saving state

1 files changed, 102 insertions, 72 deletions

diff --git a/queue.c b/queue.c
index 6ac69c11..c670c8ce 100644
--- a/queue.c
+++ b/queue.c
@@ -1,3 +1,4 @@
+// TODO: think about mutDA - I think it's no longer needed
 // TODO: start up the correct num of workers when switching to non-DA mode
 // TODO: "preforked" worker threads
 // TODO: do an if(debug) in dbgrintf - performance in release build!
@@ -64,6 +65,17 @@ static rsRetVal queueSetEnqOnly(queue_t *pThis, int bEnqOnly);
 
 /* methods */
 
+
+/* cancellation cleanup handler - frees provided mutex
+ * rgerhards, 2008-01-14
+ */
+static void queueMutexCleanup(void *arg)
+{
+	assert(arg != NULL);
+	pthread_mutex_unlock((pthread_mutex_t*) arg);
+}
+
+
 /* get the current worker state. For simplicity and speed, we have
  * NOT used our regular calling interface this time. I hope that won't
  * bite in the long term... -- rgerhards, 2008-01-17
@@ -95,12 +107,14 @@ dbgprintf("Queue 0x%lx: trying to  send command %d to thread %d\n", queueGetID(p
 	switch(tCmd) {
 		case eWRKTHRD_TERMINATING:
 			pthread_cond_destroy(&pThis->condInitDone);
+			pthread_mutex_destroy(&pThis->mut);
 			dbgprintf("Queue 0x%lx/w%d: thread terminating with %d entries left in queue, %d workers running.\n",
 				  queueGetID(pThis->pQueue), pThis->iThrd, pThis->pQueue->iQueueSize,
 				  pThis->pQueue->iCurNumWrkThrd);
 			break;
 		case eWRKTHRD_RUN_CREATED:
 			pthread_cond_init(&pThis->condInitDone, NULL);
+			pthread_mutex_init(&pThis->mut, NULL);
 			break;
 		case eWRKTHRD_RUN_INIT:
 			break;
@@ -184,7 +198,7 @@ qWrkrWaitStartup(qWrkThrd_t *pThis)
 		dbgprintf("Queue 0x%lx: waiting on worker thread %d startup\n", queueGetID(pThis->pQueue),
 			  pThis->iThrd);
 		pthread_cond_wait(&pThis->condInitDone, pThis->pQueue->mut);
-dbgprintf("startup done!\n");
+dbgprintf("worker startup done!\n");
 	}
 	pthread_mutex_unlock(pThis->pQueue->mut);
 	pthread_setcancelstate(iCancelStateSave, NULL);
@@ -287,6 +301,30 @@ queueStrtWrkThrd(queue_t *pThis, int i)
 }
 
 
+/* start the DA worker thread (if not already running)
+ */
+static inline rsRetVal
+queueStrtDAWrkr(queue_t *pThis)
+{
+	DEFiRet;
+	int iCancelStateSave;
+
+	ISOBJ_TYPE_assert(pThis, queue);
+
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &iCancelStateSave);
+dbgprintf("Queue %p: DAWrkr thread mutex lock\n", pThis);
+	pthread_mutex_lock(&pThis->pWrkThrds[0].mut);
+	pthread_cleanup_push(queueMutexCleanup, &pThis->pWrkThrds[0].mut);
+	pthread_setcancelstate(iCancelStateSave, NULL);
+	if(pThis->pWrkThrds[0].tCurrCmd == eWRKTHRD_STOPPED) {
+		iRet = queueStrtWrkThrd(pThis, 0);
+	}
+	pthread_cleanup_pop(1);
+dbgprintf("Queue %p: DAWrkr thread mutex unlock\n", pThis);
+
+	return iRet;
+}
+
 /* Starts a *new* worker thread. Function searches itself for a free index spot. It must only
  * be called when we have less than max workers active. Pending wrkr thread requests MUST have
  * been processed before calling this function. -- rgerhards, 2008-01-16
@@ -399,7 +437,7 @@ queueWakeupWrkThrds(queue_t *pThis, int bWithDAWrk)
 }
 
 
-/* This function Checks if (another) worker threads needs to be started. It
+/* This function checks if (another) worker threads needs to be started. It
  * must be called while the caller holds a lock on the queue mutex. So it must not
  * do anything that either reaquires the mutex or forces somebody else to aquire
  * it (that would lead to a deadlock).
@@ -436,7 +474,7 @@ dbgprintf("Queue %p: less than max workers are running, qsize %d, workers %d, qR
 dbgprintf("Queue %p: DA worker is no longer running, restarting, qsize %d, workers %d, qRunsDA: %d\n",
 	   pThis, pThis->iQueueSize, pThis->iCurNumWrkThrd, pThis->qRunsDA);
 			/* DA worker has timed out and needs to be restarted */
-			iRet = queueStrtWrkThrd(pThis, 0);
+			iRet = queueStrtDAWrkr(pThis);
 		}
 	}
 
