On Mon, 07 Sep 2009 13:33:25 +0200, Igor R wrote:

...

I have used a deadline_timer to generate a polling every 1 second. Unfortunely when I use the linux date command the timing is curupted. (If I set the clock back 1 min. I will be missing 60 pollings). What can I do about that?

Do you use expire_from_now()?

Well I did not. I used expires_at(expires_at() + TIMETOADD); because that is the behaviour that is specified for the timer function that I'm implementing. but I have just tested expire_from_now(). And it does the exact same thing.

On Mon, 07 Sep 2009 16:11:56 +0200, Igor R wrote:

Probably something like this would help: expires_at(ptime::microsec_clock::universal_time() + TIMETOADD);

I tried the following (asuming that it was what you ment): void GMyTask::OnAsioTimer() { std::cout << "Tick" << std::endl; m_AsioTimer.expires_at(boost::posix_time::microsec_clock::universal_time() + boost::posix_time::millisec(1000)); m_AsioTimer.async_wait(boost::bind(&GMyTask::OnAsioTimer, this)); } Problem remains the same.

On Mon, 07 Sep 2009 15:03:00 +0200, Stefan Strasser wrote:

Am Monday 07 September 2009 13:24:58 schrieb Bjarne Laursen:

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I have used a deadline_timer to generate a polling every 1 second. Unfortunely when I use the linux date command the timing is curupted. (If I set the clock back 1 min. I will be missing 60 pollings). What can I do about that? -Bjarne

I don't know how to solve that within asio but I also needed a timer like that and didn't want to create a dependency on asio just for that, so I'm using the following for now, which should also solve your problem (if you don't also use asio for other purposes):

class cache_timer{ public: cache_timer(...) : resolution(...) , thread(boost::bind(&cache_timer::run,this)) {} //throw(thread_resource_error) void run(){ while(!this_thread::interruption_requested()){ this_thread::sleep(resolution); ... } } ~cache_timer(){ //throw() this->thread.interrupt(); this->thread.join(); } private: posix_time::time_duration resolution; boost::thread thread; };

Thank you for the code. The thing is that I'm porting a central part of rather large amount of code from windows (MSVC6) into a multi target system, where the main target is linux. The original code use a combination of WaitForMultipleObjectsEx and GetTickCount to make a common destribution point for incoming data and timers. In addion a few user-modules used a function to give a CEvent and have my framework call a member function if the event becomes set. It is typical used to handle file/network/serial i/o, in windows. I have now implemented the use of asio for this central waiting point and it seem work well. Except for this problem. (And the shut down sequence, but thats another issue I need to work with) I don't know if the original windows system suffers from this problem also, but I need to come up with a solution on the new. Even if I need to give up the use of deadline_timer, I probably will continue to use asio. I just thought that I had missed some simple setup somewhere. It seem that the typical use of timers in asio (and given in examples) is to make timeout for i/o operations. And as I see it, the use of the date command will almost always make a program using asio fail.

On Tue, 08 Sep 2009 14:06:28 +0200, Ray Burkholder wrote:

One unorthodox solution would be to run NTP (www.ntp.org) on your servers. This will keep the time in sync. There should be no need for changing time on the system.

I guess that some of my customers will indeed run NTP, or some other automatic adjustment. But only occasionally when the system is connected during service. Even then, I think that it wound get a very accurate clock source. The service tool is probably a laptop, not connected to anything else during the service. Then when NTP adjust the clock we have the problem. But it's not just me. asio is a library for everyone it should behave better. I still hope to learn how to make it do that. (Although it should be default). After all, windows have timers like GetTickCount and QuaryPerformanceCounter, on Linux I think times() could be used to get a continuous nonjumping clock. A clock like that is what we need to make small timeouts for communication purposes. -Bjarne