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
|
//
// YieldAwaitable.cs
//
// Authors:
// Marek Safar <marek.safar@gmail.com>
//
// Copyright (C) 2011 Novell, Inc (http://www.novell.com)
// Copyright (C) 2011 Xamarin, Inc (http://www.xamarin.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,)
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
#if NET_4_5
using System.Threading;
using System.Threading.Tasks;
namespace System.Runtime.CompilerServices
{
public struct YieldAwaitable
{
public struct YieldAwaiter : ICriticalNotifyCompletion
{
public bool IsCompleted {
get {
return false;
}
}
public void OnCompleted (Action continuation)
{
OnCompleted (continuation, false);
}
public void UnsafeOnCompleted (Action continuation)
{
OnCompleted (continuation, true);
}
void OnCompleted (Action continuation, bool isUnsafe)
{
if (continuation == null)
throw new ArgumentNullException ("continuation");
var ctx = SynchronizationContext.Current;
if (ctx != null && ctx.GetType () != typeof (SynchronizationContext)) {
ctx.Post (l => ((Action) l) (), continuation);
return;
}
if (TaskScheduler.IsDefault) {
//
// Pass continuation as an argument to avoid allocating
// hoisting class
//
WaitCallback callBack = l => ((Action) l) ();
if (isUnsafe) {
ThreadPool.UnsafeQueueUserWorkItem (callBack, continuation);
} else {
ThreadPool.QueueUserWorkItem (callBack, continuation);
}
return;
}
new Task (continuation).Start (TaskScheduler.Current);
}
public void GetResult ()
{
}
}
public YieldAwaitable.YieldAwaiter GetAwaiter ()
{
return new YieldAwaiter ();
}
}
}
#endif
|
