Hello, We have our soft-phone application which uses PJSIP (2.1 @ rev 4701). The following deadlock was noticed while running. I do not have the complete stack trace but have a reasonable picture of the stack. Stack thread 1 (app dials a call): pj_mutex_lock(mod_ua.mutex) - blocks on this pjsip_ua_register_dlg() pjsip_dlg_create_uac() pjsua_call_make_call() - acquires PJSUA_LOCK() Stack thread 2 (an incoming call is answered by the app) pjsua_call_on_state_changed() - blocks on PJSUA_LOCK (acquired by thread 1) inv_set_state() inv_on_state_incoming() mod_inv_on_tsx_state() pjsip_dlg_on_tsx_state() mod_ua_on_tsx_state() tsx_set_state() tsx_on_state_proceeding_uas() pjsip_tsx_send_msg() - acquires tsx->grp_lock pjsip_dlg_send_response() pjsip_inv_send_msg() pjsua_call_answer2() Stack thread 3 (incoming message on same tsx as in thread 2) pj_grp_lock_acquire() - blocks on tsx->grp_lock pjsip_tsx_layer_find_tsx() find_dlg_set_for_msg() mod_ua_on_request() - acquires mod_ua.mutex (on which thread 1 is blocked) pjsip_endpt_process_rx_data() endpt_on_rx_msg() pjsip_tpmgr_received_packet() udp_on_read_complete() Seems like a typical dining philosopher's problem. Has this been seen/reported earlier? For me, a simple solution seems to be to do a try lock on (mod_ua.mutex) when been acquired by the UAC (do not want to miss notifications from network/UAS) and report failure back to application in case it fails. Any suggestions? Thanks, Anshuman -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20140523/3fbd74d1/attachment.html>
