Chris@16: #ifndef BOOST_THREAD_WIN32_SHARED_MUTEX_HPP
Chris@16: #define BOOST_THREAD_WIN32_SHARED_MUTEX_HPP
Chris@16: 
Chris@16: //  (C) Copyright 2006-8 Anthony Williams
Chris@16: //  (C) Copyright 2011-2012 Vicente J. Botet Escriba
Chris@16: //
Chris@16: //  Distributed under the Boost Software License, Version 1.0. (See
Chris@16: //  accompanying file LICENSE_1_0.txt or copy at
Chris@16: //  http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #include <boost/assert.hpp>
Chris@16: #include <boost/detail/interlocked.hpp>
Chris@16: #include <boost/thread/win32/thread_primitives.hpp>
Chris@16: #include <boost/static_assert.hpp>
Chris@16: #include <limits.h>
Chris@16: #include <boost/thread/thread_time.hpp>
Chris@16: #ifdef BOOST_THREAD_USES_CHRONO
Chris@16: #include <boost/chrono/system_clocks.hpp>
Chris@16: #include <boost/chrono/ceil.hpp>
Chris@16: #endif
Chris@16: #include <boost/thread/detail/delete.hpp>
Chris@16: 
Chris@16: #include <boost/config/abi_prefix.hpp>
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16:     class shared_mutex
Chris@16:     {
Chris@16:     private:
Chris@16:         struct state_data
Chris@16:         {
Chris@16:             unsigned shared_count:11,
Chris@16:                 shared_waiting:11,
Chris@16:                 exclusive:1,
Chris@16:                 upgrade:1,
Chris@16:                 exclusive_waiting:7,
Chris@16:                 exclusive_waiting_blocked:1;
Chris@16: 
Chris@16:             friend bool operator==(state_data const& lhs,state_data const& rhs)
Chris@16:             {
Chris@16:                 return *reinterpret_cast<unsigned const*>(&lhs)==*reinterpret_cast<unsigned const*>(&rhs);
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16: 
Chris@16:         template<typename T>
Chris@16:         T interlocked_compare_exchange(T* target,T new_value,T comparand)
Chris@16:         {
Chris@16:             BOOST_STATIC_ASSERT(sizeof(T)==sizeof(long));
Chris@16:             long const res=BOOST_INTERLOCKED_COMPARE_EXCHANGE(reinterpret_cast<long*>(target),
Chris@16:                                                               *reinterpret_cast<long*>(&new_value),
Chris@16:                                                               *reinterpret_cast<long*>(&comparand));
Chris@16:             return *reinterpret_cast<T const*>(&res);
Chris@16:         }
Chris@16: 
Chris@16:         enum
Chris@16:         {
Chris@16:             unlock_sem = 0,
Chris@16:             exclusive_sem = 1
Chris@16:         };
Chris@16: 
Chris@16:         state_data state;
Chris@16:         detail::win32::handle semaphores[2];
Chris@16:         detail::win32::handle upgrade_sem;
Chris@16: 
Chris@16:         void release_waiters(state_data old_state)
Chris@16:         {
Chris@16:             if(old_state.exclusive_waiting)
Chris@16:             {
Chris@16:                 BOOST_VERIFY(detail::win32::ReleaseSemaphore(semaphores[exclusive_sem],1,0)!=0);
Chris@16:             }
Chris@16: 
Chris@16:             if(old_state.shared_waiting || old_state.exclusive_waiting)
Chris@16:             {
Chris@16:                 BOOST_VERIFY(detail::win32::ReleaseSemaphore(semaphores[unlock_sem],old_state.shared_waiting + (old_state.exclusive_waiting?1:0),0)!=0);
Chris@16:             }
Chris@16:         }
Chris@101:         void release_shared_waiters(state_data old_state)
Chris@101:         {
Chris@101:             if(old_state.shared_waiting || old_state.exclusive_waiting)
Chris@101:             {
Chris@101:                 BOOST_VERIFY(detail::win32::ReleaseSemaphore(semaphores[unlock_sem],old_state.shared_waiting + (old_state.exclusive_waiting?1:0),0)!=0);
Chris@101:             }
Chris@101:         }
Chris@16: 
Chris@16:     public:
Chris@16:         BOOST_THREAD_NO_COPYABLE(shared_mutex)
Chris@16:         shared_mutex()
Chris@16:         {
Chris@16:             semaphores[unlock_sem]=detail::win32::create_anonymous_semaphore(0,LONG_MAX);
Chris@16:             semaphores[exclusive_sem]=detail::win32::create_anonymous_semaphore_nothrow(0,LONG_MAX);
Chris@16:             if (!semaphores[exclusive_sem])
Chris@16:             {
Chris@16:               detail::win32::release_semaphore(semaphores[unlock_sem],LONG_MAX);
Chris@16:               boost::throw_exception(thread_resource_error());
Chris@16:             }
Chris@16:             upgrade_sem=detail::win32::create_anonymous_semaphore_nothrow(0,LONG_MAX);
Chris@16:             if (!upgrade_sem)
Chris@16:             {
Chris@16:               detail::win32::release_semaphore(semaphores[unlock_sem],LONG_MAX);
Chris@16:               detail::win32::release_semaphore(semaphores[exclusive_sem],LONG_MAX);
Chris@16:               boost::throw_exception(thread_resource_error());
Chris@16:             }
Chris@16:             state_data state_={0,0,0,0,0,0};
