X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=mutex.c;h=03291c7faf9392a62d373ea0cc5e55763fbba728;hp=c1ce2a3e8740de808e70076a141b642646f9087f;hb=ae626d4ead6416adf464cf209cdf3e8b85d58190;hpb=d9a7ba88af39b1047c9f8c077280932cd12cb58e

diff --git a/mutex.c b/mutex.c
index c1ce2a3e..03291c7f 100644
--- a/mutex.c
+++ b/mutex.c
@@ -1,163 +1,144 @@
-#include <stdio.h>
 #include <string.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <time.h>
-#include <pthread.h>
 #include <sys/mman.h>
+#include <assert.h>
 
 #include "log.h"
 #include "mutex.h"
-#include "arch/arch.h"
+#include "pshared.h"
 #include "os/os.h"
-#include "helpers.h"
+#include "fio_time.h"
+#include "gettime.h"
+
+void __fio_mutex_remove(struct fio_mutex *mutex)
+{
+	assert(mutex->magic == FIO_MUTEX_MAGIC);
+	pthread_cond_destroy(&mutex->cond);
+
+	/*
+	 * Ensure any subsequent attempt to grab this mutex will fail
+	 * with an assert, instead of just silently hanging.
+	 */
+	memset(mutex, 0, sizeof(*mutex));
+}
 
 void fio_mutex_remove(struct fio_mutex *mutex)
 {
-	close(mutex->mutex_fd);
+	__fio_mutex_remove(mutex);
 	munmap((void *) mutex, sizeof(*mutex));
 }
 
-struct fio_mutex *fio_mutex_init(int value)
+int __fio_mutex_init(struct fio_mutex *mutex, int value)
 {
-	char mutex_name[] = "/tmp/.fio_mutex.XXXXXX";
-	struct fio_mutex *mutex = NULL;
-	pthread_mutexattr_t attr;
-	pthread_condattr_t cond;
-	int fd, ret, mflag;
+	int ret;
 
-	fd = mkstemp(mutex_name);
-	if (fd < 0) {
-		perror("open mutex");
-		return NULL;
-	}
+	mutex->value = value;
+	mutex->magic = FIO_MUTEX_MAGIC;
 
-#ifdef FIO_HAVE_FALLOCATE
-	ret = posix_fallocate(fd, 0, sizeof(struct fio_mutex));
-	if (ret > 0) {
-		fprintf(stderr, "posix_fallocate mutex failed: %s\n", strerror(ret));
-		goto err;
-	}
-#endif
+	ret = mutex_cond_init_pshared(&mutex->lock, &mutex->cond);
+	if (ret)
+		return ret;
 
-	if (ftruncate(fd, sizeof(struct fio_mutex)) < 0) {
-		perror("ftruncate mutex");
-		goto err;
-	}
+	return 0;
+}
+
+struct fio_mutex *fio_mutex_init(int value)
+{
+	struct fio_mutex *mutex = NULL;
 
 	mutex = (void *) mmap(NULL, sizeof(struct fio_mutex),
-				PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+				PROT_READ | PROT_WRITE,
+				OS_MAP_ANON | MAP_SHARED, -1, 0);
 	if (mutex == MAP_FAILED) {
 		perror("mmap mutex");
-		close(fd);
-		mutex = NULL;
-		goto err;
+		return NULL;
 	}
 
-	unlink(mutex_name);
-	mutex->mutex_fd = fd;
-	mutex->value = value;
+	if (!__fio_mutex_init(mutex, value))
+		return mutex;
 
-	/*
-	 * Not all platforms support process shared mutexes (FreeBSD)
-	 */
-#ifdef FIO_HAVE_PSHARED_MUTEX
-	mflag = PTHREAD_PROCESS_SHARED;
-#else
-	mflag = PTHREAD_PROCESS_PRIVATE;
-#endif
-
-	ret = pthread_mutexattr_init(&attr);
-	if (ret) {
-		log_err("pthread_mutexattr_init: %s\n", strerror(ret));
-		goto err;
-	}
-#ifdef FIO_HAVE_PSHARED_MUTEX
-	ret = pthread_mutexattr_setpshared(&attr, mflag);
-	if (ret) {
-		log_err("pthread_mutexattr_setpshared: %s\n", strerror(ret));
-		goto err;
-	}
-#endif
-
-	pthread_condattr_init(&cond);
-#ifdef FIO_HAVE_PSHARED_MUTEX
-	pthread_condattr_setpshared(&cond, mflag);
-#endif
-	pthread_cond_init(&mutex->cond, &cond);
-
-	ret = pthread_mutex_init(&mutex->lock, &attr);
-	if (ret) {
-		log_err("pthread_mutex_init: %s\n", strerror(ret));
-		goto err;
-	}
+	fio_mutex_remove(mutex);
+	return NULL;
+}
 
-	pthread_condattr_destroy(&cond);
-	pthread_mutexattr_destroy(&attr);
+static bool mutex_timed_out(struct timespec *t, unsigned int msecs)
+{
+	struct timeval tv;
+	struct timespec now;
 
