Remove conditional variable

Author: Cuda-Chen

virtio-snd.c

@@ -274,8 +274,6 @@ typedef struct {
 static vsnd_stream_sel_t v;
 
 static pthread_mutex_t virtio_snd_mutex = PTHREAD_MUTEX_INITIALIZER;
-static pthread_cond_t virtio_snd_cond = PTHREAD_COND_INITIALIZER;
-static uint8_t is_txing;
 
 /* Forward declaration */
 static void virtio_snd_cb(struct CNFADriver *dev,
@@ -700,13 +698,6 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
     /* Start of critical section */
     pthread_mutex_lock(&virtio_snd_mutex);
 
-    /* Wait until the TX queue event is ready. */
-    while (is_txing <= 0)
-        pthread_cond_wait(&virtio_snd_cond, &virtio_snd_mutex);
-
-    /* Consume event count */
-    is_txing--;
-
     /* TODO: clarify the usage of the last descriptor. */
     /* virtio-snd TX uses arbitrary number of virtqueue descriptors.
      * The first descritor descriptor contains:
@@ -799,6 +790,8 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
     /* End of critical seciont. */
     pthread_mutex_unlock(&virtio_snd_mutex);
 
+    sleep(1);
+
     return 0;
 }
 
@@ -859,6 +852,8 @@ static void virtio_queue_notify_handler(
         ram[vq_used_addr + 1] = len;    /* virtq_used_elem.len (le32) */
         queue->last_avail++;
         new_used++;
+
+        printf("last_avail %d new_avail %d\n", queue->last_avail, new_avail);
     }
 
     /* Check le32 len field of struct virtq_used_elem on the spec  */
@@ -982,8 +977,6 @@ static bool virtio_snd_reg_write(virtio_snd_state_t *vsnd,
                 break;
             case VSND_QUEUE_TX:
                 fprintf(stderr, "TX start\n");
-                is_txing++;
-                pthread_cond_signal(&virtio_snd_cond);
                 virtio_queue_notify_handler(vsnd, value,
                                             virtio_snd_tx_desc_handler);
                 fprintf(stderr, "TX end\n");