Tear down PCM frames

Author: Cuda-Chen

virtio-snd.c

@@ -234,6 +234,11 @@ typedef struct {
     uint8_t positions[VIRTIO_SND_CHMAP_MAX_SIZE];
 } virtio_snd_chmap_info_t;
 
+/* A queue to hold arbitrary number of PCM frames. */
+typedef struct {
+    void *buf;
+    struct queue_head q;
+} virtio_snd_pcm_frame_t;
 /* virtio-snd to hold the settings of each stream */
 typedef struct {
     virtio_snd_jack_info_t j;
@@ -244,7 +249,8 @@ typedef struct {
     bool is_guest_playing;
 
     // PCM frame buffer
-    void *buf;
+    virtio_snd_pcm_frame_t *pcm_frames;
+    struct queue_head pcm_frames_q;
 } virtio_snd_prop_t;
 
 static virtio_snd_config_t vsnd_configs[VSND_DEV_CNT_MAX];
@@ -434,8 +440,6 @@ static void virtio_snd_read_pcm_prepare(const virtio_snd_pcm_hdr_t *query,
     vsnd_props[stream_id].audio_host =
         CNFAInit(NULL, "semu-virtio-snd", virtio_snd_cb, 44100, 0, 1, 0,
                  vsnd_props[stream_id].pp.buffer_bytes, NULL, NULL, &v);
-    size_t sz = vsnd_props[stream_id].pp.buffer_bytes;
-    vsnd_props[stream_id].buf = malloc(sizeof(vsnd_props[stream_id].buf) * sz);
 
     /* Control the callback to prepare the buffer */
     /* TODO: add lock to avoid race condition */
@@ -518,7 +522,6 @@ static void virtio_snd_read_pcm_release(const virtio_snd_pcm_hdr_t *query,
 
     vsnd_props[stream_id].pp.hdr.hdr.code = VIRTIO_SND_R_PCM_RELEASE;
     CNFAClose(vsnd_props[stream_id].audio_host);
-    free(vsnd_props[stream_id].buf);
 
     *plen = 0;
     fprintf(stderr, "virtio_snd_read_pcm_release\n");
@@ -734,7 +737,10 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
 #endif
     int idx = 0;
     uint32_t stream_id;
-    uintptr_t base = vsnd->ram;
+    uintptr_t base = (uintptr_t) vsnd->ram;
+    struct queue_head frame_q = vsnd_props[stream_id].pcm_frames_q;
+    INIT_QUEUE_HEAD(&frame_q);
+    virtio_snd_pcm_frame_t *frame = vsnd_props[stream_id].pcm_frames;
     queue_for_each_entry(node, &q, q)
     {
         uint32_t addr = node->vq_desc.addr;
@@ -746,6 +752,7 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
                 (virtio_snd_pcm_xfer_t *) (base + addr);
             stream_id = request->stream_id;
             fprintf(stderr, "stream_id %" PRIu32 "\n", stream_id);
+            goto early_continue;
         } else if (idx == cnt - 1) {  // the last descriptor
             virtio_snd_pcm_status_t *response =
                 (virtio_snd_pcm_status_t *) (base + addr);
@@ -755,12 +762,20 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
             *plen = sizeof(*response); /* TODO: set the read length of buffer of
                                           PCM frames */
             fprintf(stderr, "TX response\n");
+            goto early_continue;
         }
 
+        frame = (virtio_snd_pcm_frame_t *) malloc(sizeof(*frame));
+        void *buf = (void *) (base + addr);
+        frame->buf = (void *) malloc(sizeof(frame->buf) * len);
+        memcpy(frame->buf, buf, len);
+        queue_push(&frame->q, &frame_q);
+
+    early_continue:
         idx++;
     }
 
-    /* Tear down the list and free space */
+    /* Tear down the descriptor list and free space. */
     idx = 0;
     virtq_desc_queue_node_t *tmp = NULL;
     queue_for_each_entry_safe(node, tmp, &q, q)
@@ -772,6 +787,19 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
     assert(idx == cnt);
     assert(queue_empty(&q));
 
+    /* Tear down the PCM frames. (should use in pcm_release) */
+    idx = 0;
+    virtio_snd_pcm_frame_t *t = NULL;
+    queue_for_each_entry_safe(frame, t, &frame_q, q)
+    {
+        free(frame->buf);
+        queue_del(&frame->q);
+        free(frame);
+        idx++;
+    }
+    assert(idx == cnt - 2);
+    assert(queue_empty(&frame_q));
+
     return 0;
 }