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Diffstat (limited to 'lib/asio/detail/scoped_lock.hpp')
-rw-r--r-- | lib/asio/detail/scoped_lock.hpp | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/lib/asio/detail/scoped_lock.hpp b/lib/asio/detail/scoped_lock.hpp new file mode 100644 index 0000000..6cbce38 --- /dev/null +++ b/lib/asio/detail/scoped_lock.hpp @@ -0,0 +1,101 @@ +// +// detail/scoped_lock.hpp +// ~~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2018 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 |