begin disk assisted queue memory queue modes (not fully implemented yet)

6 files changed, 281 insertions, 58 deletions

diff --git a/msg.c b/msg.c
index 3ffaa6bb..948274bf 100644
--- a/msg.c
+++ b/msg.c
@@ -394,9 +394,7 @@ static rsRetVal MsgSerialize(msg_t *pThis, strm_t *pStrm)
 	assert(pThis != NULL);
 	assert(pStrm != NULL);
 
-dbgprintf("MsgSerialize\n");
 	CHKiRet(objBeginSerialize(pStrm, (obj_t*) pThis));
-dbgprintf("post MsgSerialize\n");
 	objSerializeSCALAR(pStrm, iProtocolVersion, SHORT);
 	objSerializeSCALAR(pStrm, iSeverity, SHORT);
 	objSerializeSCALAR(pStrm, iFacility, SHORT);
diff --git a/obj-types.h b/obj-types.h
index 350bc95b..94651e6e 100644
--- a/obj-types.h
+++ b/obj-types.h
@@ -99,8 +99,8 @@ typedef struct obj {	/* the dummy struct that each derived class can be casted t
 		unsigned int iObjCooCKiE; /* prevent name conflict, thus the strange name */ 
 #	define ISOBJ_assert(pObj) \
 		{ \
-		assert(pObj != NULL); \
-		assert((unsigned) pObj->iObjCooCKiE == (unsigned) 0xBADEFEE); \
+		assert((pObj) != NULL); \
+		assert((unsigned) ((obj_t*)(pObj))->iObjCooCKiE == (unsigned) 0xBADEFEE); \
 		}
 #	define ISOBJ_TYPE_assert(pObj, objType) \
 		{ \
diff --git a/queue.c b/queue.c
index 17992473..87cea59d 100644
--- a/queue.c
+++ b/queue.c
@@ -1,3 +1,4 @@
+// TODO: remove bIsDA?
 // TODO: peekmsg() on first entry, with new/inprogress/deleted entry, destruction in 
 // call consumer state. Facilitates retaining messages in queue until action could
 // be called!
@@ -50,9 +51,69 @@ DEFobjStaticHelpers
 
 /* forward-definitions */
 rsRetVal queueChkPersist(queue_t *pThis);
+static void *queueWorker(void *arg);
 
 /* methods */
 
+/* send a command to a specific thread
+ */
+static inline rsRetVal
+queueTellWrkThrd(queue_t *pThis, int iIdx, qWrkCmd_t tCmd)
+{
+	DEFiRet;
+
+	ISOBJ_TYPE_assert(pThis, queue);
+	assert(iIdx >= 0 && iIdx <= pThis->iNumWorkerThreads);
+
+	pThis->pWrkThrds[iIdx].tCurrCmd = tCmd;
+
+	return iRet;
+}
+
+
+/* Starts a worker thread (on a specific index [i]!)
+ */
+static inline rsRetVal
+queueStrtWrkThrd(queue_t *pThis, int i)
+{
+	DEFiRet;
+	int iState;
+
+	ISOBJ_TYPE_assert(pThis, queue);
+	assert(i >= 0 && i <= pThis->iNumWorkerThreads);
+
+	queueTellWrkThrd(pThis, i, eWRKTHRDCMD_RUN);
+	iState = pthread_create(&(pThis->pWrkThrds[i].thrdID), NULL, queueWorker, (void*) pThis);
+	dbgprintf("Queue 0x%lx: Worker thread %x, index %d started with state %d.\n",
+		  (unsigned long) pThis, (unsigned) pThis->pWrkThrds[i].thrdID, i, iState);
+
+	return iRet;
+}
+
+
+/* send a command to all worker threads. A start index can be
+ * given. Usually, this is 0 or 1. Thread 0 is reserved to disk-assisted
+ * mode and this start index take care of the special handling it needs to
+ * receive.
+ */
+static inline rsRetVal
+queueTellWrkThrds(queue_t *pThis, int iStartIdx, qWrkCmd_t tCmd)
+{
+	DEFiRet;
+	int i;
+
+	ISOBJ_TYPE_assert(pThis, queue);
+	assert(iStartIdx == 0 || iStartIdx == 1);
+
+	/* tell the workers our request */
+	for(i = iStartIdx ; i <= pThis->iNumWorkerThreads ; ++i)
+		if(pThis->pWrkThrds[i].tCurrCmd >= eWRKTHRDCMD_TERMINATED)
+			queueTellWrkThrd(pThis, i, tCmd);
+
+	return iRet;
+}
+
+
 /* compute an absolute time timeout suitable for calls to pthread_cond_timedwait()
  * rgerhards, 2008-01-14
  */
@@ -72,7 +133,123 @@ queueTimeoutComp(struct timespec *pt, int iTimeout)
 }
 
