Use g_unix_signal_add() for signal handlers

Identified by functional-tests/17-ontology-changes timeouting randomly.

Documentation for g_unix_signal_source_new() explains why it is not safe
to call g_main_loop_quit() from a regular UNIX signal handler.

Intentionally removed the (main_loop != NULL) tests - this cannot happen.

https://bugzilla.gnome.org/show_bug.cgi?id=739234

6 files changed, 61 insertions, 99 deletions

diff --git a/src/miners/apps/tracker-main.c b/src/miners/apps/tracker-main.c
index a6ef75b8d..6d4f01278 100644
--- a/src/miners/apps/tracker-main.c
+++ b/src/miners/apps/tracker-main.c
@@ -21,10 +21,10 @@
 
 #include <stdlib.h>
 #include <locale.h>
-#include <signal.h>
 #include <errno.h>
 
 #include <glib.h>
+#include <glib-unix.h>
 #include <glib-object.h>
 #include <glib/gi18n.h>
 
@@ -67,9 +67,11 @@ static GOptionEntry entries[] = {
 	{ NULL }
 };
 
-static void
-signal_handler (int signo)
+static gboolean
+signal_handler (gpointer user_data)
 {
+	int signo = GPOINTER_TO_INT (user_data);
+
 	static gboolean in_loop = FALSE;
 
 	/* Die if we get re-entrant signals handler calls */
@@ -81,11 +83,8 @@ signal_handler (int signo)
 	case SIGTERM:
 	case SIGINT:
 		in_loop = TRUE;
-		if (main_loop != NULL) {
-			g_main_loop_quit (main_loop);
-		} else {
-			exit (0);
-		}
+		g_main_loop_quit (main_loop);
+
 		/* Fall through */
 	default:
 		if (g_strsignal (signo)) {
@@ -96,23 +95,16 @@ signal_handler (int signo)
 		}
 		break;
 	}
+
+	return G_SOURCE_CONTINUE;
 }
 
 static void
 initialize_signal_handler (void)
 {
 #ifndef G_OS_WIN32
-	struct sigaction act;
-	sigset_t         empty_mask;
-
-	sigemptyset (&empty_mask);
-	act.sa_handler = signal_handler;
-	act.sa_mask    = empty_mask;
-	act.sa_flags   = 0;
-
-	sigaction (SIGTERM, &act, NULL);
-	sigaction (SIGINT,  &act, NULL);
-	sigaction (SIGHUP,  &act, NULL);
+	g_unix_signal_add (SIGTERM, signal_handler, GINT_TO_POINTER (SIGTERM));
+	g_unix_signal_add (SIGINT, signal_handler, GINT_TO_POINTER (SIGINT));
 #endif /* G_OS_WIN32 */
 }
 
diff --git a/src/miners/fs/tracker-main.c b/src/miners/fs/tracker-main.c
index 2661b881e..31b7bc2be 100644
--- a/src/miners/fs/tracker-main.c
+++ b/src/miners/fs/tracker-main.c
@@ -22,12 +22,12 @@
 #include <string.h>
 #include <stdlib.h>
 #include <locale.h>
-#include <signal.h>
 #include <errno.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include <glib.h>
+#include <glib-unix.h>
 #include <glib-object.h>
 #include <glib/gi18n.h>
 
@@ -120,9 +120,11 @@ sanity_check_option_values (TrackerConfig *config)
 	}
 }
 
-static void
-signal_handler (int signo)
+static gboolean
+signal_handler (gpointer user_data)
 {
+	int signo = GPOINTER_TO_INT (user_data);
+
 	static gboolean in_loop = FALSE;
 
 	/* Die if we get re-entrant signals handler calls */
@@ -134,11 +136,8 @@ signal_handler (int signo)
 	case SIGTERM:
 	case SIGINT:
 		in_loop = TRUE;
-		if (main_loop != NULL) {
-			g_main_loop_quit (main_loop);
-		} else {
-			exit (0);
-		}
+		g_main_loop_quit (main_loop);
+
 		/* Fall through */
 	default:
 		if (g_strsignal (signo)) {
@@ -149,23 +148,16 @@ signal_handler (int signo)
 		}
 		break;
 	}
+
+	return G_SOURCE_CONTINUE;
 }
 
