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
|
/*
* Modification History
*
* 2001-January-11 Jason Rohrer
* Created.
*
* 2001-January-27 Jason Rohrer
* Fixed a bug in the precompiler directives.
*
* 2003-August-26 Jason Rohrer
* Added support for timeouts on wait.
*/
#include "minorGems/common.h"
#ifndef BINARY_SEMAPHORE_CLASS_INCLUDED
#define BINARY_SEMAPHORE_CLASS_INCLUDED
#include "MutexLock.h"
/**
* Binary semaphore class. Semaphore starts out with a value of 0.
*
* Note: Implementation for the functions defined here is provided
* separately for each platform (in the mac/ linux/ and win32/
* subdirectories).
*
* @author Jason Rohrer
*/
class BinarySemaphore {
public:
/**
* Constructs a binary semaphore.
*/
BinarySemaphore();
~BinarySemaphore();
/**
* Blocks on this semaphore until signal() is called by another thread.
* Note that if signal() has already been called before wait() is
* called, then this call will return immediately, though the semaphore
* is reset to 0 by this call.
*
* @param inTimeoutInMilliseconds the maximum time to wait in
* milliseconds, or -1 to wait forever. Defaults to -1.
*
* @return 1 if the semaphore was signaled, or 0 if it timed out.
*/
int wait( int inTimeoutInMilliseconds = -1 );
/**
* Signals the semaphore, allowing a waiting thread to return from
* its call to wait(). (The semaphore is set to 1 by this call if
* no thread is waiting on the semaphore currently.)
*/
void signal();
private:
// starts at 0
int mSemaphoreValue;
/**
* Used by platform-specific implementations.
*/
void *mNativeObjectPointerA;
void *mNativeObjectPointerB;
};
#endif
|