Chris@16:             state=state_;
Chris@16:         }
Chris@16: 
Chris@16:         ~shared_mutex()
Chris@16:         {
Chris@16:             detail::win32::CloseHandle(upgrade_sem);
Chris@16:             detail::win32::CloseHandle(semaphores[unlock_sem]);
Chris@16:             detail::win32::CloseHandle(semaphores[exclusive_sem]);
Chris@16:         }
Chris@16: 
Chris@16:         bool try_lock_shared()
Chris@16:         {
Chris@16:             state_data old_state=state;
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data new_state=old_state;
Chris@16:                 if(!new_state.exclusive && !new_state.exclusive_waiting_blocked)
Chris@16:                 {
Chris@16:                     ++new_state.shared_count;
Chris@16:                     if(!new_state.shared_count)
Chris@16:                     {
Chris@16:                         return false;
Chris@16:                     }
Chris@16:                 }
Chris@16: 
Chris@16:                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                 if(current_state==old_state)
Chris@16:                 {
Chris@16:                     break;
Chris@16:                 }
Chris@16:                 old_state=current_state;
Chris@16:             }
Chris@16:             return !(old_state.exclusive| old_state.exclusive_waiting_blocked);
Chris@16:         }
Chris@16: 
Chris@16:         void lock_shared()
Chris@16:         {
Chris@16: #if defined BOOST_THREAD_USES_DATETIME
Chris@16:             BOOST_VERIFY(timed_lock_shared(::boost::detail::get_system_time_sentinel()));
Chris@16: #else
Chris@16:             BOOST_VERIFY(try_lock_shared_until(chrono::steady_clock::now()));
Chris@16: #endif
Chris@16:         }
Chris@16: 
Chris@16: #if defined BOOST_THREAD_USES_DATETIME
Chris@16:         template<typename TimeDuration>
Chris@16:         bool timed_lock_shared(TimeDuration const & relative_time)
Chris@16:         {
Chris@16:             return timed_lock_shared(get_system_time()+relative_time);
Chris@16:         }
Chris@16:         bool timed_lock_shared(boost::system_time const& wait_until)
Chris@16:         {
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data old_state=state;
Chris@16:                 for(;;)
Chris@16:                 {
Chris@16:                     state_data new_state=old_state;
Chris@16:                     if(new_state.exclusive || new_state.exclusive_waiting_blocked)
Chris@16:                     {
Chris@16:                         ++new_state.shared_waiting;
Chris@16:                         if(!new_state.shared_waiting)
Chris@16:                         {
Chris@16:                             boost::throw_exception(boost::lock_error());
Chris@16:                         }
Chris@16:                     }
Chris@16:                     else
Chris@16:                     {
Chris@16:                         ++new_state.shared_count;
Chris@16:                         if(!new_state.shared_count)
Chris@16:                         {
Chris@16:                             boost::throw_exception(boost::lock_error());
Chris@16:                         }
Chris@16:                     }
Chris@16: 
Chris@16:                     state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                     if(current_state==old_state)
Chris@16:                     {
Chris@16:                         break;
Chris@16:                     }
Chris@16:                     old_state=current_state;
Chris@16:                 }
Chris@16: 
Chris@16:                 if(!(old_state.exclusive| old_state.exclusive_waiting_blocked))
Chris@16:                 {
Chris@16:                     return true;
Chris@16:                 }
Chris@16: 
Chris@101:                 unsigned long const res=detail::win32::WaitForSingleObjectEx(semaphores[unlock_sem],::boost::detail::get_milliseconds_until(wait_until), 0);
Chris@16:                 if(res==detail::win32::timeout)
Chris@16:                 {
Chris@16:                     for(;;)
Chris@16:                     {
Chris@16:                         state_data new_state=old_state;
Chris@16:                         if(new_state.exclusive || new_state.exclusive_waiting_blocked)
Chris@16:                         {
Chris@16:                             if(new_state.shared_waiting)
Chris@16:                             {
Chris@16:                                 --new_state.shared_waiting;
Chris@16:                             }
Chris@16:                         }
Chris@16:                         else
Chris@16:                         {
Chris@16:                             ++new_state.shared_count;
Chris@16:                             if(!new_state.shared_count)
Chris@16:                             {
Chris@16:                                 return false;
Chris@16:                             }
Chris@16:                         }
Chris@16: 
