mirror of
https://github.com/mod-playerbots/azerothcore-wotlk.git
synced 2025-11-29 17:38:24 +08:00
140 lines
3.7 KiB
C++
140 lines
3.7 KiB
C++
// -*- C++ -*-
|
|
|
|
//==========================================================================
|
|
/**
|
|
* @file RW_Mutex.h
|
|
*
|
|
* Moved from Synch.h.
|
|
*
|
|
* @author Douglas C. Schmidt <schmidt@cs.wustl.edu>
|
|
*/
|
|
//==========================================================================
|
|
|
|
#ifndef ACE_RW_MUTEX_H
|
|
#define ACE_RW_MUTEX_H
|
|
|
|
#include /**/ "ace/pre.h"
|
|
|
|
#include /**/ "ace/ACE_export.h"
|
|
|
|
#if !defined (ACE_LACKS_PRAGMA_ONCE)
|
|
# pragma once
|
|
#endif /* ACE_LACKS_PRAGMA_ONCE */
|
|
|
|
// ACE platform supports some form of threading.
|
|
#if defined (ACE_HAS_THREADS)
|
|
|
|
#include "ace/OS_NS_Thread.h"
|
|
|
|
ACE_BEGIN_VERSIONED_NAMESPACE_DECL
|
|
|
|
/**
|
|
* @class ACE_RW_Mutex
|
|
*
|
|
* @brief Wrapper for readers/writer locks.
|
|
*
|
|
* These are most useful for applications that have many more
|
|
* parallel readers than writers...
|
|
*/
|
|
class ACE_Export ACE_RW_Mutex
|
|
{
|
|
public:
|
|
/// Initialize a readers/writer lock.
|
|
ACE_RW_Mutex (int type = USYNC_THREAD,
|
|
const ACE_TCHAR *name = 0,
|
|
void *arg = 0);
|
|
|
|
/// Implicitly destroy a readers/writer lock
|
|
~ACE_RW_Mutex (void);
|
|
|
|
/**
|
|
* Explicitly destroy a readers/writer lock. Note that only one
|
|
* thread should call this method since it doesn't protect against
|
|
* race conditions.
|
|
*/
|
|
int remove (void);
|
|
|
|
/// Acquire a read lock, but block if a writer hold the lock.
|
|
int acquire_read (void);
|
|
|
|
/// Acquire a write lock, but block if any readers or a
|
|
/// writer hold the lock.
|
|
int acquire_write (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, @c errno is set to @c EBUSY.
|
|
*/
|
|
int tryacquire_read (void);
|
|
|
|
/// Conditionally acquire a write lock (i.e., won't block).
|
|
int tryacquire_write (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
|
|
* @c errno to @c 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).
|
|
*/
|
|
int tryacquire_write_upgrade (void);
|
|
|
|
/**
|
|
* Note, for interface uniformity with other synchronization
|
|
* wrappers we include the <acquire> method. This is implemented as
|
|
* a write-lock to safe...
|
|
*/
|
|
int acquire (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, @c errno is
|
|
* set to @c EBUSY.
|
|
*/
|
|
int tryacquire (void);
|
|
|
|
/// Unlock a readers/writer lock.
|
|
int release (void);
|
|
|
|
/// Return the underlying lock.
|
|
const ACE_rwlock_t &lock (void) const;
|
|
|
|
/// Dump the state of an object.
|
|
void dump (void) const;
|
|
|
|
/// Declare the dynamic allocation hooks.
|
|
ACE_ALLOC_HOOK_DECLARE;
|
|
|
|
protected:
|
|
/// Readers/writer lock.
|
|
ACE_rwlock_t lock_;
|
|
|
|
/// 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...
|
|
bool removed_;
|
|
|
|
private:
|
|
// = Prevent assignment and initialization.
|
|
void operator= (const ACE_RW_Mutex &);
|
|
ACE_RW_Mutex (const ACE_RW_Mutex &);
|
|
};
|
|
|
|
ACE_END_VERSIONED_NAMESPACE_DECL
|
|
|
|
#if defined (__ACE_INLINE__)
|
|
#include "ace/RW_Mutex.inl"
|
|
#endif /* __ACE_INLINE__ */
|
|
|
|
#endif /* ACE_HAS_THREADS */
|
|
|
|
#include /**/ "ace/post.h"
|
|
|
|
#endif /* ACE_RW_MUTEX_H */
|