1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
|
// Gst.GLib.ToggleRef.cs - GLib ToggleRef class implementation
//
// Author: Mike Kestner <mkestner@novell.com>
//
// Copyright <c> 2007 Novell, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of version 2 of the Lesser GNU General
// Public License as published by the Free Software Foundation.
//
// This program 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 program; if not, write to the
// Free Software Foundation, Inc., 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.
namespace Gst.GLib {
using System;
using System.Collections;
using System.Runtime.InteropServices;
internal class ToggleRef {
bool hardened;
IntPtr handle;
object reference;
GCHandle gch;
Hashtable signals;
public ToggleRef (Gst.GLib.Object target)
{
handle = target.Handle;
gch = GCHandle.Alloc (this);
reference = target;
g_object_add_toggle_ref (target.Handle, ToggleNotifyCallback, (IntPtr) gch);
g_object_unref (target.Handle);
}
public bool IsAlive {
get {
if (reference is WeakReference) {
WeakReference weak = reference as WeakReference;
return weak.IsAlive;
} else if (reference == null)
return false;
return true;
}
}
public IntPtr Handle {
get {
return handle;
}
}
public Hashtable Signals {
get {
if (signals == null)
signals = new Hashtable ();
return signals;
}
}
public Gst.GLib.Object Target {
get {
if (reference == null)
return null;
else if (reference is Gst.GLib.Object)
return reference as Gst.GLib.Object;
WeakReference weak = reference as WeakReference;
return weak.Target as Gst.GLib.Object;
}
}
public void Free ()
{
Signal[] signals = new Signal [Signals.Count];
Signals.Values.CopyTo (signals, 0);
foreach (Signal s in signals)
s.Free ();
if (hardened)
g_object_unref (handle);
else
g_object_remove_toggle_ref (handle, ToggleNotifyCallback, (IntPtr) gch);
reference = null;
gch.Free ();
}
internal void Harden ()
{
// Added for the benefit of GnomeProgram. It releases a final ref in
// an atexit handler which causes toggle ref notifications to occur after
// our delegates are gone, so we need a mechanism to override the
// notifications. This method effectively leaks all objects which invoke it,
// but since it is only used by Gnome.Program, which is a singleton object
// with program duration persistence, who cares.
g_object_ref (handle);
g_object_remove_toggle_ref (handle, ToggleNotifyCallback, (IntPtr) gch);
if (reference is WeakReference)
reference = (reference as WeakReference).Target;
hardened = true;
}
void Toggle (bool is_last_ref)
{
if (is_last_ref && reference is Gst.GLib.Object)
reference = new WeakReference (reference);
else if (!is_last_ref && reference is WeakReference) {
WeakReference weak = reference as WeakReference;
if (weak.IsAlive)
reference = weak.Target;
}
}
[UnmanagedFunctionPointer (CallingConvention.Cdecl)]
delegate void ToggleNotifyHandler (IntPtr data, IntPtr handle, bool is_last_ref);
static void RefToggled (IntPtr data, IntPtr handle, bool is_last_ref)
{
try {
GCHandle gch = (GCHandle) data;
ToggleRef tref = gch.Target as ToggleRef;
tref.Toggle (is_last_ref);
} catch (Exception e) {
ExceptionManager.RaiseUnhandledException (e, false);
}
}
static ToggleNotifyHandler toggle_notify_callback;
static ToggleNotifyHandler ToggleNotifyCallback {
get {
if (toggle_notify_callback == null)
toggle_notify_callback = new ToggleNotifyHandler (RefToggled);
return toggle_notify_callback;
}
}
[DllImport("libgobject-2.0-0.dll")]
static extern void g_object_add_toggle_ref (IntPtr raw, ToggleNotifyHandler notify_cb, IntPtr data);
[DllImport("libgobject-2.0-0.dll")]
static extern void g_object_remove_toggle_ref (IntPtr raw, ToggleNotifyHandler notify_cb, IntPtr data);
[DllImport("libgobject-2.0-0.dll")]
static extern IntPtr g_object_ref (IntPtr raw);
[DllImport("libgobject-2.0-0.dll")]
static extern void g_object_unref (IntPtr raw);
}
}
|
