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