From 86225089f2d0e82deb368e1688464e8ba84d24cf Mon Sep 17 00:00:00 2001 From: Rainer Gerhards Date: Tue, 21 Jun 2011 12:35:14 +0200 Subject: bugfix: mutex was invalidly left unlocked during action processing At least one case where this can occur is during thread shutdown, which may be initiated by lower activity. In most cases, this is quite unlikely to happen. However, if it does, data structures may be corrupted which could lead to fatal failure and segfault. I detected this via a testbench test, not a user report. But I assume that some users may have had unreproducable aborts that were cause by this bug. --- runtime/queue.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'runtime/queue.c') diff --git a/runtime/queue.c b/runtime/queue.c index 88e01a7a..00eb76c7 100644 --- a/runtime/queue.c +++ b/runtime/queue.c @@ -1678,6 +1678,7 @@ static rsRetVal ConsumerReg(qqueue_t *pThis, wti_t *pWti) { int iCancelStateSave; + int bNeedReLock = 0; /**< do we need to lock the mutex again? */ DEFiRet; ISOBJ_TYPE_assert(pThis, qqueue); @@ -1687,6 +1688,7 @@ ConsumerReg(qqueue_t *pThis, wti_t *pWti) /* we now have a non-idle batch of work, so we can release the queue mutex and process it */ d_pthread_mutex_unlock(pThis->mut); + bNeedReLock = 1; /* at this spot, we may be cancelled */ pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &iCancelStateSave); @@ -1706,12 +1708,14 @@ ConsumerReg(qqueue_t *pThis, wti_t *pWti) /* but now cancellation is no longer permitted */ pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &iCancelStateSave); - /* now we are done, but need to re-aquire the mutex */ - d_pthread_mutex_lock(pThis->mut); - finalize_it: - dbgprintf("regular consumer finished, iret=%d, szlog %d sz phys %d\n", iRet, + DBGPRINTF("regular consumer finished, iret=%d, szlog %d sz phys %d\n", iRet, getLogicalQueueSize(pThis), getPhysicalQueueSize(pThis)); + + /* now we are done, but potentially need to re-aquire the mutex */ + if(bNeedReLock) + d_pthread_mutex_lock(pThis->mut); + RETiRet; } -- cgit v1.2.3