blob: 59a97c9a1a700d5be1678a03eaeeb7a6fcbff8d9 (
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
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
/*************************************************
*
* = PACKAGE
* JACE.Concurrency
*
* = FILENAME
* Condition.java
*
*@author Irfan Pyarali
*
*************************************************/
package JACE.Concurrency;
import JACE.ASX.TimeoutException;
import JACE.ASX.TimeValue;
/**
* <hr>
* <h2>TITLE</h2>
*<blockquote>
* Abstraction for <em>traditional</em>
* condition variable
*</blockquote>
*
* <h2>DESCRIPTION</h2>
*<blockquote>
* This condition variable allows the use of one
* mutex between multiple conditions.
* This implementation is based on the C++ version of ACE.
*</blockquote>
*/
public class Condition
{
/**
* Default constructor
*@param Mutex for synchronization
*/
public Condition (Mutex mutex)
{
mutex_ = mutex;
}
/**
* Wait for condition to become signaled.
*@exception InterruptedException exception during wait
*/
public void Wait ()
throws InterruptedException
{
waiters_++;
try
{
mutex_.release();
semaphore_.acquire ();
mutex_.acquire ();
}
finally
{
waiters_--;
}
}
/**
* TimedWait for condition to become signaled.
*@exception TimeoutException wait timed out exception
*@exception InterruptedException exception during wait
*/
public void Wait (TimeValue tv)
throws TimeoutException, InterruptedException
{
waiters_++;
try
{
mutex_.release();
TimeValue start = TimeValue.getTimeOfDay ();
semaphore_.acquire (tv);
TimeValue now = TimeValue.getTimeOfDay ();
tv.minusEquals (TimeValue.minus (now, start));
mutex_.acquire (tv);
}
finally
{
waiters_--;
}
}
/**
* Signal condition. Wake one waiter (if any).
*/
public void signal ()
{
if (waiters_ > 0)
semaphore_.release ();
}
/**
* Signal condition. Wake up all waiters (if any).
*/
public void broadcast ()
{
for (int i = waiters_; i > 0; i--)
semaphore_.release ();
}
/**
* Accessor to lock
*@return Mutex
*/
public Mutex mutex ()
{
return mutex_;
}
private int waiters_;
private Semaphore semaphore_ = new Semaphore (0);
private Mutex mutex_;
}
|
