ClickHouse/base/poco/Foundation/include/Poco/NamedMutex.h
Robert Schulze b79ead9c84
Move poco to base/poco/ (#46075)
* Replicate poco into base/poco/

* De-register poco submodule

* Build poco from ClickHouse

* Exclude poco from stylecheck

* Exclude poco from whitespace check

* Exclude poco from typo check

* Remove x bit from sources/headers (the style check complained)

* Exclude poco from duplicate include check

* Fix fasttest

* Remove contrib/poco-cmake/*

* Simplify poco build descriptions

* Remove poco stuff not used by ClickHouse

* Glob poco sources

* Exclude poco from clang-tidy
2023-02-08 12:04:11 +01:00

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2.4 KiB
C++

//
// NamedMutex.h
//
// Library: Foundation
// Package: Processes
// Module: NamedMutex
//
// Definition of the NamedMutex class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_NamedMutex_INCLUDED
#define Foundation_NamedMutex_INCLUDED
#include "Poco/Foundation.h"
#include "Poco/ScopedLock.h"
#if defined(POCO_OS_FAMILY_WINDOWS) && defined(POCO_WIN32_UTF8)
#include "Poco/NamedMutex_WIN32U.h"
#elif defined(POCO_OS_FAMILY_WINDOWS)
#include "Poco/NamedMutex_WIN32.h"
#elif POCO_OS == POCO_OS_ANDROID
#include "Poco/NamedMutex_Android.h"
#elif defined(POCO_OS_FAMILY_UNIX)
#include "Poco/NamedMutex_UNIX.h"
#endif
namespace Poco {
class Foundation_API NamedMutex: private NamedMutexImpl
/// A NamedMutex (mutual exclusion) is a global synchronization
/// mechanism used to control access to a shared resource
/// in a concurrent (multi process) scenario.
/// Using the ScopedLock class is the preferred way to automatically
/// lock and unlock a mutex.
///
/// Unlike a Mutex or a FastMutex, which itself is the unit of synchronization,
/// a NamedMutex refers to a named operating system resource being the
/// unit of synchronization.
/// In other words, there can be multiple instances of NamedMutex referring
/// to the same actual synchronization object.
///
///
/// There should not be more than one instance of NamedMutex for
/// a given name in a process. Otherwise, the instances may
/// interfere with each other.
{
public:
typedef Poco::ScopedLock<NamedMutex> ScopedLock;
NamedMutex(const std::string& name);
/// creates the Mutex.
~NamedMutex();
/// destroys the Mutex.
void lock();
/// Locks the mutex. Blocks if the mutex
/// is held by another process or thread.
bool tryLock();
/// Tries to lock the mutex. Returns false immediately
/// if the mutex is already held by another process or thread.
/// Returns true if the mutex was successfully locked.
void unlock();
/// Unlocks the mutex so that it can be acquired by
/// other threads.
private:
NamedMutex();
NamedMutex(const NamedMutex&);
NamedMutex& operator = (const NamedMutex&);
};
//
// inlines
//
inline void NamedMutex::lock()
{
lockImpl();
}
inline bool NamedMutex::tryLock()
{
return tryLockImpl();
}
inline void NamedMutex::unlock()
{
unlockImpl();
}
} // namespace Poco
#endif // Foundation_NamedMutex_INCLUDED