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; }
inline void* interlocked_read_acquire(void* volatile* x) { return BOOST_INTERLOCKED_COMPARE_EXCHANGE_POINTER(x,0,0); }