Chris@16:                         state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                         if(current_state==old_state)
Chris@16:                         {
Chris@16:                             break;
Chris@16:                         }
Chris@16:                         old_state=current_state;
Chris@16:                     }
Chris@16: 
Chris@16:                     if(!(old_state.exclusive| old_state.exclusive_waiting_blocked))
Chris@16:                     {
Chris@16:                         return true;
Chris@16:                     }
Chris@16:                     return false;
Chris@16:                 }
Chris@16: 
Chris@16:                 BOOST_ASSERT(res==0);
Chris@16:             }
Chris@16:         }
Chris@16: #endif
Chris@16: 
Chris@16: #ifdef BOOST_THREAD_USES_CHRONO
Chris@16:         template <class Rep, class Period>
Chris@16:         bool try_lock_shared_for(const chrono::duration<Rep, Period>& rel_time)
Chris@16:         {
Chris@16:           return try_lock_shared_until(chrono::steady_clock::now() + rel_time);
Chris@16:         }
Chris@16:         template <class Clock, class Duration>
Chris@16:         bool try_lock_shared_until(const chrono::time_point<Clock, Duration>& t)
Chris@16:         {
Chris@16:           using namespace chrono;
Chris@16:           system_clock::time_point     s_now = system_clock::now();
Chris@16:           typename Clock::time_point  c_now = Clock::now();
Chris@16:           return try_lock_shared_until(s_now + ceil<system_clock::duration>(t - c_now));
Chris@16:         }
Chris@16:         template <class Duration>
Chris@16:         bool try_lock_shared_until(const chrono::time_point<chrono::system_clock, Duration>& t)
Chris@16:         {
Chris@16:           using namespace chrono;
Chris@16:           typedef time_point<chrono::system_clock, chrono::system_clock::duration> sys_tmpt;
Chris@16:           return try_lock_shared_until(sys_tmpt(chrono::ceil<chrono::system_clock::duration>(t.time_since_epoch())));
Chris@16:         }
Chris@16:         bool try_lock_shared_until(const chrono::time_point<chrono::system_clock, chrono::system_clock::duration>& tp)
Chris@16:         {
Chris@16:           for(;;)
Chris@16:           {
Chris@16:             state_data old_state=state;
Chris@16:             for(;;)
Chris@16:             {
Chris@16:               state_data new_state=old_state;
Chris@16:               if(new_state.exclusive || new_state.exclusive_waiting_blocked)
Chris@16:               {
Chris@16:                   ++new_state.shared_waiting;
Chris@16:                   if(!new_state.shared_waiting)
Chris@16:                   {
Chris@16:                       boost::throw_exception(boost::lock_error());
Chris@16:                   }
Chris@16:               }
Chris@16:               else
Chris@16:               {
Chris@16:                   ++new_state.shared_count;
Chris@16:                   if(!new_state.shared_count)
Chris@16:                   {
Chris@16:                       boost::throw_exception(boost::lock_error());
Chris@16:                   }
Chris@16:               }
Chris@16: 
Chris@16:               state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:               if(current_state==old_state)
Chris@16:               {
Chris@16:                   break;
Chris@16:               }
Chris@16:               old_state=current_state;
Chris@16:             }
Chris@16: 
Chris@16:             if(!(old_state.exclusive| old_state.exclusive_waiting_blocked))
Chris@16:             {
Chris@16:               return true;
Chris@16:             }
Chris@16: 
Chris@16:             chrono::system_clock::time_point n = chrono::system_clock::now();
Chris@16:             unsigned long res;
Chris@16:             if (tp>n) {
Chris@16:               chrono::milliseconds rel_time= chrono::ceil<chrono::milliseconds>(tp-n);
Chris@101:               res=detail::win32::WaitForSingleObjectEx(semaphores[unlock_sem],
Chris@101:                 static_cast<unsigned long>(rel_time.count()), 0);
Chris@16:             } else {
Chris@16:               res=detail::win32::timeout;
Chris@16:             }
Chris@16:             if(res==detail::win32::timeout)
Chris@16:             {
Chris@16:               for(;;)
Chris@16:               {
Chris@16:                 state_data new_state=old_state;
Chris@16:                 if(new_state.exclusive || new_state.exclusive_waiting_blocked)
Chris@16:                 {
Chris@16:                   if(new_state.shared_waiting)
Chris@16:                   {
Chris@16:                       --new_state.shared_waiting;
Chris@16:                   }
Chris@16:                 }
Chris@16:                 else
Chris@16:                 {
Chris@16:                   ++new_state.shared_count;
Chris@16:                   if(!new_state.shared_count)
Chris@16:                   {
