X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=mutex.c;h=1538f62c4b1a286ebe015c299031ffede126e2c4;hp=bcc37ae648c0bf440949603d762463a1ea74a7f8;hb=4e6ea2f1e9b7da6d7d1057670fcc19f063e46fd4;hpb=64d4d313ef4f537408d28fac863cf2a2b0f00175

diff --git a/mutex.c b/mutex.c
index bcc37ae6..1538f62c 100644
--- a/mutex.c
+++ b/mutex.c
@@ -6,12 +6,15 @@
 #include <pthread.h>
 #include <sys/mman.h>
 
+#include "log.h"
 #include "mutex.h"
+#include "arch/arch.h"
+#include "os/os.h"
 
 void fio_mutex_remove(struct fio_mutex *mutex)
 {
 	close(mutex->mutex_fd);
-	munmap(mutex, sizeof(*mutex));
+	munmap((void *) mutex, sizeof(*mutex));
 }
 
 struct fio_mutex *fio_mutex_init(int value)
@@ -20,7 +23,7 @@ struct fio_mutex *fio_mutex_init(int value)
 	struct fio_mutex *mutex = NULL;
 	pthread_mutexattr_t attr;
 	pthread_condattr_t cond;
-	int fd;
+	int fd, ret, mflag;
 
 	fd = mkstemp(mutex_name);
 	if (fd < 0) {
@@ -33,8 +36,8 @@ struct fio_mutex *fio_mutex_init(int value)
 		goto err;
 	}
 
-	mutex = mmap(NULL, sizeof(struct fio_mutex), PROT_READ | PROT_WRITE,
-			MAP_SHARED, fd, 0);
+	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);
@@ -46,21 +49,33 @@ struct fio_mutex *fio_mutex_init(int value)
 	mutex->mutex_fd = fd;
 	mutex->value = value;
 
-	if (pthread_mutexattr_init(&attr)) {
-		perror("pthread_mutexattr_init");
+	/*
+	 * 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;
 	}
-	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;
 	}
 
 	pthread_condattr_init(&cond);
-	pthread_condattr_setpshared(&cond, PTHREAD_PROCESS_SHARED);
+	pthread_condattr_setpshared(&cond, mflag);
 	pthread_cond_init(&mutex->cond, &cond);
 
-	if (pthread_mutex_init(&mutex->lock, &attr)) {
-		perror("pthread_mutex_init");
+	ret = pthread_mutex_init(&mutex->lock, &attr);
+	if (ret) {
+		log_err("pthread_mutex_init: %s\n", strerror(ret));
 		goto err;
 	}
 
@@ -76,8 +91,13 @@ err:
 void fio_mutex_down(struct fio_mutex *mutex)
 {
 	pthread_mutex_lock(&mutex->lock);
-	while (mutex->value == 0)
+
+	while (!mutex->value) {
+		mutex->waiters++;
 		pthread_cond_wait(&mutex->cond, &mutex->lock);
+		mutex->waiters--;
+	}
+
 	mutex->value--;
 	pthread_mutex_unlock(&mutex->lock);
 }
@@ -85,7 +105,8 @@ void fio_mutex_down(struct fio_mutex *mutex)
 void fio_mutex_up(struct fio_mutex *mutex)
 {
 	pthread_mutex_lock(&mutex->lock);
-	if (!mutex->value)
+	read_barrier();
+	if (!mutex->value && mutex->waiters)
 		pthread_cond_signal(&mutex->cond);
 	mutex->value++;
 	pthread_mutex_unlock(&mutex->lock);
@@ -94,8 +115,13 @@ void fio_mutex_up(struct fio_mutex *mutex)
 void fio_mutex_down_write(struct fio_mutex *mutex)
 {
 	pthread_mutex_lock(&mutex->lock);
-	while (mutex->value != 0)
+
+	while (mutex->value != 0) {
+		mutex->waiters++;
 		pthread_cond_wait(&mutex->cond, &mutex->lock);
+		mutex->waiters--;
+	}
+
 	mutex->value--;
 	pthread_mutex_unlock(&mutex->lock);
 }
@@ -103,8 +129,13 @@ void fio_mutex_down_write(struct fio_mutex *mutex)
 void fio_mutex_down_read(struct fio_mutex *mutex)
 {
 	pthread_mutex_lock(&mutex->lock);
-	while (mutex->value < 0)
+
+	while (mutex->value < 0) {
+		mutex->waiters++;
 		pthread_cond_wait(&mutex->cond, &mutex->lock);
+		mutex->waiters--;
+	}
+
 	mutex->value++;
 	pthread_mutex_unlock(&mutex->lock);
 }
@@ -113,7 +144,8 @@ void fio_mutex_up_read(struct fio_mutex *mutex)
 {
 	pthread_mutex_lock(&mutex->lock);
 	mutex->value--;
-	if (mutex->value >= 0)
+	read_barrier();
+	if (mutex->value >= 0 && mutex->waiters)
 		pthread_cond_signal(&mutex->cond);
 	pthread_mutex_unlock(&mutex->lock);
 }
@@ -122,7 +154,8 @@ void fio_mutex_up_write(struct fio_mutex *mutex)
 {
 	pthread_mutex_lock(&mutex->lock);
 	mutex->value++;
-	if (mutex->value >= 0)
+	read_barrier();
+	if (mutex->value >= 0 && mutex->waiters)
 		pthread_cond_signal(&mutex->cond);
 	pthread_mutex_unlock(&mutex->lock);
 }