topical media & game development
lib-of-vs-libs-Poco-include-Poco-RWLock.h / h
//
// RWLock.h
//
//
//
// Library: Foundation
// Package: Threading
// Module: RWLock
//
// Definition of the RWLock class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
ifndef Foundation_RWLock_INCLUDED
define Foundation_RWLock_INCLUDED
include "Poco/Foundation.h"
include "Poco/Exception.h"
if defined(POCO_OS_FAMILY_WINDOWS)
include "Poco/RWLock_WIN32.h"
else
include "Poco/RWLock_POSIX.h"
endif
namespace Poco {
class ScopedRWLock;
class Foundation_API RWLock: private RWLockImpl
A reader writer lock allows multiple concurrent
readers or one exclusive writer.
{
public:
typedef ScopedRWLock ScopedLock;
RWLock();
Creates the Reader/Writer lock.
~RWLock();
Destroys the Reader/Writer lock.
void readLock();
Acquires a read lock. If another thread currently holds a write lock,
waits until the write lock is released.
bool tryReadLock();
Tries to acquire a read lock. Immediately returns true if successful, or
false if another thread currently holds a write lock.
void writeLock();
Acquires a write lock. If one or more other threads currently hold
locks, waits until all locks are released. The results are undefined
if the same thread already holds a read or write lock
bool tryWriteLock();
Tries to acquire a write lock. Immediately returns true if successful,
or false if one or more other threads currently hold
locks. The result is undefined if the same thread already
holds a read or write lock.
void unlock();
Releases the read or write lock.
private:
RWLock(const RWLock&);
RWLock& operator = (const RWLock&);
};
class Foundation_API ScopedRWLock
A variant of ScopedLock for reader/writer locks.
{
public:
ScopedRWLock(RWLock& rwl, bool write = false);
~ScopedRWLock();
private:
RWLock& _rwl;
ScopedRWLock();
ScopedRWLock(const ScopedRWLock&);
ScopedRWLock& operator = (const ScopedRWLock&);
};
//
// inlines
//
inline void RWLock::readLock()
{
readLockImpl();
}
inline bool RWLock::tryReadLock()
{
return tryReadLockImpl();
}
inline void RWLock::writeLock()
{
writeLockImpl();
}
inline bool RWLock::tryWriteLock()
{
return tryWriteLockImpl();
}
inline void RWLock::unlock()
{
unlockImpl();
}
inline ScopedRWLock::ScopedRWLock(RWLock& rwl, bool write): _rwl(rwl)
{
if (write)
_rwl.writeLock();
else
_rwl.readLock();
}
inline ScopedRWLock::~ScopedRWLock()
{
_rwl.unlock();
}
} // namespace Poco
endif // Foundation_RWLock_INCLUDED
(C) Æliens
04/09/2009
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