Function pqAppendCmdQueueEntry

src/interfaces/libpq/fe-exec.c:1280–1323

* pqAppendCmdQueueEntry * Append a caller-allocated entry to the command queue, and update * conn->asyncStatus to account for it. * * The query itself must already have been put in the output buffer by the * caller. */

 * caller.
 */
void
pqAppendCmdQueueEntry(PGconn *conn, PGcmdQueueEntry *entry)
{
	Assert(entry->next == NULL);

	if (conn->cmd_queue_head == NULL)
		conn->cmd_queue_head = entry;
	else
		conn->cmd_queue_tail->next = entry;

	conn->cmd_queue_tail = entry;

	switch (conn->pipelineStatus)
	{
		case PQ_PIPELINE_OFF:
		case PQ_PIPELINE_ON:

			/*
			 * When not in pipeline aborted state, if there's a result ready
			 * to be consumed, let it be so (that is, don't change away from
			 * READY or READY_MORE); otherwise set us busy to wait for
			 * something to arrive from the server.
			 */
			if (conn->asyncStatus == PGASYNC_IDLE)
				conn->asyncStatus = PGASYNC_BUSY;
			break;

		case PQ_PIPELINE_ABORTED:

			/*
			 * In aborted pipeline state, we don't expect anything from the
			 * server (since we don't send any queries that are queued).
			 * Therefore, if IDLE then do what PQgetResult would do to let
			 * itself consume commands from the queue; if we're in any other
			 * state, we don't have to do anything.
			 */
			if (conn->asyncStatus == PGASYNC_IDLE)
			{
				resetPQExpBuffer(&conn->errorMessage);
				pqPipelineProcessQueue(conn);
			}
			break;
	}
}

/*
 * pqRecycleCmdQueueEntry