@@ -476,7 +514,10 @@ queueTurnOffDAMode(queue_t *pThis)
 	 * messages come into the queue, we may be well off with a single worker.
 	 * rgerhards, 2008-01-16
 	 */
-	if(pThis->bEnqOnly == 0 && pThis->bQueueInDestruction == 0)
+dbgprintf("Queue 0x%lx: disk-assistance being been turned off, bEnqOnly %d, bQueInDestr %d, NumWrkd %d\n",
+	  queueGetID(pThis), 
+	pThis->bEnqOnly,pThis->bQueueInDestruction,pThis->iCurNumWrkThrd);
+	if(pThis->bEnqOnly == 0 && pThis->bQueueInDestruction == 0 && pThis->iCurNumWrkThrd < 2)
 		queueStrtNewWrkThrd(pThis);
 	pThis->qRunsDA = QRUNS_REGULAR; /* tell the world we are back in non-DA mode */
 
@@ -587,6 +628,7 @@ queueStrtDA(queue_t *pThis)
 	pThis->pqDA->mutSignalOnEmpty = &pThis->mutDA;
 	pThis->pqDA->condSignalOnEmpty2 = pThis->notEmpty;
 	pThis->pqDA->bSignalOnEmpty = 2;
+	pThis->pqDA->pqParent = pThis;
 
 	CHKiRet(queueSetMaxFileSize(pThis->pqDA, pThis->iMaxFileSize));
 	CHKiRet(queueSetFilePrefix(pThis->pqDA, pThis->pszFilePrefix, pThis->lenFilePrefix));
@@ -665,7 +707,7 @@ queueInitDA(queue_t *pThis, int bEnqOnly)
 	 * In enqueue-only mode, we do not start any workers.
 	 */
 	if(pThis->bEnqOnly == 0)
-		iRet = queueStrtWrkThrd(pThis, 0);
+		iRet = queueStrtDAWrkr(pThis);
 
 	return iRet;
 }
@@ -1302,16 +1344,6 @@ static rsRetVal queueShutdownWorkers(queue_t *pThis)
 	return iRet;
 }
 
-
-/* cancellation cleanup handler - frees provided mutex
- * rgerhards, 2008-01-14
- */
-static void queueMutexCleanup(void *arg)
-{
-	assert(arg != NULL);
-	pthread_mutex_unlock((pthread_mutex_t*) arg);
-}
-
 /* This is a special consumer to feed the disk-queue in disk-assited mode.
  * When active, our own queue more or less acts as a memory buffer to the disk.
  * So this consumer just needs to drain the memory queue and submit entries
@@ -1489,8 +1521,9 @@ queueWorkerRemainActive(queue_t *pThis, qWrkThrd_t *pWrkrInst)
 	     || ((qWrkrGetState(pWrkrInst) == eWRKTHRD_SHUTDOWN) && (pThis->iQueueSize > 0)));
 dbgprintf("Queue %p/w%d: chk 1 pre empty queue, qsize %d, cont run: %d, cmd %d\n", pThis, pWrkrInst->iThrd, pThis->iQueueSize, b, qWrkrGetState(pWrkrInst));
 	if(b && pWrkrInst->iThrd == 0 && pThis->qRunsDA == QRUNS_DA) {
-		queueGetQueueSize(pThis->pqDA, &iSizeDAQueue);
-		b = pThis->iQueueSize >= pThis->iHighWtrMrk || iSizeDAQueue != 0;
+//		queueGetQueueSize(pThis->pqDA, &iSizeDAQueue);
+//		b = pThis->iQueueSize >= pThis->iHighWtrMrk || iSizeDAQueue != 0;
+		b = pThis->iQueueSize >= pThis->iHighWtrMrk || pThis->pqDA->iQueueSize != 0;
 	}
 