 
-/* first, we define type-specific handlers. The provide a generic functionality,
+
+/* --------------- code for disk-assisted (DA) queue modes -------------------- */
+
+
+/* check if we run in disk-assisted mode and record that
+ * setting for easy (and quick!) access in the future. This
+ * function must only be called from constructors and only
+ * from those that support disk-assisted modes (aka memory-
+ * based queue drivers).
+ * rgerhards, 2008-01-14
+ */
+static rsRetVal
+queueChkIsDA(queue_t *pThis)
+{
+	DEFiRet;
+
+	ISOBJ_TYPE_assert(pThis, queue);
+	if(pThis->pszFilePrefix != NULL) {
+		pThis->bIsDA = 1;
+		dbgprintf("Queue 0x%lx: is disk-assisted, disk will be used on demand\n", queueGetID(pThis));
+	} else {
+		dbgprintf("Queue 0x%lx: is NOT disk-assisted\n", queueGetID(pThis));
+	}
+
+	return iRet;
+}
+
+
+
+/* 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
+ * to the disk queue. The disk queue will then call the actual consumer from
+ * the app point of view (we chain two queues here).
+ * This function must also handle the LowWaterMark situation, at which it is
+ * switched back to in-memory queueing.
+ * rgerhards, 2008-01-14
+ */
+static inline rsRetVal
+queueDAConsumer(queue_t *pThis, int iMyThrdIndx, void *pUsr)
+{
+	DEFiRet;
+
+	ISOBJ_TYPE_assert(pThis, queue);
+	ISOBJ_assert(pUsr);
+	assert(pThis->bRunsDA);
+
+dbgprintf("Queue %p/w%d: queueDAConsumer, queue size %d\n", pThis, iMyThrdIndx, pThis->iQueueSize);
+	CHKiRet(queueEnqObj(pThis->pqDA, pUsr));
+
+finalize_it:
+	return iRet;
+}
+
+
+/* check if we need to start disk assisted mode
+ * rgerhards, 2008-01-14
+ */
+static rsRetVal
+queueChkStrtDA(queue_t *pThis)
+{
+	DEFiRet;
+
+	ISOBJ_TYPE_assert(pThis, queue);
+	if(pThis->iQueueSize < pThis->iHighWtrMrk || pThis->bRunsDA)
+		ABORT_FINALIZE(RS_RET_OK);
+
+	dbgprintf("Queue 0x%lx: %d entries - passed high water mark for disk-assisted mode, initiating...\n",
+		  queueGetID(pThis), pThis->iQueueSize);
+
+	/* create message queue */
+	CHKiRet(queueConstruct(&pThis->pqDA, QUEUETYPE_DISK , 1, 0, pThis->pConsumer));
+
+	CHKiRet(queueSetMaxFileSize(pThis->pqDA, pThis->iMaxFileSize));
+	CHKiRet(queueSetFilePrefix(pThis->pqDA, pThis->pszFilePrefix, pThis->lenFilePrefix));
+	CHKiRet(queueSetiPersistUpdCnt(pThis->pqDA, pThis->iPersistUpdCnt));
+	CHKiRet(queueSettoQShutdown(pThis->pqDA, pThis->toQShutdown));
+	CHKiRet(queueSettoActShutdown(pThis->pqDA, pThis->toActShutdown));
+	CHKiRet(queueSettoEnq(pThis->pqDA, pThis->toEnq));
+	CHKiRet(queueSetiHighWtrMrk(pThis->pqDA, 0));
+	CHKiRet(queueSetiDiscardMrk(pThis->pqDA, 0));
+
+	iRet = queueStart(pThis->pqDA);
+	/* file not found is expected, that means it is no previous QIF available */
+	if(iRet != RS_RET_OK && iRet != RS_RET_FILE_NOT_FOUND)
+		FINALIZE; /* something is wrong */
+
+	/* if we reach this point, we have a working disk queue
+	 * so we now need to change our consumer to utilize it.
+	 */
+	pThis->bRunsDA = 1; /* and that's all we need to do - the worker handles the rest ;) */
+
+	/* now we must start our DA worker thread and shutdown all others */
+	CHKiRet(queueStrtWrkThrd(pThis, 0));
+	CHKiRet(queueTellWrkThrds(pThis, 1, eWRKTHRDCMD_SHUTDOWN_IMMEDIATE));
+
+	dbgprintf("Queue 0x%lx: is now running in disk assisted mode, disk queue 0x%lx\n",
+		  queueGetID(pThis), queueGetID(pThis->pqDA));
+finalize_it:
+	if(iRet != RS_RET_OK) {
+		if(pThis->pqDA != NULL) {
+			queueDestruct(pThis->pqDA);
+			pThis->pqDA = NULL;
+		}
+		dbgprintf("Queue 0x%lx: error %d creating disk queue - giving up.\n",
+		  	  queueGetID(pThis), iRet);
+		pThis->bIsDA = 0;
+	}
+
+	return iRet;
+}
+
+
+/* --------------- end code for disk-assisted queue modes -------------------- */
+
+
+/* Now, we define type-specific handlers. The provide a generic functionality,
  * but for this specific type of queue. The mapping to these handlers happens during
  * queue construction. Later on, handlers are called by pointers present in the
  * queue instance object.
@@ -95,6 +272,8 @@ static rsRetVal qConstructFixedArray(queue_t *pThis)
 	pThis->tVars.farray.head = 0;
 	pThis->tVars.farray.tail = 0;
 
