GAppInfoMonitor: port to GContextSpecificGroup

https://bugzilla.gnome.org/show_bug.cgi?id=742599
This commit is contained in:
Ryan Lortie 2015-01-08 02:36:26 -05:00
parent c90b083fa8
commit 720274511b

View File

@ -22,6 +22,7 @@
#include "gappinfo.h"
#include "gappinfoprivate.h"
#include "gcontextspecificgroup.h"
#include "glibintl.h"
#include <gioerror.h>
@ -1057,40 +1058,6 @@ g_app_launch_context_launch_failed (GAppLaunchContext *context,
* Since: 2.40
**/
/* We have one of each of these per main context and hand them out
* according to the thread default main context at the time of the call
* to g_app_info_monitor_get().
*
* g_object_unref() is only ever called from the same context, so we
* effectively have a single-threaded scenario for each GAppInfoMonitor.
*
* We use a hashtable to cache the per-context monitor (but we do not
* hold a ref). During finalize, we remove it. This is possible
* because we don't have to worry about the usual races due to the
* single-threaded nature of each object.
*
* We keep a global list of all contexts that have a monitor for them,
* which we have to access under a lock. When we dispatch the events to
* be handled in each context, we don't pass the monitor, but the
* context itself.
*
* We dispatch from the GLib worker context, so if we passed the
* monitor, we would need to take a ref on it (in case it was destroyed
* in its own thread meanwhile). The monitor holds a ref on a context
* and the dispatch would mean that the context would hold a ref on the
* monitor. If someone stopped iterating the context at just this
* moment both the context and monitor would leak.
*
* Instead, we dispatch the context to itself. We don't hold a ref.
* There is the danger that the context will be destroyed during the
* dispatch, but if that is the case then we just won't receive our
* callback.
*
* When the dispatch occurs we just lookup the monitor in the hashtable,
* by context. We can now add and remove refs, since the context will
* have been acquired.
*/
typedef struct _GAppInfoMonitorClass GAppInfoMonitorClass;
struct _GAppInfoMonitor
@ -1104,9 +1071,8 @@ struct _GAppInfoMonitorClass
GObjectClass parent_class;
};
static GHashTable *g_app_info_monitors;
static GMutex g_app_info_monitor_lock;
static guint g_app_info_monitor_changed_signal;
static GContextSpecificGroup g_app_info_monitor_group;
static guint g_app_info_monitor_changed_signal;
G_DEFINE_TYPE (GAppInfoMonitor, g_app_info_monitor, G_TYPE_OBJECT)
@ -1115,9 +1081,7 @@ g_app_info_monitor_finalize (GObject *object)
{
GAppInfoMonitor *monitor = G_APP_INFO_MONITOR (object);
g_mutex_lock (&g_app_info_monitor_lock);
g_hash_table_remove (g_app_info_monitors, monitor->context);
g_mutex_unlock (&g_app_info_monitor_lock);
g_context_specific_group_remove (&g_app_info_monitor_group, monitor->context, monitor, NULL);
G_OBJECT_CLASS (g_app_info_monitor_parent_class)->finalize (object);
}
@ -1164,91 +1128,14 @@ g_app_info_monitor_class_init (GAppInfoMonitorClass *class)
GAppInfoMonitor *
g_app_info_monitor_get (void)
{
GAppInfoMonitor *monitor;
GMainContext *context;
context = g_main_context_get_thread_default ();
if (!context)
context = g_main_context_default ();
g_return_val_if_fail (g_main_context_acquire (context), NULL);
g_mutex_lock (&g_app_info_monitor_lock);
if (!g_app_info_monitors)
g_app_info_monitors = g_hash_table_new (NULL, NULL);
monitor = g_hash_table_lookup (g_app_info_monitors, context);
g_mutex_unlock (&g_app_info_monitor_lock);
if (!monitor)
{
monitor = g_object_new (G_TYPE_APP_INFO_MONITOR, NULL);
monitor->context = g_main_context_ref (context);
g_mutex_lock (&g_app_info_monitor_lock);
g_hash_table_insert (g_app_info_monitors, context, monitor);
g_mutex_unlock (&g_app_info_monitor_lock);
}
else
g_object_ref (monitor);
g_main_context_release (context);
return monitor;
}
static gboolean
g_app_info_monitor_emit (gpointer user_data)
{
GMainContext *context = user_data;
GAppInfoMonitor *monitor;
g_mutex_lock (&g_app_info_monitor_lock);
monitor = g_hash_table_lookup (g_app_info_monitors, context);
g_mutex_unlock (&g_app_info_monitor_lock);
/* It is possible that the monitor was already destroyed by the time
* we get here, so make sure it's not NULL.
*/
if (monitor != NULL)
{
/* We don't have to worry about another thread disposing the
* monitor but we do have to worry about the possibility that one
* of the attached handlers may do so.
*
* Take a ref so that the monitor doesn't disappear in the middle
* of the emission.
*/
g_object_ref (monitor);
g_signal_emit (monitor, g_app_info_monitor_changed_signal, 0);
g_object_unref (monitor);
}
return FALSE;
return g_context_specific_group_get (&g_app_info_monitor_group,
G_TYPE_APP_INFO_MONITOR,
G_STRUCT_OFFSET (GAppInfoMonitor, context),
NULL);
}
void
g_app_info_monitor_fire (void)
{
GHashTableIter iter;
gpointer context;
g_mutex_lock (&g_app_info_monitor_lock);
if (g_app_info_monitors)
{
g_hash_table_iter_init (&iter, g_app_info_monitors);
while (g_hash_table_iter_next (&iter, &context, NULL))
{
GSource *idle;
idle = g_idle_source_new ();
g_source_set_callback (idle, g_app_info_monitor_emit, context, NULL);
g_source_set_name (idle, "[gio] g_app_info_monitor_emit");
g_source_attach (idle, context);
g_source_unref (idle);
}
}
g_mutex_unlock (&g_app_info_monitor_lock);
g_context_specific_group_emit (&g_app_info_monitor_group, g_app_info_monitor_changed_signal);
}