On 17 April 2016 at 17:56, lh_mouse <lh_mo...@126.com> wrote: > A glance over gthr.h reminds me __gthread_time_t. There seem few requirements > documented in gthr.h. > I discussed this with Adrien Nader on mingw-w64's mailing list a few days ago. > > Specifically, here are the two questions: > 0) Should __gthread_time_t be a struct or a plain integral type? > The 'struct timespec' used by pthread is a struct introduced in POSIX. > However my implementation uses a plain uint64_t.
I don't see why it has to be a struct, it just has to be suitable as an argument to the relevant __gthread functions. If the current code assumes a struct and the Windows API calls need an integer then either the existing code needs to be made more flexible, or you need to define it as a struct and then convert to an integer inside your new gthread wrapper functions. > 1) How to obtain a __gthread_time_t representing the current time? > According to Linux man pages, the timeout parameter of > pthread_cond_timedwait() is the same as gettimeofday() - that is, it uses the > wall clock. > My implementation uses GetTickCount64() - that is, my implementation uses a > monotonic clock. std::condition_variable::__clock_t must be a typedef for the clock used by the underlying implementation, so it sounds like you should use std::chrono::steady_clock for your thread model. > Quoting from ISO/IEC WG21 Draft N4582 (C++1z): > [quote] > 30.4.1.3.1 Class timed_mutex [thread.timedmutex.class] > ... > template <class Rep, class Period> > bool try_lock_for(const chrono::duration<Rep, Period>& rel_time); > template <class Clock, class Duration> > bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time); > ... > [/quote] > the std::timed_mutex::try_lock_for() function template shall accept any clock > type, hence we have to do timestamp translation. It is also important to know > how libstdc++ handles this. All conversions are done using the std::chrono facilities, before any conversion to __gthread_time_t. That means the conversions are portable. ------------------------------------------------------------------------------ Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z _______________________________________________ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
