Boost C++ Libraries

boost/thread/pthread/mutex.hpp

#ifndef BOOST_THREAD_PTHREAD_MUTEX_HPP
#define BOOST_THREAD_PTHREAD_MUTEX_HPP
// (C) Copyright 2007-8 Anthony Williams
// (C) Copyright 2011-2012 Vicente J. Botet Escriba
// 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)

#include <pthread.h>
#include <boost/throw_exception.hpp>
#include <boost/thread/exceptions.hpp>
#include <boost/thread/locks.hpp>
#include <boost/thread/thread_time.hpp>
#include <boost/thread/xtime.hpp>
#include <boost/assert.hpp>
#include <errno.h>
#include <boost/thread/pthread/timespec.hpp>
#include <boost/thread/pthread/pthread_mutex_scoped_lock.hpp>
#ifdef BOOST_THREAD_USES_CHRONO
#include <boost/chrono/system_clocks.hpp>
#include <boost/chrono/ceil.hpp>
#endif
#include <boost/thread/detail/delete.hpp>

#ifdef _POSIX_TIMEOUTS
#if _POSIX_TIMEOUTS >= 0 && _POSIX_C_SOURCE>=200112L
#define BOOST_PTHREAD_HAS_TIMEDLOCK
#endif
#endif

#include <boost/config/abi_prefix.hpp>

namespace boost
{
    class mutex
    {
    private:
        pthread_mutex_t m;
    public:
        BOOST_THREAD_NO_COPYABLE(mutex)

        mutex()
        {
            int const res=pthread_mutex_init(&m,NULL);
            if(res)
            {
                boost::throw_exception(thread_resource_error(res, "boost:: mutex constructor failed in pthread_mutex_init"));
            }
        }
        ~mutex()
        {
            int ret;
            do
            {
                ret = pthread_mutex_destroy(&m);
            } while (ret == EINTR);
        }

        void lock()
        {
            int res;
            do
            {
                res = pthread_mutex_lock(&m);
            } while (res == EINTR);
            if (res)
            {
                boost::throw_exception(lock_error(res,"boost: mutex lock failed in pthread_mutex_lock"));
            }
        }

        void unlock()
        {
            int ret;
            do
            {
                ret = pthread_mutex_unlock(&m);
            } while (ret == EINTR);
            BOOST_VERIFY(!ret);
        }

        bool try_lock()
        {
            int res;
            do
            {
                res = pthread_mutex_trylock(&m);
            } while (res == EINTR);
            if(res && (res!=EBUSY))
            {
                // The following throw_exception has been replaced by an assertion and just return false,
                // as this is an internal error and the user can do nothing with the exception.
                //boost::throw_exception(lock_error(res,"boost: mutex try_lock failed in pthread_mutex_trylock"));
                BOOST_ASSERT_MSG(false ,"boost: mutex try_lock failed in pthread_mutex_trylock");
                return false;
            }

            return !res;
        }

#define BOOST_THREAD_DEFINES_MUTEX_NATIVE_HANDLE
        typedef pthread_mutex_t* native_handle_type;
        native_handle_type native_handle()
        {
            return &m;
        }

        typedef unique_lock<mutex> scoped_lock;
        typedef detail::try_lock_wrapper<mutex> scoped_try_lock;
    };

    typedef mutex try_mutex;

    class timed_mutex
    {
    private:
        pthread_mutex_t m;
#ifndef BOOST_PTHREAD_HAS_TIMEDLOCK
        pthread_cond_t cond;
        bool is_locked;
#endif
    public:
        BOOST_THREAD_NO_COPYABLE(timed_mutex)
        timed_mutex()
        {
            int const res=pthread_mutex_init(&m,NULL);
            if(res)
            {
                boost::throw_exception(thread_resource_error(res, "boost:: timed_mutex constructor failed in pthread_mutex_init"));
            }
#ifndef BOOST_PTHREAD_HAS_TIMEDLOCK
            int const res2=pthread_cond_init(&cond,NULL);
            if(res2)
            {
                BOOST_VERIFY(!pthread_mutex_destroy(&m));
                boost::throw_exception(thread_resource_error(res2, "boost:: timed_mutex constructor failed in pthread_cond_init"));
            }
            is_locked=false;
#endif
        }
        ~timed_mutex()
        {
            BOOST_VERIFY(!pthread_mutex_destroy(&m));
#ifndef BOOST_PTHREAD_HAS_TIMEDLOCK
            BOOST_VERIFY(!pthread_cond_destroy(&cond));
#endif
        }

        template<typename TimeDuration>
        bool timed_lock(TimeDuration const & relative_time)
        {
            return timed_lock(get_system_time()+relative_time);
        }
        bool timed_lock(boost::xtime const & absolute_time)
        {
            return timed_lock(system_time(absolute_time));
        }

