comparison DEPENDENCIES/generic/include/boost/thread/pthread/shared_mutex.hpp @ 16:2665513ce2d3

Add boost headers

+#ifndef BOOST_THREAD_PTHREAD_SHARED_MUTEX_HPP
+#define BOOST_THREAD_PTHREAD_SHARED_MUTEX_HPP
+
+//  (C) Copyright 2006-8 Anthony Williams
+//  (C) Copyright 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 <boost/assert.hpp>
+#include <boost/static_assert.hpp>
+#include <boost/thread/mutex.hpp>
+#include <boost/thread/condition_variable.hpp>
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+#include <boost/thread/detail/thread_interruption.hpp>
+#endif
+#ifdef BOOST_THREAD_USES_CHRONO
+#include <boost/chrono/system_clocks.hpp>
+#include <boost/chrono/ceil.hpp>
+#endif
+#include <boost/thread/detail/delete.hpp>
+#include <boost/assert.hpp>
+
+#include <boost/config/abi_prefix.hpp>
+
+namespace boost
+{
+    class shared_mutex
+    {
+    private:
+        class state_data
+        {
+        public:
+            state_data () :
+              shared_count(0),
+              exclusive(false),
+              upgrade(false),
+              exclusive_waiting_blocked(false)
+            {}
+
+            void assert_free() const
+            {
+                BOOST_ASSERT( ! exclusive );
+                BOOST_ASSERT( ! upgrade );
+                BOOST_ASSERT( shared_count==0 );
+            }
+
+            void assert_locked() const
+            {
+                BOOST_ASSERT( exclusive );
+                BOOST_ASSERT( shared_count==0 );
+                BOOST_ASSERT( ! upgrade );
+            }
+
+            void assert_lock_shared () const
+            {
+                BOOST_ASSERT( ! exclusive );
+                BOOST_ASSERT( shared_count>0 );
+                //BOOST_ASSERT( (! upgrade) || (shared_count>1));
+                // if upgraded there are at least 2 threads sharing the mutex,
+                // except when unlock_upgrade_and_lock has decreased the number of readers but has not taken yet exclusive ownership.
+            }
+
+            void assert_lock_upgraded () const
+            {
+                BOOST_ASSERT( ! exclusive );
+                BOOST_ASSERT(  upgrade );
+                BOOST_ASSERT(  shared_count>0 );
+            }
+
+            void assert_lock_not_upgraded () const
+            {
+                BOOST_ASSERT(  ! upgrade );
+            }
+
+            bool can_lock () const
+            {
+                return ! (shared_count || exclusive);
+            }
+
+            void exclusive_blocked (bool blocked)
+            {
+                exclusive_waiting_blocked = blocked;
+            }
+
+            void lock ()
+            {
+                exclusive = true;
+            }
+
+            void unlock ()
+            {
+                exclusive = false;
+                exclusive_waiting_blocked = false;
+            }
+
+            bool can_lock_shared () const
+            {
+                return ! (exclusive || exclusive_waiting_blocked);
+            }
+
+            bool more_shared () const
+            {
+                return shared_count > 0 ;
+            }
+            unsigned get_shared_count () const
+            {
+                return shared_count ;
+            }
+            unsigned  lock_shared ()
+            {
+                return ++shared_count;
+            }
+
+
+            void unlock_shared ()
+            {
+                --shared_count;
+            }
+
+            bool unlock_shared_downgrades()
+            {
+                  if (upgrade) {
+                      upgrade=false;
+                      exclusive=true;
+                      return true;
+                  } else {
+                      exclusive_waiting_blocked=false;
+                      return false;
+                  }
+            }
+
+            void lock_upgrade ()
+            {
+                ++shared_count;
+                upgrade=true;
