__usec_sleep() really just spins, rename it

[fio.git] / mutex.c

diff --git a/mutex.c b/mutex.c
index bcc37ae648c0bf440949603d762463a1ea74a7f8..0f13064af8f26929d3aeac09a22de8331d0e9fa3 100644 (file)
--- a/mutex.c
+++ b/mutex.c
@@ -7,11 +7,12 @@
 #include <sys/mman.h>
 
 #include "mutex.h"
+#include "arch/arch.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)
@@ -33,8 +34,8 @@ 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);
@@ -46,11 +47,11 @@ struct fio_mutex *fio_mutex_init(int value)
        mutex->mutex_fd = fd;
        mutex->value = value;
 
-       if (pthread_mutexattr_init(&attr)) {
+       if (pthread_mutexattr_init(&attr) < 0) {
                perror("pthread_mutexattr_init");
                goto err;
        }
-       if (pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED)) {
+       if (pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED) < 0) {
                perror("pthread_mutexattr_setpshared");
                goto err;
        }
@@ -59,7 +60,7 @@ struct fio_mutex *fio_mutex_init(int value)
        pthread_condattr_setpshared(&cond, PTHREAD_PROCESS_SHARED);
        pthread_cond_init(&mutex->cond, &cond);
 
-       if (pthread_mutex_init(&mutex->lock, &attr)) {
+       if (pthread_mutex_init(&mutex->lock, &attr) < 0) {
                perror("pthread_mutex_init");
                goto err;
        }
@@ -76,8 +77,13 @@ 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 +91,8 @@ 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 +101,13 @@ 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 +115,13 @@ 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 +130,8 @@ 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 +140,8 @@ 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);
 }