ACE_RW_Mutex Class Reference

Wrapper for readers/writer locks. More...

#include <RW_Mutex.h>

Inheritance diagram for ACE_RW_Mutex:

List of all members.

Public Member Functions
	ACE_RW_Mutex (int type=USYNC_THREAD, const ACE_TCHAR *name=0, void *arg=0)
	Initialize a readers/writer lock.
	~ACE_RW_Mutex (void)
	Implicitly destroy a readers/writer lock.
int	remove (void)
int	acquire_read (void)
	Acquire a read lock, but block if a writer hold the lock.
int	acquire_write (void)
int	tryacquire_read (void)
int	tryacquire_write (void)
	Conditionally acquire a write lock (i.e., won't block).
int	tryacquire_write_upgrade (void)
int	acquire (void)
int	tryacquire (void)
int	release (void)
	Unlock a readers/writer lock.
const ACE_rwlock_t &	lock (void) const
	Return the underlying lock.
void	dump (void) const
	Dump the state of an object.
Public Attributes
	ACE_ALLOC_HOOK_DECLARE
	Declare the dynamic allocation hooks.
Protected Attributes
ACE_rwlock_t	lock_
	Readers/writer lock.
bool	removed_
Private Member Functions
void	operator= (const ACE_RW_Mutex &)
	ACE_RW_Mutex (const ACE_RW_Mutex &)

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Detailed Description

Wrapper for readers/writer locks.

These are most useful for applications that have many more parallel readers than writers...

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Constructor & Destructor Documentation

ACE_RW_Mutex::ACE_RW_Mutex	(	int	type = USYNC_THREAD,
		const ACE_TCHAR *	name = 0,
		void *	arg = 0
	)

Initialize a readers/writer lock.

ACE_RW_Mutex::~ACE_RW_Mutex

(

void

)

Implicitly destroy a readers/writer lock.

ACE_RW_Mutex::ACE_RW_Mutex

(

const ACE_RW_Mutex &

)

[private]

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Member Function Documentation

int ACE_RW_Mutex::acquire

(

void

)

[inline]

Note, for interface uniformity with other synchronization wrappers we include the <acquire> method. This is implemented as a write-lock to safe...

int ACE_RW_Mutex::acquire_read

(

void

)

[inline]

Acquire a read lock, but block if a writer hold the lock.

int ACE_RW_Mutex::acquire_write

(

void

)

[inline]

Acquire a write lock, but block if any readers or a writer hold the lock.

void ACE_RW_Mutex::dump

(

void

)

const

Dump the state of an object.

Reimplemented in ACE_RW_Thread_Mutex.

const ACE_rwlock_t & ACE_RW_Mutex::lock

(

void

)

const [inline]

Return the underlying lock.

void ACE_RW_Mutex::operator=

(

const ACE_RW_Mutex &

)

[private]

int ACE_RW_Mutex::release

(

void

)

[inline]

Unlock a readers/writer lock.

int ACE_RW_Mutex::remove

(

void

)

[inline]

Explicitly destroy a readers/writer lock. Note that only one thread should call this method since it doesn't protect against race conditions.

int ACE_RW_Mutex::tryacquire

(

void

)

[inline]

Note, for interface uniformity with other synchronization wrappers we include the tryacquire() method. This is implemented as a write-lock to be safe... Returns -1 on failure. If we "failed" because someone else already had the lock, errno is set to EBUSY.

int ACE_RW_Mutex::tryacquire_read

(

void

)

[inline]

Conditionally acquire a read lock (i.e., won't block). Returns -1 on failure. If we "failed" because someone else already had the lock, errno is set to EBUSY.

int ACE_RW_Mutex::tryacquire_write

(

void

)

[inline]

Conditionally acquire a write lock (i.e., won't block).

int ACE_RW_Mutex::tryacquire_write_upgrade

(

void

)

[inline]

Conditionally upgrade a read lock to a write lock. This only works if there are no other readers present, in which case the method returns 0. Otherwise, the method returns -1 and sets errno to EBUSY. Note that the caller of this method *must* already possess this lock as a read lock (but this condition is not checked by the current implementation).

Reimplemented in ACE_RW_Thread_Mutex.

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Member Data Documentation

ACE_RW_Mutex::ACE_ALLOC_HOOK_DECLARE

Declare the dynamic allocation hooks.

Reimplemented in ACE_RW_Thread_Mutex.

ACE_rwlock_t ACE_RW_Mutex::lock_ [protected]

Readers/writer lock.

bool ACE_RW_Mutex::removed_ [protected]

Keeps track of whether remove() has been called yet to avoid multiple remove() calls, e.g., explicitly and implicitly in the destructor. This flag isn't protected by a lock, so make sure that you don't have multiple threads simultaneously calling remove() on the same object, which is a bad idea anyway...

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

• RW_Mutex.h
• RW_Mutex.cpp
• RW_Mutex.inl