USemaphore Class Reference

#include <USemaphore.h>

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 &)
	USemaphore (const USemaphore &)

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.

Constructor & Destructor Documentation

USemaphore() [1/2]

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.

~USemaphore()

virtual USemaphore::~USemaphore ( )

inlinevirtual

Definition at line 72 of file USemaphore.h.

USemaphore() [2/2]

USemaphore::USemaphore ( const USemaphore &  )

inlineprivate

Definition at line 216 of file USemaphore.h.

Member Function Documentation

acquire()

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.

acquireTry()

int USemaphore::acquireTry ( int  n )

inline

Definition at line 144 of file USemaphore.h.

operator=()

void USemaphore::operator= ( const USemaphore &  )

inlineprivate

Definition at line 211 of file USemaphore.h.

release()

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.

value()

int USemaphore::value ( )

inline

Get the USempahore's value.

Returns

the semaphore's value

Definition at line 187 of file USemaphore.h.

Member Data Documentation

_available

int USemaphore::_available

private

Definition at line 219 of file USemaphore.h.

_cond

pthread_cond_t USemaphore::_cond

private

Definition at line 218 of file USemaphore.h.

_waitMutex

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