857 lines
30 KiB
C++
857 lines
30 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 2011-2012,2017-2018 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 <cstring>
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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/thread/detail/platform_time.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 long 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 std::memcmp(&lhs, &rhs, sizeof(lhs)) == 0;
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}
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};
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static state_data interlocked_compare_exchange(state_data* target, state_data new_value, state_data comparand)
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{
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BOOST_STATIC_ASSERT(sizeof(state_data) == sizeof(long));
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long new_val, comp;
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std::memcpy(&new_val, &new_value, sizeof(new_value));
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std::memcpy(&comp, &comparand, sizeof(comparand));
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long const res=BOOST_INTERLOCKED_COMPARE_EXCHANGE(reinterpret_cast<long*>(target),
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new_val,
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comp);
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state_data result;
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std::memcpy(&result, &res, sizeof(result));
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return result;
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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(winapi::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(winapi::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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void release_shared_waiters(state_data old_state)
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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(winapi::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_={0,0,0,0,0,0};
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state=state_;
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}
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~shared_mutex()
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{
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winapi::CloseHandle(upgrade_sem);
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winapi::CloseHandle(semaphores[unlock_sem]);
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winapi::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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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;
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}
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BOOST_VERIFY(winapi::WaitForSingleObjectEx(semaphores[unlock_sem],::boost::detail::win32::infinite,0)==0);
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}
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}
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private:
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unsigned long getMs(detail::platform_duration const& d)
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{
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return static_cast<unsigned long>(d.getMs());
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}
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template <typename Duration>
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unsigned long getMs(Duration const& d)
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{
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return static_cast<unsigned long>(chrono::ceil<chrono::milliseconds>(d).count());
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}
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template <typename Clock, typename Timepoint, typename Duration>
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bool do_lock_shared_until(Timepoint const& t, Duration const& max)
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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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// If the clock is the system clock, it may jump while this function
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// is waiting. To compensate for this and time out near the correct
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// time, we call WaitForSingleObjectEx() in a loop with a short
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// timeout and recheck the time remaining each time through the loop.
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unsigned long res=0;
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for(;;)
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{
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Duration d(t - Clock::now());
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if(d <= Duration::zero()) // timeout occurred
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{
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res=detail::win32::timeout;
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break;
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}
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if(max != Duration::zero())
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{
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d = (std::min)(d, max);
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}
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res=winapi::WaitForSingleObjectEx(semaphores[unlock_sem],getMs(d),0);
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if(res!=detail::win32::timeout) // semaphore released
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{
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break;
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}
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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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public:
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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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const detail::mono_platform_timepoint t(detail::mono_platform_clock::now() + detail::platform_duration(relative_time));
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// The reference clock is steady and so no need to poll periodically, thus 0 ms max (i.e. no max)
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return do_lock_shared_until<detail::mono_platform_clock>(t, detail::platform_duration::zero());
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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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const detail::real_platform_timepoint t(wait_until);
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return do_lock_shared_until<detail::real_platform_clock>(t, detail::platform_milliseconds(BOOST_THREAD_POLL_INTERVAL_MILLISECONDS));
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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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const chrono::steady_clock::time_point t(chrono::steady_clock::now() + rel_time);
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typedef typename chrono::duration<Rep, Period> Duration;
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typedef typename common_type<Duration, typename chrono::steady_clock::duration>::type common_duration;
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// The reference clock is steady and so no need to poll periodically, thus 0 ms max (i.e. no max)
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return do_lock_shared_until<chrono::steady_clock>(t, common_duration::zero());
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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::steady_clock, Duration>& t)
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{
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typedef typename common_type<Duration, typename chrono::steady_clock::duration>::type common_duration;
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// The reference clock is steady and so no need to poll periodically, thus 0 ms max (i.e. no max)
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return do_lock_shared_until<chrono::steady_clock>(t, common_duration::zero());
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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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typedef typename common_type<Duration, typename Clock::duration>::type common_duration;
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return do_lock_shared_until<Clock>(t, common_duration(chrono::milliseconds(BOOST_THREAD_POLL_INTERVAL_MILLISECONDS)));
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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(winapi::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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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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void lock()
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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;
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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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BOOST_VERIFY(winapi::WaitForMultipleObjectsEx(2,semaphores,wait_all,::boost::detail::win32::infinite,0)<2);
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}
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}
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private:
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template <typename Clock, typename Timepoint, typename Duration>
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bool do_lock_until(Timepoint const& t, Duration const& max)
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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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// If the clock is the system clock, it may jump while this function
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// is waiting. To compensate for this and time out near the correct
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// time, we call WaitForMultipleObjectsEx() in a loop with a short
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// timeout and recheck the time remaining each time through the loop.
