condition_wariable::wait_for throws exception (with Invalid argument), if system date/time < 1970

[anonymous]

Linux, kernel 2.6.32, arm-none-linux-gnueabi-g++ 2010q1

[albel78@…]

example:

#include <iostream>

#include <boost/thread.hpp>
#include <boost/thread/locks.hpp>
#include <boost/chrono.hpp>
#include <boost/bind.hpp>




void do_thread(){

	try{
		boost::condition_variable c1;
		boost::mutex m1;
		boost::unique_lock<boost::mutex> l1(m1);

		c1.wait_for(l1,boost::chrono::seconds(1));
	}
	catch(std::runtime_error& ex){
		std::cout<<"EXCEPTION ! "<<ex.what()<<std::endl;
			
	}
	

}

int main(int argc,char** argv){


	boost::thread th1(&do_thread);


	std::string s1;
	std::cin>>s1;

	return -1;
}

[viboes]

The example works fine for me on trunk. Could you try the trunk or the lasr 1.54 version?

[albel78@…]

have some problems to reproduce, because busybox applet 'date' has builtin value check, and set system date to any value < 01-01-1970 is currently impossible.

this issue caused on development board (D2-plug,​http://www.globalscaletechnologies.com/t-d2plugdetails.aspx)

I don't know about a reason, but 3 days ago system time was changed to May 1948. (rtc chip, or something else - i don't know). Then i catched exceptions on condition_variables. Then long time debugging, and i find reason of EINVAL of pthread_cond_timed_wait: bad value of timespec (big negative value of tv_sec), which is result of this code (pthread/condition_variable.hpp):

        template <class lock_type, class Clock, class Duration>
        cv_status
        wait_until(
                lock_type& lock,
                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();
          wait_until(lock, s_now + ceil<nanoseconds>(t - c_now));
          return Clock::now() < t ? cv_status::no_timeout : cv_status::timeout;
        }

and one notice: exceptions throws only in child threads. condvars in main thread workes fine.

now i correct system time to 2013, and all is ok.

if you tell me easy way to set up May 1948 - i'm ready for any tests.

(sorry for my english) Alexey.

[viboes]

I suspect that I can not do anything for this case, if pthread_cond_timed_wait doesn't supports times before 01-01-1970.

What do you suggest?

[albel78@…]

I suggest: check for negative timespec::tv_sec and throw different exception, than "phread_cond_timed_wait: EINVAL"

debug of this issue may be not simple, if boost::condition_variable::wait_for do not called directly. In my case - exception throws from boost::this_thread::sleep_for (in child threads). And code was absolutely not ready for this surprise.

[viboes]

I don't know if it is worth including this on the library.

You could do this kind of test yourself. You can wrap the sleep_for call and do the test there.