RWCriticalSection Class Reference

Provides mutual exclusion for a critical section of code in which only one thread should execute at a time. More...

#include <rw/sync/RWCriticalSection.h>

Inheritance diagram for RWCriticalSection:

Public Types
typedef RWTLockGuard< RWCriticalSection >	LockGuard
typedef RWTLockGuard< RWCriticalSection >	ReadLockGuard
typedef RWTUnlockGuard< RWCriticalSection >	ReadUnlockGuard
typedef RWTUnlockGuard< RWCriticalSection >	UnlockGuard
typedef RWTLockGuard< RWCriticalSection >	WriteLockGuard
typedef RWTUnlockGuard< RWCriticalSection >	WriteUnlockGuard

Public Member Functions
	RWCriticalSection (RWStaticCtor)
	RWCriticalSection (RWCancellationState state=0)
	~RWCriticalSection ()
void	acquire ()
void	acquireRead ()
void	acquireWrite ()
RWCriticalSectionRep *	getCriticalSectionRep () const
void	release ()
Public Member Functions inherited from RWSynchObject
void	disableCancellation ()
void	enableCancellation (RWCancellationState)
bool	isCancellationEnabled () const
void	setCancellation (RWCancellationState)

Private Member Functions
	RWCriticalSection (const RWCriticalSection &)
RWCriticalSection &	operator= (const RWCriticalSection &)

Related Functions
(Note that these are not member functions.)
typedef RW_MUTEX_T	RWCriticalSectionRep
Related Functions inherited from RWSynchObject
#define	RW_CANCELLATION_DISABLED
#define	RW_CANCELLATION_ENABLED
typedef void(*	RWCancellationState) ()
void	rwServiceCancellation (void)

Additional Inherited Members
Protected Member Functions inherited from RWSynchObject
	RWSynchObject (RWCancellationState state=0)
	RWSynchObject (RWStaticCtor)
	RWSynchObject (const RWSynchObject &second)
RWSynchObject &	operator= (const RWSynchObject &second)
void	testCancellation ()

Detailed Description

An RWCriticalSection object is used to provide mutual exclusion for a critical section of code, i.e. code in which only one thread should execute at a time. This lock operates in a manner that is identical to RWMutexLock except that on certain platforms, for example Win32, it may yield superior performance when there is minimal contention for the lock.

Example

#include <rw/sync/RWCriticalSection.h>

void foo()
{
    static RWCriticalSection outputCritsec(RW_STATIC_CTOR);

    // ...

    int i;

    // ...

    // Protect output from multiple threads
    // using cout at the same time:
    outputCritsec.acquire();
    std::cout << "The value of i is " << i << std::endl;
    outputCritsec.release();

    // Same thing, this time using a guard:
    {
        RWCriticalSection::LockGuard lock(outputCritsec);
        std::cout << "The value of i is " << i << std::endl;
    }
}

See also

RWMutexLock

Member Typedef Documentation

typedef RWTLockGuard<RWCriticalSection> RWCriticalSection::LockGuard

Predefined type for compatible guard.

typedef RWTLockGuard<RWCriticalSection> RWCriticalSection::ReadLockGuard

Predefined type for compatible guard.

typedef RWTUnlockGuard<RWCriticalSection> RWCriticalSection::ReadUnlockGuard

Predefined type for compatible guard.

typedef RWTUnlockGuard<RWCriticalSection> RWCriticalSection::UnlockGuard

Predefined type for compatible guard.

typedef RWTLockGuard<RWCriticalSection> RWCriticalSection::WriteLockGuard

Predefined type for compatible guard.

typedef RWTUnlockGuard<RWCriticalSection> RWCriticalSection::WriteUnlockGuard

Predefined type for compatible guard.

Constructor & Destructor Documentation

RWCriticalSection::RWCriticalSection ( RWStaticCtor  )

inline

Constructs a static instance, but does no direct initialization. The RWCriticalSection is initialized on first use.

This constructor must be used only for static instances. Use of this constructor with automatically or dynamically allocated instances produces errors or other unpredictable behavior.

Static instances are zero initialized, which results in an RWCriticalSection with cancellation state of RW_CANCELLATION_DISABLED.

RWCriticalSection::RWCriticalSection ( RWCancellationState  state = 0 )

inline

Creates and initializes the critical section. Possible exceptions include RWTHRInternalError.

RWCriticalSection::~RWCriticalSection ( )

inline

Default destructor.

RWCriticalSection::RWCriticalSection ( const RWCriticalSection &  )

private

Copy construction prohibited.

Member Function Documentation

void RWCriticalSection::acquire ( void  )

inline

Blocks until the critical section is available. Possible exceptions include RWCancellation and RWTHRInternalError.

In single-threaded builds, this method returns immediately. If the section is unavailable, a debug assertion will occur, or an RWTHRInternalError will be thrown.

void RWCriticalSection::acquireRead ( )

inline

Calls acquire(). Provided for compatibility with Read/Write locks. Possible exceptions include RWCancellation and RWTHRInternalError.

void RWCriticalSection::acquireWrite ( )

inline

Calls acquire(). Provided for compatibility with Read/Write locks. Possible exceptions include RWCancellation and RWTHRInternalError.

RWCriticalSectionRep * RWCriticalSection::getCriticalSectionRep ( ) const

inline

Provides access to the underlying platform-specific critical section implementation.

RWCriticalSection& RWCriticalSection::operator= ( const RWCriticalSection &  )

private

Assignment prohibited.

void RWCriticalSection::release ( void  )

inline

Releases the critical section. Possible exceptions include RWTHRInternalError.

Friends And Related Function Documentation

typedef RW_MUTEX_T RWCriticalSectionRep

related

Typedef for the internal critical section.

Condition:

This type is used for build configurations based on Win32 threads.