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Ticket #346: deadlock in event subscription when SUBSCRIBE is followed immediately with UN-SUBSCRIBE

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git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@1395 74dad513-b988-da41-8d7b-12977e46ad98
This commit is contained in:
Benny Prijono 2007-06-27 12:52:35 +00:00
parent 5583a8074f
commit efb9b6b1c1
1 changed files with 45 additions and 2 deletions
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47
pjsip/src/pjsip-simple/evsub.c
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@ -1210,6 +1210,23 @@ on_return:
}
/* Callback to be called to terminate transaction. */
static void terminate_timer_cb(pj_timer_heap_t *timer_heap,
struct pj_timer_entry *entry)
{
pj_str_t *key;
pjsip_transaction *tsx;
PJ_UNUSED_ARG(timer_heap);
key = (pj_str_t*)entry->user_data;
tsx = pjsip_tsx_layer_find_tsx(key, PJ_FALSE);
/* Chance of race condition here */
if (tsx) {
pjsip_tsx_terminate(tsx, PJSIP_SC_REQUEST_UPDATED);
}
}
/*
* Attach subscription session to newly created transaction, if appropriate.
@ -1375,6 +1392,10 @@ static pjsip_evsub *on_new_transaction( pjsip_transaction *tsx,
if (sub->pending_sub &&
sub->pending_sub->state < PJSIP_TSX_STATE_COMPLETED)
{
pj_timer_entry *timer;
pj_str_t *key;
pj_time_val timeout = {0, 0};
PJ_LOG(4,(sub->obj_name,
"Cancelling pending subscription request"));
@ -1382,7 +1403,22 @@ static pjsip_evsub *on_new_transaction( pjsip_transaction *tsx,
* When transaction handler (below) see this status code, it
* will ignore the transaction.
*/
pjsip_tsx_terminate(sub->pending_sub, PJSIP_SC_REQUEST_UPDATED);
/* This unfortunately may cause deadlock, because at the moment
* we are holding dialog's mutex. If a response to this
* transaction is in progress in another thread, that thread
* will deadlock when trying to acquire dialog mutex, because
* it is holding the transaction mutex.
*
* So the solution is to register timer to kill this transaction.
*/
//pjsip_tsx_terminate(sub->pending_sub, PJSIP_SC_REQUEST_UPDATED);
timer = PJ_POOL_ZALLOC_T(dlg->pool, pj_timer_entry);
key = PJ_POOL_ALLOC_T(dlg->pool, pj_str_t);
pj_strdup(dlg->pool, key, &sub->pending_sub->transaction_key);
timer->cb = &terminate_timer_cb;
timer->user_data = key;
pjsip_endpt_schedule_timer(dlg->endpt, timer, &timeout);
}
sub->pending_sub = tsx;
@ -1499,8 +1535,15 @@ static void on_tsx_state_uac( pjsip_evsub *sub, pjsip_transaction *tsx,
}
/* Clear pending subscription */
if (tsx == sub->pending_sub)
if (tsx == sub->pending_sub) {
sub->pending_sub = NULL;
} else if (sub->pending_sub != NULL) {
/* This SUBSCRIBE transaction has been "renewed" with another
* SUBSCRIBE, so we can just ignore this. For example, user
* sent SUBSCRIBE followed immediately with UN-SUBSCRIBE.
*/
return;
}
/* Handle authentication. */
if (tsx->status_code==401 || tsx->status_code==407) {