 static void
 initialize_signal_handler (void)
 {
 #ifndef G_OS_WIN32
-	struct sigaction act;
-	sigset_t         empty_mask;
-
-	sigemptyset (&empty_mask);
-	act.sa_handler = signal_handler;
-	act.sa_mask    = empty_mask;
-	act.sa_flags   = 0;
-
-	sigaction (SIGTERM, &act, NULL);
-	sigaction (SIGINT,  &act, NULL);
-	sigaction (SIGHUP,  &act, NULL);
+	g_unix_signal_add (SIGTERM, signal_handler, GINT_TO_POINTER (SIGTERM));
+	g_unix_signal_add (SIGINT, signal_handler, GINT_TO_POINTER (SIGINT));
 #endif /* G_OS_WIN32 */
 }
 
diff --git a/src/miners/user-guides/tracker-main.c b/src/miners/user-guides/tracker-main.c
index b59622505..55920d9d4 100644
--- a/src/miners/user-guides/tracker-main.c
+++ b/src/miners/user-guides/tracker-main.c
@@ -21,10 +21,10 @@
 
 #include <stdlib.h>
 #include <locale.h>
-#include <signal.h>
 #include <errno.h>
 
 #include <glib.h>
+#include <glib-unix.h>
 #include <glib-object.h>
 #include <glib/gi18n.h>
 
@@ -67,9 +67,11 @@ static GOptionEntry entries[] = {
 	{ NULL }
 };
 
-static void
-signal_handler (int signo)
+static gboolean
+signal_handler (gpointer user_data)
 {
+	int signo = GPOINTER_TO_INT (user_data);
+
 	static gboolean in_loop = FALSE;
 
 	/* Die if we get re-entrant signals handler calls */
@@ -81,11 +83,8 @@ signal_handler (int signo)
 	case SIGTERM:
 	case SIGINT:
 		in_loop = TRUE;
-		if (main_loop != NULL) {
-			g_main_loop_quit (main_loop);
-		} else {
-			exit (0);
-		}
+		g_main_loop_quit (main_loop);
+
 		/* Fall through */
 	default:
 		if (g_strsignal (signo)) {
@@ -96,23 +95,16 @@ signal_handler (int signo)
 		}
 		break;
 	}
+
+	return G_SOURCE_CONTINUE;
 }
 
 static void
 initialize_signal_handler (void)
 {
 #ifndef G_OS_WIN32
-	struct sigaction act;
-	sigset_t         empty_mask;
-
-	sigemptyset (&empty_mask);
-	act.sa_handler = signal_handler;
-	act.sa_mask    = empty_mask;
-	act.sa_flags   = 0;
-
-	sigaction (SIGTERM, &act, NULL);
-	sigaction (SIGINT,  &act, NULL);
-	sigaction (SIGHUP,  &act, NULL);
+	g_unix_signal_add (SIGTERM, signal_handler, GINT_TO_POINTER (SIGTERM));
+	g_unix_signal_add (SIGINT, signal_handler, GINT_TO_POINTER (SIGINT));
 #endif /* G_OS_WIN32 */
 }
 
diff --git a/src/tracker-extract/tracker-main.c b/src/tracker-extract/tracker-main.c
index 22af4b288..a02cb0e8e 100644
--- a/src/tracker-extract/tracker-main.c
+++ b/src/tracker-extract/tracker-main.c
@@ -24,12 +24,12 @@
 #include <time.h>
 #include <stdlib.h>
 #include <locale.h>
-#include <signal.h>
 #include <errno.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include <glib-object.h>
+#include <glib-unix.h>
 #include <glib/gi18n.h>
 #include <glib/gprintf.h>
 #include <gio/gio.h>
@@ -150,9 +150,11 @@ initialize_directories (void)
 	g_free (user_data_dir);
 }
 
-static void
-signal_handler (int signo)
+static gboolean
+signal_handler (gpointer user_data)
 {
+	int signo = GPOINTER_TO_INT (user_data);
+
 	static gboolean in_loop = FALSE;
 
 	/* Die if we get re-entrant signals handler calls */
@@ -176,23 +178,16 @@ signal_handler (int signo)
 		}
 		break;
 	}
+
+	return G_SOURCE_CONTINUE;
 }
 
 static void
 initialize_signal_handler (void)
 {
 #ifndef G_OS_WIN32
-	struct sigaction act;
-	sigset_t         empty_mask;
-
-	sigemptyset (&empty_mask);
-	act.sa_handler = signal_handler;
-	act.sa_mask    = empty_mask;
-	act.sa_flags   = 0;
-
-	sigaction (SIGTERM, &act, NULL);
-	sigaction (SIGINT,  &act, NULL);
-	sigaction (SIGHUP,  &act, NULL);
+	g_unix_signal_add (SIGTERM, signal_handler, GINT_TO_POINTER (SIGTERM));
+	g_unix_signal_add (SIGINT, signal_handler, GINT_TO_POINTER (SIGINT));
 #endif /* G_OS_WIN32 */
 }
 
