Repository: S1mpleBug/muduo_cpp11
Branch: main
Commit: 5a0a98235a91
Files: 40
Total size: 63.1 KB

Directory structure:
gitextract_yawb7po4/

├── Acceptor.cc
├── Acceptor.h
├── Buffer.cc
├── Buffer.h
├── CMakeLists.txt
├── Callbacks.h
├── Channel.cc
├── Channel.h
├── CurrentThread.cc
├── CurrentThread.h
├── DefaultPoller.cc
├── EPollPoller.cc
├── EPollPoller.h
├── EventLoop.cc
├── EventLoop.h
├── EventLoopThread.cc
├── EventLoopThread.h
├── EventLoopThreadPool.cc
├── EventLoopThreadPool.h
├── InetAddress.cc
├── InetAddress.h
├── Logger.cc
├── Logger.h
├── Poller.cc
├── Poller.h
├── README.md
├── Socket.cc
├── Socket.h
├── TcpConnection.cc
├── TcpConnection.h
├── TcpServer.cc
├── TcpServer.h
├── Thread.cc
├── Thread.h
├── Timestamp.cc
├── Timestamp.h
├── build.sh
├── example/
│   ├── Makefile
│   └── testserver.cc
└── noncopyable.h

================================================
FILE CONTENTS
================================================

================================================
FILE: Acceptor.cc
================================================
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <unistd.h>

#include "Acceptor.h"
#include "Logger.h"
#include "InetAddress.h"

static int createNonblocking()
{
    int sockfd = ::socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, IPPROTO_TCP);
    if (sockfd < 0)
    {
        LOG_FATAL("%s:%s:%d listen socket create err:%d\n", __FILE__, __FUNCTION__, __LINE__, errno);
    }
    return sockfd;
}

Acceptor::Acceptor(EventLoop *loop, const InetAddress &listenAddr, bool reuseport)
    : loop_(loop)
    , acceptSocket_(createNonblocking())
    , acceptChannel_(loop, acceptSocket_.fd())
    , listenning_(false)
{
    acceptSocket_.setReuseAddr(true);
    acceptSocket_.setReusePort(true);
    acceptSocket_.bindAddress(listenAddr);
    // TcpServer::start() => Acceptor.listen() 如果有新用户连接 要执行一个回调(accept => connfd => 打包成Channel => 唤醒subloop)
    // baseloop监听到有事件发生 => acceptChannel_(listenfd) => 执行该回调函数
    acceptChannel_.setReadCallback(
        std::bind(&Acceptor::handleRead, this));
}

Acceptor::~Acceptor()
{
    acceptChannel_.disableAll();    // 把从Poller中感兴趣的事件删除掉
    acceptChannel_.remove();        // 调用EventLoop->removeChannel => Poller->removeChannel 把Poller的ChannelMap对应的部分删除
}

void Acceptor::listen()
{
    listenning_ = true;
    acceptSocket_.listen();         // listen
    acceptChannel_.enableReading(); // acceptChannel_注册至Poller !重要
}

// listenfd有事件发生了，就是有新用户连接了
void Acceptor::handleRead()
{
    InetAddress peerAddr;
    int connfd = acceptSocket_.accept(&peerAddr);
    if (connfd >= 0)
    {
        if (NewConnectionCallback_)
        {
            NewConnectionCallback_(connfd, peerAddr); // 轮询找到subLoop 唤醒并分发当前的新客户端的Channel
        }
        else
        {
            ::close(connfd);
        }
    }
    else
    {
        LOG_ERROR("%s:%s:%d accept err:%d\n", __FILE__, __FUNCTION__, __LINE__, errno);
        if (errno == EMFILE)
        {
            LOG_ERROR("%s:%s:%d sockfd reached limit\n", __FILE__, __FUNCTION__, __LINE__);
        }
    }
}

================================================
FILE: Acceptor.h
================================================
#pragma once

#include <functional>

#include "noncopyable.h"
#include "Socket.h"
#include "Channel.h"

class EventLoop;
class InetAddress;

class Acceptor : noncopyable
{
public:
    using NewConnectionCallback = std::function<void(int sockfd, const InetAddress &)>;

