From ed61d214191f5ecc7a00ae01a89cb8d9cd501872 Mon Sep 17 00:00:00 2001
From: Richard Mudgett <rmudgett@digium.com>
Date: Thu, 5 Sep 2013 17:10:28 +0000
Subject: [PATCH] chan_iax2: Fix bridgecallno deadlock avoidance.
* Fix bridgecallno deadlock avoidance. When doing deadlock avoidance, you
need to retest the status of values for each loop to see if you still need
the lock for bridgecallno.
* As a safety check, after acquiring the bridgecallno lock you should
check if iaxs[bridgecallno] is NULL just like the current callno checks.
* Move setting thread->iostate to IAX_IOSTATE_IDLE to after processing any
deferred frames to ensure that the iostate is IDLE when it is placed back
into the idle list. defer_full_frame() tries to ensure
iax2_process_thread() wakes up to process the frame.
........
Merged revisions 398379 from http://svn.asterisk.org/svn/asterisk/branches/1.8
git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@398380 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
channels/chan_iax2.c | 55 +++++++++++++++++++++++---------------------
1 file changed, 29 insertions(+), 26 deletions(-)
diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c
index 21bd1fc2e7..05e88b9b64 100644
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -810,7 +810,7 @@ struct chan_iax2_pvt {
/*! Status of knowledge of peer ADSI capability */
int peeradsicpe;
- /*! Who we are bridged to */
+ /*! Callno of native bridge peer. (Valid if nonzero) */
unsigned short bridgecallno;
int pingid; /*!< Transmit PING request */
@@ -11510,13 +11510,13 @@ immediatedial:
}
break;
case IAX_COMMAND_TXREJ:
- if (iaxs[fr->callno]->bridgecallno) {
- while (ast_mutex_trylock(&iaxsl[iaxs[fr->callno]->bridgecallno])) {
- DEADLOCK_AVOIDANCE(&iaxsl[fr->callno]);
- }
- if (!iaxs[fr->callno]) {
- break;
- }
+ while (iaxs[fr->callno]
+ && iaxs[fr->callno]->bridgecallno
+ && ast_mutex_trylock(&iaxsl[iaxs[fr->callno]->bridgecallno])) {
+ DEADLOCK_AVOIDANCE(&iaxsl[fr->callno]);
+ }
+ if (!iaxs[fr->callno]) {
+ break;
}
iaxs[fr->callno]->transferring = TRANSFER_NONE;
@@ -11527,20 +11527,21 @@ immediatedial:
break;
}
- if (iaxs[iaxs[fr->callno]->bridgecallno]->transferring) {
+ if (iaxs[iaxs[fr->callno]->bridgecallno]
+ && iaxs[iaxs[fr->callno]->bridgecallno]->transferring) {
iaxs[iaxs[fr->callno]->bridgecallno]->transferring = TRANSFER_NONE;
send_command(iaxs[iaxs[fr->callno]->bridgecallno], AST_FRAME_IAX, IAX_COMMAND_TXREJ, 0, NULL, 0, -1);
}
ast_mutex_unlock(&iaxsl[iaxs[fr->callno]->bridgecallno]);
break;
case IAX_COMMAND_TXREADY:
- if (iaxs[fr->callno]->bridgecallno) {
- while (ast_mutex_trylock(&iaxsl[iaxs[fr->callno]->bridgecallno])) {
- DEADLOCK_AVOIDANCE(&iaxsl[fr->callno]);
- }
- if (!iaxs[fr->callno]) {
- break;
- }
+ while (iaxs[fr->callno]
+ && iaxs[fr->callno]->bridgecallno
+ && ast_mutex_trylock(&iaxsl[iaxs[fr->callno]->bridgecallno])) {
+ DEADLOCK_AVOIDANCE(&iaxsl[fr->callno]);
+ }
+ if (!iaxs[fr->callno]) {
+ break;
}
if (iaxs[fr->callno]->transferring == TRANSFER_BEGIN) {
@@ -11559,8 +11560,9 @@ immediatedial:
break;
}
- if (!(iaxs[iaxs[fr->callno]->bridgecallno]->transferring == TRANSFER_READY) &&
- !(iaxs[iaxs[fr->callno]->bridgecallno]->transferring == TRANSFER_MREADY)) {
+ if (!iaxs[iaxs[fr->callno]->bridgecallno]
+ || (iaxs[iaxs[fr->callno]->bridgecallno]->transferring != TRANSFER_READY
+ && iaxs[iaxs[fr->callno]->bridgecallno]->transferring != TRANSFER_MREADY)) {
ast_mutex_unlock(&iaxsl[iaxs[fr->callno]->bridgecallno]);
break;
}
@@ -11944,11 +11946,10 @@ static void *iax2_process_thread(void *data)
break;
}
- if (thread->iostate == IAX_IOSTATE_IDLE)
- continue;
-
/* See what we need to do */
switch (thread->iostate) {
+ case IAX_IOSTATE_IDLE:
+ continue;
case IAX_IOSTATE_READY:
thread->actions++;
thread->iostate = IAX_IOSTATE_PROCESSING;
@@ -11961,14 +11962,10 @@ static void *iax2_process_thread(void *data)
#ifdef SCHED_MULTITHREADED
thread->schedfunc(thread->scheddata);
#endif
+ break;
default:
break;
}
- time(&thread->checktime);
- thread->iostate = IAX_IOSTATE_IDLE;
-#ifdef DEBUG_SCHED_MULTITHREAD
- thread->curfunc[0]='\0';
-#endif
/* The network thread added us to the active_thread list when we were given
* frames to process, Now that we are done, we must remove ourselves from
@@ -11979,6 +11976,12 @@ static void *iax2_process_thread(void *data)
/* Make sure another frame didn't sneak in there after we thought we were done. */
handle_deferred_full_frames(thread);
+
+ time(&thread->checktime);
+ thread->iostate = IAX_IOSTATE_IDLE;
+#ifdef DEBUG_SCHED_MULTITHREAD
+ thread->curfunc[0]='\0';
+#endif
}
/*!
--
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