Tear down list and allocated spaces

Author: Cuda-Chen

queue.h

@@ -31,7 +31,7 @@ static inline void queue_push(struct queue_head *node, struct queue_head *head)
     head->prev = node;
 }
 
-static inline int head_empty(const struct queue_head *head)
+static inline int queue_empty(const struct queue_head *head)
 {
     return (head->next == head);
 }
@@ -85,4 +85,14 @@ static inline void queue_del_init(struct queue_head *node)
          entry = queue_entry(entry->member.next, __typeof__(*entry), member))
 #endif
 
+#define queue_for_each_safe(node, safe, head)                    \
+    for (node = (head)->next, safe = node->next; node != (head); \
+         node = safe, safe = node->next)
+
+#define queue_for_each_entry_safe(entry, safe, head, member)                \
+    for (entry = queue_entry((head)->next, __typeof__(*entry), member),     \
+        safe = queue_entry(entry->member.next, __typeof__(*entry), member); \
+         &entry->member != (head); entry = safe,                            \
+        safe = queue_entry(safe->member.next, __typeof__(*entry), member))
+
 #endif

virtio-snd.c

@@ -739,13 +739,16 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
     {
         uint32_t addr = node->vq_desc.addr;
         uint32_t len = node->vq_desc.len;
-        fprintf(stderr, "idx %d addr %" PRIu32 " len %" PRIu32 "\n", idx, addr, len);
+        fprintf(stderr, "idx %d addr %" PRIu32 " len %" PRIu32 "\n", idx, addr,
+                len);
         if (idx == 0) {  // the first descriptor
-            const virtio_snd_pcm_xfer_t *request = (virtio_snd_pcm_xfer_t *)(base + addr);
+            const virtio_snd_pcm_xfer_t *request =
+                (virtio_snd_pcm_xfer_t *) (base + addr);
             stream_id = request->stream_id;
             fprintf(stderr, "stream_id %" PRIu32 "\n", stream_id);
         } else if (idx == cnt - 1) {  // the last descriptor
-            virtio_snd_pcm_status_t *response = (virtio_snd_pcm_status_t *)(base + addr);
+            virtio_snd_pcm_status_t *response =
+                (virtio_snd_pcm_status_t *) (base + addr);
             response->status = VIRTIO_SND_S_OK;
             response->latency_bytes =
                 0;                     /* TODO: show the actual latency bytes */
@@ -757,6 +760,18 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
         idx++;
     }
 
+    /* Tear down the list and free space */
+    idx = 0;
+    virtq_desc_queue_node_t *tmp = NULL;
+    queue_for_each_entry_safe(node, tmp, &q, q)
+    {
+        queue_del(&node->q);
+        free(node);
+        idx++;
+    }
+    assert(idx == cnt);
+    assert(queue_empty(&q));
+
     return 0;
 }