    Acceptor(EventLoop *loop, const InetAddress &listenAddr, bool reuseport);
    ~Acceptor();

    void setNewConnectionCallback(const NewConnectionCallback &cb) { NewConnectionCallback_ = cb; }

    bool listenning() const { return listenning_; }
    void listen();

private:
    void handleRead();

    EventLoop *loop_; // Acceptor用的就是用户定义的那个baseLoop 也称作mainLoop
    Socket acceptSocket_;
    Channel acceptChannel_;
    NewConnectionCallback NewConnectionCallback_;
    bool listenning_;
};

================================================
FILE: Buffer.cc
================================================
#include <errno.h>
#include <sys/uio.h>
#include <unistd.h>

#include "Buffer.h"

/**
 * 从fd上读取数据 Poller工作在LT模式
 * Buffer缓冲区是有大小的！ 但是从fd上读取数据的时候 却不知道tcp数据的最终大小
 *
 * @description: 从socket读到缓冲区的方法是使用readv先读至buffer_，
 * Buffer_空间如果不够会读入到栈上65536个字节大小的空间，然后以append的
 * 方式追加入buffer_。既考虑了避免系统调用带来开销，又不影响数据的接收。
 **/
ssize_t Buffer::readFd(int fd, int *saveErrno)
{
    // 栈额外空间，用于从套接字往出读时，当buffer_暂时不够用时暂存数据，待buffer_重新分配足够空间后，在把数据交换给buffer_。
    char extrabuf[65536] = {0}; // 栈上内存空间 65536/1024 = 64KB

    /*
    struct iovec {
        ptr_t iov_base; // iov_base指向的缓冲区存放的是readv所接收的数据或是writev将要发送的数据
        size_t iov_len; // iov_len在各种情况下分别确定了接收的最大长度以及实际写入的长度
    };
    */

    // 使用iovec分配两个连续的缓冲区
    struct iovec vec[2];
    const size_t writable = writableBytes(); // 这是Buffer底层缓冲区剩余的可写空间大小 不一定能完全存储从fd读出的数据

    // 第一块缓冲区，指向可写空间
    vec[0].iov_base = begin() + writerIndex_;
    vec[0].iov_len = writable;
    // 第二块缓冲区，指向栈空间
    vec[1].iov_base = extrabuf;
    vec[1].iov_len = sizeof(extrabuf);

    // when there is enough space in this buffer, don't read into extrabuf.
    // when extrabuf is used, we read 128k-1 bytes at most.
    // 这里之所以说最多128k-1字节，是因为若writable为64k-1，那么需要两个缓冲区 第一个64k-1 第二个64k 所以做多128k-1
    // 如果第一个缓冲区>=64k 那就只采用一个缓冲区 而不使用栈空间extrabuf[65536]的内容
    const int iovcnt = (writable < sizeof(extrabuf)) ? 2 : 1;
    const ssize_t n = ::readv(fd, vec, iovcnt);

    if (n < 0)
    {
        *saveErrno = errno;
    }
    else if (n <= writable) // Buffer的可写缓冲区已经够存储读出来的数据了
    {
        writerIndex_ += n;
    }
    else // extrabuf里面也写入了n-writable长度的数据
    {
        writerIndex_ = buffer_.size();
        append(extrabuf, n - writable); // 对buffer_扩容 并将extrabuf存储的另一部分数据追加至buffer_
    }
    return n;
}

// inputBuffer_.readFd表示将对端数据读到inputBuffer_中，移动writerIndex_指针
// outputBuffer_.writeFd标示将数据写入到outputBuffer_中，从readerIndex_开始，可以写readableBytes()个字节
ssize_t Buffer::writeFd(int fd, int *saveErrno)
{
    ssize_t n = ::write(fd, peek(), readableBytes());
    if (n < 0)
    {
        *saveErrno = errno;
    }
    return n;
}

================================================
FILE: Buffer.h
================================================
#pragma once

