Merge lp:~ted/ubuntu-app-launch/cgmanager-connection-timeout into lp:ubuntu-app-launch/rtm-14.09

[Ted Gould]

Attenting to connect to cgmanager for 1 second and then failing and reporting a recoverable error.

Make it so that we don't block on building the cgmanager connection, which might be failing because of an error in cgmanager. But instead of making all of Unity freeze, we want to handle the error and not block. We need to track it though so we can start getting an idea of how often and what conditions it's happening in.

[Charles Kerr (charlesk)]

Reviewed @ https://code.launchpad.net/~ted/ubuntu-app-launch/cgmanager-connection-timeout/+merge/241463, LGTM

review: Approve

=== modified file 'CMakeLists.txt'
--- CMakeLists.txt	2014-09-29 19:31:36 +0000
+++ CMakeLists.txt	2014-11-11 22:11:41 +0000
@@ -78,7 +78,7 @@
 # Helpers
 ####################
 
-add_library(helpers STATIC helpers.c helpers-shared.c)
+add_library(helpers STATIC helpers.c helpers-shared.c libubuntu-app-launch/recoverable-problem.c)
 target_link_libraries(helpers ${GIO2_LIBRARIES} ${JSONGLIB_LIBRARIES} ${CLICK_LIBRARIES})
 
 ####################

=== modified file 'helpers-shared.c'
--- helpers-shared.c	2014-08-11 16:41:40 +0000
+++ helpers-shared.c	2014-11-11 22:11:41 +0000
@@ -22,6 +22,7 @@
 #include <cgmanager/cgmanager.h>
 
 #include "ual-tracepoint.h"
+#include "libubuntu-app-launch/recoverable-problem.h"
 
 /* Check to make sure we have the sections and keys we want */
 static gboolean
@@ -97,34 +98,110 @@
 	return keyfile;
 }
 
+/* Quick way to get the pid of cgmanager to report a bug on it */
+static GPid
+discover_cgmanager_pid (void)
+{
+	gchar * outbuf = NULL;
+	GPid outpid = 0;
+	
+	if (g_spawn_command_line_sync("pidof cgmanager", &outbuf, NULL, NULL, NULL)) {
+		outpid = g_ascii_strtoull(outbuf, NULL, 10);
+	}
+
+	g_free(outbuf);
+
+	return outpid;
+}
+
+/* Structure to handle data for the cgmanager connection
+   set of callbacks */
+typedef struct {
+	GMainLoop * loop;
+	GCancellable * cancel;
+	GDBusConnection * con;
+} cgm_connection_t;
+
+/* Function that gets executed when we timeout trying to connect. This
+   is related to: LP #1377332 */
+static gboolean
+cgroup_manager_connection_timeout_cb (gpointer data)
+{
+	GPid cgmanager_pid = 0;
+	cgm_connection_t * connection = (cgm_connection_t *)data;
+
+	g_cancellable_cancel(connection->cancel);
+
+	cgmanager_pid = discover_cgmanager_pid();
+	if (cgmanager_pid != 0) {
+		report_recoverable_problem("ubuntu-app-launch-cgmanager-connection-timeout", cgmanager_pid, FALSE, NULL);
+	}
+
+	return G_SOURCE_CONTINUE;
+}
+
+static void
+cgroup_manager_connection_core_cb (GDBusConnection *(*finish_func)(GAsyncResult * res, GError ** error), GAsyncResult * res, cgm_connection_t * connection)
+{
+	GError * error = NULL;
+
+	connection->con = finish_func(res, &error);
+
+	if (error != NULL) {
+		g_warning("Unable to get cgmanager connection: %s", error->message);
+		g_error_free(error);
+	}
+
+	g_main_loop_quit(connection->loop);
+}
+
+static void
+cgroup_manager_connection_bus_cb (GObject * obj, GAsyncResult * res, gpointer data)
+{
+	cgroup_manager_connection_core_cb(g_bus_get_finish, res, (cgm_connection_t *)data);
+}
+
+static void
+cgroup_manager_connection_addr_cb (GObject * obj, GAsyncResult * res, gpointer data)
+{
+	cgroup_manager_connection_core_cb(g_dbus_connection_new_for_address_finish, res, (cgm_connection_t *)data);
+}
+
 /* Get the connection to the cgroup manager */
 GDBusConnection *
 cgroup_manager_connection (void)
 {
-	GError * error = NULL;
-
-	GDBusConnection * cgmanager = NULL;
+	cgm_connection_t connection = {
+		.loop = g_main_loop_new(NULL, FALSE),
+		.con = NULL,
+		.cancel = g_cancellable_new()
+	};
+	guint timeout = g_timeout_add_seconds(1, cgroup_manager_connection_timeout_cb, &connection);
 