+	queueChkIsDA(pThis);
+
 finalize_it:
 	return iRet;
 }
@@ -150,6 +329,8 @@ static rsRetVal qConstructLinkedList(queue_t *pThis)
 	pThis->tVars.linklist.pRoot = 0;
 	pThis->tVars.linklist.pLast = 0;
 
+	queueChkIsDA(pThis);
+
 	return iRet;
 }
 
@@ -443,7 +624,6 @@ static rsRetVal qDelDirect(queue_t __attribute__((unused)) *pThis, __attribute__
 }
 
 
-
 /* --------------- end type-specific handlers -------------------- */
 
 
@@ -496,14 +676,11 @@ static rsRetVal
 queueWrkThrdTrm(queue_t *pThis, qWrkCmd_t tShutdownCmd, long iTimeout)
 {
 	DEFiRet;
-	int i;
 	int bTimedOut;
 	struct timespec t;
 
 	/* first tell the workers our request */
-	for(i = 0 ; i < pThis->iNumWorkerThreads ; ++i)
-		if(pThis->pWrkThrds[i].tCurrCmd != eWRKTHRDCMD_TERMINATED)
-			pThis->pWrkThrds[i].tCurrCmd = tShutdownCmd;
+	queueTellWrkThrds(pThis, 0, tShutdownCmd);
 
 	/* awake them... */
 	pthread_cond_broadcast(pThis->notEmpty);
@@ -547,8 +724,8 @@ queueWrkThrdCancel(queue_t *pThis)
 	pthread_cond_broadcast(pThis->notEmpty);
 
 	/* first tell the workers our request */
-	for(i = 0 ; i < pThis->iNumWorkerThreads ; ++i)
-		if(pThis->pWrkThrds[i].tCurrCmd != eWRKTHRDCMD_TERMINATED) {
+	for(i = 0 ; i <= pThis->iNumWorkerThreads ; ++i)
+		if(pThis->pWrkThrds[i].tCurrCmd >= eWRKTHRDCMD_TERMINATED) {
 			dbgprintf("Queue 0x%lx: canceling worker thread %d\n", queueGetID(pThis), i);
 			pthread_cancel(pThis->pWrkThrds[i].thrdID);
 		}
@@ -598,16 +775,20 @@ static rsRetVal queueShutdownWorkers(queue_t *pThis)
 	 * And, most importantly, this is needed if we have an indifitite termination
 	 * time set (timeout == 0)! -- rgerhards, 2008-01-14
 	 */
-	for(i = 0 ; i < pThis->iNumWorkerThreads ; ++i) {
-dbgprintf("join thred %d\n", i);
-		pthread_join(pThis->pWrkThrds[i].thrdID, NULL);
+	for(i = 0 ; i <= pThis->iNumWorkerThreads ; ++i) {
+		if(pThis->pWrkThrds[i].tCurrCmd != eWRKTHRDCMD_NEVER_RAN) {
+			dbgprintf("Queue 0x%lx: joining worker thread %d\n", queueGetID(pThis), i);
+			pthread_join(pThis->pWrkThrds[i].thrdID, NULL);
+		}
 	}
 