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unsigned long wait_res=0;
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for(;;)
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{
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Duration d(t - Clock::now());
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if(d <= Duration::zero()) // timeout occurred
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{
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wait_res=detail::win32::timeout;
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break;
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}
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if(max != Duration::zero())
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{
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d = (std::min)(d, max);
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}
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#ifndef UNDER_CE
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wait_res=winapi::WaitForMultipleObjectsEx(2,semaphores,true,getMs(d),0);
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#else
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wait_res=winapi::WaitForMultipleObjectsEx(2,semaphores,false,getMs(d),0);
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#endif
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//wait_res=winapi::WaitForMultipleObjectsEx(2,semaphores,wait_all,getMs(d), 0);
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if(wait_res!=detail::win32::timeout) // semaphore released
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{
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break;
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}
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}
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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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bool must_notify = false;
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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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must_notify = true;
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}
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}
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}
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else
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{
|
|
new_state.exclusive=true;
|
|
}
|
|
|
|
state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
|
|
if (must_notify)
|
|
{
|
|
BOOST_VERIFY(winapi::ReleaseSemaphore(semaphores[unlock_sem],1,0)!=0);
|
|
}
|
|
|
|
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);
|
|
}
|
|
}
|
|
public:
|
|
|
|
#if defined BOOST_THREAD_USES_DATETIME
|
|
bool timed_lock(boost::system_time const& wait_until)
|
|
{
|
|
const detail::real_platform_timepoint t(wait_until);
|
|
return do_lock_until<detail::real_platform_clock>(t, detail::platform_milliseconds(BOOST_THREAD_POLL_INTERVAL_MILLISECONDS));
|
|
}
|
|
template<typename TimeDuration>
|
|
bool timed_lock(TimeDuration const & relative_time)
|
|
{
|
|
const detail::mono_platform_timepoint t(detail::mono_platform_clock::now() + detail::platform_duration(relative_time));
|
|
// The reference clock is steady and so no need to poll periodically, thus 0 ms max (i.e. no max)
|
|
return do_lock_until<detail::mono_platform_clock>(t, detail::platform_duration::zero());
|
|
}
|
|
#endif
|
|
#ifdef BOOST_THREAD_USES_CHRONO
|
|
template <class Rep, class Period>
|
|
bool try_lock_for(const chrono::duration<Rep, Period>& rel_time)
|
|
{
|
|
const chrono::steady_clock::time_point t(chrono::steady_clock::now() + rel_time);
|
|
typedef typename chrono::duration<Rep, Period> Duration;
|
|
typedef typename common_type<Duration, typename chrono::steady_clock::duration>::type common_duration;
|
|
// The reference clock is steady and so no need to poll periodically, thus 0 ms max (i.e. no max)
|
|
return do_lock_until<chrono::steady_clock>(t, common_duration::zero());
|
|
}
|
|
template <class Duration>
|
|
bool try_lock_until(const chrono::time_point<chrono::steady_clock, Duration>& t)
|
|
{
|
|
typedef typename common_type<Duration, typename chrono::steady_clock::duration>::type common_duration;
|
|
// The reference clock is steady and so no need to poll periodically, thus 0 ms max (i.e. no max)
|
|
return do_lock_until<chrono::steady_clock>(t, common_duration::zero());
|
|
}
|
|
template <class Clock, class Duration>
|
|
bool try_lock_until(const chrono::time_point<Clock, Duration>& t)
|
|
{
|
|
typedef typename common_type<Duration, typename Clock::duration>::type common_duration;
|
|
return do_lock_until<Clock>(t, common_duration(chrono::milliseconds(BOOST_THREAD_POLL_INTERVAL_MILLISECONDS)));
|
|
}
|
|
#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(winapi::WaitForSingleObjectEx(semaphores[unlock_sem],winapi::infinite,0)==0);
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
new_state.shared_waiting=0;
|
|
if(last_reader)
|
|
{
|
|
if(new_state.exclusive_waiting)
|
|
{
|
|
--new_state.exclusive_waiting;
|
|
new_state.exclusive_waiting_blocked=false;
|
|
}
|
|
}
|
|
|
|
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_shared_waiters(old_state);
|
|
}
|
|
// #7720
|
|
//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(winapi::WaitForSingleObjectEx(upgrade_sem,detail::win32::infinite,0)==0);
|
|
}
|
|
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);
|
|
}
|
|
|
|
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
|