+            }
+            bool can_lock_upgrade () const
+            {
+                return ! (exclusive || exclusive_waiting_blocked || upgrade);
+            }
+
+            void unlock_upgrade ()
+            {
+                upgrade=false;
+                --shared_count;
+            }
+
+        //private:
+            unsigned shared_count;
+            bool exclusive;
+            bool upgrade;
+            bool exclusive_waiting_blocked;
+        };
+
+
+
+        state_data state;
+        boost::mutex state_change;
+        boost::condition_variable shared_cond;
+        boost::condition_variable exclusive_cond;
+        boost::condition_variable upgrade_cond;
+
+        void release_waiters()
+        {
+            exclusive_cond.notify_one();
+            shared_cond.notify_all();
+        }
+
+    public:
+
+        BOOST_THREAD_NO_COPYABLE(shared_mutex)
+
+        shared_mutex()
+        {
+        }
+
+        ~shared_mutex()
+        {
+        }
+
+        void lock_shared()
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+            boost::this_thread::disable_interruption do_not_disturb;
+#endif
+            boost::unique_lock<boost::mutex> lk(state_change);
+            while(!state.can_lock_shared())
+            {
+                shared_cond.wait(lk);
+            }
+            state.lock_shared();
+        }
+
+        bool try_lock_shared()
+        {
+            boost::unique_lock<boost::mutex> lk(state_change);
+
+            if(!state.can_lock_shared())
+            {
+                return false;
+            }
+            state.lock_shared();
+            return true;
+        }
+
+#if defined BOOST_THREAD_USES_DATETIME
+        bool timed_lock_shared(system_time const& timeout)
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+            boost::this_thread::disable_interruption do_not_disturb;
+#endif
+            boost::unique_lock<boost::mutex> lk(state_change);
+
+            while(!state.can_lock_shared())
+            {
+                if(!shared_cond.timed_wait(lk,timeout))
+                {
+                    return false;
+                }
+            }
+            state.lock_shared();
+            return true;
+        }
+
+        template<typename TimeDuration>
+        bool timed_lock_shared(TimeDuration const & relative_time)
+        {
+            return timed_lock_shared(get_system_time()+relative_time);
+        }
+#endif
+#ifdef BOOST_THREAD_USES_CHRONO
+        template <class Rep, class Period>
+        bool try_lock_shared_for(const chrono::duration<Rep, Period>& rel_time)
+        {
+          return try_lock_shared_until(chrono::steady_clock::now() + rel_time);
+        }
+        template <class Clock, class Duration>
+        bool try_lock_shared_until(const chrono::time_point<Clock, Duration>& abs_time)
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+          boost::this_thread::disable_interruption do_not_disturb;
+#endif
+          boost::unique_lock<boost::mutex> lk(state_change);
+
+          while(!state.can_lock_shared())
+          //while(state.exclusive || state.exclusive_waiting_blocked)
+          {
+              if(cv_status::timeout==shared_cond.wait_until(lk,abs_time))
+              {
+                  return false;
+              }
+          }
+          state.lock_shared();
+          return true;
+        }
+#endif
+        void unlock_shared()
+        {
+            boost::unique_lock<boost::mutex> lk(state_change);
+            state.assert_lock_shared();
+            state.unlock_shared();
+            if (! state.more_shared())
+            {
+                if (state.upgrade)
+                {
+                    // As there is a thread doing a unlock_upgrade_and_lock that is waiting for ! state.more_shared()
+                    // avoid other threads to lock, lock_upgrade or lock_shared, so only this thread is notified.
