[Asterisk-code-review] channel: Fix issues in hangup scenarios caused by frame def... (asterisk[13])
George Joseph
asteriskteam at digium.com
Mon Nov 14 14:29:57 CST 2016
George Joseph has uploaded a new change for review. ( https://gerrit.asterisk.org/4422 )
Change subject: channel: Fix issues in hangup scenarios caused by frame deferral
......................................................................
channel: Fix issues in hangup scenarios caused by frame deferral
ASTERISK-26343
Change-Id: I06dbf7366e26028251964143454a77d017bb61c8
(cherry picked from commit 0be46aaf6b8b9eb5b0160ec591cdc2c6e1802a6d)
(cherry picked from commit 7263a17ca046923c245296a3cee21df0e4bd499a)
---
M include/asterisk/channel.h
M main/autoservice.c
M main/channel.c
3 files changed, 108 insertions(+), 0 deletions(-)
git pull ssh://gerrit.asterisk.org:29418/asterisk refs/changes/22/4422/1
diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index a76e606..c9e537f 100644
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -966,6 +966,16 @@
* The channel is executing a subroutine or macro
*/
AST_FLAG_SUBROUTINE_EXEC = (1 << 27),
+ /*!
+ * The channel is currently in an operation where
+ * frames should be deferred.
+ */
+ AST_FLAG_DEFER_FRAMES = (1 << 28),
+ /*!
+ * The channel is currently deferring hangup frames
+ * in addition to other frame types.
+ */
+ AST_FLAG_DEFER_HANGUP_FRAMES = (1 << 29),
};
/*! \brief ast_bridge_config flags */
@@ -4681,4 +4691,43 @@
*/
enum ast_channel_error ast_channel_errno(void);
+/*!
+ * \brief Retrieve the deferred read queue.
+ */
+struct ast_readq_list *ast_channel_deferred_readq(struct ast_channel *chan);
+
+/*!
+ * \brief Start deferring deferrable frames on this channel
+ *
+ * Sometimes, a channel gets entered into a mode where a "main" application
+ * is tasked with servicing frames on the channel, but that application does
+ * not need to act on those frames. However, it would be imprudent to simply
+ * drop important frames. This function can be called so that important frames
+ * will be deferred, rather than placed in the channel frame queue as normal.
+ *
+ * Hangups are an interesting frame type. Hangups will always be detectable by
+ * a reader when a channel is deferring frames. If the defer_hangups parameter
+ * is non-zero, then the hangup frame will also be duplicated and deferred, so
+ * that the next reader of the channel will get the hangup frame, too.
+ *
+ * \pre chan MUST be locked before calling
+ *
+ * \param chan The channel on which frames should be deferred
+ * \param defer_hangups Defer hangups in addition to other deferrable frames
+ */
+void ast_channel_start_defer_frames(struct ast_channel *chan, int defer_hangups);
+
+/*!
+ * \brief Stop deferring deferrable frames on this channel
+ *
+ * When it is time to stop deferring frames on the channel, all deferred frames
+ * will be queued onto the channel's read queue so that the next servicer of
+ * the channel can handle those frames as necessary.
+ *
+ * \pre chan MUST be locked before calling
+ *
+ * \param chan The channel on which to stop deferring frames.
+ */
+void ast_channel_stop_defer_frames(struct ast_channel *chan);
+
#endif /* _ASTERISK_CHANNEL_H */
diff --git a/main/autoservice.c b/main/autoservice.c
index 305ab23..e6eb1ef 100644
--- a/main/autoservice.c
+++ b/main/autoservice.c
@@ -220,6 +220,7 @@
as->orig_end_dtmf_flag = ast_test_flag(ast_channel_flags(chan), AST_FLAG_END_DTMF_ONLY) ? 1 : 0;
if (!as->orig_end_dtmf_flag)
ast_set_flag(ast_channel_flags(chan), AST_FLAG_END_DTMF_ONLY);
+ ast_channel_start_defer_frames(chan, 1);
ast_channel_unlock(chan);
AST_LIST_LOCK(&aslist);
diff --git a/main/channel.c b/main/channel.c
index 278104c..0a7865d 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -1061,6 +1061,26 @@
return tmp;
}
+void ast_channel_start_defer_frames(struct ast_channel *chan, int defer_hangups)
+{
+ ast_set_flag(ast_channel_flags(chan), AST_FLAG_DEFER_FRAMES);