-	return mutex;
-err:
-	if (mutex)
-		fio_mutex_remove(mutex);
+	gettimeofday(&tv, NULL);
+	now.tv_sec = tv.tv_sec;
+	now.tv_nsec = tv.tv_usec * 1000;
 
-	unlink(mutex_name);
-	return NULL;
+	return mtime_since(t, &now) >= msecs;
 }
 
-int fio_mutex_down_timeout(struct fio_mutex *mutex, unsigned int seconds)
+int fio_mutex_down_timeout(struct fio_mutex *mutex, unsigned int msecs)
 {
+	struct timeval tv_s;
+	struct timespec base;
 	struct timespec t;
 	int ret = 0;
 
-	clock_gettime(CLOCK_REALTIME, &t);
-	t.tv_sec += seconds;
+	assert(mutex->magic == FIO_MUTEX_MAGIC);
+
+	gettimeofday(&tv_s, NULL);
+	base.tv_sec = t.tv_sec = tv_s.tv_sec;
+	base.tv_nsec = t.tv_nsec = tv_s.tv_usec * 1000;
+
+	t.tv_sec += msecs / 1000;
+	t.tv_nsec += ((msecs * 1000000ULL) % 1000000000);
+	if (t.tv_nsec >= 1000000000) {
+		t.tv_nsec -= 1000000000;
+		t.tv_sec++;
+	}
 
 	pthread_mutex_lock(&mutex->lock);
 
+	mutex->waiters++;
 	while (!mutex->value && !ret) {
-		mutex->waiters++;
+		/*
+		 * Some platforms (FreeBSD 9?) seems to return timed out
+		 * way too early, double check.
+		 */
 		ret = pthread_cond_timedwait(&mutex->cond, &mutex->lock, &t);
-		mutex->waiters--;
+		if (ret == ETIMEDOUT && !mutex_timed_out(&base, msecs))
+			ret = 0;
 	}
+	mutex->waiters--;
 
 	if (!ret) {
 		mutex->value--;
 		pthread_mutex_unlock(&mutex->lock);
+		return 0;
 	}
 
+	pthread_mutex_unlock(&mutex->lock);
 	return ret;
 }
 
-void fio_mutex_down(struct fio_mutex *mutex)
+bool fio_mutex_down_trylock(struct fio_mutex *mutex)
 {
-	pthread_mutex_lock(&mutex->lock);
+	bool ret = true;
 
-	while (!mutex->value) {
-		mutex->waiters++;
-		pthread_cond_wait(&mutex->cond, &mutex->lock);
-		mutex->waiters--;
-	}
-
-	mutex->value--;
-	pthread_mutex_unlock(&mutex->lock);
-}
+	assert(mutex->magic == FIO_MUTEX_MAGIC);
 
-void fio_mutex_up(struct fio_mutex *mutex)
-{
 	pthread_mutex_lock(&mutex->lock);
-	read_barrier();
-	if (!mutex->value && mutex->waiters)
-		pthread_cond_signal(&mutex->cond);
-	mutex->value++;
+	if (mutex->value) {
+		mutex->value--;
+		ret = false;
+	}
 	pthread_mutex_unlock(&mutex->lock);
+
+	return ret;
 }
 
-void fio_mutex_down_write(struct fio_mutex *mutex)
+void fio_mutex_down(struct fio_mutex *mutex)
 {
+	assert(mutex->magic == FIO_MUTEX_MAGIC);
+
 	pthread_mutex_lock(&mutex->lock);
 
-	while (mutex->value != 0) {
+	while (!mutex->value) {
 		mutex->waiters++;
 		pthread_cond_wait(&mutex->cond, &mutex->lock);
 		mutex->waiters--;
@@ -167,36 +148,20 @@ void fio_mutex_down_write(struct fio_mutex *mutex)
 	pthread_mutex_unlock(&mutex->lock);
 }
 
-void fio_mutex_down_read(struct fio_mutex *mutex)
+void fio_mutex_up(struct fio_mutex *mutex)
 {
-	pthread_mutex_lock(&mutex->lock);
+	int do_wake = 0;
 
-	while (mutex->value < 0) {
-		mutex->waiters++;
-		pthread_cond_wait(&mutex->cond, &mutex->lock);
-		mutex->waiters--;
-	}
-
-	mutex->value++;
-	pthread_mutex_unlock(&mutex->lock);
-}
+	assert(mutex->magic == FIO_MUTEX_MAGIC);
 
-void fio_mutex_up_read(struct fio_mutex *mutex)
-{
 	pthread_mutex_lock(&mutex->lock);
-	mutex->value--;
 	read_barrier();
-	if (mutex->value >= 0 && mutex->waiters)
-		pthread_cond_signal(&mutex->cond);
-	pthread_mutex_unlock(&mutex->lock);
-}
-
-void fio_mutex_up_write(struct fio_mutex *mutex)
-{
-	pthread_mutex_lock(&mutex->lock);
+	if (!mutex->value && mutex->waiters)
+		do_wake = 1;
 	mutex->value++;
-	read_barrier();
-	if (mutex->value >= 0 && mutex->waiters)
+
+	if (do_wake)
 		pthread_cond_signal(&mutex->cond);
+
 	pthread_mutex_unlock(&mutex->lock);
 }