[asio] deadline_timer callback is not called
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Hi, I've yet posted a question about this topic but I not solve, so I try to ask again. PS: I used the same solution (in conjunction with asio::serial_port) in another project and, there, it works! I'm working on a library and I have only one static io_service and io_service::work like in the following code: ---------------------- START CODE ------------------------ typedef boost::shared_ptrboost::asio::io_service::work io_work_ptr; // Main io_service static boost::asio::io_service io_service; static boost::scoped_ptrboost::thread io_service_thread; static io_work_ptr p_work; static bool thread_started; void io_worker_thread(void) { #if(WIN32 && _WIN32_DCOM) struct com_init { com_init() { CoInitializeEx(NULL, COINIT_APARTMENTTHREADED); } ~com_init() { CoUninitialize(); } } initializer_object; #endif io_service.run(); }; bool CreateMainThread() { if (!thread_started) { try { // create the work object on the heap: // [Reference counting] // This object is a simple pointer because // it is assigned to each created objects // These objects store it in a shared_ptr so, // when the last object is destroyed // The io_service::work is destroyed as well p_work.reset( new boost::asio::io_service::work(io_service) ); // Instead of start the worker thread directly by // passing the io_service object, // I call the io_worker_thread function where // I can do some initialization tasks like // calling CoInitializeEx for COM io_service_thread.reset(new boost::thread(io_worker_thread)); thread_started = !thread_started; return true; } catch (boost::thread_resource_error e) { // Failed to create the new thread return false; } } else return true; } /*! * \brief Factory function for AudioPlayer objects creation */ EXTERN_C EUROAUDIOLIB_API AudioPlayerHndl CALL CreateAudioPlayer() { if (!CreateMainThread()) return NULL; // create the new object AudioPlayer* pAudioPlayer = new AudioPlayer; pAudioPlayer->io_worker_ptr = p_work; return pAudioPlayer; }; ---------------------- END CODE ------------------------ In the above code pAudioPlayer->io_worker_ptr is declared as: io_work_ptr p_work; In a class I have to use the timer, so I initialize it with the global io_service object: ---------------------- START CODE ------------------------ boost::asio::deadline_timer rx_timer_; WaveStream::WaveStream() : rx_timer_(io_service) { }; void WaveStream::ProcessRTPPacket() { // RTP Packet received ...... //Start a new timer or renew it rx_timer_.expires_from_now( boost::posix_time::milliseconds( 1000 ) ); io_service.reset(); // We managed to cancel the timer. Start new asynchronous wait. rx_timer_.async_wait( boost::bind(&WaveStream::handle_timeout, this, _1) ); .... } void WaveStream::handle_timeout(const boost::system::error_code& error) { std::cout << "BOOST TIMER RAISED!!" << endl; // A Timeout is raised: a stream is end if (!error) {...} }; ---------------------- END CODE ------------------------ But the callbak is never called!! Since ProcessRTPPacket is called frequently, I try also to move the timer on another point just for test with the same effect! Where could be the mistake? Thanks in advance! Daniele.
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Igor R ha scritto:
io_service.run(); Put some debug message here, to see when the io_service::run ends.
Hi Igor, thanks for you reply. I've put some debug code: ---------------------- START CODE ------------------------ void io_worker_thread(void) { io_service.run(); std::cout << ">>>> io_service.run() TERMINATED! <<<<" << endl; }; ---------------------- END CODE ------------------------ And the io_service.run() never returns, neither at the end of the application. This was caused because I had declared the io_service::work* like a shared_ptr. I change its declaration to simply: static boost::asio::io_service::work* p_work; And now io_service.run() ends only at the application end. So, when I call the timer, the io_service should run!! I try to add a call to io_service.run() after the timer async_wait: ---------------------- START CODE ------------------------ { ..... //Start a new timer or renew it rx_timer_.expires_from_now( boost::posix_time::milliseconds( 2000 ) ); // We managed to cancel the timer. Start new asynchronous wait. rx_timer_.async_wait( boost::bind(&WaveStream::handle_timeout, this, _1) ); io_service.run(); std::cout << "io_service.run() called " << endl; } void WaveStream::handle_timeout(const boost::system::error_code& error) { std::cout << "BOOST TIMER RAISED!!" << endl; }; ---------------------- END CODE ------------------------ ..and in this manner the callback is called immediately after the io_service.run() without waiting and in output I see: BOOST TIMER RAISED!! io_service.run() called BOOST TIMER RAISED!! io_service.run() called BOOST TIMER RAISED!! io_service.run() called BOOST TIMER RAISED!! io_service.run() called BOOST TIMER RAISED!! Suggestions? Daniele.
