LinGui: allow multiple instances of the gui to run

Each instance has a queue named "queue.<pid>".  On startup, the gui
opens and locks with lockf a file "ghb.pid.<pid>".  Then it searches
for any other ghb.pid.<pid> files that exist that are not locked.  If
it finds one, then some instance of ghb exited and may have left behind
a queue.  Try to reload it.  If there are no items in the queue, continue
looking for unlocked ghb.pid.<pid> files.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@3212 b64f7644-9d1e-0410-96f1-a4d463321fa5

4 files changed, 162 insertions, 21 deletions

diff --git a/gtk/src/main.c b/gtk/src/main.c
index a6a12fc9d..aade07e06 100644
--- a/gtk/src/main.c
+++ b/gtk/src/main.c
@@ -698,21 +698,7 @@ main (int argc, char *argv[])
 	ghb_hal_init();
 #endif
 
-	if (!ghb_lock_file("queue_lock"))
-	{
-    	const gchar *markup =
-        	N_("<b><big>Another instance of HandBrake is already running.</big></b>\n"
-        	"\n"
-        	"Only one instance of HandBrake may run.\n");
-        GtkWidget *dialog = gtk_message_dialog_new_with_markup(NULL,
-            GTK_DIALOG_MODAL,
-            GTK_MESSAGE_ERROR,
-            GTK_BUTTONS_CLOSE,
-            _(markup));
-        gtk_dialog_run(GTK_DIALOG(dialog));
-        gtk_widget_destroy(dialog);
-        exit(EXIT_FAILURE);
-	}
+	ghb_write_pid_file();
 	ud = g_malloc0(sizeof(signal_user_data_t));
 	ud->debug = ghb_debug;
 	g_log_set_handler (NULL, G_LOG_LEVEL_DEBUG, debug_log_handler, ud);
diff --git a/gtk/src/presets.c b/gtk/src/presets.c
index d83038796..7d7e84430 100644
--- a/gtk/src/presets.c
+++ b/gtk/src/presets.c
@@ -1151,6 +1151,104 @@ ghb_lock_file(const gchar *name)
 #endif
 }
 
+void
+ghb_write_pid_file()
+{
+#if !defined(_WIN32)
+	gchar *config, *path;
+	pid_t pid;
+	FILE *fp;
+	int fd, lock;
+
+	pid = getpid();
+
+	config = ghb_get_user_config_dir(NULL);
+	path = g_strdup_printf ("%s/ghb.pid.%d", config, pid);
+
+	fp = g_fopen(path, "w");
+	fprintf(fp, "%d\n", pid);
+	fclose(fp);
+
+	fd = open(path, O_RDWR|O_CREAT, S_IRUSR|S_IWUSR);
+	lock = lockf(fd, F_TLOCK, 0);
+
+	g_free(config);
+	g_free(path);
+#endif
+}
+
+void
+ghb_unlink_pid_file(int pid)
+{
+	gchar *config, *path;
+
+	config = ghb_get_user_config_dir(NULL);
+	path = g_strdup_printf ("%s/ghb.pid.%d", config, pid);
+
+	if (g_file_test(path, G_FILE_TEST_IS_REGULAR))
+	{
+		g_unlink(path);
+	}
+
+	g_free(config);
+	g_free(path);
+}
+
+int
+ghb_find_pid_file()
+{
+	const gchar *file;
+	gchar *config;
+
+	config = ghb_get_user_config_dir(NULL);
+
+	if (g_file_test(config, G_FILE_TEST_IS_DIR))
+	{
+		GDir *gdir = g_dir_open(config, 0, NULL);
+		file = g_dir_read_name(gdir);
+		while (file)
+		{
+			if (strncmp(file, "ghb.pid.", 8) == 0)
+			{
+				gchar *path;
+				int fd, lock = 1;
+				pid_t my_pid;
+				int pid;
+
+				sscanf(file, "ghb.pid.%d", &pid);
+				my_pid = getpid();
+				if (my_pid == pid)
+				{
+					file = g_dir_read_name(gdir);
+					continue;
+				}
+
+				path = g_strdup_printf("%s/%s", config, file);
+				fd = g_open(path, O_RDWR);
+				if (fd >= 0)
+				{
+					lock = lockf(fd, F_TLOCK, 0);
+				}
+				if (lock == 0)
+				{
+					close(fd);
+					g_dir_close(gdir);
+					g_unlink(path);
+					g_free(path);
+					g_free(config);
+					return pid;
+				}
+				g_free(path);
+				close(fd);
+			}
+			file = g_dir_read_name(gdir);
+		}
+		g_dir_close(gdir);
+	}
+	g_free(config);
+	return -1;
+}
+
 static void
 remove_plist(const gchar *name)
 {
@@ -1806,19 +1904,61 @@ remove_std_presets(signal_user_data_t *ud)
 void
 ghb_save_queue(GValue *queue)
 {
-	store_plist(queue, "queue");
+	pid_t pid;
+	char *path;
+
+	pid = getpid();
+	path = g_strdup_printf ("queue.%d", pid);
+	store_plist(queue, path);
+	g_free(path);
 }
 
