Fix problem with mutexes and MONOTONIC clock

[fio.git] / mutex.c

diff --git a/mutex.c b/mutex.c
index bb417c2741d3c22cd41c707d3a62bc34e0238de1..ab7dc7044aa8c8e2f549da7a5e089e9e71322717 100644 (file)
--- a/mutex.c
+++ b/mutex.c
@@ -3,83 +3,185 @@
 #include <unistd.h>
 #include <stdlib.h>
 #include <fcntl.h>
+#include <time.h>
 #include <pthread.h>
 #include <sys/mman.h>
 
+#include "log.h"
 #include "mutex.h"
+#include "arch/arch.h"
+#include "os/os.h"
 
-void fio_sem_remove(struct fio_sem *sem)
+void fio_mutex_remove(struct fio_mutex *mutex)
 {
-       unlink(sem->sem_name);
-       munmap(sem, sizeof(*sem));
+       close(mutex->mutex_fd);
+       munmap((void *) mutex, sizeof(*mutex));
 }
 
-struct fio_sem *fio_sem_init(int value)
+struct fio_mutex *fio_mutex_init(int value)
 {
+       char mutex_name[] = "/tmp/.fio_mutex.XXXXXX";
+       struct fio_mutex *mutex = NULL;
        pthread_mutexattr_t attr;
-       struct fio_sem *sem;
-       char sem_name[32];
-       int fd;
+       pthread_condattr_t cond;
+       int fd, ret, mflag;
 
-       sprintf(sem_name, "/tmp/.fio_lock.XXXXXX");
-       fd = mkstemp(sem_name);
+       fd = mkstemp(mutex_name);
        if (fd < 0) {
-               perror("open sem");
+               perror("open mutex");
                return NULL;
        }
 
-       if (ftruncate(fd, sizeof(struct fio_sem)) < 0) {
-               perror("ftruncate sem");
-               return NULL;
+       if (ftruncate(fd, sizeof(struct fio_mutex)) < 0) {
+               perror("ftruncate mutex");
+               goto err;
        }
 
-       sem = mmap(NULL, sizeof(struct fio_sem), PROT_READ | PROT_WRITE,
-                       MAP_SHARED, fd, 0);
-       if (sem == MAP_FAILED) {
-               perror("mmap sem");
+       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);
-               unlink(sem_name);
-               return NULL;
+               mutex = NULL;
+               goto err;
        }
 
-       close(fd);
-       sem->value = value;
-       strcpy(sem->sem_name, sem_name);
+       unlink(mutex_name);
+       mutex->mutex_fd = fd;
+       mutex->value = value;
+
+       /*
+        * Not all platforms support process shared mutexes (FreeBSD)
+        */
+#ifdef FIO_HAVE_PSHARED_MUTEX
+       mflag = PTHREAD_PROCESS_SHARED;
+#else
+       mflag = PTHREAD_PROCESS_PRIVATE;
+#endif
 
-       if (pthread_mutexattr_init(&attr)) {
-               perror("pthread_mutexattr_init");
+       ret = pthread_mutexattr_init(&attr);
+       if (ret) {
+               log_err("pthread_mutexattr_init: %s\n", strerror(ret));
                goto err;
        }
-       if (pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED)) {
-               perror("pthread_mutexattr_setpshared");
+       ret = pthread_mutexattr_setpshared(&attr, mflag);
+       if (ret) {
+               log_err("pthread_mutexattr_setpshared: %s\n", strerror(ret));
                goto err;
        }
-       if (pthread_mutex_init(&sem->lock, &attr)) {
-               perror("pthread_mutex_init");
+
+       pthread_condattr_init(&cond);
+       pthread_condattr_setpshared(&cond, mflag);
+       pthread_condattr_setclock(&cond, CLOCK_MONOTONIC);
+       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;
        }
 
-       return sem;
+       return mutex;
 err:
-       munmap(sem, sizeof(*sem));
-       unlink(sem_name);
+       if (mutex)
+               fio_mutex_remove(mutex);
+
+       unlink(mutex_name);
        return NULL;
 }
 
-void fio_sem_down(struct fio_sem *sem)
+int fio_mutex_down_timeout(struct fio_mutex *mutex, unsigned int seconds)
+{
+       struct timespec t;
+       int ret = 0;
+
+       clock_gettime(CLOCK_REALTIME, &t);
+       t.tv_sec += seconds;
+
+       pthread_mutex_lock(&mutex->lock);
+
+       while (!mutex->value && !ret) {
+               mutex->waiters++;
+               ret = pthread_cond_timedwait(&mutex->cond, &mutex->lock, &t);
+               mutex->waiters--;
+       }
+
+       if (!ret) {
+               mutex->value--;
+               pthread_mutex_unlock(&mutex->lock);
+       }
+
+       return ret;
+}
+
+void fio_mutex_down(struct fio_mutex *mutex)
+{
+       pthread_mutex_lock(&mutex->lock);
+
+       while (!mutex->value) {
+               mutex->waiters++;
+               pthread_cond_wait(&mutex->cond, &mutex->lock);
+               mutex->waiters--;
+       }
+
+       mutex->value--;
+       pthread_mutex_unlock(&mutex->lock);
+}
+
+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++;
+       pthread_mutex_unlock(&mutex->lock);
+}
+
+void fio_mutex_down_write(struct fio_mutex *mutex)
+{
+       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);
+}
+
+void fio_mutex_down_read(struct fio_mutex *mutex)
+{
+       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);
+}
+
+void fio_mutex_up_read(struct fio_mutex *mutex)
 {
-       pthread_mutex_lock(&sem->lock);
-       while (sem->value == 0)
-               pthread_cond_wait(&sem->cond, &sem->lock);
-       sem->value--;
-       pthread_mutex_unlock(&sem->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);
 }
 
-void fio_sem_up(struct fio_sem *sem)
+void fio_mutex_up_write(struct fio_mutex *mutex)
 {
-       pthread_mutex_lock(&sem->lock);
-       if (!sem->value)
-               pthread_cond_signal(&sem->cond);
-       sem->value++;
-       pthread_mutex_unlock(&sem->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);
 }