| Summary: | ASTERISK-24356: PJSIP: Directed pickup causes deadlock | ||||
| Reporter: | Richard Mudgett (rmudgett) | Labels: | |||
| Date Opened: | 2014-09-25 13:32:18 | Date Closed: | 2014-10-03 12:33:33 | ||
| Priority: | Major | Regression? | |||
| Status: | Closed/Complete | Components: | Channels/chan_pjsip | ||
| Versions: | 13.0.0-beta2 | Frequency of Occurrence | Frequent | ||
| Related Issues: |
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| Environment: | Attachments: | ( 0) backtrace.txt ( 1) core_show_locks.txt ( 2) jira_asterisk_24356_v13.patch | |||
| Description: | Performing a directed pickup of PJSIP channels can result in a deadlock.
Steps to reproduce: # Party A(100) calls Party B(200) # External process uses an AMI Originate to have Party C(202) pickup the call to Party B. # When Party C answers, a deadlock is likely to happen. Party B and C happen to be Digium D40 phones. Sample extensions.conf: {noformat} [connected_line_send] exten = s,1,NoOp(Connected line update) same = n,Return [call_pickup] exten = s,1,NoOp(Directed pickup) same = n,PickupChan(${PICKUP_CHAN}) same = n,Hangup() [default] exten = 200,1,NoOp(Party A calling Party B) same = n,Set(__CONNECTED_LINE_SEND_SUB=connected_line_send,s,1) same = n,Dial(PJSIP/200,30,kKtT) same = n,Hangup() {noformat} AMI Originate to pickup call to Party B {noformat} Action: Originate CallerID: PBX <0> Channel: PJSIP/202 Timeout: 30000 Context: call_pickup Exten: s Priority: 1 Account: pickmeup Variable: PICKUP_CHAN=PJSIP/200 {noformat} The deadlock is between the channel masquerade to pickup the call and the PJSIP channel processing a 180 Ringing message. I think a recent change made this deadlock more likely to happen. | ||||
| Comments: | By: Richard Mudgett (rmudgett) 2014-09-25 13:44:00.307-0500 [^backtrace.txt] - The threads marked with BUGBUG are involved in the pickup. Thread 4 and 2 are in deadlock. [^core_show_locks.txt] - Captured before attaching gdb to get backtrace. By: Richard Mudgett (rmudgett) 2014-09-29 17:07:13.401-0500 [^jira_asterisk_24356_v13.patch] - Patch that suspends the PJSIP channel serializer thread before starting a masquerade involving that channel. This avoids the deadlock while the masquerade is fixing up the private channel pointers. | ||||