From d9526bc6c8922b5165b031b003f7b53624f73008 Mon Sep 17 00:00:00 2001
From: Richard Mudgett <rmudgett@digium.com>
Date: Mon, 29 Aug 2011 21:17:51 +0000
Subject: [PATCH] Merged revisions 333786 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/10
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r333786 | rmudgett | 2011-08-29 16:12:29 -0500 (Mon, 29 Aug 2011) | 13 lines
Merged revisions 333784-333785 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.8
........
r333784 | rmudgett | 2011-08-29 16:05:43 -0500 (Mon, 29 Aug 2011) | 2 lines
Fix deadlock potential of chan_mobile.c:mbl_ast_hangup().
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r333785 | rmudgett | 2011-08-29 16:06:16 -0500 (Mon, 29 Aug 2011) | 1 line
Add some do not hold locks notes to channel.h
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................
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@333789 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
addons/chan_mobile.c | 17 +++--------------
include/asterisk/channel.h | 18 +++++++++++++++++-
2 files changed, 20 insertions(+), 15 deletions(-)
diff --git a/addons/chan_mobile.c b/addons/chan_mobile.c
index 7c14927298..743f811689 100644
--- a/addons/chan_mobile.c
+++ b/addons/chan_mobile.c
@@ -1318,21 +1318,10 @@ static int mbl_queue_hangup(struct mbl_pvt *pvt)
static int mbl_ast_hangup(struct mbl_pvt *pvt)
{
- int res = 0;
- for (;;) {
- if (pvt->owner) {
- if (ast_channel_trylock(pvt->owner)) {
- DEADLOCK_AVOIDANCE(&pvt->lock);
- } else {
- res = ast_hangup(pvt->owner);
- /* no need to unlock, ast_hangup() frees the
- * channel */
- break;
- }
- } else
- break;
+ if (pvt->owner) {
+ ast_hangup(pvt->owner);
}
- return res;
+ return 0;
}
/*!
diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index 031c6f7e93..44f0a20f35 100644
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -1108,6 +1108,7 @@ struct ast_datastore *ast_channel_datastore_find(struct ast_channel *chan, const
* \retval NULL failure
* \retval non-NULL successfully allocated channel
*
+ * \note Absolutely _NO_ channel locks should be held before calling this function.
* \note By default, new channels are set to the "s" extension
* and "default" context.
*/
@@ -1119,6 +1120,16 @@ struct ast_channel * attribute_malloc __attribute__((format(printf, 13, 14)))
const char *file, int line, const char *function,
const char *name_fmt, ...);
+/*!
+ * \brief Create a channel structure
+ *
+ * \retval NULL failure
+ * \retval non-NULL successfully allocated channel
+ *
+ * \note Absolutely _NO_ channel locks should be held before calling this function.
+ * \note By default, new channels are set to the "s" extension
+ * and "default" context.
+ */
#define ast_channel_alloc(needqueue, state, cid_num, cid_name, acctcode, exten, context, linkedid, amaflag, ...) \
__ast_channel_alloc(needqueue, state, cid_num, cid_name, acctcode, exten, context, linkedid, amaflag, \
__FILE__, __LINE__, __FUNCTION__, __VA_ARGS__)
@@ -1251,6 +1262,7 @@ void ast_change_name(struct ast_channel *chan, const char *newname);
* if it is still there and also release the current reference to the channel.
*
* \return NULL, convenient for clearing invalid pointers
+ * \note Absolutely _NO_ channel locks should be held before calling this function.
*
* \since 1.8
*/
@@ -1380,6 +1392,7 @@ int ast_channel_trace_serialize(struct ast_channel *chan, struct ast_str **out);
/*!
* \brief Hang up a channel
+ * \note Absolutely _NO_ channel locks should be held before calling this function.
* \note This function performs a hard hangup on a channel. Unlike the soft-hangup, this function
* performs all stream stopping, etc, on the channel that needs to end.
* chan is no longer valid after this call.
@@ -1960,7 +1973,9 @@ int ast_channel_bridge(struct ast_channel *c0,struct ast_channel *c1,
* p->owner pointer) that is affected by the change. The physical layer of the original
* channel is hung up.
*
- * \note Neither channel passed here needs to be locked before calling this function.
+ * \note Neither channel passed here should be locked before
+ * calling this function. This function performs deadlock
+ * avoidance involving these two channels.
*/
int ast_channel_masquerade(struct ast_channel *original, struct ast_channel *clone);
@@ -2569,6 +2584,7 @@ struct ast_channel *ast_channel_iterator_next(struct ast_channel_iterator *i);
* This function executes a callback one time for each active channel on the
* system. The channel is provided as an argument to the function.
*
+ * \note Absolutely _NO_ channel locks should be held before calling this function.
* \since 1.8
*/
struct ast_channel *ast_channel_callback(ao2_callback_data_fn *cb_fn, void *arg,
--
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