| #ifndef BOOST_BASIC_TIMED_MUTEX_WIN32_HPP |
| #define BOOST_BASIC_TIMED_MUTEX_WIN32_HPP |
| |
| // basic_timed_mutex_win32.hpp |
| // |
| // (C) Copyright 2006-8 Anthony Williams |
| // |
| // Distributed under the Boost Software License, Version 1.0. (See |
| // accompanying file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| |
| #include <boost/assert.hpp> |
| #include "thread_primitives.hpp" |
| #include "interlocked_read.hpp" |
| #include <boost/thread/thread_time.hpp> |
| #include <boost/thread/xtime.hpp> |
| #include <boost/detail/interlocked.hpp> |
| |
| #include <boost/config/abi_prefix.hpp> |
| |
| namespace boost |
| { |
| namespace detail |
| { |
| struct basic_timed_mutex |
| { |
| BOOST_STATIC_CONSTANT(unsigned char,lock_flag_bit=31); |
| BOOST_STATIC_CONSTANT(unsigned char,event_set_flag_bit=30); |
| BOOST_STATIC_CONSTANT(long,lock_flag_value=1<<lock_flag_bit); |
| BOOST_STATIC_CONSTANT(long,event_set_flag_value=1<<event_set_flag_bit); |
| long active_count; |
| void* event; |
| |
| void initialize() |
| { |
| active_count=0; |
| event=0; |
| } |
| |
| void destroy() |
| { |
| #ifdef BOOST_MSVC |
| #pragma warning(push) |
| #pragma warning(disable:4312) |
| #endif |
| void* const old_event=BOOST_INTERLOCKED_EXCHANGE_POINTER(&event,0); |
| #ifdef BOOST_MSVC |
| #pragma warning(pop) |
| #endif |
| if(old_event) |
| { |
| win32::CloseHandle(old_event); |
| } |
| } |
| |
| |
| bool try_lock() |
| { |
| return !win32::interlocked_bit_test_and_set(&active_count,lock_flag_bit); |
| } |
| |
| void lock() |
| { |
| BOOST_VERIFY(timed_lock(::boost::detail::get_system_time_sentinel())); |
| } |
| bool timed_lock(::boost::system_time const& wait_until) |
| { |
| if(!win32::interlocked_bit_test_and_set(&active_count,lock_flag_bit)) |
| { |
| return true; |
| } |
| long old_count=active_count; |
| for(;;) |
| { |
| long const new_count=(old_count&lock_flag_value)?(old_count+1):(old_count|lock_flag_value); |
| long const current=BOOST_INTERLOCKED_COMPARE_EXCHANGE(&active_count,new_count,old_count); |
| if(current==old_count) |
| { |
| break; |
| } |
| old_count=current; |
| } |
| |
| if(old_count&lock_flag_value) |
| { |
| bool lock_acquired=false; |
| void* const sem=get_event(); |
| |
| do |
| { |
| if(win32::WaitForSingleObject(sem,::boost::detail::get_milliseconds_until(wait_until))!=0) |
| { |
| BOOST_INTERLOCKED_DECREMENT(&active_count); |
| return false; |
| } |
| old_count&=~lock_flag_value; |
| old_count|=event_set_flag_value; |
| for(;;) |
| { |
| long const new_count=((old_count&lock_flag_value)?old_count:((old_count-1)|lock_flag_value))&~event_set_flag_value; |
| long const current=BOOST_INTERLOCKED_COMPARE_EXCHANGE(&active_count,new_count,old_count); |
| if(current==old_count) |
| { |
| break; |
| } |
| old_count=current; |
| } |
| lock_acquired=!(old_count&lock_flag_value); |
| } |
| while(!lock_acquired); |
| } |
| return true; |
| } |
| |
| template<typename Duration> |
| bool timed_lock(Duration const& timeout) |
| { |
| return timed_lock(get_system_time()+timeout); |
| } |
| |
| bool timed_lock(boost::xtime const& timeout) |
| { |
| return timed_lock(system_time(timeout)); |
| } |
| |
| void unlock() |
| { |
| long const offset=lock_flag_value; |
| long const old_count=BOOST_INTERLOCKED_EXCHANGE_ADD(&active_count,lock_flag_value); |
| if(!(old_count&event_set_flag_value) && (old_count>offset)) |
| { |
| if(!win32::interlocked_bit_test_and_set(&active_count,event_set_flag_bit)) |
| { |
| win32::SetEvent(get_event()); |
| } |
| } |
| } |
| |
| private: |
| void* get_event() |
| { |
| void* current_event=::boost::detail::interlocked_read_acquire(&event); |
| |
| if(!current_event) |
| { |
| void* const new_event=win32::create_anonymous_event(win32::auto_reset_event,win32::event_initially_reset); |
| #ifdef BOOST_MSVC |
| #pragma warning(push) |
| #pragma warning(disable:4311) |
| #pragma warning(disable:4312) |
| #endif |
| void* const old_event=BOOST_INTERLOCKED_COMPARE_EXCHANGE_POINTER(&event,new_event,0); |
| #ifdef BOOST_MSVC |
| #pragma warning(pop) |
| #endif |
| if(old_event!=0) |
| { |
| win32::CloseHandle(new_event); |
| return old_event; |
| } |
| else |
| { |
| return new_event; |
| } |
| } |
| return current_event; |
| } |
| |
| }; |
| |
| } |
| } |
| |
| #define BOOST_BASIC_TIMED_MUTEX_INITIALIZER {0} |
| |
| #include <boost/config/abi_suffix.hpp> |
| |
| #endif |