X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=mutex.c;h=9fab715bd7429e87b2690000d49a69bbaea3785a;hp=9f0f094dc11793feace1975ac880a636999030a7;hb=63463983ce10e9678c5ad309608630eea873b4df;hpb=69a852f567ab20358fe21b7815626c27a4214b42

diff --git a/mutex.c b/mutex.c
index 9f0f094d..9fab715b 100644
--- a/mutex.c
+++ b/mutex.c
@@ -4,117 +4,218 @@
 #include <stdlib.h>
 #include <fcntl.h>
 #include <time.h>
+#include <errno.h>
 #include <pthread.h>
 #include <sys/mman.h>
+#include <assert.h>
 
+#include "fio.h"
 #include "log.h"
 #include "mutex.h"
 #include "arch/arch.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 cond_init_pshared(pthread_cond_t *cond)
 {
-	char mutex_name[] = "/tmp/.fio_mutex.XXXXXX";
-	struct fio_mutex *mutex = NULL;
-	pthread_mutexattr_t attr;
-	pthread_condattr_t cond;
-	int fd, ret, mflag;
+	pthread_condattr_t cattr;
+	int ret;
 
-	fd = mkstemp(mutex_name);
-	if (fd < 0) {
-		perror("open mutex");
-		return NULL;
+	ret = pthread_condattr_init(&cattr);
+	if (ret) {
+		log_err("pthread_condattr_init: %s\n", strerror(ret));
+		return ret;
 	}
 
-	if (ftruncate(fd, sizeof(struct fio_mutex)) < 0) {
-		perror("ftruncate mutex");
-		goto err;
+#ifdef CONFIG_PSHARED
+	ret = pthread_condattr_setpshared(&cattr, PTHREAD_PROCESS_SHARED);
+	if (ret) {
+		log_err("pthread_condattr_setpshared: %s\n", strerror(ret));
+		return ret;
 	}
-
-	mutex = (void *) mmap(NULL, sizeof(struct fio_mutex),
-				PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-	if (mutex == MAP_FAILED) {
-		perror("mmap mutex");
-		close(fd);
-		mutex = NULL;
-		goto err;
+#endif
+	ret = pthread_cond_init(cond, &cattr);
+	if (ret) {
+		log_err("pthread_cond_init: %s\n", strerror(ret));
+		return ret;
 	}
 
-	unlink(mutex_name);
-	mutex->mutex_fd = fd;
-	mutex->value = value;
+	return 0;
+}
 
-	/*
-	 * Not all platforms support process shared mutexes (FreeBSD)
-	 */
-#ifdef FIO_HAVE_PSHARED_MUTEX
-	mflag = PTHREAD_PROCESS_SHARED;
-#else
-	mflag = PTHREAD_PROCESS_PRIVATE;
-#endif
+int mutex_init_pshared(pthread_mutex_t *mutex)
+{
+	pthread_mutexattr_t mattr;
+	int ret;
 
-	ret = pthread_mutexattr_init(&attr);
+	ret = pthread_mutexattr_init(&mattr);
 	if (ret) {
 		log_err("pthread_mutexattr_init: %s\n", strerror(ret));
-		goto err;
+		return ret;
 	}
-	ret = pthread_mutexattr_setpshared(&attr, mflag);
+
+	/*
+	 * Not all platforms support process shared mutexes (FreeBSD)
+	 */
+#ifdef CONFIG_PSHARED
+	ret = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
 	if (ret) {
 		log_err("pthread_mutexattr_setpshared: %s\n", strerror(ret));
-		goto err;
+		return ret;
 	}
-
-	pthread_condattr_init(&cond);
-	pthread_condattr_setpshared(&cond, mflag);
-	pthread_cond_init(&mutex->cond, &cond);
-
-	ret = pthread_mutex_init(&mutex->lock, &attr);
+#endif
+	ret = pthread_mutex_init(mutex, &mattr);
 	if (ret) {
 		log_err("pthread_mutex_init: %s\n", strerror(ret));
-		goto err;
+		return ret;
 	}
 
-	return mutex;
-err:
-	if (mutex)
-		fio_mutex_remove(mutex);
+	return 0;
+}
+
+int mutex_cond_init_pshared(pthread_mutex_t *mutex, pthread_cond_t *cond)
+{
+	int ret;
+
+	ret = mutex_init_pshared(mutex);
+	if (ret)
+		return ret;
+
+	ret = cond_init_pshared(cond);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+int __fio_mutex_init(struct fio_mutex *mutex, int value)
+{
+	int ret;
+
+	mutex->value = value;
+	mutex->magic = FIO_MUTEX_MAGIC;
 
-	unlink(mutex_name);
+	ret = mutex_cond_init_pshared(&mutex->lock, &mutex->cond);
+	if (ret)
+		return ret;
+
+	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,
+				OS_MAP_ANON | MAP_SHARED, -1, 0);
+	if (mutex == MAP_FAILED) {
+		perror("mmap mutex");
+		return NULL;
+	}
+
+	if (!__fio_mutex_init(mutex, value))
+		return mutex;
+
+	fio_mutex_remove(mutex);
 	return NULL;
 }
 
-int fio_mutex_down_timeout(struct fio_mutex *mutex, unsigned int seconds)
+static bool mutex_timed_out(struct timespec *t, unsigned int msecs)
+{
+	struct timeval tv;
+	struct timespec now;
+
+	gettimeofday(&tv, NULL);
+	now.tv_sec = tv.tv_sec;
+	now.tv_nsec = tv.tv_usec * 1000;
+
+	return mtime_since(t, &now) >= msecs;
+}
+
+int fio_mutex_down_timeout(struct fio_mutex *mutex, unsigned int msecs)
 {
+	struct timeval tv_s;
 	struct timespec t;
 	int ret = 0;
 