#include <vector>
#include <string>
#include <algorithm>
#include <stddef.h>

// 网络库底层的缓冲区类型定义
class Buffer
{
public:
    static const size_t kCheapPrepend = 8;
    static const size_t kInitialSize = 1024;

    explicit Buffer(size_t initalSize = kInitialSize)
        : buffer_(kCheapPrepend + initalSize)
        , readerIndex_(kCheapPrepend)
        , writerIndex_(kCheapPrepend)
    {
    }

    size_t readableBytes() const { return writerIndex_ - readerIndex_; }
    size_t writableBytes() const { return buffer_.size() - writerIndex_; }
    size_t prependableBytes() const { return readerIndex_; }

    // 返回缓冲区中可读数据的起始地址
    const char *peek() const { return begin() + readerIndex_; }
    void retrieve(size_t len)
    {
        if (len < readableBytes())
        {
            readerIndex_ += len; // 说明应用只读取了可读缓冲区数据的一部分，就是len长度 还剩下readerIndex+=len到writerIndex_的数据未读
        }
        else // len == readableBytes()
        {
            retrieveAll();
        }
    }
    void retrieveAll()
    {
        readerIndex_ = kCheapPrepend;
        writerIndex_ = kCheapPrepend;
    }

    // 把onMessage函数上报的Buffer数据 转成string类型的数据返回
    std::string retrieveAllAsString() { return retrieveAsString(readableBytes()); }
    std::string retrieveAsString(size_t len)
    {
        std::string result(peek(), len);
        retrieve(len); // 上面一句把缓冲区中可读的数据已经读取出来 这里肯定要对缓冲区进行复位操作
        return result;
    }

    // buffer_.size - writerIndex_
    void ensureWritableBytes(size_t len)
    {
        if (writableBytes() < len)
        {
            makeSpace(len); // 扩容
        }
    }

    // 把[data, data+len]内存上的数据添加到writable缓冲区当中
    void append(const char *data, size_t len)
    {
        ensureWritableBytes(len);
        std::copy(data, data+len, beginWrite());
        writerIndex_ += len;
    }
    char *beginWrite() { return begin() + writerIndex_; }
    const char *beginWrite() const { return begin() + writerIndex_; }

    // 从fd上读取数据
    ssize_t readFd(int fd, int *saveErrno);
    // 通过fd发送数据
    ssize_t writeFd(int fd, int *saveErrno);

private:
    // vector底层数组首元素的地址 也就是数组的起始地址
    char *begin() { return &*buffer_.begin(); }
    const char *begin() const { return &*buffer_.begin(); }

    void makeSpace(size_t len)
    {
        /**
         * | kCheapPrepend |xxx| reader | writer |                     // xxx标示reader中已读的部分
         * | kCheapPrepend | reader ｜          len          |
         **/
        if (writableBytes() + prependableBytes() < len + kCheapPrepend) // 也就是说 len > xxx + writer的部分
        {
            buffer_.resize(writerIndex_ + len);
        }
        else // 这里说明 len <= xxx + writer 把reader搬到从xxx开始 使得xxx后面是一段连续空间
        {
            size_t readable = readableBytes(); // readable = reader的长度
            std::copy(begin() + readerIndex_,
                      begin() + writerIndex_,  // 把这一部分数据拷贝到begin+kCheapPrepend起始处
                      begin() + kCheapPrepend);
            readerIndex_ = kCheapPrepend;
            writerIndex_ = readerIndex_ + readable;
        }
    }

    std::vector<char> buffer_;
    size_t readerIndex_;
    size_t writerIndex_;
};


================================================
FILE: CMakeLists.txt
================================================
cmake_minimum_required(VERSION 2.5)
project(mymuduo)

# mymuduo最终编译成so动态库 设置动态库的路径 放置项目根目录的lib文件夹下面
set(LIBRARY_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/lib)

# 设置调试信息  以及启动C++11语言标准
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g -std=c++11")

# 定义参与编译的源代码文件
aux_source_directory(. SRC_LIST)

# 编译动态库
add_library(mymuduo SHARED ${SRC_LIST})

================================================
FILE: Callbacks.h
================================================
#pragma once

