102 lines
1.8 KiB
C++
102 lines
1.8 KiB
C++
|
//
|
||
|
// detail/scoped_lock.hpp
|
||
|
// ~~~~~~~~~~~~~~~~~~~~~~
|
||
|
//
|
||
|
// Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com)
|
||
|
//
|
||
|
// Distributed under the Boost Software License, Version 1.0. (See accompanying
|
||
|
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
||
|
//
|
||
|
|
||
|
#ifndef ASIO_DETAIL_SCOPED_LOCK_HPP
|
||
|
#define ASIO_DETAIL_SCOPED_LOCK_HPP
|
||
|
|
||
|
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
|
||
|
# pragma once
|
||
|
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
|
||
|
|
||
|
#include "asio/detail/noncopyable.hpp"
|
||
|
|
||
|
#include "asio/detail/push_options.hpp"
|
||
|
|
||
|
namespace asio {
|
||
|
namespace detail {
|
||
|
|
||
|
// Helper class to lock and unlock a mutex automatically.
|
||
|
template <typename Mutex>
|
||
|
class scoped_lock
|
||
|
: private noncopyable
|
||
|
{
|
||
|
public:
|
||
|
// Tag type used to distinguish constructors.
|
||
|
enum adopt_lock_t { adopt_lock };
|
||
|
|
||
|
// Constructor adopts a lock that is already held.
|
||
|
scoped_lock(Mutex& m, adopt_lock_t)
|
||
|
: mutex_(m),
|
||
|
locked_(true)
|
||
|
{
|
||
|
}
|
||
|
|
||
|
// Constructor acquires the lock.
|
||
|
explicit scoped_lock(Mutex& m)
|
||
|
: mutex_(m)
|
||
|
{
|
||
|
mutex_.lock();
|
||
|
locked_ = true;
|
||
|
}
|
||
|
|
||
|
// Destructor releases the lock.
|
||
|
~scoped_lock()
|
||
|
{
|
||
|
if (locked_)
|
||
|
mutex_.unlock();
|
||
|
}
|
||
|
|
||
|
// Explicitly acquire the lock.
|
||
|
void lock()
|
||
|
{
|
||
|
if (!locked_)
|
||
|
{
|
||
|
mutex_.lock();
|
||
|
locked_ = true;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// Explicitly release the lock.
|
||
|
void unlock()
|
||
|
{
|
||
|
if (locked_)
|
||
|
{
|
||
|
mutex_.unlock();
|
||
|
locked_ = false;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// Test whether the lock is held.
|
||
|
bool locked() const
|
||
|
{
|
||
|
return locked_;
|
||
|
}
|
||
|
|
||
|
// Get the underlying mutex.
|
||
|
Mutex& mutex()
|
||
|
{
|
||
|
return mutex_;
|
||
|
}
|
||
|
|
||
|
private:
|
||
|
// The underlying mutex.
|
||
|
Mutex& mutex_;
|
||
|
|
||
|
// Whether the mutex is currently locked or unlocked.
|
||
|
bool locked_;
|
||
|
};
|
||
|
|
||
|
} // namespace detail
|
||
|
} // namespace asio
|
||
|
|
||
|
#include "asio/detail/pop_options.hpp"
|
||
|
|
||
|
#endif // ASIO_DETAIL_SCOPED_LOCK_HPP
|