Chris@16:                       return false;
Chris@16:                   }
Chris@16:                 }
Chris@16: 
Chris@16:                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                 if(current_state==old_state)
Chris@16:                 {
Chris@16:                     break;
Chris@16:                 }
Chris@16:                 old_state=current_state;
Chris@16:               }
Chris@16: 
Chris@16:               if(!(old_state.exclusive| old_state.exclusive_waiting_blocked))
Chris@16:               {
Chris@16:                 return true;
Chris@16:               }
Chris@16:               return false;
Chris@16:             }
Chris@16: 
Chris@16:             BOOST_ASSERT(res==0);
Chris@16:           }
Chris@16:         }
Chris@16: #endif
Chris@16: 
Chris@16:         void unlock_shared()
Chris@16:         {
Chris@16:             state_data old_state=state;
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data new_state=old_state;
Chris@16:                 bool const last_reader=!--new_state.shared_count;
Chris@16: 
Chris@16:                 if(last_reader)
Chris@16:                 {
Chris@16:                     if(new_state.upgrade)
Chris@16:                     {
Chris@16:                         new_state.upgrade=false;
Chris@16:                         new_state.exclusive=true;
Chris@16:                     }
Chris@16:                     else
Chris@16:                     {
Chris@16:                         if(new_state.exclusive_waiting)
Chris@16:                         {
Chris@16:                             --new_state.exclusive_waiting;
Chris@16:                             new_state.exclusive_waiting_blocked=false;
Chris@16:                         }
Chris@16:                         new_state.shared_waiting=0;
Chris@16:                     }
Chris@16:                 }
Chris@16: 
Chris@16:                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                 if(current_state==old_state)
Chris@16:                 {
Chris@16:                     if(last_reader)
Chris@16:                     {
Chris@16:                         if(old_state.upgrade)
Chris@16:                         {
Chris@16:                             BOOST_VERIFY(detail::win32::ReleaseSemaphore(upgrade_sem,1,0)!=0);
Chris@16:                         }
Chris@16:                         else
Chris@16:                         {
Chris@16:                             release_waiters(old_state);
Chris@16:                         }
Chris@16:                     }
Chris@16:                     break;
Chris@16:                 }
Chris@16:                 old_state=current_state;
Chris@16:             }
Chris@16:         }
Chris@16: 
Chris@16:         void lock()
Chris@16:         {
Chris@16: #if defined BOOST_THREAD_USES_DATETIME
Chris@16:             BOOST_VERIFY(timed_lock(::boost::detail::get_system_time_sentinel()));
Chris@16: #else
Chris@16:             BOOST_VERIFY(try_lock_until(chrono::steady_clock::now()));
Chris@16: #endif
Chris@16:         }
Chris@16: 
Chris@16: #if defined BOOST_THREAD_USES_DATETIME
Chris@16:         template<typename TimeDuration>
Chris@16:         bool timed_lock(TimeDuration const & relative_time)
Chris@16:         {
Chris@16:             return timed_lock(get_system_time()+relative_time);
Chris@16:         }
Chris@16: #endif
Chris@16: 
Chris@16:         bool try_lock()
Chris@16:         {
Chris@16:             state_data old_state=state;
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data new_state=old_state;
Chris@16:                 if(new_state.shared_count || new_state.exclusive)
Chris@16:                 {
Chris@16:                     return false;
Chris@16:                 }
Chris@16:                 else
Chris@16:                 {
Chris@16:                     new_state.exclusive=true;
Chris@16:                 }
Chris@16: 
Chris@16:                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                 if(current_state==old_state)
Chris@16:                 {
Chris@16:                     break;
Chris@16:                 }
Chris@16:                 old_state=current_state;
Chris@16:             }
Chris@16:             return true;
Chris@16:         }
Chris@16: 
Chris@16: 
Chris@16: #if defined BOOST_THREAD_USES_DATETIME
Chris@16:         bool timed_lock(boost::system_time const& wait_until)
Chris@16:         {
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data old_state=state;
Chris@16: 
Chris@16:                 for(;;)
Chris@16:                 {
Chris@16:                     state_data new_state=old_state;
Chris@16:                     if(new_state.shared_count || new_state.exclusive)
Chris@16:                     {
Chris@16:                         ++new_state.exclusive_waiting;
Chris@16:                         if(!new_state.exclusive_waiting)
