Boost::Chrono Assertion at startup

[meckschlager@…]

steady_clock::time_point now = steady_clock::now(); sometimes causes

Assertion failed: 0 && "Boost::Chrono - Internal Error", file C:\Projects\Librari
es\src\boost\boost_1_48_0\boost/chrono/detail/inlined/win/chrono.hpp, line 44
on Windows XP, boost 1.48

[meckschlager@…]

Now I see, boost::chrono is all thread unsafe and I was reading the time from 2 threads simultaneously (I guess that's so not uncommon) Is that really good? Locking the time reading method seems a bit weird to me...

[viboes]

Replying to meckschlager@…:

Now I see, boost::chrono is all thread unsafe and I was reading the time from 2 threads simultaneously (I guess that's so not uncommon)

Why do you think that the code is thread unsafe?

Is that really good? Locking the time reading method seems a bit weird to me...

What is weird for you?

[viboes]

Replying to meckschlager@…:

steady_clock::time_point now = steady_clock::now(); sometimes causes Assertion failed: 0 && "Boost::Chrono - Internal Error", file C:\Projects\Librari es\src\boost\boost_1_48_0\boost/chrono/detail/inlined/win/chrono.hpp, line 44 on Windows XP, boost 1.48

The code in question is

    if ( (nanosecs_per_tic <= 0.0L) ||
            (!boost::detail::win32::QueryPerformanceCounter( &pcount )) )
    {
      BOOST_ASSERT(0 && "Boost::Chrono - Internal Error");
      return steady_clock::time_point();
    }

could you check which condition is true?

[meckschlager@…]

Hi, thanks embracing that issue up!

Why do you think that the code is thread unsafe?

It states so in the chrono users guide "All functions in the library are thread-unsafe except when noted explicitly." (http://www.boost.org/doc/libs/1_52_0/doc/html/chrono/users_guide.html) thats why I came to the working solution

lock steady_clock::time_point now = steady_clock::now(); unlock

Now, it just seems unnecessary that multiple threads might have to wait to get the current time, which many os methods would return without requiring a lock.

cheers m.

[viboes]

Replying to meckschlager@…:

Hi, thanks embracing that issue up!

Why do you think that the code is thread unsafe?

It states so in the chrono users guide "All functions in the library are thread-unsafe except when noted explicitly." (http://www.boost.org/doc/libs/1_52_0/doc/html/chrono/users_guide.html) thats why I came to the working solution

lock steady_clock::time_point now = steady_clock::now(); unlock

Now, it just seems unnecessary that multiple threads might have to wait to get the current time, which many os methods would return without requiring a lock.

Hrr! I would fix this on the documentation, call to Clock::now() should be thread safe.

Thanks for the report.

[viboes]

I have fixed the documentation in revision [83511]. have you analyzed which condition was failing?

[viboes]

Replying to viboes:

I have fixed the documentation in revision [83511]. have you analyzed which condition was failing?

Could you tell me which is the result of

boost::detail::win32::QueryPerformanceCounter( &pcount ) 

when the program asserts?

[viboes]

I can not reproduce this error. Without your help I'm unable to help you? Reopen it if you have some insight.