glib/gio/glocalfilemonitor.h
Ryan Lortie 33762a4173 glocalfile: add private worker monitor APIs
Add a convenient and race-free method of watching local files from the
GLib worker thread.

Without this, the race-free way to create a monitor that dispatches
events to the worker thread looked something like this:

 - dispatch an idle to the worker thread
 - from the idle, create the monitor and connect signals
 - from the original thread, wait (on a cond?) until the worker thread
   has finished setting up the monitor
 - read the file that you were monitoring

which is just ridiculously complicated...

To use the new API:

  monitor = g_local_file_monitor_new_in_worker ("/path/to/some/file",
                                                G_FILE_MONITOR_NONE,
                                                &error);
  g_assert_no_error (error);

  g_signal_connect (monitor, "changed", G_CALLBACK (callback), NULL);

  g_local_file_monitor_start (monitor);

'callback' will run from the GLib worker thread.

This is the reason that the start() call was introduced in the previous
commit.  The backends that don't use the start() call will have a very
thin race between creating the monitor and connecting the signal, but
hopefully they will be fixed soon.

These new APIs will be used (at least) from gdesktopappinfo to watch for
changes in the desktop file directories.

https://bugzilla.gnome.org/show_bug.cgi?id=704887
2013-10-03 10:37:47 -04:00

80 lines
3.1 KiB
C

/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2006-2007 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* Author: Alexander Larsson <alexl@redhat.com>
*/
#ifndef __G_LOCAL_FILE_MONITOR_H__
#define __G_LOCAL_FILE_MONITOR_H__
#include <gio/gfilemonitor.h>
G_BEGIN_DECLS
#define G_TYPE_LOCAL_FILE_MONITOR (g_local_file_monitor_get_type ())
#define G_LOCAL_FILE_MONITOR(o) (G_TYPE_CHECK_INSTANCE_CAST ((o), G_TYPE_LOCAL_FILE_MONITOR, GLocalFileMonitor))
#define G_LOCAL_FILE_MONITOR_CLASS(k) (G_TYPE_CHECK_CLASS_CAST ((k), G_TYPE_LOCAL_FILE_MONITOR, GLocalFileMonitorClass))
#define G_IS_LOCAL_FILE_MONITOR(o) (G_TYPE_CHECK_INSTANCE_TYPE ((o), G_TYPE_LOCAL_FILE_MONITOR))
#define G_IS_LOCAL_FILE_MONITOR_CLASS(k) (G_TYPE_CHECK_CLASS_TYPE ((k), G_TYPE_LOCAL_FILE_MONITOR))
#define G_LOCAL_FILE_MONITOR_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS ((o), G_TYPE_LOCAL_FILE_MONITOR, GLocalFileMonitorClass))
#define G_LOCAL_FILE_MONITOR_EXTENSION_POINT_NAME "gio-local-file-monitor"
#define G_NFS_FILE_MONITOR_EXTENSION_POINT_NAME "gio-nfs-file-monitor"
typedef struct _GLocalFileMonitor GLocalFileMonitor;
typedef struct _GLocalFileMonitorClass GLocalFileMonitorClass;
struct _GLocalFileMonitor
{
GFileMonitor parent_instance;
gchar *filename;
GFileMonitorFlags flags;
};
struct _GLocalFileMonitorClass
{
GFileMonitorClass parent_class;
gboolean (* is_supported) (void);
void (* start) (GLocalFileMonitor *local_monitor);
};
#ifdef G_OS_UNIX
GLIB_AVAILABLE_IN_ALL
#endif
GType g_local_file_monitor_get_type (void) G_GNUC_CONST;
GFileMonitor * _g_local_file_monitor_new (const char *pathname,
GFileMonitorFlags flags,
GMainContext *context,
gboolean is_remote_fs,
gboolean do_start,
GError **error);
void g_local_file_monitor_start (GLocalFileMonitor *local_monitor);
/* Actually in glocalfile.c */
GLocalFileMonitor * g_local_file_monitor_new_in_worker (const char *pathname,
GFileMonitorFlags flags,
GError **error);
G_END_DECLS
#endif /* __G_LOCAL_FILE_MONITOR_H__ */