Chris@16:                         {
Chris@16:                             boost::throw_exception(boost::lock_error());
Chris@16:                         }
Chris@16: 
Chris@16:                         new_state.exclusive_waiting_blocked=true;
Chris@16:                     }
Chris@16:                     else
Chris@16:                     {
Chris@16:                         new_state.exclusive=true;
Chris@16:                     }
Chris@16: 
Chris@16:                     state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                     if(current_state==old_state)
Chris@16:                     {
Chris@16:                         break;
Chris@16:                     }
Chris@16:                     old_state=current_state;
Chris@16:                 }
Chris@16: 
Chris@16:                 if(!old_state.shared_count && !old_state.exclusive)
Chris@16:                 {
Chris@16:                     return true;
Chris@16:                 }
Chris@16:                 #ifndef UNDER_CE
Chris@16:                 const bool wait_all = true;
Chris@16:                 #else
Chris@16:                 const bool wait_all = false;
Chris@16:                 #endif
Chris@101:                 unsigned long const wait_res=detail::win32::WaitForMultipleObjectsEx(2,semaphores,wait_all,::boost::detail::get_milliseconds_until(wait_until), 0);
Chris@16:                 if(wait_res==detail::win32::timeout)
Chris@16:                 {
Chris@16:                     for(;;)
Chris@16:                     {
Chris@16:                         bool must_notify = false;
Chris@16:                         state_data new_state=old_state;
Chris@16:                         if(new_state.shared_count || new_state.exclusive)
Chris@16:                         {
Chris@16:                             if(new_state.exclusive_waiting)
Chris@16:                             {
Chris@16:                                 if(!--new_state.exclusive_waiting)
Chris@16:                                 {
Chris@16:                                     new_state.exclusive_waiting_blocked=false;
Chris@16:                                     must_notify = true;
Chris@16:                                 }
Chris@16:                             }
Chris@16:                         }
Chris@16:                         else
Chris@16:                         {
Chris@16:                             new_state.exclusive=true;
Chris@16:                         }
Chris@16: 
Chris@16:                         state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                         if (must_notify)
Chris@16:                         {
Chris@16:                           BOOST_VERIFY(detail::win32::ReleaseSemaphore(semaphores[unlock_sem],1,0)!=0);
Chris@16:                         }
Chris@16: 
Chris@16:                         if(current_state==old_state)
Chris@16:                         {
Chris@16:                             break;
Chris@16:                         }
Chris@16:                         old_state=current_state;
Chris@16:                     }
Chris@16:                     if(!old_state.shared_count && !old_state.exclusive)
Chris@16:                     {
Chris@16:                         return true;
Chris@16:                     }
Chris@16:                     return false;
Chris@16:                 }
Chris@16:                 BOOST_ASSERT(wait_res<2);
Chris@16:             }
Chris@16:         }
Chris@16: #endif
Chris@16: #ifdef BOOST_THREAD_USES_CHRONO
Chris@16:         template <class Rep, class Period>
Chris@16:         bool try_lock_for(const chrono::duration<Rep, Period>& rel_time)
Chris@16:         {
Chris@16:           return try_lock_until(chrono::steady_clock::now() + rel_time);
Chris@16:         }
Chris@16:         template <class Clock, class Duration>
Chris@16:         bool try_lock_until(const chrono::time_point<Clock, Duration>& t)
Chris@16:         {
Chris@16:           using namespace chrono;
Chris@16:           system_clock::time_point     s_now = system_clock::now();
Chris@16:           typename Clock::time_point  c_now = Clock::now();
Chris@16:           return try_lock_until(s_now + ceil<system_clock::duration>(t - c_now));
Chris@16:         }
Chris@16:         template <class Duration>
Chris@16:         bool try_lock_until(const chrono::time_point<chrono::system_clock, Duration>& t)
Chris@16:         {
Chris@16:           using namespace chrono;
Chris@16:           typedef time_point<chrono::system_clock, chrono::system_clock::duration> sys_tmpt;
Chris@16:           return try_lock_until(sys_tmpt(chrono::ceil<chrono::system_clock::duration>(t.time_since_epoch())));
Chris@16:         }
Chris@16:         bool try_lock_until(const chrono::time_point<chrono::system_clock, chrono::system_clock::duration>& tp)
Chris@16:         {
Chris@16:           for(;;)
