[/
  (C) Copyright 2007-8 Anthony Williams.
  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).
]

[section:shared_mutex Class `shared_mutex`]

    #include <boost/thread/shared_mutex.hpp>

    class shared_mutex
    {
    public:
        shared_mutex();
        ~shared_mutex();

        void lock_shared();
        bool try_lock_shared();
        bool timed_lock_shared(system_time const& timeout);
        void unlock_shared();

        void lock();
        bool try_lock();
        bool timed_lock(system_time const& timeout);
        void unlock();

        void lock_upgrade();
        void unlock_upgrade();

        void unlock_upgrade_and_lock();
        void unlock_and_lock_upgrade();
        void unlock_and_lock_shared();
        void unlock_upgrade_and_lock_shared();
    };

The class `boost::shared_mutex` provides an implementation of a multiple-reader / single-writer mutex. It implements the
__upgrade_lockable_concept__.

Multiple concurrent calls to __lock_ref__, __try_lock_ref__, __timed_lock_ref__, __lock_shared_ref__, __try_lock_shared_ref__ and
__timed_lock_shared_ref__ shall be permitted.


[endsect]