 	if (g_getenv("UBUNTU_APP_LAUNCH_CG_MANAGER_SESSION_BUS")) {
 		/* For working dbusmock */
 		g_debug("Connecting to CG Manager on session bus");
-		cgmanager = g_bus_get_sync(G_BUS_TYPE_SESSION, NULL, &error);
+		g_bus_get(G_BUS_TYPE_SESSION,
+			connection.cancel,
+			cgroup_manager_connection_bus_cb,
+			&connection);
 	} else {
-		cgmanager = g_dbus_connection_new_for_address_sync(
+		g_dbus_connection_new_for_address(
 			CGMANAGER_DBUS_PATH,
 			G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT,
 			NULL, /* Auth Observer */
-			NULL, /* Cancellable */
-			&error);
-	}
-
-	if (error != NULL) {
-		g_warning("Unable to connect to cgroup manager: %s", error->message);
-		g_error_free(error);
-		return NULL;
-	}
-
-	return cgmanager;
+			connection.cancel, /* Cancellable */
+			cgroup_manager_connection_addr_cb,
+			&connection);
+	}
+
+	g_main_loop_run(connection.loop);
+
+	g_source_remove(timeout);
+	g_main_loop_unref(connection.loop);
+	g_object_unref(connection.cancel);
+
+	return connection.con;
 }
 
 /* Get the PIDs for a particular cgroup */

=== modified file 'libubuntu-app-launch/CMakeLists.txt'
--- libubuntu-app-launch/CMakeLists.txt	2014-09-29 19:57:03 +0000
+++ libubuntu-app-launch/CMakeLists.txt	2014-11-11 22:11:41 +0000
@@ -29,9 +29,6 @@
 click-exec.c
 desktop-exec.c
 ubuntu-app-launch-trace.c
-recoverable-problem.c
-"${CMAKE_SOURCE_DIR}/helpers-shared.c"
-"${CMAKE_SOURCE_DIR}/helpers.c"
 )
 
 add_library(ubuntu-launcher SHARED ${LAUNCHER_SOURCES})
@@ -51,6 +48,7 @@
 	${JSONGLIB_LIBRARIES}
 	${CLICK_LIBRARIES}
 	${ZEITGEIST_LIBRARIES}
+	helpers
 	-Wl,--no-undefined
 )
 

=== modified file 'tests/CMakeLists.txt'
--- tests/CMakeLists.txt	2014-09-15 19:40:02 +0000
+++ tests/CMakeLists.txt	2014-11-11 22:11:41 +0000
@@ -35,7 +35,7 @@
 
 add_executable (libual-test
 	libual-test.cc)
-target_link_libraries (libual-test helpers gtest ${GTEST_LIBS} ${LIBUPSTART_LIBRARIES} ${DBUSTEST_LIBRARIES} ubuntu-launcher)
+target_link_libraries (libual-test gtest ${GTEST_LIBS} ${LIBUPSTART_LIBRARIES} ${DBUSTEST_LIBRARIES} ubuntu-launcher)
 
 add_executable (data-spew
 	data-spew.c)

=== modified file 'tests/helper-test.cc'
--- tests/helper-test.cc	2014-06-14 16:05:36 +0000
+++ tests/helper-test.cc	2014-11-11 22:11:41 +0000
@@ -428,7 +428,7 @@
 	g_setenv("TEST_CLICK_USER", "test-user", TRUE);
 
 	desktop = manifest_to_desktop(CMAKE_SOURCE_DIR "/click-app-dir/", "com.test.good_application_1.2.3");
-	ASSERT_STREQ(desktop, CMAKE_SOURCE_DIR "/click-app-dir/application.desktop");
+	ASSERT_STREQ(CMAKE_SOURCE_DIR "/click-app-dir/application.desktop", desktop);
 	g_free(desktop);
 	desktop = NULL;