Thanks. Can you please tell me what do you mean by 'wait (until an xtime)'? On 6/16/07, me22 wrote:

On 16/06/07, Meryl Silverburgh wrote:

...

Can you please tell me if i can do this with boost::thread library? 1. create a timer (say 5 seconds) which execute a function in a different thread when it expires. 2. the creator can cancel the timer before it expires.

It's not premade, but you could do it easily enough. Start a thread which will wait (until an xtime), then call a function (stored in a boost::function perhaps), so long as a flag isn't set (you could make that in a shared_ptr<bool> to avoid lifetime worries).

Starting a thread for each one probably wouldn't be too scalable, but it should work.

~ Scott _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

me22 wrote:

See the thread::sleep function: http://boost.org/doc/html/boost/thread.html#id1006145-bb

Looking at the documentation here: http://boost.org/doc/html/boost/xtime.html I still have a couple of questions about using xtime. 1) Presumably the 'platform-specific-type' is a floating value of some sort rather than an integer? 2) What are the valid values for 'clock_type' in the function xtime_get? K

me22 wrote:

On 16/06/07, Meryl Silverburgh wrote:

...

Can you please tell me if i can do this with boost::thread library? 1. create a timer (say 5 seconds) which execute a function in a different thread when it expires. 2. the creator can cancel the timer before it expires.

It's not premade, but you could do it easily enough. Start a thread which will wait (until an xtime), then call a function (stored in a boost::function perhaps), so long as a flag isn't set (you could make that in a shared_ptr<bool> to avoid lifetime worries).

That works. However, it's nicer to use a 'condition' instead of a global flag and a 'timed_wait' on that condition to put the thread asleep. This way the condition will wake up the thread so it can be reused. I'll attach a simple "interval timer" that uses a condition variable to terminate the thread. Changing it to the "stop watch timer" described in the OP should be a matter of just adding some more conditions. Regards, Tobias #include <string> #include <iostream> #include #include #include class timer : boost::noncopyable { boost::xtime wait_time, next_time; boost::mutex monitor; boost::condition aborted; boost::thread thread; public: explicit timer(boost::xtime const & interval) : wait_time(interval) , thread( boost::bind(& timer::thread_body, this) ) { } ~timer() { aborted.notify_one(); thread.join(); } private: void calc_next_time() { boost::xtime_get(& next_time, boost::TIME_UTC); next_time.sec += wait_time.sec; next_time.nsec += wait_time.nsec; next_time.sec += next_time.nsec / 1000000000; next_time.nsec %= 1000000000; } void thread_body() { boost::mutex::scoped_lock lock(monitor); for (;;) { calc_next_time(); if (aborted.timed_wait(lock, next_time)) break; std::cout << "event" << std::endl; } } }; int main() { boost::xtime interval = { 0, 200000000 }; timer t(interval); std::string s; std::getline(std::cin, s); return 0; }

I checked asio timer before, when I was looking for boost timer library. The smallest time granularity of asio::deadlime_timer is second. I did not find any example or document of asio that mentioned about smaller granularity. ++++++++++++++++++++++++++++++++++++ Goldiom Systems LLC - Information and Communication Technology Provider Email: fanzhe.cui@goldiom.com Tel: 973-210-4254 www.goldiom.com From: boost-users-bounces@lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Sergey Nikulov Sent: Monday, June 18, 2007 1:16 AM To: boost-users@lists.boost.org Subject: Re: [Boost-users] How to create a timer in boost::thread You can check boost::asio (http://asio.sourceforge.net/) Here you can find pretty simple examples for boost::asio::deadline_timer which is (I think so) answer on both of your questions. HTH, Sergey 2007/6/17, Meryl Silverburgh : Hi, Can you please tell me if i can do this with boost::thread library? 1. create a timer (say 5 seconds) which execute a function in a different thread when it expires. 2. the creator can cancel the timer before it expires. Thank you. _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users