102 lines
1.8 KiB
C++
102 lines
1.8 KiB
C++
//
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// detail/scoped_lock.hpp
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// ~~~~~~~~~~~~~~~~~~~~~~
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//
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// Copyright (c) 2003-2023 Christopher M. Kohlhoff (chris at kohlhoff dot com)
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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#ifndef ASIO_DETAIL_SCOPED_LOCK_HPP
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#define ASIO_DETAIL_SCOPED_LOCK_HPP
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#if defined(_MSC_VER) && (_MSC_VER >= 1200)
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# pragma once
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#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
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#include "asio/detail/noncopyable.hpp"
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#include "asio/detail/push_options.hpp"
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namespace asio {
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namespace detail {
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// Helper class to lock and unlock a mutex automatically.
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template <typename Mutex>
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class scoped_lock
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: private noncopyable
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{
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public:
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// Tag type used to distinguish constructors.
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enum adopt_lock_t { adopt_lock };
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// Constructor adopts a lock that is already held.
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scoped_lock(Mutex& m, adopt_lock_t)
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: mutex_(m),
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locked_(true)
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{
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}
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// Constructor acquires the lock.
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explicit scoped_lock(Mutex& m)
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: mutex_(m)
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{
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mutex_.lock();
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locked_ = true;
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}
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// Destructor releases the lock.
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~scoped_lock()
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{
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if (locked_)
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mutex_.unlock();
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}
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// Explicitly acquire the lock.
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void lock()
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{
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if (!locked_)
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{
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mutex_.lock();
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locked_ = true;
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}
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}
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// Explicitly release the lock.
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void unlock()
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{
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if (locked_)
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{
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mutex_.unlock();
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locked_ = false;
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}
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}
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// Test whether the lock is held.
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bool locked() const
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{
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return locked_;
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}
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// Get the underlying mutex.
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Mutex& mutex()
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{
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return mutex_;
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}
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private:
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// The underlying mutex.
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Mutex& mutex_;
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// Whether the mutex is currently locked or unlocked.
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bool locked_;
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};
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} // namespace detail
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} // namespace asio
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#include "asio/detail/pop_options.hpp"
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#endif // ASIO_DETAIL_SCOPED_LOCK_HPP
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