 dbgprintf("Queue %p/w%d: pre empty queue, qsize %d, cont run: %d\n", pThis, pWrkrInst->iThrd, pThis->iQueueSize, b);
@@ -1578,13 +1611,23 @@ dbgprintf("Queue 0x%lx/w%d: start worker run, queue cmd currently %d\n",
 		if(pThis->iQueueSize == 0) {
 			dbgprintf("Queue 0x%lx/w%d: queue EMPTY, waiting for next message.\n",
 				  queueGetID(pThis), iMyThrdIndx);
-			/* TODO: check if the parent DA worker is running and, if not, initiate it */
+			/* check if the parent DA worker is running and, if not, initiate it. Thanks
+			 * to queueStrtDAWrkr (), we do not actually need to check (that routines does
+			 * that for us, but we need to aquire the parent queue's mutex to call it.
+			 */
+			if(pThis->pqParent != NULL) {
+			dbgprintf("Queue %p: pre start parent %p worker\n", pThis, pThis->pqParent);
+				queueStrtDAWrkr(pThis->pqParent);
+			}
+
 			if(pThis->bSignalOnEmpty > 0) {
 				/* we need to signal our parent queue that we are empty */
 	dbgprintf("Queue %p/w%d: signal parent we are empty\n", pThis, iMyThrdIndx);
-				pthread_mutex_lock(pThis->mutSignalOnEmpty);
+				//pthread_mutex_lock(pThis->mutSignalOnEmpty); // TODO: this was commented out
+				pthread_mutex_lock(pThis->pqParent->mut); // TODO: this was commented out
 				pthread_cond_signal(pThis->condSignalOnEmpty);
-				pthread_mutex_unlock(pThis->mutSignalOnEmpty);
+				//pthread_mutex_unlock(pThis->mutSignalOnEmpty); // TODO: this was commented out
+				pthread_mutex_unlock(pThis->pqParent->mut); // TODO: this was commented out
 	dbgprintf("Queue %p/w%d: signaling parent empty done\n", pThis, iMyThrdIndx);
 			}
 			if(pThis->bSignalOnEmpty > 1) {
@@ -1596,7 +1639,8 @@ dbgprintf("Queue 0x%lx/w%d: start worker run, queue cmd currently %d\n",
 			 * iQueueSize and tCmd have not changed since the while().
 			 */
 	dbgprintf("Queue %p/w%d: pre condwait ->notEmpty, worker shutdown %d\n", pThis, iMyThrdIndx, pThis->toWrkShutdown);
-			if(pThis->toWrkShutdown == -1) {
+			/* DA worker and first worker never have an inactivity timeout */
+			if(pWrkrInst->iThrd < 2 || pThis->toWrkShutdown == -1) {
 	dbgprintf("worker never times out!\n");
 				/* never shut down any started worker */
 				pthread_cond_wait(pThis->notEmpty, pThis->mut);
@@ -1804,11 +1848,13 @@ rsRetVal queueStart(queue_t *pThis) /* this is the ConstructionFinalizer */
 	if(!bInitialized) {
 		dbgprintf("Queue 0x%lx: queue starts up without (loading) any disk state\n", queueGetID(pThis));
 		/* fire up the worker threads */
+		queueStrtNewWrkThrd(pThis);
 		// TODO: preforked workers! queueStrtAllWrkThrds(pThis);
 	}
 	pThis->bQueueStarted = 1;
 
 finalize_it:
+dbgprintf("queueStart() exit, iret %d\n", iRet);
 	return iRet;
 }
 
@@ -1923,68 +1969,52 @@ pThis->bSaveOnShutdown = 1; // TODO: Test remove
 
 	pThis->bQueueInDestruction = 1; /* indicate we are in destruction (modifies some behaviour) */
 
-	/* optimize parameters for shutdown of DA-enabled queues */
-	if(pThis->bIsDA) {
-dbgprintf("IsDA queue, modifying params for draining\n");
-		pThis->iHighWtrMrk = 1; /* make sure we drain */
-		pThis->iLowWtrMrk = 0; /* disable low water mark algo */
-		if(pThis->qRunsDA == QRUNS_REGULAR) {
-			if(pThis->iQueueSize > 0) {
-				queueInitDA(pThis, QUEUE_MODE_ENQONLY); /* initiate DA mode */
+	/* we do not need to take care of any messages left in queue if we are in enqueue only mode */
+	if(!pThis->bEnqOnly) {
+		/* in regular mode, need look at termination */
+		/* optimize parameters for shutdown of DA-enabled queues */
+		if(pThis->bIsDA && pThis->iQueueSize > 0) { // TODO: atomic iQueueSize!
+	dbgprintf("IsDA queue, modifying params for draining\n");
+			pThis->iHighWtrMrk = 1; /* make sure we drain */
+			pThis->iLowWtrMrk = 0; /* disable low water mark algo */
+			if(pThis->qRunsDA == QRUNS_REGULAR) {
+				if(pThis->iQueueSize > 0) {
+					queueInitDA(pThis, QUEUE_MODE_ENQONLY); /* initiate DA mode */
+				}
+			} else {
+				queueSetEnqOnly(pThis->pqDA, QUEUE_MODE_ENQONLY); /* turn on enqueue-only mode */
 			}
-		} else {
-			queueSetEnqOnly(pThis->pqDA, QUEUE_MODE_ENQONLY); /* turn on enqueue-only mode */
-		}
-		if(pThis->bSaveOnShutdown) {
-dbgprintf("bSaveOnShutdown set, eternal timeout set\n");
-			pThis->toQShutdown = QUEUE_TIMEOUT_ETERNAL;
+			if(pThis->bSaveOnShutdown) {
+	dbgprintf("bSaveOnShutdown set, eternal timeout set\n");
+				pThis->toQShutdown = QUEUE_TIMEOUT_ETERNAL;
+			}
+			/* now we need to activate workers (read doc/dev_queue.html) */
 		}
-		/* now we need to activate workers (read doc/dev_queue.html) */
-	}
 
