Fix timeout of send thread in Async client for v5

When the outgoing packets fails to be sent due to hitting the limitation of the inflight maximum, it will wait on send_cond/send_sem. Send thread should be woken up on PUBACK message received. So it does not need to wait until timeout (1 second).

Signed-off-by: Tiejun Zhou <[email protected]>

src/MQTTAsyncUtils.c

@@ -3078,7 +3078,15 @@ static MQTTPacket* MQTTAsync_cycle(SOCKET* sock, unsigned long timeout, int* rc)
 				else if (msgtype == PUBREC)
 					*rc = MQTTProtocol_handlePubrecs(pack, *sock, &pubToRemove);
 				else if (msgtype == PUBACK)
+				{
 					*rc = MQTTProtocol_handlePubacks(pack, *sock, &pubToRemove);
+					if (sendThread_state != STOPPED)
+#if !defined(_WIN32) && !defined(_WIN64)
+						Thread_signal_cond(send_cond);
+#else
+						Thread_post_sem(send_sem);
+#endif
+				}
 				if (!m)
 					Log(LOG_ERROR, -1, "PUBCOMP, PUBACK or PUBREC received for no client, msgid %d", msgid);
 				if (m && (msgtype != PUBREC || ackrc >= MQTTREASONCODE_UNSPECIFIED_ERROR))