#ifdef BOOST_PTHREAD_HAS_TIMEDLOCK
        void lock()
        {
            BOOST_VERIFY(!pthread_mutex_lock(&m));
        }

        void unlock()
        {
            BOOST_VERIFY(!pthread_mutex_unlock(&m));
        }

        bool try_lock()
        {
            int const res=pthread_mutex_trylock(&m);
            BOOST_ASSERT(!res || res==EBUSY);
            return !res;
        }


    private:
        bool do_try_lock_until(struct timespec const &timeout)
        {
          int const res=pthread_mutex_timedlock(&m,&timeout);
          BOOST_ASSERT(!res || res==ETIMEDOUT);
          return !res;
        }
    public:

#else
        void lock()
        {
            boost::pthread::pthread_mutex_scoped_lock const local_lock(&m);
            while(is_locked)
            {
                BOOST_VERIFY(!pthread_cond_wait(&cond,&m));
            }
            is_locked=true;
        }

        void unlock()
        {
            boost::pthread::pthread_mutex_scoped_lock const local_lock(&m);
            is_locked=false;
            BOOST_VERIFY(!pthread_cond_signal(&cond));
        }

        bool try_lock()
        {
            boost::pthread::pthread_mutex_scoped_lock const local_lock(&m);
            if(is_locked)
            {
                return false;
            }
            is_locked=true;
            return true;
        }

    private:
        bool do_try_lock_until(struct timespec const &timeout)
        {
            boost::pthread::pthread_mutex_scoped_lock const local_lock(&m);
            while(is_locked)
            {
                int const cond_res=pthread_cond_timedwait(&cond,&m,&timeout);
                if(cond_res==ETIMEDOUT)
                {
                    return false;
                }
                BOOST_ASSERT(!cond_res);
            }
            is_locked=true;
            return true;
        }
    public:
#endif

        bool timed_lock(system_time const & abs_time)
        {
            struct timespec const ts=detail::get_timespec(abs_time);
            return do_try_lock_until(ts);
        }

#ifdef BOOST_THREAD_USES_CHRONO
        template <class Rep, class Period>
        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time)
        {
          return try_lock_until(chrono::steady_clock::now() + rel_time);
        }
        template <class Clock, class Duration>
        bool try_lock_until(const chrono::time_point<Clock, Duration>& t)
        {
          using namespace chrono;
          system_clock::time_point     s_now = system_clock::now();
          typename Clock::time_point  c_now = Clock::now();
          return try_lock_until(s_now + ceil<nanoseconds>(t - c_now));
        }
        template <class Duration>
        bool try_lock_until(const chrono::time_point<chrono::system_clock, Duration>& t)
        {
          using namespace chrono;
          typedef time_point<system_clock, nanoseconds> nano_sys_tmpt;
          return try_lock_until(nano_sys_tmpt(ceil<nanoseconds>(t.time_since_epoch())));
        }
        bool try_lock_until(const chrono::time_point<chrono::system_clock, chrono::nanoseconds>& tp)
        {
          using namespace chrono;
          nanoseconds d = tp.time_since_epoch();
          timespec ts;
          seconds s = duration_cast<seconds>(d);
          ts.tv_sec = static_cast<long>(s.count());
          ts.tv_nsec = static_cast<long>((d - s).count());
          return do_try_lock_until(ts);
        }
#endif

#define BOOST_THREAD_DEFINES_TIMED_MUTEX_NATIVE_HANDLE
        typedef pthread_mutex_t* native_handle_type;
        native_handle_type native_handle()
        {
            return &m;
        }

        typedef unique_lock<timed_mutex> scoped_timed_lock;
        typedef detail::try_lock_wrapper<timed_mutex> scoped_try_lock;
        typedef scoped_timed_lock scoped_lock;
    };

}

#include <boost/config/abi_suffix.hpp>


#endif