 	/* as we may have cancelled a thread, clean up our internal structure. All are
 	 * terminated now. For simplicity, we simply overwrite the states.
 	 */
-	for(i = 0 ; i < pThis->iNumWorkerThreads ; ++i) {
-		pThis->pWrkThrds[i].tCurrCmd = eWRKTHRDCMD_TERMINATED;
+	for(i = 0 ; i <= pThis->iNumWorkerThreads ; ++i) {
+		if(pThis->pWrkThrds[i].tCurrCmd != eWRKTHRDCMD_NEVER_RAN) {
+			pThis->pWrkThrds[i].tCurrCmd = eWRKTHRDCMD_TERMINATED;
+		}
 	}
 
 	dbgprintf("Queue 0x%lx: worker threads terminated, remaining queue size %d.\n",
@@ -617,6 +798,45 @@ dbgprintf("join thred %d\n", i);
 }
 
 
+/* This is a helper for queueWorker() it either calls the configured
+ * consumer or the DA-consumer (if in disk-assisted mode). It is NOT
+ * protected by the queue mutex.
+ * rgerhards, 2008-01-14
+ */
+static inline rsRetVal
+queueWorkerCallConsumer(queue_t *pThis, int iMyThrdIndx, void *pUsr)
+{
+	DEFiRet;
+	rsRetVal iRetLocal;
+	int iSeverity;
+
+	if(pThis->bRunsDA) {
+		queueDAConsumer(pThis, iMyThrdIndx, pUsr);
+	} else {
+		/* we are running in normal, non-disk-assisted mode */
+		/* do a quick check if we need to drain the queue */
+		if(pThis->iDiscardMrk > 0 && pThis->iQueueSize >= pThis->iDiscardMrk) {
+			iRetLocal = objGetSeverity(pUsr, &iSeverity);
+			if(iRetLocal == RS_RET_OK && iSeverity >= pThis->iDiscardSeverity) {
+				dbgprintf("Queue 0x%lx/w%d: dequeue/queue nearly full (%d entries), "
+					  "discarded severity %d message\n",
+					  queueGetID(pThis), iMyThrdIndx, pThis->iQueueSize, iSeverity);
+				objDestruct(pUsr);
+			}
+		} else {
+			dbgprintf("Queue 0x%lx/w%d: worker executes consumer...\n",
+				   queueGetID(pThis), iMyThrdIndx);
+			iRetLocal = pThis->pConsumer(pUsr);
+			if(iRetLocal != RS_RET_OK)
+				dbgprintf("Queue 0x%lx/w%d: Consumer returned iRet %d\n",
+					  queueGetID(pThis), iMyThrdIndx, iRetLocal);
+		}
+	}
+
+	return iRet;
+}
+
+
 /* Each queue has one associated worker (consumer) thread. It will pull
  * the message from the queue and pass it to a user-defined function.
  * This function was provided on construction. It MUST be thread-safe.
@@ -630,8 +850,6 @@ queueWorker(void *arg)
 	sigset_t sigSet;
 	int iMyThrdIndx;	/* index for this thread in queue thread table */
 	int iCancelStateSave;
-	int iSeverity;
-	rsRetVal iRetLocal;
 
 	assert(pThis != NULL);
 
@@ -639,7 +857,7 @@ queueWorker(void *arg)
 	pthread_sigmask(SIG_BLOCK, &sigSet, NULL);
 
