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Lock continuation before calling event handler. #4142

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shinrich merged 1 commit into from
Sep 6, 2018
Merged

Lock continuation before calling event handler. #4142

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5 changes: 4 additions & 1 deletion iocore/hostdb/HostDB.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -1592,7 +1592,10 @@ HostDBContinuation::probeEvent(int /* event ATS_UNUSED */, Event *e)
EThread *t = e ? e->ethread : this_ethread();

MUTEX_TRY_LOCK(lock, action.mutex, t);
if (!lock.is_locked()) {
// Go ahead and grab the continuation mutex or just grab the action mutex again of there is no continuation mutex
MUTEX_TRY_LOCK(lock2, (action.continuation && action.continuation->mutex) ? action.continuation->mutex : action.mutex, t);
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@bryancall bryancall Aug 28, 2018

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Does this only happen with the global session pool? I was talking to @zwoop about this earlier today.

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@shinrich shinrich Sep 6, 2018

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I have only tested with the global pool environment.

// Don't continue unless we have both mutexes
if (!lock.is_locked() || !lock2.is_locked()) {
mutex->thread_holding->schedule_in(this, HOST_DB_RETRY_PERIOD);
return EVENT_CONT;
}
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