-	clock_gettime(CLOCK_MONOTONIC, &t);
-	t.tv_sec += seconds;
+	assert(mutex->magic == FIO_MUTEX_MAGIC);
+
+	gettimeofday(&tv_s, NULL);
+	t.tv_sec = tv_s.tv_sec;
+	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(&t, msecs))
+			ret = 0;
 	}
+	mutex->waiters--;
 
 	if (!ret) {
 		mutex->value--;
 		pthread_mutex_unlock(&mutex->lock);
+		return 0;
+	}
+
+	pthread_mutex_unlock(&mutex->lock);
+	return ret;
+}
+
+bool fio_mutex_down_trylock(struct fio_mutex *mutex)
+{
+	bool ret = true;
+
+	assert(mutex->magic == FIO_MUTEX_MAGIC);
+
+	pthread_mutex_lock(&mutex->lock);
+	if (mutex->value) {
+		mutex->value--;
+		ret = false;
 	}
+	pthread_mutex_unlock(&mutex->lock);
 
 	return ret;
 }
 
 void fio_mutex_down(struct fio_mutex *mutex)
 {
+	assert(mutex->magic == FIO_MUTEX_MAGIC);
+
 	pthread_mutex_lock(&mutex->lock);
 
 	while (!mutex->value) {
@@ -129,58 +230,91 @@ void fio_mutex_down(struct fio_mutex *mutex)
 
 void fio_mutex_up(struct fio_mutex *mutex)
 {
+	int do_wake = 0;
+
+	assert(mutex->magic == FIO_MUTEX_MAGIC);
+
 	pthread_mutex_lock(&mutex->lock);
 	read_barrier();
 	if (!mutex->value && mutex->waiters)
-		pthread_cond_signal(&mutex->cond);
+		do_wake = 1;
 	mutex->value++;
 	pthread_mutex_unlock(&mutex->lock);
+
+	if (do_wake)
+		pthread_cond_signal(&mutex->cond);
 }
 
-void fio_mutex_down_write(struct fio_mutex *mutex)
+void fio_rwlock_write(struct fio_rwlock *lock)
 {
-	pthread_mutex_lock(&mutex->lock);
-
-	while (mutex->value != 0) {
-		mutex->waiters++;
-		pthread_cond_wait(&mutex->cond, &mutex->lock);
-		mutex->waiters--;
-	}
-
-	mutex->value--;
-	pthread_mutex_unlock(&mutex->lock);
+	assert(lock->magic == FIO_RWLOCK_MAGIC);
+	pthread_rwlock_wrlock(&lock->lock);
 }
 
-void fio_mutex_down_read(struct fio_mutex *mutex)
+void fio_rwlock_read(struct fio_rwlock *lock)
 {
-	pthread_mutex_lock(&mutex->lock);
-
-	while (mutex->value < 0) {
-		mutex->waiters++;
-		pthread_cond_wait(&mutex->cond, &mutex->lock);
-		mutex->waiters--;
-	}
+	assert(lock->magic == FIO_RWLOCK_MAGIC);
+	pthread_rwlock_rdlock(&lock->lock);
+}
 
-	mutex->value++;
-	pthread_mutex_unlock(&mutex->lock);
+void fio_rwlock_unlock(struct fio_rwlock *lock)
+{
+	assert(lock->magic == FIO_RWLOCK_MAGIC);
+	pthread_rwlock_unlock(&lock->lock);
 }
 
-void fio_mutex_up_read(struct fio_mutex *mutex)
+void fio_rwlock_remove(struct fio_rwlock *lock)
 {
-	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);
+	assert(lock->magic == FIO_RWLOCK_MAGIC);
+	munmap((void *) lock, sizeof(*lock));
 }
 
-void fio_mutex_up_write(struct fio_mutex *mutex)
+struct fio_rwlock *fio_rwlock_init(void)
 {
-	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);
+	struct fio_rwlock *lock;
+	pthread_rwlockattr_t attr;
+	int ret;
+
+	lock = (void *) mmap(NULL, sizeof(struct fio_rwlock),
+				PROT_READ | PROT_WRITE,
+				OS_MAP_ANON | MAP_SHARED, -1, 0);
+	if (lock == MAP_FAILED) {
+		perror("mmap rwlock");
+		lock = NULL;
+		goto err;
+	}
+
+	lock->magic = FIO_RWLOCK_MAGIC;
+
+	ret = pthread_rwlockattr_init(&attr);
+	if (ret) {
+		log_err("pthread_rwlockattr_init: %s\n", strerror(ret));
+		goto err;
+	}
+#ifdef CONFIG_PSHARED
+	ret = pthread_rwlockattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
+	if (ret) {
+		log_err("pthread_rwlockattr_setpshared: %s\n", strerror(ret));
+		goto destroy_attr;
+	}
+
+	ret = pthread_rwlock_init(&lock->lock, &attr);
+#else
+	ret = pthread_rwlock_init(&lock->lock, NULL);
+#endif
+
+	if (ret) {
+		log_err("pthread_rwlock_init: %s\n", strerror(ret));
+		goto destroy_attr;
+	}
+
+	pthread_rwlockattr_destroy(&attr);
+
+	return lock;
+destroy_attr:
+	pthread_rwlockattr_destroy(&attr);
+err:
+	if (lock)
+		fio_rwlock_remove(lock);
+	return NULL;
 }