+                    state.upgrade=false;
+                    state.exclusive=true;
+                    lk.unlock();
+                    upgrade_cond.notify_one();
+                }
+                else
+                {
+                    state.exclusive_waiting_blocked=false;
+                    lk.unlock();
+                }
+                release_waiters();
+            }
+        }
+
+        void lock()
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+            boost::this_thread::disable_interruption do_not_disturb;
+#endif
+            boost::unique_lock<boost::mutex> lk(state_change);
+
+            while (state.shared_count || state.exclusive)
+            {
+                state.exclusive_waiting_blocked=true;
+                exclusive_cond.wait(lk);
+            }
+            state.exclusive=true;
+        }
+
+#if defined BOOST_THREAD_USES_DATETIME
+        bool timed_lock(system_time const& timeout)
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+            boost::this_thread::disable_interruption do_not_disturb;
+#endif
+            boost::unique_lock<boost::mutex> lk(state_change);
+
+            while(state.shared_count || state.exclusive)
+            {
+                state.exclusive_waiting_blocked=true;
+                if(!exclusive_cond.timed_wait(lk,timeout))
+                {
+                    if(state.shared_count || state.exclusive)
+                    {
+                        state.exclusive_waiting_blocked=false;
+                        release_waiters();
+                        return false;
+                    }
+                    break;
+                }
+            }
+            state.exclusive=true;
+            return true;
+        }
+
+        template<typename TimeDuration>
+        bool timed_lock(TimeDuration const & relative_time)
+        {
+            return timed_lock(get_system_time()+relative_time);
+        }
+#endif
+#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>& abs_time)
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+          boost::this_thread::disable_interruption do_not_disturb;
+#endif
+          boost::unique_lock<boost::mutex> lk(state_change);
+
+          while(state.shared_count || state.exclusive)
+          {
+              state.exclusive_waiting_blocked=true;
+              if(cv_status::timeout == exclusive_cond.wait_until(lk,abs_time))
+              {
+                  if(state.shared_count || state.exclusive)
+                  {
+                      state.exclusive_waiting_blocked=false;
+                      release_waiters();
+                      return false;
+                  }
+                  break;
+              }
+          }
+          state.exclusive=true;
+          return true;
+        }
+#endif
+
+        bool try_lock()
+        {
+            boost::unique_lock<boost::mutex> lk(state_change);
+
+            if(state.shared_count || state.exclusive)
+            {
+                return false;
+            }
+            else
+            {
+                state.exclusive=true;
+                return true;
+            }
+
+        }
+
+        void unlock()
+        {
+            boost::unique_lock<boost::mutex> lk(state_change);
+            state.assert_locked();
+            state.exclusive=false;
+            state.exclusive_waiting_blocked=false;
+            state.assert_free();
+            release_waiters();
+        }
+
+        void lock_upgrade()
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+            boost::this_thread::disable_interruption do_not_disturb;
+#endif
+            boost::unique_lock<boost::mutex> lk(state_change);
+            while(state.exclusive || state.exclusive_waiting_blocked || state.upgrade)
+            {
+                shared_cond.wait(lk);
+            }
+            state.lock_shared();
+            state.upgrade=true;
+        }
+
+#if defined BOOST_THREAD_USES_DATETIME
+        bool timed_lock_upgrade(system_time const& timeout)
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+            boost::this_thread::disable_interruption do_not_disturb;
+#endif
+            boost::unique_lock<boost::mutex> lk(state_change);
+            while(state.exclusive || state.exclusive_waiting_blocked || state.upgrade)
+            {
+                if(!shared_cond.timed_wait(lk,timeout))
+                {
+                    if(state.exclusive || state.exclusive_waiting_blocked || state.upgrade)
+                    {
+                        return false;
+                    }
+                    break;
+                }
+            }
+            state.lock_shared();
+            state.upgrade=true;
+            return true;
+        }
+
+        template<typename TimeDuration>
