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
|
/* ****************************************************************************
*
* Copyright (c) Microsoft Corporation.
*
* This source code is subject to terms and conditions of the Microsoft Public License. A
* copy of the license can be found in the License.html file at the root of this distribution. If
* you cannot locate the Microsoft Public License, please send an email to
* dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound
* by the terms of the Microsoft Public License.
*
* You must not remove this notice, or any other, from this software.
*
*
* ***************************************************************************/
using System;
using System.Runtime.InteropServices;
namespace Microsoft.Scripting.Utils {
#if SILVERLIGHT
// TODO: finalizers in user types aren't supported in Silverlight
// we need to come up with another solution for Python's _weakref library
public struct WeakHandle {
private WeakReference _weakRef;
public WeakHandle(object target, bool trackResurrection) {
_weakRef = new WeakReference(target, trackResurrection);
GC.SuppressFinalize(this._weakRef);
}
public bool IsAlive { get { return _weakRef != null && _weakRef.IsAlive; } }
public object Target { get { return _weakRef != null ? _weakRef.Target : null; } }
public void Free() {
if (_weakRef != null) {
GC.ReRegisterForFinalize(_weakRef);
_weakRef.Target = null;
_weakRef = null;
}
}
}
#else
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1815:OverrideEqualsAndOperatorEqualsOnValueTypes")] // TODO: fix
public struct WeakHandle {
private GCHandle weakRef;
public WeakHandle(object target, bool trackResurrection) {
this.weakRef = GCHandle.Alloc(target, trackResurrection ? GCHandleType.WeakTrackResurrection : GCHandleType.Weak);
}
public bool IsAlive { get { return weakRef.IsAllocated; } }
public object Target { get { return weakRef.Target; } }
public void Free() { weakRef.Free(); }
}
#endif
}
|
