blob: dfb4faea3064f541a58b88ecd261d45d97e9845b (
plain) (
blame)
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
|
//
// ========================================================================
// Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package org.eclipse.jetty.util;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.util.concurrent.CancellationException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicReference;
/* ------------------------------------------------------------ */
/**
* TODO
*/
public class BlockingCallback implements Callback
{
private static Throwable SUCCEEDED=new Throwable()
{
@Override
public String toString() { return "SUCCEEDED"; }
};
private final CountDownLatch _latch = new CountDownLatch(1);
private final AtomicReference<Throwable> _state = new AtomicReference<>();
public BlockingCallback()
{}
@Override
public void succeeded()
{
if (_state.compareAndSet(null,SUCCEEDED))
_latch.countDown();
}
@Override
public void failed(Throwable cause)
{
if (_state.compareAndSet(null,cause))
_latch.countDown();
}
/** Block until the Callback has succeeded or failed and
* after the return leave in the state to allow reuse.
* This is useful for code that wants to repeatable use a FutureCallback to convert
* an asynchronous API to a blocking API.
* @throws IOException if exception was caught during blocking, or callback was cancelled
*/
public void block() throws IOException
{
try
{
_latch.await();
Throwable state=_state.get();
if (state==SUCCEEDED)
return;
if (state instanceof IOException)
throw (IOException) state;
if (state instanceof CancellationException)
throw (CancellationException) state;
throw new IOException(state);
}
catch (final InterruptedException e)
{
throw new InterruptedIOException(){{initCause(e);}};
}
finally
{
_state.set(null);
}
}
@Override
public String toString()
{
return String.format("%s@%x{%s}",BlockingCallback.class.getSimpleName(),hashCode(),_state.get());
}
}
|