#include <memory>
#include <functional>

class Buffer;
class TcpConnection;
class Timestamp;

using TcpConnectionPtr = std::shared_ptr<TcpConnection>;
using ConnectionCallback = std::function<void(const TcpConnectionPtr &)>;
using CloseCallback = std::function<void(const TcpConnectionPtr &)>;
using WriteCompleteCallback = std::function<void(const TcpConnectionPtr &)>;
using HighWaterMarkCallback = std::function<void(const TcpConnectionPtr &, size_t)>;

using MessageCallback = std::function<void(const TcpConnectionPtr &,
                                           Buffer *,
                                           Timestamp)>;

================================================
FILE: Channel.cc
================================================
#include <sys/epoll.h>

#include "Channel.h"
#include "EventLoop.h"
#include "Logger.h"

const int Channel::kNoneEvent = 0;
const int Channel::kReadEvent = EPOLLIN | EPOLLPRI;
const int Channel::kWriteEvent = EPOLLOUT;

// EventLoop: ChannelList Poller
Channel::Channel(EventLoop *loop, int fd)
    : loop_(loop)
    , fd_(fd)
    , events_(0)
    , revents_(0)
    , index_(-1)
    , tied_(false)
{
}

Channel::~Channel()
{
}

// channel的tie方法什么时候调用过?  TcpConnection => channel
/**
 * TcpConnection中注册了Chnanel对应的回调函数，传入的回调函数均为TcpConnection
 * 对象的成员方法，因此可以说明一点就是：Channel的结束一定早于TcpConnection对象！
 * 此处用tie去解决TcoConnection和Channel的生命周期时长问题，从而保证了Channel对
 * 象能够在TcpConnection销毁前销毁。
 **/
void Channel::tie(const std::shared_ptr<void> &obj)
{
    tie_ = obj;
    tied_ = true;
}

/**
 * 当改变channel所表示的fd的events事件后，update负责再poller里面更改fd相应的事件epoll_ctl
 **/
void Channel::update()
{
    // 通过channel所属的eventloop，调用poller的相应方法，注册fd的events事件
    loop_->updateChannel(this);
}

// 在channel所属的EventLoop中把当前的channel删除掉
void Channel::remove()
{
    loop_->removeChannel(this);
}

void Channel::handleEvent(Timestamp receiveTime)
{
    if (tied_)
    {
        std::shared_ptr<void> guard = tie_.lock();
        if (guard)
        {
            handleEventWithGuard(receiveTime);
        }
        // 如果提升失败了 就不做任何处理 说明Channel的TcpConnection对象已经不存在了
    }
    else
    {
        handleEventWithGuard(receiveTime);
    }
}

void Channel::handleEventWithGuard(Timestamp receiveTime)
{
    LOG_INFO("channel handleEvent revents:%d\n", revents_);
    // 关闭
    if ((revents_ & EPOLLHUP) && !(revents_ & EPOLLIN)) // 当TcpConnection对应Channel 通过shutdown 关闭写端 epoll触发EPOLLHUP
    {
        if (closeCallback_)
        {
            closeCallback_();
        }
    }
    // 错误
    if (revents_ & EPOLLERR)
    {
        if (errorCallback_)
        {
            errorCallback_();
        }
    }
    // 读
    if (revents_ & (EPOLLIN | EPOLLPRI))
    {
        if (readCallback_)
        {
            readCallback_(receiveTime);
        }
    }
    // 写
    if (revents_ & EPOLLOUT)
    {
        if (writeCallback_)
        {
            writeCallback_();
        }
    }
}

================================================
FILE: Channel.h
================================================
#pragma once

#include <functional>
#include <memory>

#include "noncopyable.h"
#include "Timestamp.h"

class EventLoop;

/**
 * 理清楚 EventLoop、Channel、Poller之间的关系  Reactor模型上对应多路事件分发器
 * Channel理解为通道 封装了sockfd和其感兴趣的event 如EPOLLIN、EPOLLOUT事件 还绑定了poller返回的具体事件
 **/
class Channel : noncopyable
{
public:
    using EventCallback = std::function<void()>; // muduo仍使用typedef
    using ReadEventCallback = std::function<void(Timestamp)>;

    Channel(EventLoop *loop, int fd);
    ~Channel();

    // fd得到Poller通知以后 处理事件 handleEvent在EventLoop::loop()中调用
    void handleEvent(Timestamp receiveTime);