@@ -385,10 +380,11 @@ main (int argc, char *argv[])
 	controller = tracker_extract_controller_new (decorator);
 	tracker_miner_start (TRACKER_MINER (decorator));
 
-	initialize_signal_handler ();
-
 	/* Main loop */
 	main_loop = g_main_loop_new (NULL, FALSE);
+
+	initialize_signal_handler ();
+
 	g_main_loop_run (main_loop);
 
 	my_main_loop = main_loop;
diff --git a/src/tracker-store/tracker-main.vala b/src/tracker-store/tracker-main.vala
index 8d991c6eb..468586710 100644
--- a/src/tracker-store/tracker-main.vala
+++ b/src/tracker-store/tracker-main.vala
@@ -77,7 +77,7 @@ License which can be viewed at:
 
 	static bool in_loop = false;
 
-	static void signal_handler (int signo) {
+	static bool signal_handler (int signo) {
 		/* Die if we get re-entrant signals handler calls */
 		if (in_loop) {
 			Process.exit (1);
@@ -101,20 +101,13 @@ License which can be viewed at:
 			}
 			break;
 		}
+
+		return true;
 	}
 
 	static void initialize_signal_handler () {
-		var empty_mask = Posix.sigset_t ();
-		Posix.sigemptyset (empty_mask);
-
-		var act = Posix.sigaction_t ();
-		act.sa_handler = signal_handler;
-		act.sa_mask = empty_mask;
-		act.sa_flags = 0;
-
-		Posix.sigaction (Posix.SIGTERM, act, null);
-		Posix.sigaction (Posix.SIGINT, act, null);
-		Posix.sigaction (Posix.SIGHUP, act, null);
+		Unix.signal_add (Posix.SIGTERM, () => signal_handler (Posix.SIGTERM));
+		Unix.signal_add (Posix.SIGINT, () => signal_handler (Posix.SIGINT));
 	}
 
 	static void initialize_priority () {
@@ -298,9 +291,10 @@ License which can be viewed at:
 		 * doing what they do and shutdown.
 		 */
 		if (!shutdown) {
+			main_loop = new MainLoop ();
+
 			initialize_signal_handler ();
 
-			main_loop = new MainLoop ();
 			main_loop.run ();
 		}
 
diff --git a/src/tracker/tracker-daemon.c b/src/tracker/tracker-daemon.c
index f37f1a166..7cda3e3bb 100644
--- a/src/tracker/tracker-daemon.c
+++ b/src/tracker/tracker-daemon.c
@@ -27,6 +27,7 @@
 #endif
 
 #include <glib.h>
+#include <glib-unix.h>
 #include <glib/gi18n.h>
 #include <glib/gprintf.h>
 
@@ -206,9 +207,11 @@ parse_watch (const gchar  *option_name,
 	return TRUE;
 }
 
-static void
-signal_handler (int signo)
+static gboolean
+signal_handler (gpointer user_data)
 {
+	int signo = GPOINTER_TO_INT (user_data);
+
 	static gboolean in_loop = FALSE;
 
 	/* Die if we get re-entrant signals handler calls */
@@ -232,22 +235,15 @@ signal_handler (int signo)
 		}
 		break;
 	}
+
+	return G_SOURCE_CONTINUE;
 }
 
 static void
 initialize_signal_handler (void)
 {
-	struct sigaction act;
-	sigset_t empty_mask;
-
-	sigemptyset (&empty_mask);
-	act.sa_handler = signal_handler;
-	act.sa_mask = empty_mask;
-	act.sa_flags = 0;
-
-	sigaction (SIGTERM, &act, NULL);
-	sigaction (SIGINT, &act, NULL);
-	sigaction (SIGHUP, &act, NULL);
+	g_unix_signal_add (SIGTERM, signal_handler, GINT_TO_POINTER (SIGTERM));
+	g_unix_signal_add (SIGINT, signal_handler, GINT_TO_POINTER (SIGINT));
 }
 
 static gboolean