LockManager Class Reference

Lock manager. More...

Public Member Functions
void	addLock (const char *name, pthread_mutex_t *lock)
	Registers a new lock. More...
void	acquireLock (int id, pthread_mutex_t *lock)
	Implements the lock operation. More...
void	releaseLock (int id, pthread_mutex_t *lock)
	Implements the unlock operation. More...
string	getLockTable () const
	Returns the lock table in a string. More...

Detailed Description

The lock manager is responsible for managing the locks used during the concurrent sections of the program. Each lock must first be registered using addLock. The state of locks are adjusted via the acquireLock and releaseLock methods.

Member Function Documentation

void LockManager::addLock	(	const char *	name,
		pthread_mutex_t *	lock
	)

Registers a new lock.

Parameters

[in]	name	name of lock
[in]	lock	lock variable

void LockManager::acquireLock	(	int	id,
		pthread_mutex_t *	lock
	)

Thread takes a lock if available. If the lock is unavailable, the thread will wait until it acquires the lock.

Parameters

[in]	id	id of thread trying to acquire lock
[in]	lock	lock variable

void LockManager::releaseLock	(	int	id,
		pthread_mutex_t *	lock
	)

Gives up the lock. If one or more threads are waiting, one thread will be woken up and given the lock. If no threads are waiting, the lock is returned to the unlocked state.

Parameters

[in]	id	id of thread trying to acquire lock
[in]	lock	lock variable

string LockManager::getLockTable

(

)

const

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