2014/1/9 Vicente J. Botet Escriba <vicente.botet@wanadoo.fr>
struct X {
operator bool() {} };
struct Y { operator bool() {} };
X x; Y y;
if ( x == y) // does compile
I don't see the problem with explicit conversion
you can compare X and Y You are surely right, but I don't see how? Could you show it?
Is there an example showing this on the repository? no its is an implementation in side the framework, e.g. class scheduler which holds the user-defined or the default implementation of the scheduler-impl (default is round_robin) Could you post here an example at the user level?
Can the scheduler be shared between threads?
no - not the schedulers (== classes derived from interface algorithm, e.g. round_robin and round_robin_ws) which might be share-able between threads but I doubt that it would make sense - a scheduler derived from alogrithm schedules the fibers running in the current thread Why do the user needs to own the scheduler?
Maybe schedulers need to take care of a single time_point, but the other
classes should provide an time related interface using any clock.
OK - boost.chrono is your domain. functions accepting a time_duration/time_point (from boost.chrono) can always be mapped/applied to steady_clock/system_clock?
No mapping can be done between clocks and there is no need to do this mapping. This is how standard chrono libray was designed. Please take a look at the following implementation
template <class Clock, class Duration> bool try_lock_until(const chrono::time_point<Clock, Duration>& t) { using namespace chrono; system_clock::time_point s_now = system_clock::now(); typename Clock::time_point c_now = Clock::now(); return try_lock_until(s_now + ceil<nanoseconds>(t - c_now)); } template <class Duration> bool try_lock_until(const chrono::time_point<chrono::system_clock, Duration>& t) { using namespace chrono; typedef time_point<system_clock, nanoseconds> nano_sys_tmpt; return try_lock_until(nano_sys_tmpt(ceil<nanoseconds>(t.time_ since_epoch()))); }
Note that only the try_lock_until(const chrono::time_point<chrono::system_clock, nanoseconds>& ) function needs to be virtual.
seem to me at the first look that it woul be compilcate in teh case of boost.fiber because: - the scheduler (derived from algorithm, e.g. for instance round_robin) uses internally a specific clock type (steady_clock) I give you un example using system_clock. The opposite is of course possible - member-functions of sync classes like condition_variable::wait_for() takes a time_duration or condition_variable::wait_until() a time_point And? Take a look at the thread implementation of e.g. libc++ which is
Le 09/01/14 23:29, Oliver Kowalke a écrit : form me the best one.
time_duration + time_point can be of arbitrary clock-type from boost.chrono? No. can I simply add a time_duration different fro msteady_clock to steady_clock::now()? There is no time_duration time. Just duration. duration can be added to any system_clock::time_point, steady_clock::time_point or whatever timepoint<Clock, Duration>.
I made some adaptations to boost::barrier that could also have a sens for
fibers.
OK - what are those adaptations? See http://www.boost.org/doc/libs/1_55_0/doc/html/thread/ synchronization.html#thread.synchronization.barriers and http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/ n3817.html#barrier_operations
OK - that's new to me, but I don't know the use case of completion function etc. - do you have some hints?
From the pointed proposal "
A Note on Completion Functions and Templates
The proposed barrier takes an optional completion function, which may either return void or size_t. A barrier may thus do one of three things after all threads have called |count_down_and_wait()|:
* Reset itself automatically (if given no completion function.) * Invoke the completion function and then reset itself automatically (if given a function returning void). * Invoke the completion function and use the return value to reset itself (if given a function returning size_t)."
As you can see this parameter is most of the time related to how to reset the barrier counter.
ready this too but do you have an example code demonstrating a use case, sorry I've no idea which use cases would require a completion function?
The completion function can be used to reset the barrier to whatever new value you want, for example. Vicente