USemaphore Class Reference

#include <USemaphore.h>

List of all members.

Public Member Functions
bool	acquire (int n=1, int ms=0)
int	acquireTry (int n)
void	release (int n=1)
	USemaphore (int initValue=0)
int	value ()
virtual	~USemaphore ()
Private Member Functions
void	operator= (const USemaphore &S)
	USemaphore (const USemaphore &S)
Private Attributes
int	_available
pthread_cond_t	_cond
pthread_mutex_t	_waitMutex

---

Detailed Description

A semaphore class.

On an acquire() call, the calling thread is blocked if the USemaphore's value is <= 0. It is unblocked when release() is called. The function acquire() decreases by 1 (default) the semaphore's value and release() increases it by 1 (default).

Example:

 USemaphore s;
 s.acquire(); // Will wait until s.release() is called by another thread.

See also:

UMutex

Definition at line 54 of file USemaphore.h.

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Constructor & Destructor Documentation

USemaphore::USemaphore

(

int

initValue = 0

)

[inline]

The constructor. The semaphore waits on acquire() when its value is <= 0.

Parameters:

n	number to initialize

Definition at line 61 of file USemaphore.h.

virtual USemaphore::~USemaphore

(

)

[inline, virtual]

Definition at line 72 of file USemaphore.h.

USemaphore::USemaphore

(

const USemaphore &

S

)

[inline, private]

Definition at line 216 of file USemaphore.h.

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Member Function Documentation

bool USemaphore::acquire	(	int	n = 1,
		int	ms = 0
	)		[inline]

Acquire the semaphore. If semaphore's value is <=0, the calling thread will wait until the count acquired is released.

See also:

release()

Parameters:

n	number to acquire
t	time to wait (ms), a value <=0 means infinite

Returns:

true on success, false on error/timeout

Definition at line 101 of file USemaphore.h.

int USemaphore::acquireTry

(

int

n

)

[inline]

Definition at line 144 of file USemaphore.h.

void USemaphore::operator=

(

const USemaphore &

S

)

[inline, private]

Definition at line 211 of file USemaphore.h.

void USemaphore::release

(

int

n = 1

)

[inline]

Release the semaphore, increasing its value by 1 and signaling waiting threads (which called acquire()).

Definition at line 168 of file USemaphore.h.

int USemaphore::value

(

)

[inline]

Get the USempahore's value.

Returns:

the semaphore's value

Definition at line 187 of file USemaphore.h.

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Member Data Documentation

int USemaphore::_available [private]

Definition at line 219 of file USemaphore.h.

pthread_cond_t USemaphore::_cond [private]

Definition at line 218 of file USemaphore.h.

pthread_mutex_t USemaphore::_waitMutex [private]

Definition at line 217 of file USemaphore.h.

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The documentation for this class was generated from the following file:

• USemaphore.h