+        bool timed_lock_upgrade(TimeDuration const & relative_time)
+        {
+            return timed_lock_upgrade(get_system_time()+relative_time);
+        }
+#endif
+#ifdef BOOST_THREAD_USES_CHRONO
+        template <class Rep, class Period>
+        bool try_lock_upgrade_for(const chrono::duration<Rep, Period>& rel_time)
+        {
+          return try_lock_upgrade_until(chrono::steady_clock::now() + rel_time);
+        }
+        template <class Clock, class Duration>
+        bool try_lock_upgrade_until(const chrono::time_point<Clock, Duration>& abs_time)
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+          boost::this_thread::disable_interruption do_not_disturb;
+#endif
+          boost::unique_lock<boost::mutex> lk(state_change);
+          while(state.exclusive || state.exclusive_waiting_blocked || state.upgrade)
+          {
+              if(cv_status::timeout == shared_cond.wait_until(lk,abs_time))
+              {
+                  if(state.exclusive || state.exclusive_waiting_blocked || state.upgrade)
+                  {
+                      return false;
+                  }
+                  break;
+              }
+          }
+          state.lock_shared();
+          state.upgrade=true;
+          return true;
+        }
+#endif
+        bool try_lock_upgrade()
+        {
+            boost::unique_lock<boost::mutex> lk(state_change);
+            if(state.exclusive || state.exclusive_waiting_blocked || state.upgrade)
+            {
+                return false;
+            }
+            else
+            {
+                state.lock_shared();
+                state.upgrade=true;
+                state.assert_lock_upgraded();
+                return true;
+            }
+        }
+
+        void unlock_upgrade()
+        {
+            boost::unique_lock<boost::mutex> lk(state_change);
+            //state.upgrade=false;
+            state.unlock_upgrade();
+            if(! state.more_shared() )
+            {
+                state.exclusive_waiting_blocked=false;
+                release_waiters();
+            } else {
+                shared_cond.notify_all();
+            }
+        }
+
+        // Upgrade <-> Exclusive
+        void unlock_upgrade_and_lock()
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+            boost::this_thread::disable_interruption do_not_disturb;
+#endif
+            boost::unique_lock<boost::mutex> lk(state_change);
+            state.assert_lock_upgraded();
+            state.unlock_shared();
+            while (state.more_shared())
+            {
+                upgrade_cond.wait(lk);
+            }
+            state.upgrade=false;
+            state.exclusive=true;
+            state.assert_locked();
+        }
+
+        void unlock_and_lock_upgrade()
+        {
+            boost::unique_lock<boost::mutex> lk(state_change);
+            state.assert_locked();
+            state.exclusive=false;
+            state.upgrade=true;
+            state.lock_shared();
+            state.exclusive_waiting_blocked=false;
+            state.assert_lock_upgraded();
+            release_waiters();
+        }
+
+        bool try_unlock_upgrade_and_lock()
+        {
+          boost::unique_lock<boost::mutex> lk(state_change);
+          state.assert_lock_upgraded();
+          if(    !state.exclusive
+              && !state.exclusive_waiting_blocked
+              && state.upgrade
+              && state.shared_count==1)
+          {
+            state.shared_count=0;
+            state.exclusive=true;
+            state.upgrade=false;
+            state.assert_locked();
+            return true;
+          }
+          return false;
+        }
+#ifdef BOOST_THREAD_USES_CHRONO
+        template <class Rep, class Period>
+        bool
+        try_unlock_upgrade_and_lock_for(
+                                const chrono::duration<Rep, Period>& rel_time)
+        {
+          return try_unlock_upgrade_and_lock_until(
+                                 chrono::steady_clock::now() + rel_time);
+        }
+        template <class Clock, class Duration>
+        bool
+        try_unlock_upgrade_and_lock_until(
+                          const chrono::time_point<Clock, Duration>& abs_time)
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+          boost::this_thread::disable_interruption do_not_disturb;
+#endif
+          boost::unique_lock<boost::mutex> lk(state_change);
+          state.assert_lock_upgraded();
+          if (state.shared_count != 1)
+          {
+              for (;;)
+              {
+                cv_status status = shared_cond.wait_until(lk,abs_time);
+                if (state.shared_count == 1)
+                  break;
+                if(status == cv_status::timeout)
+                  return false;
+              }
+          }
