Current implementation of event listener in virt-serial does not support keepalive,

it does not generate nor capable to answer to keepalive requests, which
causes libvirt connection to disconnect every 30 seconds (interval*timeout
in libvirtd.conf). Furthermore, it does not clean up filehandlers and leaves
hanging sockets. Also, if other thread opens its own connection to libvirt
(i.e. checkpoint.c), event function in virt-serial.c just updates event listener
file handler with a wrong one, what causes checkpoint.c malfunctions, fence_virtd hangs
and so on. This patch uses default event listener implementation from libvirt and
resolves theese problems.

server/virt-serial.c

@@ -27,20 +27,6 @@
 
 #define STREQ(a,b) (strcmp((a),(b)) == 0)
 
-/* handle globals */
-static int h_fd = -1;
-static virEventHandleType h_event = 0;
-static virEventHandleCallback h_cb = NULL;
-static virFreeCallback h_ff = NULL;
-static void *h_opaque = NULL;
-
-/* timeout globals */
-#define TIMEOUT_MS 1000
-static int t_active = 0;
-static int t_timeout = -1;
-static virEventTimeoutCallback t_cb = NULL;
-static virFreeCallback t_ff = NULL;
-static void *t_opaque = NULL;
 static pthread_t event_tid = 0;
 static int run = 0;
 
@@ -48,20 +34,6 @@ static int run = 0;
 const char *eventToString(int event);
 int myDomainEventCallback1(virConnectPtr conn, virDomainPtr dom,
 			   int event, int detail, void *opaque);
-int myEventAddHandleFunc(int fd, int event,
-			 virEventHandleCallback cb,
-			 void *opaque, virFreeCallback ff);
-void myEventUpdateHandleFunc(int watch, int event);
-int myEventRemoveHandleFunc(int watch);
-
-int myEventAddTimeoutFunc(int timeout,
-			  virEventTimeoutCallback cb,
-			  void *opaque, virFreeCallback ff);
-void myEventUpdateTimeoutFunc(int timer, int timout);
-int myEventRemoveTimeoutFunc(int timer);
-
-int myEventHandleTypeToPollEvent(virEventHandleType events);
-virEventHandleType myPollEventToEventHandleType(int events);
 
 void usage(const char *pname);
 
@@ -70,103 +42,6 @@ struct domain_info {
 	virDomainEventType event;
 };
 
-
-/* EventImpl Functions */
-int
-myEventHandleTypeToPollEvent(virEventHandleType events)
-{
-	int ret = 0;
-	if (events & VIR_EVENT_HANDLE_READABLE)
-		ret |= POLLIN;
-	if (events & VIR_EVENT_HANDLE_WRITABLE)
-		ret |= POLLOUT;
-	if (events & VIR_EVENT_HANDLE_ERROR)
-		ret |= POLLERR;
-	if (events & VIR_EVENT_HANDLE_HANGUP)
-		ret |= POLLHUP;
-	return ret;
-}
-
-virEventHandleType
-myPollEventToEventHandleType(int events)
-{
-	virEventHandleType ret = 0;
-	if (events & POLLIN)
-		ret |= VIR_EVENT_HANDLE_READABLE;
-	if (events & POLLOUT)
-		ret |= VIR_EVENT_HANDLE_WRITABLE;
-	if (events & POLLERR)
-		ret |= VIR_EVENT_HANDLE_ERROR;
-	if (events & POLLHUP)
-		ret |= VIR_EVENT_HANDLE_HANGUP;
-
-	return ret;
-}
-
-int
-myEventAddHandleFunc(int fd, int event,
-		     virEventHandleCallback cb,
-		     void *opaque, virFreeCallback ff)
-{
-	DEBUG1("Add handle %d %d %p %p %p", fd, event, cb, opaque, ff);
-	h_fd = fd;
-	h_event = myEventHandleTypeToPollEvent(event);
-	h_cb = cb;
-	h_opaque = opaque;
-	h_ff = ff;
-	return 0;
-}
-
-void
-myEventUpdateHandleFunc(int fd, int event)
-{
-	DEBUG1("Updated Handle %d %d", fd, event);
-	h_event = myEventHandleTypeToPollEvent(event);
-	return;
-}
-
-int
-myEventRemoveHandleFunc(int fd)
-{
-	DEBUG1("Removed Handle %d", fd);
-	h_fd = 0;
-	if (h_ff)
-		(h_ff) (h_opaque);
-	return 0;
-}
-
-int
-myEventAddTimeoutFunc(int timeout,
-		      virEventTimeoutCallback cb,
-		      void *opaque, virFreeCallback ff)
-{
-	DEBUG1("Adding Timeout %d %p %p", timeout, cb, opaque);
-	t_active = 1;
-	t_timeout = timeout;
-	t_cb = cb;
-	t_ff = ff;
-	t_opaque = opaque;
-	return 0;
-}
-
-void
-myEventUpdateTimeoutFunc(int timer, int timeout)
-{
-	/*DEBUG1("Timeout updated %d %d", timer, timeout); */
-	t_timeout = timeout;
-}
-
-int
-myEventRemoveTimeoutFunc(int timer)
-{
-	DEBUG1("Timeout removed %d", timer);
-	t_active = 0;
-	if (t_ff)
-		(t_ff) (t_opaque);
-	return 0;
-}
-
-
 static int
 is_in_directory(const char *dir, const char *pathspec)
 {
@@ -395,6 +270,30 @@ struct event_args {
 	int wake_fd;
 };
 
