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ACE_RW_Mutex Class Reference

Wrapper for readers/writer locks. More...

#include <RW_Mutex.h>

Inheritance diagram for ACE_RW_Mutex:

[legend]List of all members.

Public Methods
	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.
int	removed_
Private Methods
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

ACE_INLINE int ACE_RW_Mutex::acquire (  void    )

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

ACE_INLINE int ACE_RW_Mutex::acquire_read (  void    )

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

ACE_INLINE int ACE_RW_Mutex::acquire_write (  void    )

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.

ACE_INLINE const ACE_rwlock_t & ACE_RW_Mutex::lock (  void    )  const

Return the underlying lock.

void ACE_RW_Mutex::operator= (  const ACE_RW_Mutex &    )  [private]

ACE_INLINE int ACE_RW_Mutex::release (  void    )

Unlock a readers/writer lock.

ACE_INLINE int ACE_RW_Mutex::remove (  void    )

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

ACE_INLINE int ACE_RW_Mutex::tryacquire (  void    )

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>.

ACE_INLINE int ACE_RW_Mutex::tryacquire_read (  void    )

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>.

ACE_INLINE int ACE_RW_Mutex::tryacquire_write (  void    )

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

ACE_INLINE int ACE_RW_Mutex::tryacquire_write_upgrade (  void    )

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.

int 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:

• /export2/deucetmp/bala/release_try/ACE_wrappers/ace/RW_Mutex.h
• /export2/deucetmp/bala/release_try/ACE_wrappers/ace/RW_Mutex.cpp
• /export2/deucetmp/bala/release_try/ACE_wrappers/ace/RW_Mutex.inl

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