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RWLock Class Reference

#include <RWLock.h>

Inheritance diagram for RWLock:

List of all members.

Public Methods
	RWLock () throw (Synchronization_Exception)
virtual	~RWLock () throw ()
Lockable *	getReadLock ()
Lockable *	getWriteLock ()
Protected Methods
virtual bool	allowReader ()
virtual bool	allowWriter ()
virtual void	beforeRead () throw (Synchronization_Exception)
virtual void	beforeWrite () throw (Synchronization_Exception)
virtual bool	beforeRead (unsigned long) throw (Synchronization_Exception)
virtual bool	beforeWrite (unsigned long) throw (Synchronization_Exception)
virtual void	postRead () throw (Synchronization_Exception)
virtual void	postWrite () throw (Synchronization_Exception)
Protected Attributes
FastMutex	_mtxLock
	Serialize access to this object.
Condition	_condRead
	Notified on read ready.
Condition	_condWrite
	Notified on write read.
Lockable *	_readLock
	RLock.
Lockable *	_writeLock
	WLock.
volatile int	_fairnessCounter
	track fairness.
volatile int	_activeReaders
	track the current readers.
volatile int	_activeWriters
	track the current writers.
volatile int	_waitingReaders
	track the waiting readers.
volatile int	_waitingWriters
	track the waiting writers.
Friends
class	RLock
	friend.
class	WLock
	friend.

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Detailed Description

Author:

Eric Crahen <crahen@cse.buffalo.edu>

Date:

<2002-05-28T20:19:52-0400>

Version:

2.1.3

Read/Write lock provide a set of coordinated Lockable object that allow many Readers while there is no update in progress, but only 1 Writer & 0 Readers during an update

Because the general case where an RWLock would be used is one where you have more readers than writers, this lock will have a bias toward readers

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Constructor & Destructor Documentation

RWLock (    )  throw (Synchronization_Exception)

Create a new RWLock Exceptions: Initialization_Exception  - thrown if resources could not be allocated

virtual ~RWLock (    )  throw () [virtual]

Destroy this RWLock

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Member Function Documentation

virtual bool allowReader (    )  [protected, virtual]

Checked before a lock is acquired. Changing this function in a subclass can create RWLocks with different biases. Returns: bool - true, allow lock to be acquired, false block Reimplemented in BiasedRWLock, and FairRWLock.

virtual bool allowWriter (    )  [protected, virtual]

Checked before a lock is acquired. Changing this function in a subclass can create RWLocks with different biases. Returns: bool - true, allow lock to be acquired, false block

virtual bool beforeRead (  unsigned    long )  throw (Synchronization_Exception) [protected, virtual]

Called just before a read lock tryAcquire() Parameters: long  - timeout the read will be called with

virtual void beforeRead (    )  throw (Synchronization_Exception) [protected, virtual]

Called just prior to a read lock acquire()

virtual bool beforeWrite (  unsigned    long )  throw (Synchronization_Exception) [protected, virtual]

Called just before a write lock tryAcquire() Parameters: long  - timeout the write will be called with

virtual void beforeWrite (    )  throw (Synchronization_Exception) [protected, virtual]

Called just prior to a write lock acquire()

Lockable* getReadLock (    )  [inline]

Get a reference to the read lock Returns: Lockable read lock

Lockable* getWriteLock (    )  [inline]

Get a reference to the write lock Returns: Lockable write lock

virtual void postRead (    )  throw (Synchronization_Exception) [protected, virtual]

Called after a read lock is released

virtual void postWrite (    )  throw (Synchronization_Exception) [protected, virtual]

Called after a write lock is released

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

• RWLock.h

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