Merged revisions 88826 via svnmerge from
authorMark Michelson <mmichelson@digium.com>
Mon, 5 Nov 2007 23:31:00 +0000 (23:31 +0000)
committerMark Michelson <mmichelson@digium.com>
Mon, 5 Nov 2007 23:31:00 +0000 (23:31 +0000)
https://origsvn.digium.com/svn/asterisk/branches/1.4

........
r88826 | mmichelson | 2007-11-05 17:29:29 -0600 (Mon, 05 Nov 2007) | 6 lines

Reworked deadlock avoidance in __ast_read. Restored audio to
callback agents.

(closes issue #11071, reported by callguy, patched by me, tested by callguy and Ted Brown)

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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@88827 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/channel.c

index d23c2b9..7f83622 100644 (file)
@@ -2121,14 +2121,20 @@ static void ast_read_generator_actions(struct ast_channel *chan, struct ast_fram
 static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
 {
        struct ast_frame *f = NULL;     /* the return value */
-       struct ast_channel *base = NULL;
        int blah;
        int prestate;
+       int count = 0;
 
        /* this function is very long so make sure there is only one return
-        * point at the end (there is only one exception to this).
+        * point at the end (there are only two exceptions to this).
         */
-       ast_channel_lock(chan);
+       while(ast_channel_trylock(chan)) {
+               if(count++ > 10) 
+                       /*cannot goto done since the channel is not locked*/
+                       return &ast_null_frame;
+               usleep(1);
+       }
+
        if (chan->masq) {
                if (ast_do_masquerade(chan))
                        ast_log(LOG_WARNING, "Failed to perform masquerade\n");
@@ -2145,23 +2151,6 @@ static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
        }
        prestate = chan->_state;
 
-       /* Check if there's an underlying channel */
-       if (chan->tech->get_base_channel && (base = chan->tech->get_base_channel(chan)) != chan) {
-               int count = 0;
-               while (!base || ast_mutex_trylock(&base->lock)) {
-                       if (count++ > 10) {
-                               f = &ast_null_frame;
-                               goto done;
-                       }
-                       ast_mutex_unlock(&chan->lock);
-                       usleep(1);
-                       ast_mutex_lock(&chan->lock);
-                       base = chan->tech->get_base_channel(chan);
-               }
-               ast_mutex_unlock(&chan->lock);
-               chan = base;
-       }
-
        if (!ast_test_flag(chan, AST_FLAG_DEFER_DTMF | AST_FLAG_EMULATE_DTMF | AST_FLAG_IN_DTMF) && 
            !ast_strlen_zero(chan->dtmfq) && 
                (ast_tvzero(chan->dtmf_tv) || ast_tvdiff_ms(ast_tvnow(), chan->dtmf_tv) > AST_MIN_DTMF_GAP) ) {