--- mqtt/src/daemon.c	2011/12/16 12:16:17	1.1.2.24
+++ mqtt/src/daemon.c	2011/12/16 12:55:30	1.1.2.26
@@ -79,6 +79,10 @@ stopSession(struct tagSession *sess)
 	mqtt_msg_t msg = { NULL, 0 };
 	int ret;
 
+	ioTRACE(4);
+
+	assert(sess);
+
 	pthread_mutex_lock(&mtx_sess);
 	TAILQ_REMOVE(&Sessions, sess, sess_node);
 	pthread_mutex_unlock(&mtx_sess);
@@ -96,6 +100,57 @@ stopSession(struct tagSession *sess)
 	finiSession(sess);
 }
 
+static int
+KASession(struct tagSession *sess)
+{
+	u_char basebuf[USHRT_MAX];
+	mqtt_msg_t msg = { NULL, 0 }, buf = { basebuf, sizeof basebuf };
+	int ret;
+	struct pollfd pfd;
+
+	ioTRACE(4);
+
+	assert(sess);
+
+	/* ping request */
+	ret = mqtt_msgPINGREQ(&msg);
+	if ((ret = send(sess->sess_sock, msg.msg_base, ret, 0)) == -1) {
+		ioDEBUG(3, "Error:: send(%d) #%d - %s", sess->sess_sock, errno, strerror(errno));
+		stopSession(sess);
+		return -1;
+	} else {
+		ioDEBUG(5, "Sended %d bytes for ping request", ret);
+		free(msg.msg_base);
+		memset(&msg, 0, sizeof msg);
+	}
+
+	pfd.fd = sess->sess_sock;
+	pfd.events = POLLIN | POLLPRI;
+	if ((ret = poll(&pfd, 1, sess->sess_ka)) == -1) {
+		ioDEBUG(3, "Error:: poll(%d) #%d - %s", sess->sess_sock, errno, strerror(errno));
+		stopSession(sess);
+		return -1;
+	} else if (!ret) {
+		/* problem!!! session is abandoned ... must be disconnect! */
+		stopSession(sess);
+		return 1;
+	}
+	/* receive & decode packet */
+	if (recv(sess->sess_sock, buf.msg_base, buf.msg_len, 0) == -1) {
+		ioDEBUG(3, "Error:: recv(%d) #%d - %s", sess->sess_sock, errno, strerror(errno));
+		stopSession(sess);
+		return -1;
+	}
+	if (mqtt_readPINGRESP(&buf)) {
+		/* problem!!! session is broken, not hear ping response ... must be disconnect! */
+		stopSession(sess);
+		return 2;
+	}
+
+	/* Keep Alive is OK! */
+	return 0;
+}
+
 static void *
 thrSession(struct tagSession *sess)
 {
@@ -120,6 +175,8 @@ startSession(sched_task_t *task)
 
 	ioTRACE(4);
 
+	assert(task);
+
 	sess = initSession(TASK_FD(task), TASK_ARG(task));
 	if (!sess) {
 		io_freeVar(TASK_ARG(task));
@@ -162,6 +219,7 @@ startSession(sched_task_t *task)
 		ioDEBUG(2, "Old session %s should be disconnect!", sess->sess_cid);
 		TAILQ_FOREACH(s, &Sessions, sess_node)
 			if (!strcmp(s->sess_cid, sess->sess_cid)) {
+				/* found stale session & disconnect it! */
 				stopSession(s);
 				break;
 			}