-	// TODO: we may need to startup a regular worker if not in DA mode!
-	/* wait until all pending workers are started up */
-	qWrkrWaitAllWrkrStartup(pThis);
+		/* wait until all pending workers are started up */
+		qWrkrWaitAllWrkrStartup(pThis);
 
-	/* terminate our own worker threads */
-	if(pThis->pWrkThrds != NULL) {
-		queueShutdownWorkers(pThis);
-	}
+		// We need to startup a worker if we are in non-DA mode and the queue is not empty and not in enque-only mode */
+	dbgprintf("Queue %p: queueDestruct probing if any regular workers need to be started, CurWrkr %d, qsize %d, qRunsDA %d\n",
+		  pThis, pThis->iCurNumWrkThrd, pThis->iQueueSize, pThis->qRunsDA);
+		pthread_mutex_lock(pThis->mut);
+	dbgprintf("queueDestruct mutex locked\n");
+		if(pThis->iCurNumWrkThrd == 0 && pThis->iQueueSize > 0 && !pThis->bEnqOnly) {
+	dbgprintf("Queue %p: queueDestruct must start regular workers!\n", pThis);
+			queueStrtNewWrkThrd(pThis);
+		}
+		pthread_mutex_unlock(pThis->mut);
+	dbgprintf("queueDestruct mutex unlocked\n");
 
-#if 0
-	/* if running DA, switch the DA queue to enqueue-only mode. That saves us some CPU cycles as
-	 * its workers do no longer need to run. It also prevents longer-running actions to spring into
-	 * existence while we are draining the main (memory) queue. -- rgerhads, 2008-01-16
-	 */
-	if(pThis->qRunsDA != QRUNS_REGULAR) {
-		queueSetEnqOnly(pThis->pqDA, QUEUE_MODE_ENQONLY); /* turn on enqueue-only mode */
-		if(pThis->bSaveOnShutdown)
-			pThis->toQShutdown = QUEUE_TIMEOUT_ETERNAL;
+		/* wait again in case a new worker was started */
+		qWrkrWaitAllWrkrStartup(pThis);
 	}
 
-	/* then, terminate our own worker threads */
+	/* terminate our own worker threads */
 	if(pThis->pWrkThrds != NULL) {
 		queueShutdownWorkers(pThis);
 	}
 
-	/* If we currently run in DA mode, the in-memory queue is already persisted to disk.
-	 * If we are not in DA mode, we may have data left in in-memory queues, this data will
-	 * be lost if we do not persist it to a disk queue. So, if configured to do so, we will
-	 * now start DA mode just to drain our queue. -- rgerhards, 2008-01-16
-	 * TODO: move to persist function!
-	 */
-	if(pThis->iQueueSize > 0 && pThis->bSaveOnShutdown && pThis->bIsDA) {
-		dbgprintf("Queue 0x%lx: in-memory queue contains %d entries after worker shutdown - using DA to save to disk\n",
-			queueGetID(pThis), pThis->iQueueSize);
-		pThis->iLowWtrMrk = 0; /* disable low water mark algo */
-		pThis->iHighWtrMrk = 1; /* make sure we drain */
-		queueInitDA(pThis, QUEUE_MODE_ENQONLY);	/* start DA queue in enqueue-only mode */
-		qWrkrWaitStartup(QUEUE_PTR_DA_WORKER(pThis)); /* wait until DA worker has actually started */
-		pThis->toQShutdown = QUEUE_TIMEOUT_ETERNAL;
-		queueShutdownWorkers(pThis); /* and tell it to shut down. The trick is it will run until q is drained */
-	}
-#endif
-
 	/* if still running DA, terminate disk queue */
 	if(pThis->qRunsDA != QRUNS_REGULAR)
 		queueDestruct(&pThis->pqDA);