SemaphoreManager Class Reference

Semaphore manager. More...

Public Member Functions
void	addSemaphore (const char *name, sem_t *sem, int value)
	Registers a new semaphore. More...
void	waitSemaphore (int id, sem_t *sem)
	Implements the wait operation for a semaphore. More...
void	signalSemaphore (int id, sem_t *sem)
	Implements the signal (post) operation for a semaphore. More...
string	getSemaphoreTable () const
	Returns the semaphore table in a string. More...

Detailed Description

The semaphore manager is responsible for managing the semaphores used during the concurrent sections of the program. Each semaphore must first be registered using addSemaphore. The state of semaphores are adjusted via the waitSemaphore and signalSemaphore methods.

Member Function Documentation

void SemaphoreManager::addSemaphore	(	const char *	name,
		sem_t *	sem,
		int	value
	)

Registers a new semaphore.

Parameters

[in]	name	name of semaphore
[in]	sem	semaphore variable
[in]	value	initial value of semaphore

void SemaphoreManager::waitSemaphore	(	int	id,
		sem_t *	sem
	)

Decrement the semaphore. If the value is negative, the thread must wait until woken up by a subsequent post operation.

Parameters

[in]	id	id of thread performing wait
[in]	sem	semaphore variable

void SemaphoreManager::signalSemaphore	(	int	id,
		sem_t *	sem
	)

Increment the semaphore. If one or more threads are waiting, one thread will be woken up.

Parameters

[in]	id	id of thread performing signal (post)
[in]	sem	semaphore variable

string SemaphoreManager::getSemaphoreTable

(

)

const

Returns the semaphore table in a string in a trace-friendly format.