 GValue*
 ghb_load_queue()
 {
-	return load_plist("queue");
+	GValue *queue;
+	pid_t pid;
+	char *path;
+
+	pid = getpid();
+	path = g_strdup_printf ("queue.%d", pid);
+	queue = load_plist(path);
+	g_free(path);
+	return queue;
+}
+
+GValue*
+ghb_load_old_queue(int pid)
+{
+	GValue *queue;
+	char *path;
+
+	path = g_strdup_printf ("queue.%d", pid);
+	queue = load_plist(path);
+	g_free(path);
+	return queue;
+}
+
+void
+ghb_remove_old_queue_file(int pid)
+{
+	char *path;
+
+	path = g_strdup_printf ("queue.%d", pid);
+	remove_plist(path);
+	g_free(path);
 }
 
 void
 ghb_remove_queue_file()
 {
-	remove_plist("queue");
+	pid_t pid;
+	char *path;
+
+	pid = getpid();
+	path = g_strdup_printf ("queue.%d", pid);
+	remove_plist(path);
+	g_free(path);
 }
 
 typedef struct
diff --git a/gtk/src/presets.h b/gtk/src/presets.h
index a4da4ed74..89f778092 100644
--- a/gtk/src/presets.h
+++ b/gtk/src/presets.h
@@ -27,7 +27,9 @@ void ghb_prefs_save(GValue *settings);
 void ghb_pref_save(GValue *settings, const gchar *key);
 void ghb_save_queue(GValue *queue);
 GValue* ghb_load_queue();
-void ghb_remove_queue_file(void);;
+GValue* ghb_load_old_queue(int pid);
+void ghb_remove_queue_file(void);
+void ghb_remove_old_queue_file(int pid);
 gchar* ghb_get_user_config_dir(gchar *subdir);
 void ghb_settings_to_ui(signal_user_data_t *ud, GValue *dict);
 void ghb_clear_presets_selection(signal_user_data_t *ud);
@@ -42,5 +44,8 @@ void ghb_prefs_store(void);
 void ghb_pref_set(GValue *settings, const gchar *key);
 gboolean ghb_lock_file(const gchar *name);
 void ghb_refresh_preset(signal_user_data_t *ud);
+int ghb_find_pid_file();
+void ghb_unlink_pid_file(int pid);
+void ghb_write_pid_file();
 
 #endif // _GHB_PRESETS_H_
diff --git a/gtk/src/queuehandler.c b/gtk/src/queuehandler.c
index 24eded5d6..3b91a2464 100644
--- a/gtk/src/queuehandler.c
+++ b/gtk/src/queuehandler.c
@@ -1259,13 +1259,20 @@ ghb_reload_queue(signal_user_data_t *ud)
 	GValue *queue;
 	gint unfinished = 0;
 	gint count, ii;
+	gint pid;
 	gint status;
 	GValue *settings;
 	gchar *message;
 
 	g_debug("ghb_reload_queue");
 
-	queue = ghb_load_queue();
+find_pid:
+	pid = ghb_find_pid_file();
+	if (pid < 0)
+		return FALSE;
+
+	queue = ghb_load_old_queue(pid);
+	ghb_remove_old_queue_file(pid);
 	// Look for unfinished entries
 	count = ghb_array_len(queue);
 	for (ii = 0; ii < count; ii++)
@@ -1277,6 +1284,9 @@ ghb_reload_queue(signal_user_data_t *ud)
 			unfinished++;
 		}
 	}
+	if (!unfinished)
+		goto find_pid;
+
 	if (unfinished)
 	{
 		message = g_strdup_printf(
@@ -1314,11 +1324,11 @@ ghb_reload_queue(signal_user_data_t *ud)
 				add_to_queue_list(ud, settings, NULL);
 			}
 			ghb_queue_buttons_grey(ud);
+			ghb_save_queue(ud->queue);
 		}
 		else
 		{
 			ghb_value_free(queue);
-			ghb_remove_queue_file();
 		}
 		g_free(message);
 	}