 	/* first find myself in the queue's thread table */
-	for(iMyThrdIndx = 0 ; iMyThrdIndx < pThis->iNumWorkerThreads ; ++iMyThrdIndx)
+	for(iMyThrdIndx = 0 ; iMyThrdIndx <= pThis->iNumWorkerThreads ; ++iMyThrdIndx)
 		if(pThis->pWrkThrds[iMyThrdIndx].thrdID == pthread_self())
 			break;
 	assert(pThis->pWrkThrds[iMyThrdIndx].thrdID == pthread_self());
@@ -678,27 +896,11 @@ queueWorker(void *arg)
 			/* do actual processing (the lengthy part, runs in parallel)
 			 * If we had a problem while dequeing, we do not call the consumer,
 			 * but we otherwise ignore it. This is in the hopes that it will be
-			 * self-healing. Howerver, this is really not a good thing.
+			 * self-healing. However, this is really not a good thing.
 			 * rgerhards, 2008-01-03
 			 */
 			if(iRet == RS_RET_OK) {
-				/* do a quick check if we need to drain the queue */
-				if(pThis->iDiscardMrk > 0 && pThis->iQueueSize >= pThis->iDiscardMrk) {
-					iRetLocal = objGetSeverity(pUsr, &iSeverity);
-					if(iRetLocal == RS_RET_OK && iSeverity >= pThis->iDiscardSeverity) {
-						dbgprintf("Queue 0x%lx/w%d: dequeue/queue nearly full (%d entries), "
-							  "discarded severity %d message\n",
-							  queueGetID(pThis), iMyThrdIndx, pThis->iQueueSize, iSeverity);
-						objDestruct(pUsr);
-					}
-				} else {
-					dbgprintf("Queue 0x%lx/w%d: worker executes consumer...\n",
-						   queueGetID(pThis), iMyThrdIndx);
-					iRetLocal = pThis->pConsumer(pUsr);
-					if(iRetLocal != RS_RET_OK)
-						dbgprintf("Queue 0x%lx/w%d: Consumer returned iRet %d\n",
-							  queueGetID(pThis), iMyThrdIndx, iRetLocal);
-				}
+				queueWorkerCallConsumer(pThis, iMyThrdIndx, pUsr);
 			} else {
 				dbgprintf("Queue 0x%lx/w%d: error %d dequeueing element - ignoring, but strange things "
 				          "may happen\n", queueGetID(pThis), iMyThrdIndx, iRet);
@@ -825,7 +1027,6 @@ finalize_it:
 rsRetVal queueStart(queue_t *pThis) /* this is the ConstructionFinalizer */
 {
 	DEFiRet;
-	int iState;
 	int i;
 
 	assert(pThis != NULL);
@@ -837,15 +1038,15 @@ rsRetVal queueStart(queue_t *pThis) /* this is the ConstructionFinalizer */
 		   pThis->iMaxFileSize);
 
 	if(pThis->qType != QUEUETYPE_DIRECT) {
-		if((pThis->pWrkThrds = calloc(pThis->iNumWorkerThreads, sizeof(qWrkThrd_t))) == NULL)
+		if((pThis->pWrkThrds = calloc(pThis->iNumWorkerThreads + 1, sizeof(qWrkThrd_t))) == NULL)
 			ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);
 
+		/* worker 0 is reserved for disk-assisted mode */
+		queueTellWrkThrd(pThis, 0, eWRKTHRDCMD_NEVER_RAN);
+
 		/* fire up the worker threads */
-		for(i = 0 ; i < pThis->iNumWorkerThreads ; ++i) {
-			pThis->pWrkThrds[i].tCurrCmd = eWRKTHRDCMD_RUN;
-			iState = pthread_create(&(pThis->pWrkThrds[i].thrdID), NULL, queueWorker, (void*) pThis);
-			dbgprintf("Queue 0x%lx: Worker thread %x, index %d started with state %d.\n",
-				  (unsigned long) pThis, (unsigned) pThis->pWrkThrds[i].thrdID, i, iState);
+		for(i = 1 ; i <= pThis->iNumWorkerThreads ; ++i) {
+			queueStrtWrkThrd(pThis, i);
 		}
 	}
 
@@ -982,6 +1183,10 @@ rsRetVal queueDestruct(queue_t *pThis)
 		pThis->pWrkThrds = NULL;
 	}
 