Chris@16:           {
Chris@16:             state_data old_state=state;
Chris@16: 
Chris@16:             for(;;)
Chris@16:             {
Chris@16:               state_data new_state=old_state;
Chris@16:               if(new_state.shared_count || new_state.exclusive)
Chris@16:               {
Chris@16:                 ++new_state.exclusive_waiting;
Chris@16:                 if(!new_state.exclusive_waiting)
Chris@16:                 {
Chris@16:                     boost::throw_exception(boost::lock_error());
Chris@16:                 }
Chris@16: 
Chris@16:                 new_state.exclusive_waiting_blocked=true;
Chris@16:               }
Chris@16:               else
Chris@16:               {
Chris@16:                 new_state.exclusive=true;
Chris@16:               }
Chris@16: 
Chris@16:               state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:               if(current_state==old_state)
Chris@16:               {
Chris@16:                 break;
Chris@16:               }
Chris@16:               old_state=current_state;
Chris@16:             }
Chris@16: 
Chris@16:             if(!old_state.shared_count && !old_state.exclusive)
Chris@16:             {
Chris@16:                 return true;
Chris@16:             }
Chris@16:             #ifndef UNDER_CE
Chris@16:             const bool wait_all = true;
Chris@16:             #else
Chris@16:             const bool wait_all = false;
Chris@16:             #endif
Chris@16: 
Chris@16:             chrono::system_clock::time_point n = chrono::system_clock::now();
Chris@16:             unsigned long wait_res;
Chris@16:             if (tp>n) {
Chris@16:               chrono::milliseconds rel_time= chrono::ceil<chrono::milliseconds>(tp-chrono::system_clock::now());
Chris@101:               wait_res=detail::win32::WaitForMultipleObjectsEx(2,semaphores,wait_all,
Chris@101:                   static_cast<unsigned long>(rel_time.count()), 0);
Chris@16:             } else {
Chris@16:               wait_res=detail::win32::timeout;
Chris@16:             }
Chris@16:             if(wait_res==detail::win32::timeout)
Chris@16:             {
Chris@16:               for(;;)
Chris@16:               {
Chris@16:                 bool must_notify = false;
Chris@16:                 state_data new_state=old_state;
Chris@16:                 if(new_state.shared_count || new_state.exclusive)
Chris@16:                 {
Chris@16:                   if(new_state.exclusive_waiting)
Chris@16:                   {
Chris@16:                     if(!--new_state.exclusive_waiting)
Chris@16:                     {
Chris@16:                       new_state.exclusive_waiting_blocked=false;
Chris@16:                       must_notify = true;
Chris@16:                     }
Chris@16:                   }
Chris@16:                 }
Chris@16:                 else
Chris@16:                 {
Chris@16:                   new_state.exclusive=true;
Chris@16:                 }
Chris@16: 
Chris@16:                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                 if (must_notify)
Chris@16:                 {
Chris@16:                   BOOST_VERIFY(detail::win32::ReleaseSemaphore(semaphores[unlock_sem],1,0)!=0);
Chris@16:                 }
Chris@16:                 if(current_state==old_state)
Chris@16:                 {
Chris@16:                   break;
Chris@16:                 }
Chris@16:                 old_state=current_state;
Chris@16:               }
Chris@16:               if(!old_state.shared_count && !old_state.exclusive)
Chris@16:               {
Chris@16:                 return true;
Chris@16:               }
Chris@16:               return false;
Chris@16:             }
Chris@16:             BOOST_ASSERT(wait_res<2);
Chris@16:           }
Chris@16:         }
Chris@16: #endif
Chris@16: 
Chris@16:         void unlock()
Chris@16:         {
Chris@16:             state_data old_state=state;
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data new_state=old_state;
Chris@16:                 new_state.exclusive=false;
Chris@16:                 if(new_state.exclusive_waiting)
Chris@16:                 {
Chris@16:                     --new_state.exclusive_waiting;
Chris@16:                     new_state.exclusive_waiting_blocked=false;
Chris@16:                 }
Chris@16:                 new_state.shared_waiting=0;
Chris@16: 
Chris@16:                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                 if(current_state==old_state)
Chris@16:                 {
Chris@16:                     break;
Chris@16:                 }
Chris@16:                 old_state=current_state;
Chris@16:             }
Chris@16:             release_waiters(old_state);
Chris@16:         }
Chris@16: 
Chris@16:         void lock_upgrade()
Chris@16:         {
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data old_state=state;
