it is possible to do so.
diff --git a/qemu-thread-posix.c b/qemu-thread-posix.c index 6a3d3a1..048db8f 100644 --- a/qemu-thread-posix.c +++ b/qemu-thread-posix.c @@ -122,36 +122,100 @@ 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 } int qemu_sem_timedwait(QemuSemaphore *sem, int ms) { int rc; +#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) + struct timespec ts; + clock_gettime(CLOCK_REALTIME, &ts); + if (ms) { + int nsec = ts.tv_nsec + (ms % 1000) * 1000000; + ts.tv_sec += ms / 1000 + nsec / 1000000000; + ts.tv_nsec = nsec % 1000000000; + } + + 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 { @@ -181,10 +245,19 @@ 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 +266,7 @@ 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..1c098c2 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 {
OpenBSD and Darwin do not have sem_timedwait. Implement a fallback for them. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- qemu-thread-posix.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++ qemu-thread-posix.h | 6 +++++ 2 file modificati, 80 inserzioni(+)