Re: [boost] why is not boost::asio::deadline_timer.wait() blocking in this case?

From: Qiu Yuzhou (qbowater_at_[hidden])
Date: 2008-06-06 11:18:23

Inner of asio use absolute time in timer queue.The absolute time have
been calculated when the deadline_timer be constructing,not when the
wait() be executing. When you passing a relative time,it then calculate
the absolute time when it will timeout. Member function
expires_from_now() of deadline_timer also has same behavior.
Sorry for my poor english.
> While trying to understand the difference between wait() and async_wait,
> I modified the tutorial example a little to test 2 timers at the same
> time like this:
> 
>  
> 
> int test_timer()
> 
> {
> 
>     boost::asio::io_service io;
> 
>  
> 
>     size_t delay1 = 5;
> 
>     size_t delay2 = 3;
> 
>  
> 
>     boost::asio::deadline_timer t1(io,
> boost::posix_time::seconds(delay1));
> 
>     boost::asio::deadline_timer t2(io,
> boost::posix_time::seconds(delay2));
> 
>  
> 
>     boost::timer t;
> 
>     t2.wait();
> 
>     std::cout << t.elapsed() << " sec elapsed!\n";
> 
>  
> 
>     t1.wait();
> 
>     std::cout << t.elapsed() << " sec elapsed!\n";
> 
>  
> 
>     return 0;
> 
> }
> 
>  
> 
> I got this output:
> 
> 3.004 sec elapsed!
> 
> 5.007 sec elapsed!
> 
> However, I was expecting t2 and t1 to execute sequentially and thus
> getting:
> 
> 3.004 sec elapsed!
> 
> 8 sec elapsed!
> 
>  
> 
> What was wrong with my understanding about synchronous waiting here?
> Thanks.
> 
>  
> 
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