[glib/wip/gdesktopappinfo: 5/13] glocalfile: add private worker monitor APIs

[Ryan Lortie <ryanl src gnome org>]

commit af0b2679201bfa059fc941031728acc75b99e8d2
Author: Ryan Lortie <desrt desrt ca>
Date:   Thu Jul 25 14:05:36 2013 -0400

    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.

 gio/glocaldirectorymonitor.c |   10 ++++++----
 gio/glocaldirectorymonitor.h |    7 +++++++
 gio/glocalfile.c             |   26 ++++++++++++++++++++++++--
 gio/glocalfilemonitor.c      |    6 ++++--
 gio/glocalfilemonitor.h      |    7 +++++++
 5 files changed, 48 insertions(+), 8 deletions(-)
---
diff --git a/gio/glocaldirectorymonitor.c b/gio/glocaldirectorymonitor.c
index 588f6e1..942643e 100644
--- a/gio/glocaldirectorymonitor.c
+++ b/gio/glocaldirectorymonitor.c
@@ -200,9 +200,11 @@ mounts_changed (GUnixMountMonitor *mount_monitor,
 
 GFileMonitor*
 _g_local_directory_monitor_new (const char         *dirname,
-                               GFileMonitorFlags   flags,
+                                GFileMonitorFlags   flags,
+                                GMainContext       *context,
                                 gboolean            is_remote_fs,
-                               GError            **error)
+                                gboolean            do_start,
+                                GError            **error)
 {
   GFileMonitor *monitor = NULL;
   GType type = G_TYPE_INVALID;
@@ -218,12 +220,12 @@ _g_local_directory_monitor_new (const char         *dirname,
                                           G_STRUCT_OFFSET (GLocalDirectoryMonitorClass, is_supported));
 
   if (type != G_TYPE_INVALID)
-    monitor = G_FILE_MONITOR (g_object_new (type, "dirname", dirname, "flags", flags, NULL));
+    monitor = G_FILE_MONITOR (g_object_new (type, "dirname", dirname, "flags", flags, "context", context, 
NULL));
   else
     g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED,
                          _("Unable to find default local directory monitor type"));
 
-  if (monitor)
+  if (monitor && do_start)
     g_local_directory_monitor_start (G_LOCAL_DIRECTORY_MONITOR (monitor));
 
   return monitor;
diff --git a/gio/glocaldirectorymonitor.h b/gio/glocaldirectorymonitor.h
index 16d8ac1..94740bd 100644
--- a/gio/glocaldirectorymonitor.h
+++ b/gio/glocaldirectorymonitor.h
@@ -70,10 +70,17 @@ GType           g_local_directory_monitor_get_type (void) G_GNUC_CONST;
 
 GFileMonitor * _g_local_directory_monitor_new      (const char         *dirname,
                                                     GFileMonitorFlags   flags,
+                                                    GMainContext       *context,
                                                     gboolean            is_remote_fs,
+                                                    gboolean            do_start,
                                                     GError            **error);
 void            g_local_directory_monitor_start    (GLocalDirectoryMonitor *local_monitor);
 
+/* Actually in glocalfile.c */
+GLocalDirectoryMonitor *  g_local_directory_monitor_new_in_worker (const char         *pathname,
+                                                                   GFileMonitorFlags   flags,
+                                                                   GError            **error);
+
 G_END_DECLS
 
 #endif /* __G_LOCAL_DIRECTORY_MONITOR_H__ */
diff --git a/gio/glocalfile.c b/gio/glocalfile.c
index 67e8313..4734577 100644
--- a/gio/glocalfile.c
+++ b/gio/glocalfile.c
@@ -68,6 +68,8 @@
 #include "glib-unix.h"
 #endif
 
+#include "glib-private.h"
+
 #ifdef G_OS_WIN32
 #include <windows.h>
 #include <io.h>
@@ -2501,7 +2503,7 @@ g_local_file_monitor_dir (GFile             *file,
                          GError           **error)
 {
   GLocalFile* local_file = G_LOCAL_FILE(file);
-  return _g_local_directory_monitor_new (local_file->filename, flags, is_remote (local_file->filename), 
error);
+  return _g_local_directory_monitor_new (local_file->filename, flags, NULL, is_remote 
(local_file->filename), TRUE, error);
 }
 
 static GFileMonitor*
@@ -2511,7 +2513,27 @@ g_local_file_monitor_file (GFile             *file,
                           GError           **error)
 {
   GLocalFile* local_file = G_LOCAL_FILE(file);
-  return _g_local_file_monitor_new (local_file->filename, flags, is_remote (local_file->filename), error);
+  return _g_local_file_monitor_new (local_file->filename, flags, NULL, is_remote (local_file->filename), 
TRUE, error);
+}
+
+GLocalDirectoryMonitor *
+g_local_directory_monitor_new_in_worker (const char         *pathname,
+                                         GFileMonitorFlags   flags,
+                                         GError            **error)
+{
+  return (gpointer) _g_local_directory_monitor_new (pathname, flags,
+                                                    GLIB_PRIVATE_CALL (g_get_worker_context) (),
+                                                    is_remote (pathname), FALSE, error);
+}
+
+GLocalFileMonitor *
+g_local_file_monitor_new_in_worker (const char         *pathname,
+                                    GFileMonitorFlags   flags,
+                                    GError            **error)
+{
+  return (gpointer) _g_local_file_monitor_new (pathname, flags,
+                                               GLIB_PRIVATE_CALL (g_get_worker_context) (),
+                                               is_remote (pathname), FALSE, error);
 }
 
 static void
diff --git a/gio/glocalfilemonitor.c b/gio/glocalfilemonitor.c
index 765b98f..a4cbeae 100644
--- a/gio/glocalfilemonitor.c
+++ b/gio/glocalfilemonitor.c
@@ -122,7 +122,9 @@ static void g_local_file_monitor_class_init (GLocalFileMonitorClass *klass)
 GFileMonitor*
 _g_local_file_monitor_new (const char         *pathname,
                            GFileMonitorFlags   flags,
+                           GMainContext       *context,
                            gboolean            is_remote_fs,
+                           gboolean            do_start,
                            GError            **error)
 {
   GFileMonitor *monitor = NULL;
@@ -139,12 +141,12 @@ _g_local_file_monitor_new (const char         *pathname,
                                           G_STRUCT_OFFSET (GLocalFileMonitorClass, is_supported));
 
   if (type != G_TYPE_INVALID)
-    monitor = G_FILE_MONITOR (g_object_new (type, "filename", pathname, "flags", flags, NULL));
+    monitor = G_FILE_MONITOR (g_object_new (type, "filename", pathname, "flags", flags, "context", context, 
NULL));
   else
     g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED,
                          _("Unable to find default local file monitor type"));
 
-  if (monitor)
+  if (monitor && do_start)
     g_local_file_monitor_start (G_LOCAL_FILE_MONITOR (monitor));
 
   return monitor;
diff --git a/gio/glocalfilemonitor.h b/gio/glocalfilemonitor.h
index e6bb623..74baaa4 100644
--- a/gio/glocalfilemonitor.h
+++ b/gio/glocalfilemonitor.h
@@ -63,10 +63,17 @@ 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__ */