+	/* if running DA, terminate disk queue */
+	if(pThis->bRunsDA)
+		queueDestruct(pThis->pqDA);
+
 	/* persist the queue (we always do that - queuePersits() does cleanup it the queue is empty) */
 	CHKiRet_Hdlr(queuePersist(pThis)) {
 		dbgprintf("Queue 0x%lx: error %d persisting queue - data lost!\n", (unsigned long) pThis, iRet);
@@ -1020,6 +1225,9 @@ queueSetFilePrefix(queue_t *pThis, uchar *pszPrefix, size_t iLenPrefix)
 	if(pThis->pszFilePrefix != NULL)
 		free(pThis->pszFilePrefix);
 
+	if(pszPrefix == NULL) /* just unset the prefix! */
+		ABORT_FINALIZE(RS_RET_OK);
+
 	if((pThis->pszFilePrefix = malloc(sizeof(uchar) * iLenPrefix + 1)) == NULL)
 		ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);
 	memcpy(pThis->pszFilePrefix, pszPrefix, iLenPrefix + 1);
@@ -1037,7 +1245,7 @@ queueSetMaxFileSize(queue_t *pThis, size_t iMaxFileSize)
 {
 	DEFiRet;
 
-	assert(pThis != NULL);
+	ISOBJ_TYPE_assert(pThis, queue);
 	
 	if(iMaxFileSize < 1024) {
 		ABORT_FINALIZE(RS_RET_VALUE_TOO_LOW);
@@ -1080,6 +1288,7 @@ queueEnqObj(queue_t *pThis, void *pUsr)
 		pthread_mutex_lock(pThis->mut);
 	}
 
+	/* first check if we can discard anything */
 	if(pThis->iDiscardMrk > 0 && pThis->iQueueSize >= pThis->iDiscardMrk) {
 		iRetLocal = objGetSeverity(pUsr, &iSeverity);
 		if(iRetLocal == RS_RET_OK && iSeverity >= pThis->iDiscardSeverity) {
@@ -1094,7 +1303,11 @@ queueEnqObj(queue_t *pThis, void *pUsr)
 		}
 	}
 
+	/* then check if we need to add an assistance disk queue */
+	if(pThis->bIsDA)
+		CHKiRet(queueChkStrtDA(pThis));
 		
+	/* and finally (try to) enqueue what is left over */
 	while(pThis->iMaxQueueSize > 0 && pThis->iQueueSize >= pThis->iMaxQueueSize) {
 		dbgprintf("Queue 0x%lx: enqueueMsg: queue FULL - waiting to drain.\n", queueGetID(pThis));
 		queueTimeoutComp(&t, pThis->toEnq);
@@ -1130,6 +1343,7 @@ DEFpropSetMeth(queue, iHighWtrMrk, int);
 DEFpropSetMeth(queue, iLowWtrMrk, int);
 DEFpropSetMeth(queue, iDiscardMrk, int);
 DEFpropSetMeth(queue, iDiscardSeverity, int);
+DEFpropSetMeth(queue, bIsDA, int);
 
 
 /* This function can be used as a generic way to set properties. Only the subset
diff --git a/queue.h b/queue.h
index 1e3dc97f..fa81fe1a 100644
--- a/queue.h
+++ b/queue.h
@@ -61,10 +61,12 @@ typedef struct qLinkedList_S {
 } qLinkedList_t;
 
 typedef enum {
-	eWRKTHRDCMD_RUN,
-	eWRKTHRDCMD_SHUTDOWN,
-	eWRKTHRDCMD_SHUTDOWN_IMMEDIATE,
-	eWRKTHRDCMD_TERMINATED	/* granted, that's more a state than a cmd - thread is dead... */
+	eWRKTHRDCMD_NEVER_RAN = 0,	/* granted, that's more a state than a cmd - thread is dead... */
+	eWRKTHRDCMD_TERMINATED = 1,	/* granted, that's more a state than a cmd - thread is dead... */
+	/* ALL active states MUST be numerically higher than eWRKTHRDCMD_TERMINATED and NONE must be lower! */
+	eWRKTHRDCMD_RUN = 2,
+	eWRKTHRDCMD_SHUTDOWN = 3,
+	eWRKTHRDCMD_SHUTDOWN_IMMEDIATE = 4
 } qWrkCmd_t;	/* commands for queue worker threads */
 