Chris@16:                 for(;;)
Chris@16:                 {
Chris@16:                     state_data new_state=old_state;
Chris@16:                     if(new_state.exclusive || new_state.exclusive_waiting_blocked || new_state.upgrade)
Chris@16:                     {
Chris@16:                         ++new_state.shared_waiting;
Chris@16:                         if(!new_state.shared_waiting)
Chris@16:                         {
Chris@16:                             boost::throw_exception(boost::lock_error());
Chris@16:                         }
Chris@16:                     }
Chris@16:                     else
Chris@16:                     {
Chris@16:                         ++new_state.shared_count;
Chris@16:                         if(!new_state.shared_count)
Chris@16:                         {
Chris@16:                             boost::throw_exception(boost::lock_error());
Chris@16:                         }
Chris@16:                         new_state.upgrade=true;
Chris@16:                     }
Chris@16: 
Chris@16:                     state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                     if(current_state==old_state)
Chris@16:                     {
Chris@16:                         break;
Chris@16:                     }
Chris@16:                     old_state=current_state;
Chris@16:                 }
Chris@16: 
Chris@16:                 if(!(old_state.exclusive|| old_state.exclusive_waiting_blocked|| old_state.upgrade))
Chris@16:                 {
Chris@16:                     return;
Chris@16:                 }
Chris@16: 
Chris@101:                 BOOST_VERIFY(!detail::win32::WaitForSingleObjectEx(semaphores[unlock_sem],detail::win32::infinite, 0));
Chris@16:             }
Chris@16:         }
Chris@16: 
Chris@16:         bool try_lock_upgrade()
Chris@16:         {
Chris@16:             state_data old_state=state;
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data new_state=old_state;
Chris@16:                 if(new_state.exclusive || new_state.exclusive_waiting_blocked || new_state.upgrade)
Chris@16:                 {
Chris@16:                     return false;
Chris@16:                 }
Chris@16:                 else
Chris@16:                 {
Chris@16:                     ++new_state.shared_count;
Chris@16:                     if(!new_state.shared_count)
Chris@16:                     {
Chris@16:                         return false;
Chris@16:                     }
Chris@16:                     new_state.upgrade=true;
Chris@16:                 }
Chris@16: 
Chris@16:                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                 if(current_state==old_state)
Chris@16:                 {
Chris@16:                     break;
Chris@16:                 }
Chris@16:                 old_state=current_state;
Chris@16:             }
Chris@16:             return true;
Chris@16:         }
Chris@16: 
Chris@16:         void unlock_upgrade()
Chris@16:         {
Chris@16:             state_data old_state=state;
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data new_state=old_state;
Chris@16:                 new_state.upgrade=false;
Chris@16:                 bool const last_reader=!--new_state.shared_count;
Chris@16: 
Chris@16:                 if(last_reader)
Chris@16:                 {
Chris@16:                     if(new_state.exclusive_waiting)
Chris@16:                     {
Chris@16:                         --new_state.exclusive_waiting;
Chris@16:                         new_state.exclusive_waiting_blocked=false;
Chris@16:                     }
Chris@16:                     new_state.shared_waiting=0;
Chris@16:                 }
Chris@16: 
Chris@16:                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                 if(current_state==old_state)
Chris@16:                 {
Chris@16:                     if(last_reader)
Chris@16:                     {
Chris@16:                         release_waiters(old_state);
Chris@16:                     }
Chris@101:                     else {
Chris@101:                         release_shared_waiters(old_state);
Chris@101:                     }
Chris@16:                     // #7720
Chris@16:                     //else {
Chris@16:                     //    release_waiters(old_state);
Chris@16:                     //}
Chris@16:                     break;
Chris@16:                 }
Chris@16:                 old_state=current_state;
Chris@16:             }
Chris@16:         }
Chris@16: 
Chris@16:         void unlock_upgrade_and_lock()
Chris@16:         {
Chris@16:             state_data old_state=state;
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data new_state=old_state;
Chris@16:                 bool const last_reader=!--new_state.shared_count;
Chris@16: 
Chris@16:                 if(last_reader)
Chris@16:                 {
