1 // excerpts from http://code.google.com/p/muduo/
2 //
3 // Use of this source code is governed by a BSD-style license
4 // that can be found in the License file.
5 //
6 // Author: Shuo Chen (chenshuo at chenshuo dot com)
7 
8 #include "EventLoop.h"
9 
10 #include "Channel.h"
11 #include "Poller.h"
12 #include "TimerQueue.h"
13 
14 #include "logging/Logging.h"
15 
16+#include <boost/bind.hpp>
17+
18 #include <assert.h>
19+#include <sys/eventfd.h>
20 
21 using namespace muduo;
22 
23 __thread EventLoop* t_loopInThisThread = 0;
24 const int kPollTimeMs = 10000;
25 
26+static int createEventfd()
27+{
28+  int evtfd = ::eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
29+  if (evtfd < 0)
30+  {
31+    LOG_SYSERR << "Failed in eventfd";
32+    abort();
33+  }
34+  return evtfd;
35+}
36+
37 EventLoop::EventLoop()
38   : looping_(false),
39     quit_(false),
40+    callingPendingFunctors_(false),
41     threadId_(CurrentThread::tid()),
42     poller_(new Poller(this)),
43     timerQueue_(new TimerQueue(this)),
44+    wakeupFd_(createEventfd()),
45+    wakeupChannel_(new Channel(this, wakeupFd_))
46 {
47   LOG_TRACE << "EventLoop created " << this << " in thread " << threadId_;
48   if (t_loopInThisThread)
49   {
50     LOG_FATAL << "Another EventLoop " << t_loopInThisThread
51               << " exists in this thread " << threadId_;
52   }
53   else
54   {
55     t_loopInThisThread = this;
56   }
57+  wakeupChannel_->setReadCallback(
58+      boost::bind(&EventLoop::handleRead, this));
59+  // we are always reading the wakeupfd
60+  wakeupChannel_->enableReading();
61 }
62 
63 EventLoop::~EventLoop()
64 {
65   assert(!looping_);
66+  ::close(wakeupFd_);
67   t_loopInThisThread = NULL;
68 }
69 
70 void EventLoop::loop()
71 {
72   assert(!looping_);
73   assertInLoopThread();
74   looping_ = true;
75   quit_ = false;
76 
77   while (!quit_)
78   {
79     activeChannels_.clear();
80     pollReturnTime_ = poller_->poll(kPollTimeMs, &activeChannels_);
81     for (ChannelList::iterator it = activeChannels_.begin();
82         it != activeChannels_.end(); ++it)
83     {
84       (*it)->handleEvent();
85     }
86+    doPendingFunctors();
87   }
88 
89   LOG_TRACE << "EventLoop " << this << " stop looping";
90   looping_ = false;
91 }
92 
93 void EventLoop::quit()
94 {
95   quit_ = true;
96+  if (!isInLoopThread())
97+  {
98+    wakeup();
99+  }
100 }
101 
102+void EventLoop::runInLoop(const Functor& cb)
103+{
104+  if (isInLoopThread())
105+  {
106+    cb();
107+  }
108+  else
109+  {
110+    queueInLoop(cb);
111+  }
112+}
113+
114+void EventLoop::queueInLoop(const Functor& cb)
115+{
116+  {
117+  MutexLockGuard lock(mutex_);
118+  pendingFunctors_.push_back(cb);
119+  }
120+
121+  if (!isInLoopThread() || callingPendingFunctors_)
122+  {
123+    wakeup();
124+  }
125+}
126 
127 TimerId EventLoop::runAt(const Timestamp& time, const TimerCallback& cb)
128 {
129   return timerQueue_->addTimer(cb, time, 0.0);
130 }
131 
132 TimerId EventLoop::runAfter(double delay, const TimerCallback& cb)
133 {
134   Timestamp time(addTime(Timestamp::now(), delay));
135   return runAt(time, cb);
136 }
137 
138 TimerId EventLoop::runEvery(double interval, const TimerCallback& cb)
139 {
140   Timestamp time(addTime(Timestamp::now(), interval));
141   return timerQueue_->addTimer(cb, time, interval);
142 }
143 
144 void EventLoop::updateChannel(Channel* channel)
145 {
146   assert(channel->ownerLoop() == this);
147   assertInLoopThread();
148   poller_->updateChannel(channel);
149 }
150 
151 void EventLoop::abortNotInLoopThread()
152 {
153   LOG_FATAL << "EventLoop::abortNotInLoopThread - EventLoop " << this
154             << " was created in threadId_ = " << threadId_
155             << ", current thread id = " <<  CurrentThread::tid();
156 }
157 
158+void EventLoop::wakeup()
159+{
160+  uint64_t one = 1;
161+  ssize_t n = ::write(wakeupFd_, &one, sizeof one);
162+  if (n != sizeof one)
163+  {
164+    LOG_ERROR << "EventLoop::wakeup() writes " << n << " bytes instead of 8";
165+  }
166+}
167+
168+void EventLoop::handleRead()
169+{
170+  uint64_t one = 1;
171+  ssize_t n = ::read(wakeupFd_, &one, sizeof one);
172+  if (n != sizeof one)
173+  {
174+    LOG_ERROR << "EventLoop::handleRead() reads " << n << " bytes instead of 8";
175+  }
176+}
177+
178+void EventLoop::doPendingFunctors()
179+{
180+  std::vector<Functor> functors;
181+  callingPendingFunctors_ = true;
182+
183+  {
184+  MutexLockGuard lock(mutex_);
185+  functors.swap(pendingFunctors_);
186+  }
187+
188+  for (size_t i = 0; i < functors.size(); ++i)
189+  {
190+    functors[i]();
191+  }
192+  callingPendingFunctors_ = false;
193+}
194+
195