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PollThread.cc Go to the documentation of this file. #ifndef PLATFORM_APERIOS #include "PollThread.h" #include <errno.h> #include <signal.h> //better to put this here instead of the header using namespace std; void PollThread::start() { launching=initialPoll=true; startTime.Set(); Thread::start(); } void PollThread::stop() { Thread::stop(); interrupt(); // break thread out of any long sleep commands } void PollThread::interrupt() { if(launching) //can't interrupt before thread has been launched! return; if(signal(SIGALRM,handleInterrupt)==SIG_ERR) perror("PollThread::run(): initial signal()"); sendSignal(SIGALRM); } bool PollThread::poll() { unsigned int sleeptime=runloop(); if(sleeptime==-1U) return false; period.Set(static_cast<long>(sleeptime)); return true; } void PollThread::interrupted() { if(!initialPoll) { if(period-startTime.Age()<1L) { delay=0L; } else { while(!(period-startTime.Age()<1L)) startTime-=period; startTime+=period; delay=period; } } } void * PollThread::run() { launching=false; timespec sleepSpec,remainSpec; if(startTime.Age()<delay) { sleepSpec=delay-startTime.Age(); while(nanosleep(&sleepSpec,&remainSpec)) { if(errno!=EINTR) { perror("PollThread::run(): initial nanosleep"); break; } //interrupted() may have changed delay to indicate remaining sleep time if(delay<1L || delay<startTime.Age()) break; sleepSpec=delay-startTime.Age(); } } testCancel(); if(!poll()) return returnValue; initialPoll=false; bool wasInterrupted=true; // need to add delay instead of period for the first time, same as if an interrupt occurred for(;;) { bool noSleep=false; if(TimeET(0,0)<period) { if(trackPollTime) { if(wasInterrupted) { if(delay<0L || startTime.Age()<delay) {} else startTime+=delay; } else { if(startTime.Age()<period) {} else startTime+=period; } //the idea with this part is that if we get behind, (because of poll() taking longer than period) // then we want to quick poll again as fast as we can to catch up, but we don't want to backlog // such that we'll be quick-calling multiple times once we do catch up if(period<startTime.Age()) { noSleep=true; while(period<startTime.Age()) startTime+=period; startTime-=period; //back off one -- the amount we've overshot counts towards the next period } sleepSpec=period-startTime.Age(); } else { sleepSpec=period; startTime.Set(); } wasInterrupted=false; while(!noSleep && nanosleep(&sleepSpec,&remainSpec)) { wasInterrupted=true; if(errno!=EINTR) { perror("PollThread::run(): periodic nanosleep"); break; } //interrupted() should have changed delay and/or period to indicate remaining sleep time if(delay<1L || delay<startTime.Age()) break; sleepSpec=delay-startTime.Age(); } } else { startTime.Set(); } testCancel(); if(!poll()) return returnValue; } // this return is just to satisfy warnings with silly compiler return returnValue; //never happens -- cancel or bad poll would exit } //void PollThread::cancelled() { //signal handlers are global, not per-thread, so if we reset the handler, then the next interrupt will cause the program to end :( //signal(SIGALRM,SIG_DFL); //} void PollThread::handleInterrupt(int /*signal*/) { if(signal(SIGALRM,SIG_DFL)==SIG_ERR) perror("PollThread::handleInterrupt(): could not re-enable signal"); PollThread * cur=dynamic_cast<PollThread*>(Thread::getCurrent()); if(cur==NULL) { std::cerr << "PollThread::handleInterrupt called from non-PollThread" << endl; return; } if(cur->noCancelDepth==0) cur->testCancel(); cur->interrupted(); } /*! @file * @brief * @author Ethan Tira-Thompson (ejt) (Creator) * * $Author: ejt $ * $Name: tekkotsu-3_0 $ * $Revision: 1.10 $ * $State: Exp $ * $Date: 2006/08/07 21:55:27 $ */ #endif

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