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Igor R ha scritto:
I try to add a call to io_service.run() after the timer async_wait:
Why? You already run io_service within io_worker_thread(), don't you? What you have to do is just: ...expires_from_now(...); ...async_wait(...);
It was only a test, also doing so the first io_service.run() does not returns! Ok, Using only ...expires_from_now(...); ...async_wait(...); I don't know why but...it doesn't work! Also I don't know why in the other project it works! The only difference is that, in the other project, I used boost_1_39_0 (while in this one I use boost_1_40_0) and I calling the timers inside the asio::serial_port::async_read_some callback! I know that is quite difficult for you to help me not knowing the code, but.. How could cause this kind of behavior? Thanks, Daniele
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How could cause this kind of behavior?
Another guess: do you call the timer functions (expires_from_now(), async_wait() ) from the thread that is running io_service or from another one? That is, who calls ProcessRTPPacket() function? If it's called from another thread, can you try the following: // instead of calling expires_from_now(), async_wait() directly... yourTimer_.get_io_service().post(boost::bind(&WaveStream::setTimer, this)); //... void setTimer() { // Some debug message, to see if the function is called. ...expires_from_now(...); ...async_wait(...); } Now see if setTimer is called. If it's not called, you've got some problem with your io_service - it's not running properly.
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Igor R ha scritto:
How could cause this kind of behavior?
Another guess: do you call the timer functions (expires_from_now(), async_wait() ) from the thread that is running io_service or from another one? That is, who calls ProcessRTPPacket() function? If it's called from another thread, can you try the following:
No, from another one. The thread that run the io_service simply runs it: void io_worker_thread(void) { io_service.run(); std::cout << ">>> io_service.run() TERMINATED! <<<<<" << endl; }; ProcessRTPPacket() is a library "event" and maybe it is called from another thread! Mmmm...so maybe, in the other project, it worked because I called timers into the asio::serial_port::async_read_some callback that should be inside the io_service thread! Isn't it?
// instead of calling expires_from_now(), async_wait() directly... yourTimer_.get_io_service().post(boost::bind(&WaveStream::setTimer, this)); //...
void setTimer() { // Some debug message, to see if the function is called. ...expires_from_now(...); ...async_wait(...); }
Now see if setTimer is called.
Yes, the setTimer is called, but the timer callback not! Cheers, Daniele.
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Mmmm...so maybe, in the other project, it worked because I called timers into the asio::serial_port::async_read_some callback that should be inside the io_service thread! Isn't it?
asio::deadline_timer is not thread-safe, so you're not allowed to access it from multiple threads. Since it's being processed by the io_service from within its thread, you have to post any timer method to the io_service (as far as I understand).
Yes, the setTimer is called, but the timer callback not!
You call expires_from_now and async_wait from setTimer(), and the handler is not called? Well, that's weird. Ensure you pass reasonable time duration. Try to use the overload that returns an error: boost::system::error_code er; expires_from_now(seconds(1), er); What does it return in "er"?
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Igor R ha scritto:
Yes, the setTimer is called, but the timer callback not!
You call expires_from_now and async_wait from setTimer(), and the handler is not called? Well, that's weird. Ensure you pass reasonable time duration. Try to use the overload that returns an error: boost::system::error_code er; expires_from_now(seconds(1), er);
Oh, I'm sorry. It was my fault. I forgot to remove a call, all these test make me crazy!! :-P Calling: rx_timer_.get_io_service().post(boost::bind(&WaveStream::StartTimer, this)); the StartTimer is not called!!! So... The io_service should be running but the post() does not work so, what can I check? Thanks for the support! Daniele.
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the StartTimer is not called!!!
So... The io_service should be running but the post() does not work so, what can I check?
Probably, some handler (called by io_service) blocks? Check all the stuff, which is called directly or indirectly from within the handlers -- remember that if one of your handlers blocks, the other once won't have a chance to run.
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Igor R ha scritto:
Probably, some handler (called by io_service) blocks? Check all the stuff, which is called directly or indirectly from within the handlers -- remember that if one of your handlers blocks, the other once won't have a chance to run.
Mmm...I do nothing more than: 1- Create a io_service::work on the heap; 2- Create a new Thread; 3- Call the io_service.run() within this new thread; 4- Assign the io_service::work* to a boost::shared_ptr; 5- Use the timer we discuss; No other io_service use! For now I discard the deadline timer "option" and I create a custom timer with a Thread and Sleep! :-( If u have other suggestions, are welcome! Thanks a lot, Daniele.
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Mmm...I do nothing more than: 1- Create a io_service::work on the heap; 2- Create a new Thread; 3- Call the io_service.run() within this new thread; 4- Assign the io_service::work* to a boost::shared_ptr; 5- Use the timer we discuss; Well, if your code that simple, you can extract a minimal reproducing excerpt and post it here - then other people will be able to try and debug it. Just remove anything unrelated to the timer problem (maybe after you do this, the problem will disappear :) ).
If u have other suggestions, are welcome!
I never encountered such a problem. It seems that your io_service dosn't work properly, but why it happens, I don't know.
participants (2)
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Daniele Barzotti
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Igor R