blob: 75b4e5d855a541062182da1d596e4377f6f42cfc (
plain)
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
|
/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
package org.apache.qpid.qmf2.common;
// Misc Imports
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;
/**
* This is an implementation of a QMF2 WorkQueue. In practice this is likely to be used by an Agent or Console.
*
* @author Fraser Adams
*/
public class WorkQueue
{
/**
* Used to implement a thread safe queue of WorkItem objects
*/
private BlockingQueue<WorkItem> _workQueue = new LinkedBlockingQueue<WorkItem>();
/**
* Return the count of pending WorkItems that can be retrieved.
* @return the count of pending WorkItems that can be retrieved.
*/
public int size()
{
return _workQueue.size();
}
/**
* Obtains the next pending work item - blocking version
*
* @return the next pending work item, or null if none available.
*/
public WorkItem getNextWorkitem()
{
try
{
return _workQueue.take();
}
catch (InterruptedException ie)
{
return null;
}
}
/**
* Obtains the next pending work item - balking version
*
* @param timeout the timeout in seconds. If timeout = 0 it returns immediately with either a WorkItem or null
* @return the next pending work item, or null if none available.
*/
public WorkItem getNextWorkitem(long timeout)
{
try
{
return _workQueue.poll(timeout, TimeUnit.SECONDS);
}
catch (InterruptedException ie)
{
return null;
}
}
/**
* Adds a WorkItem to the WorkQueue.
*
* @param item the WorkItem passed to the WorkQueue
*/
public void addWorkItem(WorkItem item)
{
// We wrap the blocking put() method in a loop "just in case" InterruptedException occurs
// if it does we retry the put otherwise we carry on, notify then exit.
while (true)
{
try
{
_workQueue.put(item);
break;
}
catch (InterruptedException ie)
{
continue;
}
}
}
}
|
