EventLoopThread（IO线程类）
EventLoopThreadPool（IO线程池类）
IO线程池的功能是开启若干个IO线程，并让这些IO线程处于事件循环的状态
下面的这些代码可能和前面给出的源代码有些不一样，
阅读的同学请注意了
EventLoopThreadPool头文件
eventloopthreadpool.h
[cpp
// Copyright 2010, Shuo Chen. All rights reserved.
// 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)
//
// This is an internal header file, you should not include this.
#ifndef MUDUO_NET_EVENTLOOPTHREADPOOL_H
#define MUDUO_NET_EVENTLOOPTHREADPOOL_H
#include
#include
#include
#include
#include
#include
namespace muduo
{
namespace net
{
class EventLoop;
class EventLoopThread;
class EventLoopThreadPool : boost::noncopyable
{
public:
typedef boost::function ThreadInitCallback;
EventLoopThreadPool(EventLoop* baseLoop);
~EventLoopThreadPool();
void setThreadNum(int numThreads) { numThreads_ = numThreads; }
void start(const ThreadInitCallback& cb = ThreadInitCallback());
EventLoop* getNextLoop();
private:
EventLoop* baseLoop_; // 与Acceptor所属EventLoop相同
bool started_; /*是否启动*/
int numThreads_; // 线程数
int next_; // 新连接到来，所选择的EventLoop对象下标
boost::ptr_vector threads_; // IO线程列表
std::vector loops_; // EventLoop列表
};
}
}
#endif // MUDUO_NET_EVENTLOOPTHREADPOOL_H
EventLoopThreadPool源文件
eventloopthreadpool.cc
[cpp]
// Copyright 2010, Shuo Chen. All rights reserved.
// 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
#include
#include
#include
using namespace muduo;
using namespace muduo::net;
EventLoopThreadPool::EventLoopThreadPool(EventLoop* baseLoop)
: baseLoop_(baseLoop), // 与Acceptor所属EventLoop相同
started_(false),
numThreads_(0),
next_(0)
{
}
EventLoopThreadPool::~EventLoopThreadPool()
{
// Don't delete loop, it's stack variable
}
/*每个线程初始化时的回调函数cb*/
void EventLoopThreadPool::start(const ThreadInitCallback& cb)
{
assert(!started_);
baseLoop_->assertInLoopThread();
started_ = true;
for (int i = 0; i < numThreads_; ++i)
{
EventLoopThread* t = new EventLoopThread(cb);
threads_.push_back(t);
loops_.push_back(t->startLoop()); // 启动EventLoopThread线程，在进入事件循环之前，会调用cb
}
if (numThreads_ == 0 && cb)
{
// 只有一个EventLoop，在这个EventLoop进入事件循环之前，调用cb
cb(baseLoop_);
}
}
EventLoop* EventLoopThreadPool::getNextLoop()
{
baseLoop_->assertInLoopThread();
EventLoop* loop = baseLoop_;
// 如果loops_为空，则loop指向baseLoop_
// 如果不为空，按照round-robin（RR，轮叫）的调度方式选择一个EventLoop
if (!loops_.empty())
{
// round-robin
loop = loops_[next_];
++next_;
if (implicit_cast(next_) >= loops_.size())
{
ne