xref: /recipes/reactor/s07-s06-EventLoop.cc.diff

 // excerpts from http://code.google.com/p/muduo/
 //
 // Use of this source code is governed by a BSD-style license
 // that can be found in the License file.
 //
 // Author: Shuo Chen (chenshuo at chenshuo dot com)
 
 #include "EventLoop.h"
 
 #include "Channel.h"
 #include "Poller.h"
 #include "TimerQueue.h"
 
 #include "logging/Logging.h"
 
 #include <boost/bind.hpp>
 
 #include <assert.h>
 #include <sys/eventfd.h>
 
 using namespace muduo;
 
 __thread EventLoop* t_loopInThisThread = 0;
 const int kPollTimeMs = 10000;
 
 static int createEventfd()
 {
   int evtfd = ::eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
   if (evtfd < 0)
   {
     LOG_SYSERR << "Failed in eventfd";
     abort();
   }
   return evtfd;
 }
 
 EventLoop::EventLoop()
   : looping_(false),
     quit_(false),
     callingPendingFunctors_(false),
     threadId_(CurrentThread::tid()),
     poller_(new Poller(this)),
     timerQueue_(new TimerQueue(this)),
     wakeupFd_(createEventfd()),
     wakeupChannel_(new Channel(this, wakeupFd_))
 {
   LOG_TRACE << "EventLoop created " << this << " in thread " << threadId_;
   if (t_loopInThisThread)
   {
     LOG_FATAL << "Another EventLoop " << t_loopInThisThread
               << " exists in this thread " << threadId_;
   }
   else
   {
     t_loopInThisThread = this;
   }
   wakeupChannel_->setReadCallback(
       boost::bind(&EventLoop::handleRead, this));
   // we are always reading the wakeupfd
   wakeupChannel_->enableReading();
 }
 
 EventLoop::~EventLoop()
 {
   assert(!looping_);
   ::close(wakeupFd_);
   t_loopInThisThread = NULL;
 }
 
 void EventLoop::loop()
 {
   assert(!looping_);
   assertInLoopThread();
   looping_ = true;
   quit_ = false;
 
   while (!quit_)
   {
     activeChannels_.clear();
     pollReturnTime_ = poller_->poll(kPollTimeMs, &activeChannels_);
     for (ChannelList::iterator it = activeChannels_.begin();
         it != activeChannels_.end(); ++it)
     {
!      (*it)->handleEvent(pollReturnTime_);
     }
     doPendingFunctors();
   }
 
   LOG_TRACE << "EventLoop " << this << " stop looping";
   looping_ = false;
 }
 
 void EventLoop::quit()
 {
   quit_ = true;
   if (!isInLoopThread())
   {
     wakeup();
   }
 }
 
 void EventLoop::runInLoop(const Functor& cb)
 {
   if (isInLoopThread())
   {
     cb();
   }
   else
   {
     queueInLoop(cb);
   }
 }
 
 void EventLoop::queueInLoop(const Functor& cb)
 {
   {
   MutexLockGuard lock(mutex_);
   pendingFunctors_.push_back(cb);
   }
 
   if (!isInLoopThread() || callingPendingFunctors_)
   {
     wakeup();
   }
 }
 
 TimerId EventLoop::runAt(const Timestamp& time, const TimerCallback& cb)
 {
   return timerQueue_->addTimer(cb, time, 0.0);
 }
 
 TimerId EventLoop::runAfter(double delay, const TimerCallback& cb)
 {
   Timestamp time(addTime(Timestamp::now(), delay));
   return runAt(time, cb);
 }
 
 TimerId EventLoop::runEvery(double interval, const TimerCallback& cb)
 {
   Timestamp time(addTime(Timestamp::now(), interval));
   return timerQueue_->addTimer(cb, time, interval);
 }
 
 void EventLoop::updateChannel(Channel* channel)
 {
   assert(channel->ownerLoop() == this);
   assertInLoopThread();
   poller_->updateChannel(channel);
 }
 
 void EventLoop::removeChannel(Channel* channel)
 {
   assert(channel->ownerLoop() == this);
   assertInLoopThread();
   poller_->removeChannel(channel);
 }
 
 void EventLoop::abortNotInLoopThread()
 {
   LOG_FATAL << "EventLoop::abortNotInLoopThread - EventLoop " << this
             << " was created in threadId_ = " << threadId_
             << ", current thread id = " <<  CurrentThread::tid();
 }
 
 void EventLoop::wakeup()
 {
   uint64_t one = 1;
   ssize_t n = ::write(wakeupFd_, &one, sizeof one);
   if (n != sizeof one)
   {
     LOG_ERROR << "EventLoop::wakeup() writes " << n << " bytes instead of 8";
   }
 }
 
 void EventLoop::handleRead()
 {
   uint64_t one = 1;
   ssize_t n = ::read(wakeupFd_, &one, sizeof one);
   if (n != sizeof one)
   {
     LOG_ERROR << "EventLoop::handleRead() reads " << n << " bytes instead of 8";
   }
 }
 
 void EventLoop::doPendingFunctors()
 {
   std::vector<Functor> functors;
   callingPendingFunctors_ = true;
 
   {
   MutexLockGuard lock(mutex_);
   functors.swap(pendingFunctors_);
   }
 
   for (size_t i = 0; i < functors.size(); ++i)
   {
     functors[i]();
   }
   callingPendingFunctors_ = false;
 }