From 720a8d349602fbfb6c33ea2b2dc19da73c880ce9 Mon Sep 17 00:00:00 2001
From: Nicolas Pennequin <nicolas@nicolas-laptop.(none)>
Date: Tue, 16 Oct 2007 23:21:31 +0200
Subject: [PATCH] Replace yield_codec() with a call to queue_wait_w_tmo()

This achieves the same purpose, but in a more elegant way.

(suggested by jhMikeS)
---
 apps/buffering.c | 74 +++++++++++++++++++++++++++++---------------------------
 1 file changed, 38 insertions(+), 36 deletions(-)

diff --git a/apps/buffering.c b/apps/buffering.c
index fae876ae0..fceb8747c 100644
--- a/apps/buffering.c
+++ b/apps/buffering.c
@@ -355,30 +355,13 @@ static bool filebuf_is_lowdata(void)
     return BUF_USED < AUDIO_FILEBUF_CRITICAL;
 }
 
-/* Yield to the codec thread for as long as possible if it is in need of data.
-   Return true if the caller should break to let the buffering thread process
-   new queue events */
-static bool yield_codec(void)
-{
-    yield();
-
-    if (!queue_empty(&buffering_queue))
-        return true;
-
-    while (pcmbuf_is_lowdata() && !filebuf_is_lowdata())
-    {
-        sleep(2);
-
-        if (!queue_empty(&buffering_queue))
-            return true;
-    }
-
-    return false;
-}
-
-/* Buffer data for the given handle. Return the amount of data buffered
-   or -1 if the handle wasn't found */
-static ssize_t buffer_handle(int handle_id)
+/* Buffer data for the given handle. Return when finished or when an event was
+   received on the buffering queue.
+   ev is where queue events will be received. If buffering wasn't interrupted,
+   ev->id == SYS_TIMEOUT.
+   Return value is the amount of data buffered, or -1 if the handle wasn't found
+*/
+static ssize_t buffer_handle(int handle_id, struct queue_event *ev)
 {
     DEBUGF("buffer_handle(%d)\n", handle_id);
     struct memory_handle *h = find_handle(handle_id);
@@ -447,9 +430,20 @@ static ssize_t buffer_handle(int handle_id)
         /* DEBUGF("buffer_handle(%d): buffered %ld bytes. done: %ld. remaining: %ld.\n",
                h->id, rc, h->available, h->filerem); */
 
-        /* Stop buffering if new queue events have arrived */
-        if (yield_codec())
+        /* Sleep a bit and stop buffering if new queue events have arrived */
+        queue_wait_w_tmo(&buffering_queue, ev, 10);
+
+        if (ev->id == Q_BUFFER_HANDLE && (int)ev->data == handle_id) {
+            /* Don't stop buffering if the request is to buffer the same file */
+            LOGFQUEUE("buffering < Q_BUFFER_HANDLE");
+            DEBUGF("buffer_handle: continuing buffering of handle %d\n",
+                   handle_id);
+        }
+        else if (ev->id != SYS_TIMEOUT) {
+            /* An event was received, break the loop so it can be treated */
+            DEBUGF("buffer_handle: event received, interrupting buffering\n");
             break;
+        }
     }
 
     if (h->filerem == 0) {
@@ -556,13 +550,15 @@ static void shrink_handle(int handle_id)
 
 /* Fill the buffer by buffering as much data as possible for handles that still
    have data left to buffer */
-static void fill_buffer(void)
+static void fill_buffer(struct queue_event *ev)
 {
     DEBUGF("fill buffer()\n");
     struct memory_handle *m = first_handle;
     while (m) {
         if (m->filerem > 0) {
-            buffer_handle(m->id);
+            buffer_handle(m->id, ev);
+            if (ev->id != SYS_TIMEOUT)
+                return;
         }
         m = m->next;
     }
@@ -652,10 +648,10 @@ management functions for all the actual handle management work.
 
 
 /* Reserve space in the buffer for a file.
-   filename: name of the file to open
-   offset: offset at which to start buffering the file, useful when the first
-           (offset-1) bytes of the file aren't needed.
-   return value: <0 if the file cannot be opened, or one file already
+   filename : name of the file to open
+   offset   : offset at which to start buffering the file, useful when the first
+              (offset-1) bytes of the file aren't needed.
+   returns  : <0 if the file cannot be opened, or one file already
    queued to be opened, otherwise the handle for the file in the buffer
 */
 int bufopen(char *file, size_t offset, enum data_type type)
@@ -964,12 +960,15 @@ void buffering_thread(void)
             register_ata_idle_func(ata_fillbuffer_callback);
 #endif
 
+next_event:
         switch (ev.id)
         {
             case Q_BUFFER_HANDLE:
                 LOGFQUEUE("buffering < Q_BUFFER_HANDLE");
                 queue_reply(&buffering_queue, 1);
-                buffer_handle((int)ev.data);
+                buffer_handle((int)ev.data, &ev);
+                /* ev is now an event received by buffer_handle() */
+                goto next_event;
                 break;
 
             case Q_RESET_HANDLE:
@@ -986,8 +985,10 @@ void buffering_thread(void)
                 if (!ata_disk_is_active())
                     break;
 #endif
-                if (num_handles > 0 && data_rem() > 0)
-                    fill_buffer();
+                if (num_handles > 0 && data_rem() > 0) {
+                    fill_buffer(&ev);
+                    goto next_event;
+                }
                 break;
 #endif /* MEM > 8 */
 
@@ -1031,7 +1032,8 @@ void buffering_thread(void)
         {
             DEBUGF("%ld bytes left to buffer and the buffer is low\n",
                    (long)data_rem());
-            fill_buffer();
+            fill_buffer(&ev);
+            goto next_event;
         }
     }
 }
-- 
2.11.4.GIT