Use pthread condition variables instead of semaphores

(Unnamed semaphores are not implemented on Mac OS X...)

diff --git a/src/write.c b/src/write.c
index 29a8f21f0acc5be377f0c8b72bf4736a82c604b0..5b586ceea23f8795cff7c28623ce2ff573df59a1 100644 (file)
--- a/src/write.c
+++ b/src/write.c
@@ -43,7 +43,6 @@
 #include "xpress.h"
 
 #ifdef ENABLE_MULTITHREADED_COMPRESSION
 #include "xpress.h"
 
 #ifdef ENABLE_MULTITHREADED_COMPRESSION

-#include <semaphore.h>

 #include <pthread.h>
 #endif
 
 #include <pthread.h>
 #endif
 


@@ -547,13 +546,14 @@ out:
 
 #ifdef ENABLE_MULTITHREADED_COMPRESSION
 struct shared_queue {
 
 #ifdef ENABLE_MULTITHREADED_COMPRESSION
 struct shared_queue {

-       sem_t filled_slots;
-       sem_t empty_slots;
-       pthread_mutex_t lock;
+       unsigned size;

        unsigned front;
        unsigned back;
        unsigned front;
        unsigned back;

+       unsigned filled_slots;

        void **array;
        void **array;

-       unsigned size;
+       pthread_mutex_t lock;
+       pthread_cond_t msg_avail_cond;
+       pthread_cond_t space_avail_cond;

 };
 
 static int shared_queue_init(struct shared_queue *q, unsigned size)
 };
 
 static int shared_queue_init(struct shared_queue *q, unsigned size)


@@ -561,46 +561,52 @@ static int shared_queue_init(struct shared_queue *q, unsigned size)
        q->array = CALLOC(sizeof(q->array[0]), size);
        if (!q->array)
                return WIMLIB_ERR_NOMEM;
        q->array = CALLOC(sizeof(q->array[0]), size);
        if (!q->array)
                return WIMLIB_ERR_NOMEM;

-
-       sem_init(&q->filled_slots, 0, 0);
-       sem_init(&q->empty_slots, 0, size);
-       pthread_mutex_init(&q->lock, NULL);
+       q->filled_slots = 0;

        q->front = 0;
        q->back = size - 1;
        q->size = size;
        q->front = 0;
        q->back = size - 1;
        q->size = size;

+       pthread_mutex_init(&q->lock, NULL);
+       pthread_cond_init(&q->msg_avail_cond, NULL);
+       pthread_cond_init(&q->space_avail_cond, NULL);

        return 0;
 }
 
 static void shared_queue_destroy(struct shared_queue *q)
 {
        return 0;
 }
 
 static void shared_queue_destroy(struct shared_queue *q)
 {

-       sem_destroy(&q->filled_slots);
-       sem_destroy(&q->empty_slots);
-       pthread_mutex_destroy(&q->lock);

        FREE(q->array);
        FREE(q->array);

+       pthread_mutex_destroy(&q->lock);
+       pthread_cond_destroy(&q->msg_avail_cond);
+       pthread_cond_destroy(&q->space_avail_cond);

 }
 
 static void shared_queue_put(struct shared_queue *q, void *obj)
 {
 }
 
 static void shared_queue_put(struct shared_queue *q, void *obj)
 {

-       sem_wait(&q->empty_slots);

        pthread_mutex_lock(&q->lock);
        pthread_mutex_lock(&q->lock);

+       while (q->filled_slots == q->size)
+               pthread_cond_wait(&q->space_avail_cond, &q->lock);

 
        q->back = (q->back + 1) % q->size;
        q->array[q->back] = obj;
 
        q->back = (q->back + 1) % q->size;
        q->array[q->back] = obj;

+       q->filled_slots++;

 
 

-       sem_post(&q->filled_slots);
+       pthread_cond_broadcast(&q->msg_avail_cond);

        pthread_mutex_unlock(&q->lock);
 }
 
 static void *shared_queue_get(struct shared_queue *q)
 {
        pthread_mutex_unlock(&q->lock);
 }
 
 static void *shared_queue_get(struct shared_queue *q)
 {

-       sem_wait(&q->filled_slots);
+       void *obj;
+

        pthread_mutex_lock(&q->lock);
        pthread_mutex_lock(&q->lock);

+       while (q->filled_slots == 0)
+               pthread_cond_wait(&q->msg_avail_cond, &q->lock);

 
 

-       void *obj = q->array[q->front];
+       obj = q->array[q->front];

        q->array[q->front] = NULL;
        q->front = (q->front + 1) % q->size;
        q->array[q->front] = NULL;
        q->front = (q->front + 1) % q->size;

+       q->filled_slots--;

 
 

-       sem_post(&q->empty_slots);
+       pthread_cond_broadcast(&q->space_avail_cond);

        pthread_mutex_unlock(&q->lock);
        return obj;
 }
        pthread_mutex_unlock(&q->lock);
        return obj;
 }