Merged revisions 279945 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r279945 | dvossel | 2010-07-27 15:33:40 -0500 (Tue, 27 Jul 2010) | 19 lines
  
  remove empty audiohook write list on channel
  
  If a channel has an audiohook write list created on it, that
  list stays on the channel until the channel is destroyed.  There
  is no reason to keep that list on the channel if it becomes empty.
  If it is empty that just means we are doing needless translating
  for every ast_read and ast_write.  This patch removes the audiohook
  list from the channel once it is detected to be empty on either a
  read or write.  If a audiohook is added back to the channel after
  this list is destroyed, the list just gets recreated as if it never
  existed to begin with.
  
  (closes issue #17630)
  Reported by: manvirr
  
  Review: https://reviewboard.asterisk.org/r/799/
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.2@279946 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/audiohook.h

@@ -200,6 +200,13 @@ int ast_audiohook_detach_source(struct ast_channel *chan, const char *source);
  */
 int ast_audiohook_remove(struct ast_channel *chan, struct ast_audiohook *audiohook);
 
+/*!
+ * \brief determines if a audiohook_list is empty or not.
+ *
+ * retval 0 false, 1 true
+ */
+int ast_audiohook_write_list_empty(struct ast_audiohook_list *audiohook_list);
+
 /*! \brief Pass a frame off to be handled by the audiohook core
  * \param chan Channel that the list is coming off of
  * \param audiohook_list List of audiohooks

main/audiohook.c

@@ -723,6 +723,17 @@ static struct ast_frame *audio_audiohook_write_list(struct ast_channel *chan, st
 	return end_frame;
 }
 
+int ast_audiohook_write_list_empty(struct ast_audiohook_list *audiohook_list)
+{
+	if (AST_LIST_EMPTY(&audiohook_list->spy_list) &&
+		AST_LIST_EMPTY(&audiohook_list->whisper_list) &&
+		AST_LIST_EMPTY(&audiohook_list->manipulate_list)) {
+
+		return 1;
+	}
+	return 0;
+}
+
 /*! \brief Pass a frame off to be handled by the audiohook core
  * \param chan Channel that the list is coming off of
  * \param audiohook_list List of audiohooks
@@ -740,7 +751,6 @@ struct ast_frame *ast_audiohook_write_list(struct ast_channel *chan, struct ast_
 	else
 		return frame;
 }
-			
 
 /*! \brief Wait for audiohook trigger to be triggered
  * \param audiohook Audiohook to wait on

main/channel.c

@@ -3162,6 +3162,11 @@ done:
 	if (chan->music_state && chan->generator && chan->generator->digit && f && f->frametype == AST_FRAME_DTMF_END)
 		chan->generator->digit(chan, f->subclass);
 
+	if (chan->audiohooks && ast_audiohook_write_list_empty(chan->audiohooks)) {
+		/* The list gets recreated if audiohooks are added again later */
+		ast_audiohook_detach_list(chan->audiohooks);
+		chan->audiohooks = NULL;
+	}
 	ast_channel_unlock(chan);
 	return f;
 }
@@ -3851,6 +3856,11 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr)
 		chan->fout = FRAMECOUNT_INC(chan->fout);
 	}
 done:
+	if (chan->audiohooks && ast_audiohook_write_list_empty(chan->audiohooks)) {
+		/* The list gets recreated if audiohooks are added again later */
+		ast_audiohook_detach_list(chan->audiohooks);
+		chan->audiohooks = NULL;
+	}
 	ast_channel_unlock(chan);
 	return res;
 }