    // 设置回调函数对象
    void setReadCallback(ReadEventCallback cb) { readCallback_ = std::move(cb); }
    void setWriteCallback(EventCallback cb) { writeCallback_ = std::move(cb); }
    void setCloseCallback(EventCallback cb) { closeCallback_ = std::move(cb); }
    void setErrorCallback(EventCallback cb) { errorCallback_ = std::move(cb); }

    // 防止当channel被手动remove掉 channel还在执行回调操作
    void tie(const std::shared_ptr<void> &);

    int fd() const { return fd_; }
    int events() const { return events_; }
    void set_revents(int revt) { revents_ = revt; }

    // 设置fd相应的事件状态 相当于epoll_ctl add delete
    void enableReading() { events_ |= kReadEvent; update(); }
    void disableReading() { events_ &= ~kReadEvent; update(); }
    void enableWriting() { events_ |= kWriteEvent; update(); }
    void disableWriting() { events_ &= ~kWriteEvent; update(); }
    void disableAll() { events_ = kNoneEvent; update(); }

    // 返回fd当前的事件状态
    bool isNoneEvent() const { return events_ == kNoneEvent; }
    bool isWriting() const { return events_ & kWriteEvent; }
    bool isReading() const { return events_ & kReadEvent; }

    int index() { return index_; }
    void set_index(int idx) { index_ = idx; }

    // one loop per thread
    EventLoop *ownerLoop() { return loop_; }
    void remove();
private:

    void update();
    void handleEventWithGuard(Timestamp receiveTime);

    static const int kNoneEvent;
    static const int kReadEvent;
    static const int kWriteEvent;

    EventLoop *loop_; // 事件循环
    const int fd_;    // fd，Poller监听的对象
    int events_;      // 注册fd感兴趣的事件
    int revents_;     // Poller返回的具体发生的事件
    int index_;

    std::weak_ptr<void> tie_;
    bool tied_;

    // 因为channel通道里可获知fd最终发生的具体的事件events，所以它负责调用具体事件的回调操作
    ReadEventCallback readCallback_;
    EventCallback writeCallback_;
    EventCallback closeCallback_;
    EventCallback errorCallback_;
};

================================================
FILE: CurrentThread.cc
================================================
#include "CurrentThread.h"

namespace CurrentThread
{
    __thread int t_cachedTid = 0;

    void cacheTid()
    {
        if (t_cachedTid == 0)
        {
            t_cachedTid = static_cast<pid_t>(::syscall(SYS_gettid));
        }
    }
}

================================================
FILE: CurrentThread.h
================================================
#pragma once

#include <unistd.h>
#include <sys/syscall.h>

namespace CurrentThread
{
    extern __thread int t_cachedTid; // 保存tid缓存 因为系统调用非常耗时 拿到tid后将其保存

    void cacheTid();

    inline int tid() // 内联函数只在当前文件中起作用
    {
        if (__builtin_expect(t_cachedTid == 0, 0)) // __builtin_expect 是一种底层优化 此语句意思是如果还未获取tid 进入if 通过cacheTid()系统调用获取tid
        {
            cacheTid();
        }
        return t_cachedTid;
    }
}

================================================
FILE: DefaultPoller.cc
================================================
#include <stdlib.h>

#include "Poller.h"
#include "EPollPoller.h"

Poller *Poller::newDefaultPoller(EventLoop *loop)
{
    if (::getenv("MUDUO_USE_POLL"))
    {
        return nullptr; // 生成poll的实例
    }
    else
    {
        return new EPollPoller(loop); // 生成epoll的实例
    }
}

================================================
FILE: EPollPoller.cc
================================================
#include <errno.h>
#include <unistd.h>
#include <string.h>

#include "EPollPoller.h"
#include "Logger.h"
#include "Channel.h"

const int kNew = -1;    // 某个channel还没添加至Poller          // channel的成员index_初始化为-1
const int kAdded = 1;   // 某个channel已经添加至Poller
const int kDeleted = 2; // 某个channel已经从Poller删除