Chris@16:                     new_state.upgrade=false;
Chris@16:                     new_state.exclusive=true;
Chris@16:                 }
Chris@16: 
Chris@16:                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                 if(current_state==old_state)
Chris@16:                 {
Chris@16:                     if(!last_reader)
Chris@16:                     {
Chris@101:                         BOOST_VERIFY(!detail::win32::WaitForSingleObjectEx(upgrade_sem,detail::win32::infinite, 0));
Chris@16:                     }
Chris@16:                     break;
Chris@16:                 }
Chris@16:                 old_state=current_state;
Chris@16:             }
Chris@16:         }
Chris@16: 
Chris@16:         void unlock_and_lock_upgrade()
Chris@16:         {
Chris@16:             state_data old_state=state;
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data new_state=old_state;
Chris@16:                 new_state.exclusive=false;
Chris@16:                 new_state.upgrade=true;
Chris@16:                 ++new_state.shared_count;
Chris@16:                 if(new_state.exclusive_waiting)
Chris@16:                 {
Chris@16:                     --new_state.exclusive_waiting;
Chris@16:                     new_state.exclusive_waiting_blocked=false;
Chris@16:                 }
Chris@16:                 new_state.shared_waiting=0;
Chris@16: 
Chris@16:                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                 if(current_state==old_state)
Chris@16:                 {
Chris@16:                     break;
Chris@16:                 }
Chris@16:                 old_state=current_state;
Chris@16:             }
Chris@16:             release_waiters(old_state);
Chris@16:         }
Chris@16: //        bool try_unlock_upgrade_and_lock()
Chris@16: //        {
Chris@16: //          return false;
Chris@16: //        }
Chris@16: //#ifdef BOOST_THREAD_USES_CHRONO
Chris@16: //        template <class Rep, class Period>
Chris@16: //        bool
Chris@16: //        try_unlock_upgrade_and_lock_for(
Chris@16: //                                const chrono::duration<Rep, Period>& rel_time)
Chris@16: //        {
Chris@16: //          return try_unlock_upgrade_and_lock_until(
Chris@16: //                                 chrono::steady_clock::now() + rel_time);
Chris@16: //        }
Chris@16: //        template <class Clock, class Duration>
Chris@16: //        bool
Chris@16: //        try_unlock_upgrade_and_lock_until(
Chris@16: //                          const chrono::time_point<Clock, Duration>& abs_time)
Chris@16: //        {
Chris@16: //          return false;
Chris@16: //        }
Chris@16: //#endif
Chris@16: 
Chris@16:         void unlock_and_lock_shared()
Chris@16:         {
Chris@16:             state_data old_state=state;
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data new_state=old_state;
Chris@16:                 new_state.exclusive=false;
Chris@16:                 ++new_state.shared_count;
Chris@16:                 if(new_state.exclusive_waiting)
Chris@16:                 {
Chris@16:                     --new_state.exclusive_waiting;
Chris@16:                     new_state.exclusive_waiting_blocked=false;
Chris@16:                 }
Chris@16:                 new_state.shared_waiting=0;
Chris@16: 
Chris@16:                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                 if(current_state==old_state)
Chris@16:                 {
Chris@16:                     break;
Chris@16:                 }
Chris@16:                 old_state=current_state;
Chris@16:             }
Chris@16:             release_waiters(old_state);
Chris@16:         }
Chris@16:         void unlock_upgrade_and_lock_shared()
Chris@16:         {
Chris@16:             state_data old_state=state;
Chris@16:             for(;;)
Chris@16:             {
Chris@16:                 state_data new_state=old_state;
Chris@16:                 new_state.upgrade=false;
Chris@16:                 if(new_state.exclusive_waiting)
Chris@16:                 {
Chris@16:                     --new_state.exclusive_waiting;
Chris@16:                     new_state.exclusive_waiting_blocked=false;
Chris@16:                 }
Chris@16:                 new_state.shared_waiting=0;
Chris@16: 
Chris@16:                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
Chris@16:                 if(current_state==old_state)
Chris@16:                 {
Chris@16:                     break;
Chris@16:                 }
Chris@16:                 old_state=current_state;
Chris@16:             }
Chris@16:             release_waiters(old_state);
Chris@16:         }
Chris@16: 
Chris@16:     };
Chris@16:     typedef shared_mutex upgrade_mutex;
Chris@16: 
Chris@16: }
Chris@16: 
Chris@16: #include <boost/config/abi_suffix.hpp>
Chris@16: 
Chris@16: #endif