Use the write-to-a-pipe trick from the signal handler instead of queueing

2006-11-23  Federico Mena Quintero  <federico@novell.com>

	Use the write-to-a-pipe trick from the signal handler instead of
	queueing an idle handler from there.

	* src/nautilus-main.c (setup_debug_log_signals): Set up a pair of
	pipes for the SIGUSR1 handler; set up a GIOChannel on them.
	(sigusr1_handler): Write a byte to our pipe instead of queueing an
	idle handler.
	(debug_log_io_cb): Replaces dump_debug_log_idle_cb().  Read from
	the pipe, and dump the debug log.

	Add a configuration file for the logging mechanism.  You create
	~/nautilus-debug-log.conf as a GKeyFile.

	* libnautilus-private/nautilus-debug-log.c
	(nautilus_debug_log_load_configuration): New function; loads the
	configuration from a key file like this:

		[debug log]
		enable domains = foo; bar; baz
		max lines = 1000

	* libnautilus-private/nautilus-debug-log.c (dump_configuration):
	New utility function.
	(nautilus_debug_log_dump): At the end of the log, dump the
	configuration used for the debug log so that the user can
	re-create it later.

	* libnautilus-private/nautilus-debug-log.h: New prototype for
	nautilus_debug_log_load_configuration().

	* src/nautilus-main.c (setup_debug_log): Load the debug log's
	configuration from ~/nautilus-debug-log.conf
	(setup_debug_log_domains): Removed.

	* src/nautilus-main.c (log_override_cb): If the log level of the
	message is G_LOG_LEVEL_DEBUG, don't log it as a milestone.  We'll
	use this log level for miscellaneous debugging messages from
	gnome-vfs.  Also, don't send G_LOG_LEVEL_DEBUG messages to the
	default log handler, to avoid a huge ~/.xsession-errors.
	(setup_debug_log_domains): Enable logging for
	NAUTILUS_DEBUG_LOG_DOMAIN_GLOG.

1 files changed, 32 insertions, 15 deletions

diff --git a/src/nautilus-main.c b/src/nautilus-main.c
index 25d51f99d..61c43d9df 100644
--- a/src/nautilus-main.c
+++ b/src/nautilus-main.c
@@ -210,9 +210,16 @@ dump_debug_log (void)
 	g_free (filename);
 }
 
+static int debug_log_pipes[2];
+
 static gboolean
-dump_debug_log_idle_cb (gpointer data)
+debug_log_io_cb (GIOChannel *io, GIOCondition condition, gpointer data)
 {
+	char a;
+
+	while (read (debug_log_pipes[0], &a, 1) != 1)
+		;
+
 	nautilus_debug_log (TRUE, NAUTILUS_DEBUG_LOG_DOMAIN_USER,
 			    "user requested dump of debug log");
 
@@ -230,7 +237,8 @@ static struct sigaction old_bus_sa;
 static void
 sigusr1_handler (int sig)
 {
-	g_idle_add (dump_debug_log_idle_cb, NULL);
+	while (write (debug_log_pipes[1], "a", 1) != 1)
+		;
 }
 
 static void
@@ -280,6 +288,13 @@ static void
 setup_debug_log_signals (void)
 {
 	struct sigaction sa;
+	GIOChannel *io;
+
+	if (pipe (debug_log_pipes) == -1)
+		g_error ("Could not create pipe() for debug log");
+
+	io = g_io_channel_unix_new (debug_log_pipes[0]);
+	g_io_add_watch (io, G_IO_IN, debug_log_io_cb, NULL);
 
 	sa.sa_handler = sigusr1_handler;
 	sigemptyset (&sa.sa_mask);
@@ -297,16 +312,6 @@ setup_debug_log_signals (void)
 	sigaction(SIGBUS,  &sa, &old_bus_sa);
 }
 
-static void
-setup_debug_log_domains (void)
-{
-	const char *domains[] = {
-		NAUTILUS_DEBUG_LOG_DOMAIN_ASYNC
-	};
-
-	nautilus_debug_log_enable_domains (domains, G_N_ELEMENTS (domains));
-}
-
 static GLogFunc default_log_handler;
 
 static void
@@ -315,9 +320,16 @@ log_override_cb (const gchar   *log_domain,
 		 const gchar   *message,
 		 gpointer       user_data)
 {
-	nautilus_debug_log (TRUE, NAUTILUS_DEBUG_LOG_DOMAIN_GLOG, "%s", message);
+	gboolean is_debug;
+	gboolean is_milestone;
+
+	is_debug = ((log_level & G_LOG_LEVEL_DEBUG) != 0);
+	is_milestone = !is_debug;
 
-	(* default_log_handler) (log_domain, log_level, message, user_data);
+	nautilus_debug_log (is_milestone, NAUTILUS_DEBUG_LOG_DOMAIN_GLOG, "%s", message);
+
+	if (!is_debug)
+		(* default_log_handler) (log_domain, log_level, message, user_data);
 }
 
 static void
@@ -329,7 +341,12 @@ setup_debug_log_glog (void)
 static void
 setup_debug_log (void)
 {
-	setup_debug_log_domains ();
+	char *config_filename;
+
+	config_filename = g_build_filename (g_get_home_dir (), "nautilus-debug-log.conf", NULL);
+	nautilus_debug_log_load_configuration (config_filename, NULL); /* NULL GError */
+	g_free (config_filename);
+
 	setup_debug_log_signals ();
 	setup_debug_log_glog ();
 }