Do not check for thread shutdown on every pass through the connector

src/connector.c

@@ -633,6 +633,7 @@ static int connector_loop(proc_instance_t *pi, cdata_t *cdata)
 	int64_t client_id64, client_id;
 	unixsock_t *us = &pi->us;
 	ckpool_t *ckp = pi->ckp;
+	uint8_t test_cycle = 0;
 	char *buf = NULL;
 
 	do {
@@ -647,6 +648,8 @@ static int connector_loop(proc_instance_t *pi, cdata_t *cdata)
 	LOGWARNING("%s connector ready", ckp->name);
 
 retry:
+	if (!++test_cycle) {
+		/* Test for pthread join every 256 messages */
 		if (unlikely(!pthread_tryjoin_np(cdata->pth_sender, NULL))) {
 			LOGEMERG("Connector sender thread shutdown, exiting");
 			ret = 1;
@@ -657,6 +660,7 @@ retry:
 			ret = 1;
 			goto out;
 		}
+	}
 
 	Close(sockd);
 	sockd = accept(us->sockd, NULL, NULL);