+ ast_set2_flag(ast_channel_flags(chan), defer_hangups, AST_FLAG_DEFER_HANGUP_FRAMES);
+}
+
+void ast_channel_stop_defer_frames(struct ast_channel *chan)
+{
+ ast_clear_flag(ast_channel_flags(chan), AST_FLAG_DEFER_FRAMES);
+
+ /* Move the deferred frames onto the channel read queue, ahead of other queued frames */
+ ast_queue_frame_head(chan, AST_LIST_FIRST(ast_channel_deferred_readq(chan)));
+ /* ast_frfree will mosey down the list and free them all */
+ if (!AST_LIST_EMPTY(ast_channel_deferred_readq(chan))) {
+ ast_frfree(AST_LIST_FIRST(ast_channel_deferred_readq(chan)));
+ }
+ /* Reset the list to be empty */
+ AST_LIST_HEAD_INIT_NOLOCK(ast_channel_deferred_readq(chan));
+}
+
static int __ast_queue_frame(struct ast_channel *chan, struct ast_frame *fin, int head, struct ast_frame *after)
{
struct ast_frame *f;
@@ -1532,6 +1552,10 @@
if (ast_opt_transmit_silence && !ast_channel_generatordata(chan)) {
silgen = ast_channel_start_silence_generator(chan);
}
+
+ ast_channel_lock(chan);
+ ast_channel_start_defer_frames(chan, 0);
+ ast_channel_unlock(chan);
start = ast_tvnow();
while ((ms = ast_remaining_ms(start, timeout_ms))) {
@@ -3884,6 +3908,36 @@
/* Check for pending read queue */
if (!AST_LIST_EMPTY(ast_channel_readq(chan))) {
int skip_dtmf = should_skip_dtmf(chan);
+
+ if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_DEFER_FRAMES)) {
+ AST_LIST_TRAVERSE_SAFE_BEGIN(ast_channel_readq(chan), f, frame_list) {
+ if (ast_is_deferrable_frame(f)) {
+ if(f->frametype == AST_FRAME_CONTROL &&
+ (f->subclass.integer == AST_CONTROL_HANGUP ||
+ f->subclass.integer == AST_CONTROL_END_OF_Q)) {
+ /* Hangup is a special case. We want to defer the frame, but we also do not
+ * want to remove it from the frame queue. So rather than just moving the frame
+ * over, we duplicate it and move the copy to the deferred readq.
+ *
+ * The reason for this? This way, whoever calls ast_read() will get a NULL return
+ * immediately and can tell the channel has hung up and do what it needs to. Also,
+ * when frame deferral finishes, then whoever calls ast_read() next will also get
+ * the hangup.
+ */
+ if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_DEFER_HANGUP_FRAMES)) {
+ struct ast_frame *dup;
+
+ dup = ast_frdup(f);
+ AST_LIST_INSERT_TAIL(ast_channel_deferred_readq(chan), dup, frame_list);
+ }
+ } else {
+ AST_LIST_INSERT_TAIL(ast_channel_deferred_readq(chan), f, frame_list);
+ AST_LIST_REMOVE_CURRENT(frame_list);
+ }
+ }
+ }
+ AST_LIST_TRAVERSE_SAFE_END;
+ }
AST_LIST_TRAVERSE_SAFE_BEGIN(ast_channel_readq(chan), f, frame_list) {
/* We have to be picky about which frame we pull off of the readq because
@@ -10216,6 +10270,7 @@
ast_party_connected_line_copy(ast_channel_connected(macro_chan), connected);
}
+ ast_channel_start_defer_frames(macro_chan, 0);
ast_channel_unlock(macro_chan);
retval = ast_app_run_macro(autoservice_chan, macro_chan, macro, macro_args);
@@ -10266,6 +10321,7 @@
ast_party_redirecting_copy(ast_channel_redirecting(macro_chan), redirecting);
}
+ ast_channel_start_defer_frames(macro_chan, 0);
ast_channel_unlock(macro_chan);
retval = ast_app_run_macro(autoservice_chan, macro_chan, macro, macro_args);
@@ -10309,6 +10365,7 @@
ast_party_connected_line_copy(ast_channel_connected(sub_chan), connected);
}
+ ast_channel_start_defer_frames(sub_chan, 0);
ast_channel_unlock(sub_chan);
retval = ast_app_run_sub(autoservice_chan, sub_chan, sub, sub_args, 0);
@@ -10352,6 +10409,7 @@
ast_party_redirecting_copy(ast_channel_redirecting(sub_chan), redirecting);
}
+ ast_channel_start_defer_frames(sub_chan, 0);
ast_channel_unlock(sub_chan);
retval = ast_app_run_sub(autoservice_chan, sub_chan, sub, sub_args, 0);
--
To view, visit https://gerrit.asterisk.org/4422
To unsubscribe, visit https://gerrit.asterisk.org/settings
Gerrit-MessageType: newchange
Gerrit-Change-Id: I06dbf7366e26028251964143454a77d017bb61c8
Gerrit-PatchSet: 1
Gerrit-Project: asterisk
Gerrit-Branch: 13
Gerrit-Owner: George Joseph <gjoseph at digium.com>
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