 typedef struct qWrkThrd_s {
@@ -114,6 +116,9 @@ typedef struct queue_s {
 	size_t lenFilePrefix;
 	int iNumberFiles;	/* how many files make up the queue? */
 	size_t iMaxFileSize;	/* max size for a single queue file */
+	int bIsDA;		/* is this queue disk assisted? */
+	int bRunsDA;		/* is this queue actually *running* disk assisted? */
+	struct queue_s *pqDA;	/* queue for disk-assisted modes */
 	/* now follow queueing mode specific data elements */
 	union {			/* different data elements based on queue type (qType) */
 		struct {
diff --git a/stream.c b/stream.c
index a641637b..99766b4f 100644
--- a/stream.c
+++ b/stream.c
@@ -71,7 +71,6 @@ static rsRetVal strmOpenFile(strm_t *pThis)
 	if(pThis->fd != -1)
 		ABORT_FINALIZE(RS_RET_OK);
 
-dbgprintf("strmOpenFile actual open %p, iFileNumDigits: %d\n", pThis, pThis->iFileNumDigits);
 	if(pThis->pszFName == NULL)
 		ABORT_FINALIZE(RS_RET_FILE_PREFIX_MISSING);
 
diff --git a/syslogd.c b/syslogd.c
index d3c93f92..4dcfa337 100644
--- a/syslogd.c
+++ b/syslogd.c
@@ -3361,10 +3361,18 @@ init(void)
 		iMainMsgQueueNumWorkers = 1;
 	}
 
-	if(MainMsgQueType == QUEUETYPE_DISK && pszWorkDir == NULL) {
-		fprintf(stderr, "No $WorkDirectory specified - can not run main message queue in 'disk' mode. "
-			        "Using 'FixedArray' instead.\n");
-		MainMsgQueType = QUEUETYPE_FIXED_ARRAY;
+	if(MainMsgQueType == QUEUETYPE_DISK) {
+		errno = 0;	/* for logerror! */
+		if(pszWorkDir == NULL) {
+			logerror("No $WorkDirectory specified - can not run main message queue in 'disk' mode. "
+				 "Using 'FixedArray' instead.\n");
+			MainMsgQueType = QUEUETYPE_FIXED_ARRAY;
+		}
+		if(pszMainMsgQFName == NULL) {
+			logerror("No $MainMsgQueueFileName specified - can not run main message queue in "
+				 "'disk' mode. Using 'FixedArray' instead.\n");
+			MainMsgQueType = QUEUETYPE_FIXED_ARRAY;
+		}
 	}
 
 	/* switch the message object to threaded operation, if necessary */
@@ -3384,13 +3392,12 @@ init(void)
 		logerrorInt("Invalid " #directive ", error %d. Ignored, running with default setting", iRet); \
 	}
 #	define setQPROPstr(func, directive, data) \
-	CHKiRet_Hdlr(func(pMsgQueue, data, strlen((char*) data))) { \
+	CHKiRet_Hdlr(func(pMsgQueue, data, (data == NULL)? 0 : strlen((char*) data))) { \
 		logerrorInt("Invalid " #directive ", error %d. Ignored, running with default setting", iRet); \
 	}
 
 	setQPROP(queueSetMaxFileSize, "$MainMsgQueueFileSize", iMainMsgQueMaxFileSize);
-	setQPROPstr(queueSetFilePrefix, "$MainMsgQueueFileName",
-		    (pszMainMsgQFName == NULL ? (uchar*) "mainq" : pszMainMsgQFName));
+	setQPROPstr(queueSetFilePrefix, "$MainMsgQueueFileName", pszMainMsgQFName);
 	setQPROP(queueSetiPersistUpdCnt, "$MainMsgQueueCheckpointInterval", iMainMsgQPersistUpdCnt);
 	setQPROP(queueSettoQShutdown, "$MainMsgQueueTimeoutShutdown", iMainMsgQtoQShutdown );
 	setQPROP(queueSettoActShutdown, "$MainMsgQueueTimeoutActionCompletion", iMainMsgQtoActShutdown);