xref: /titanic_41/usr/src/cmd/lms/SyncLib/Include/Lock.h (revision 617e2443dfc17fe44fd44c0675d6aad2ffc9df42)

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//////////////////////////////////////////////////////////////////////////
// Lock.h
//
// This file contains the definition and implementation of the Lock class
// and the TryLock class
//////////////////////////////////////////////////////////////////////////
#ifndef _LAD_LOCK_H
#define _LAD_LOCK_H
#include "RWLock.h"

#ifndef NULL
#define NULL 0
#endif

class Lock
{
public:
	Lock(Semaphore &sem) : _sem(&sem), _rw_lock(NULL)
	{
		_sem->acquire();
	}

	Lock(RWLock &rw_lock, RWLock::RWMode mode = RWLock::READ_ONLY) :
	_sem(NULL), _rw_lock(&rw_lock)
	{
		_rw_lock->acquire(mode);
	}

	~Lock()
	{
		if (_sem) {
			_sem->release();
		}
		if (_rw_lock) {
			_rw_lock->release();
		}

	}

private:
	Semaphore *_sem;
	RWLock *_rw_lock;
};

class TryLock
{
public:
	TryLock(Semaphore &sem, bool &is_locked) : _sem(&sem)
	{
		_locked = _sem->acquireTry();
		is_locked = _locked;
	}

	~TryLock()
	{
		if (_locked) {
			_sem->release();
		}
	}

private:
	bool _locked;
	Semaphore *_sem;
};

#endif //_LAD_LOCK_H