Function BuildQueueStatusContext

src/backend/utils/resscheduler/resqueue.c:2089–2198

* This copies out the current state of resource queues. */

 * This copies out the current state of resource queues.
 */
static void
BuildQueueStatusContext(QueueStatusContext *fctx)
{
	int			num_calls = 0;
	int			numRecords;
	int			i;
	HASH_SEQ_STATUS status;
	ResQueueData *queue = NULL;

	Assert(fctx);
	Assert(fctx->record);

	/*
	 * Take all the partition locks. This is necessary as we want to to use
	 * the same lock order as the rest of the code - i.e. partition locks
	 * *first* *then* the queue lock (otherwise we could deadlock ourselves).
	 */
	for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
		LWLockAcquire(LockHashPartitionLockByIndex(i), LW_EXCLUSIVE);

	/*
	 * Lock resource queue structures.
	 */
	LWLockAcquire(ResQueueLock, LW_EXCLUSIVE);

	/* Initialize for a sequential scan of the resource queue hash. */
	hash_seq_init(&status, ResQueueHash);
	num_calls = hash_get_num_entries(ResQueueHash);
	Assert(num_calls == ResScheduler->num_queues);

	numRecords = 0;
	while ((queue = (ResQueueData *) hash_seq_search(&status)) != NULL)
	{
		QueueStatusRec *record = &fctx->record[numRecords];
		int			j;
		ResLimit	limits = NULL;
		uint32		hashcode;

		/**
		 * Gather thresholds and current values on activestatements, cost and memory
		 */
		limits = queue->limits;

		record->queueid = queue->queueid;

		for (j = 0; j < NUM_RES_LIMIT_TYPES; j++)
		{
			switch (limits[j].type)
			{
				case RES_COUNT_LIMIT:
					record->queuecountthreshold = limits[j].threshold_value;
					record->queuecountvalue = limits[j].current_value;
					break;

				case RES_COST_LIMIT:
					record->queuecostthreshold = limits[j].threshold_value;
					record->queuecostvalue = limits[j].current_value;
					break;