can_add_handle() can be removed, but its logic must remain: before adding a handle, we need to make sure the there'll be space left for the curent one to finish buffering. This should fix the audio dropout problems people were experiencing.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15374 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 14 insertions, 3 deletions

diff --git a/apps/buffering.c b/apps/buffering.c
index b527264..97f85df 100644
--- a/apps/buffering.c
+++ b/apps/buffering.c
@@ -231,9 +231,20 @@ static struct memory_handle *add_handle(size_t data_size, const bool can_wrap,
 
     mutex_lock(&llist_mutex);
 
-    /* Allocate the remainder of the space for the current handle */
-    if (cur_handle)
-        new_widx = RINGBUF_ADD(cur_handle->widx, cur_handle->filerem);
+    if (cur_handle && cur_handle->filerem > 0) {
+        /* the current handle hasn't finished buffering. We can only add
+           a new one if there is already enough free space to finish
+           the buffering. */
+        size_t req = cur_handle->filerem + sizeof(struct memory_handle);
+        if (RINGBUF_ADD_CROSS(cur_handle->widx, req, buf_ridx) >= 0) {
+            /* Not enough space */
+            mutex_unlock(&llist_mutex);
+            return NULL;
+        } else {
+            /* Allocate the remainder of the space for the current handle */
+            new_widx = RINGBUF_ADD(cur_handle->widx, cur_handle->filerem);
+        }
+    }
 
     /* align buf_widx to 4 bytes up */
     new_widx = (RINGBUF_ADD(new_widx, 3)) & ~3;