+void
+connectClose(virConnectPtr conn ATTRIBUTE_UNUSED,
+                         int reason,
+                         void *opaque ATTRIBUTE_UNUSED)
+{
+	switch (reason) {
+	case VIR_CONNECT_CLOSE_REASON_ERROR:
+		dbg_printf(2, "Connection closed due to I/O error\n");
+		break;
+	case VIR_CONNECT_CLOSE_REASON_EOF:
+		dbg_printf(2, "Connection closed due to end of file\n");
+		break;
+	case VIR_CONNECT_CLOSE_REASON_KEEPALIVE:
+		dbg_printf(2, "Connection closed due to keepalive timeout\n");
+		break;
+	case VIR_CONNECT_CLOSE_REASON_CLIENT:
+		dbg_printf(2, "Connection closed due to client request\n");
+		break;
+	default:
+		dbg_printf(2, "Connection closed due to unknown reason\n");
+		break;
+	};
+	run = 0;
+}
 
 int
 myDomainEventCallback1(virConnectPtr conn,
@@ -425,7 +324,6 @@ event_thread(void *arg)
 	struct event_args *args = (struct event_args *)arg;
 	virConnectPtr dconn = NULL;
 	int callback1ret = -1;
-	int sts;
 
 	dbg_printf(3, "Libvirt event listener starting\n");
 	if (args->uri)
@@ -434,13 +332,10 @@ event_thread(void *arg)
 		dbg_printf(3," * Socket path: %s\n", args->path);
 	dbg_printf(3," * Mode: %s\n", args->mode ? "VMChannel" : "Serial");
 
-top:
+	if (virEventRegisterDefaultImpl() < 0) {
-	virEventRegisterImpl(myEventAddHandleFunc,
+		dbg_printf(1, "Failed to register default event impl\n");
-			     myEventUpdateHandleFunc,
+		goto out;
-			     myEventRemoveHandleFunc,
+	}
-			     myEventAddTimeoutFunc,
-			     myEventUpdateTimeoutFunc,
-			     myEventRemoveTimeoutFunc);
 
 	dconn = virConnectOpen(args->uri);
 	if (!dconn) {
@@ -448,6 +343,8 @@ top:
 		goto out;
 	}
 
+	virConnectRegisterCloseCallback(dconn, connectClose, NULL, NULL);
+
 	DEBUG0("Registering domain event cbs");
 
 	registerExisting(dconn, args->path, args->mode);
@@ -455,43 +352,14 @@ top:
 	callback1ret =
 	    virConnectDomainEventRegister(dconn, myDomainEventCallback1, arg, NULL);
 
-	if (callback1ret == 0) {
+	if (callback1ret != -1) {
+		if (virConnectSetKeepAlive(dconn, 5, 5) < 0) {
+			dbg_printf(1, "Failed to start keepalive protocol\n");
+			run = 0;
+		}
 		while (run) {
-			struct pollfd pfd = {
+			if (virEventRunDefaultImpl() < 0) {
-				.fd = h_fd,
+				dbg_printf(1, "RunDefaultImpl Failed\n");
-				.events = h_event,
-				.revents = 0
-			};
-
-			sts = poll(&pfd, 1, TIMEOUT_MS);
-			/* We are assuming timeout of 0 here - so execute every time */
-			if (t_cb && t_active) {
-				t_cb(t_timeout, t_opaque);
-			}
-
-			if (sts == 0) {
-				/* DEBUG0("Poll timeout"); */
-				continue;
-			}
-
-			if (sts < 0) {
-				DEBUG0("Poll failed");
-				continue;
-			}
-
-			if (pfd.revents & POLLHUP) {
-				DEBUG0("Reset by peer");
-				virConnectDomainEventDeregister(dconn, myDomainEventCallback1);
-				if (dconn && virConnectClose(dconn) < 0)
-					dbg_printf(1, "error closing libvirt connection\n");
-				DEBUG0("Attempting to reinitialize libvirt connection");
-				goto top;
-			}
-
-			if (h_cb) {
-				h_cb(0, h_fd,
-				     myPollEventToEventHandleType(pfd.revents & h_event),
-				     h_opaque);
 			}
 		}