+          state.upgrade=false;
+          state.exclusive=true;
+          state.exclusive_waiting_blocked=false;
+          state.shared_count=0;
+          return true;
+        }
+#endif
+
+        // Shared <-> Exclusive
+        void unlock_and_lock_shared()
+        {
+            boost::unique_lock<boost::mutex> lk(state_change);
+            state.assert_locked();
+            state.exclusive=false;
+            state.lock_shared();
+            state.exclusive_waiting_blocked=false;
+            release_waiters();
+        }
+
+#ifdef BOOST_THREAD_PROVIDES_SHARED_MUTEX_UPWARDS_CONVERSIONS
+        bool try_unlock_shared_and_lock()
+        {
+          boost::unique_lock<boost::mutex> lk(state_change);
+          state.assert_lock_shared();
+          if(    !state.exclusive
+              && !state.exclusive_waiting_blocked
+              && !state.upgrade
+              && state.shared_count==1)
+          {
+            state.shared_count=0;
+            state.exclusive=true;
+            return true;
+          }
+          return false;
+        }
+#ifdef BOOST_THREAD_USES_CHRONO
+        template <class Rep, class Period>
+            bool
+            try_unlock_shared_and_lock_for(
+                                const chrono::duration<Rep, Period>& rel_time)
+        {
+          return try_unlock_shared_and_lock_until(
+                                 chrono::steady_clock::now() + rel_time);
+        }
+        template <class Clock, class Duration>
+            bool
+            try_unlock_shared_and_lock_until(
+                          const chrono::time_point<Clock, Duration>& abs_time)
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+          boost::this_thread::disable_interruption do_not_disturb;
+#endif
+          boost::unique_lock<boost::mutex> lk(state_change);
+          state.assert_lock_shared();
+          if (state.shared_count != 1)
+          {
+              for (;;)
+              {
+                cv_status status = shared_cond.wait_until(lk,abs_time);
+                if (state.shared_count == 1)
+                  break;
+                if(status == cv_status::timeout)
+                  return false;
+              }
+          }
+          state.upgrade=false;
+          state.exclusive=true;
+          state.exclusive_waiting_blocked=false;
+          state.shared_count=0;
+          return true;
+        }
+#endif
+#endif
+
+        // Shared <-> Upgrade
+        void unlock_upgrade_and_lock_shared()
+        {
+            boost::unique_lock<boost::mutex> lk(state_change);
+            state.assert_lock_upgraded();
+            state.upgrade=false;
+            state.exclusive_waiting_blocked=false;
+            release_waiters();
+        }
+
+#ifdef BOOST_THREAD_PROVIDES_SHARED_MUTEX_UPWARDS_CONVERSIONS
+        bool try_unlock_shared_and_lock_upgrade()
+        {
+          boost::unique_lock<boost::mutex> lk(state_change);
+          state.assert_lock_shared();
+          if(    !state.exclusive
+              && !state.exclusive_waiting_blocked
+              && !state.upgrade
+              )
+          {
+            state.upgrade=true;
+            return true;
+          }
+          return false;
+        }
+#ifdef BOOST_THREAD_USES_CHRONO
+        template <class Rep, class Period>
+            bool
+            try_unlock_shared_and_lock_upgrade_for(
+                                const chrono::duration<Rep, Period>& rel_time)
+        {
+          return try_unlock_shared_and_lock_upgrade_until(
+                                 chrono::steady_clock::now() + rel_time);
+        }
+        template <class Clock, class Duration>
+            bool
+            try_unlock_shared_and_lock_upgrade_until(
+                          const chrono::time_point<Clock, Duration>& abs_time)
+        {
+#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
+          boost::this_thread::disable_interruption do_not_disturb;
+#endif
+          boost::unique_lock<boost::mutex> lk(state_change);
+          state.assert_lock_shared();
+          if(    state.exclusive
+              || state.exclusive_waiting_blocked
+              || state.upgrade
+              )
+          {
+              for (;;)
+              {
+                cv_status status = exclusive_cond.wait_until(lk,abs_time);
+                if(    ! state.exclusive
+                    && ! state.exclusive_waiting_blocked
+                    && ! state.upgrade
+                    )
+                  break;
+                if(status == cv_status::timeout)
+                  return false;
+              }
+          }
+          state.upgrade=true;
+          return true;
+        }
+#endif
+#endif
+    };
+
+    typedef shared_mutex upgrade_mutex;
+}
+
+#include <boost/config/abi_suffix.hpp>
+
+#endif