EPollPoller::EPollPoller(EventLoop *loop)
    : Poller(loop)
    , epollfd_(::epoll_create1(EPOLL_CLOEXEC))
    , events_(kInitEventListSize) // vector<epoll_event>(16)
{
    if (epollfd_ < 0)
    {
        LOG_FATAL("epoll_create error:%d \n", errno);
    }
}

EPollPoller::~EPollPoller()
{
    ::close(epollfd_);
}

Timestamp EPollPoller::poll(int timeoutMs, ChannelList *activeChannels)
{
    // 由于频繁调用poll 实际上应该用LOG_DEBUG输出日志更为合理 当遇到并发场景 关闭DEBUG日志提升效率
    LOG_INFO("func=%s => fd total count:%lu\n", __FUNCTION__, channels_.size());

    int numEvents = ::epoll_wait(epollfd_, &*events_.begin(), static_cast<int>(events_.size()), timeoutMs);
    int saveErrno = errno;
    Timestamp now(Timestamp::now());

    if (numEvents > 0)
    {
        LOG_INFO("%d events happend\n", numEvents); // LOG_DEBUG最合理
        fillActiveChannels(numEvents, activeChannels);
        if (numEvents == events_.size()) // 扩容操作
        {
            events_.resize(events_.size() * 2);
        }
    }
    else if (numEvents == 0)
    {
        LOG_DEBUG("%s timeout!\n", __FUNCTION__);
    }
    else
    {
        if (saveErrno != EINTR)
        {
            errno = saveErrno;
            LOG_ERROR("EPollPoller::poll() error!");
        }
    }
    return now;
}

// channel update remove => EventLoop updateChannel removeChannel => Poller updateChannel removeChannel
void EPollPoller::updateChannel(Channel *channel)
{
    const int index = channel->index();
    LOG_INFO("func=%s => fd=%d events=%d index=%d\n", __FUNCTION__, channel->fd(), channel->events(), index);

    if (index == kNew || index == kDeleted)
    {
        if (index == kNew)
        {
            int fd = channel->fd();
            channels_[fd] = channel;
        }
        else // index == kAdd
        {
        }
        channel->set_index(kAdded);
        update(EPOLL_CTL_ADD, channel);
    }
    else // channel已经在Poller中注册过了
    {
        int fd = channel->fd();
        if (channel->isNoneEvent())
        {
            update(EPOLL_CTL_DEL, channel);
            channel->set_index(kDeleted);
        }
        else
        {
            update(EPOLL_CTL_MOD, channel);
        }
    }
}

// 从Poller中删除channel
void EPollPoller::removeChannel(Channel *channel)
{
    int fd = channel->fd();
    channels_.erase(fd);

    LOG_INFO("func=%s => fd=%d\n", __FUNCTION__, fd);

    int index = channel->index();
    if (index == kAdded)
    {
        update(EPOLL_CTL_DEL, channel);
    }
    channel->set_index(kNew);
}

// 填写活跃的连接
void EPollPoller::fillActiveChannels(int numEvents, ChannelList *activeChannels) const
{
    for (int i = 0; i < numEvents; ++i)
    {
        Channel *channel = static_cast<Channel *>(events_[i].data.ptr);
        channel->set_revents(events_[i].events);
        activeChannels->push_back(channel); // EventLoop就拿到了它的Poller给它返回的所有发生事件的channel列表了
    }
}

// 更新channel通道 其实就是调用epoll_ctl add/mod/del
void EPollPoller::update(int operation, Channel *channel)
{
    epoll_event event;
    ::memset(&event, 0, sizeof(event));

    int fd = channel->fd();

    event.events = channel->events();
    event.data.fd = fd;
    event.data.ptr = channel;

    if (::epoll_ctl(epollfd_, operation, fd, &event) < 0)
    {
        if (operation == EPOLL_CTL_DEL)
        {
            LOG_ERROR("epoll_ctl del error:%d\n", errno);
        }
        else
        {
            LOG_FATAL("epoll_ctl add/mod error:%d\n", errno);
        }
    }
}

================================================
FILE: EPollPoller.h
================================================
#pragma once

#include <vector>
#include <sys/epoll.h>

#include "Poller.h"
#include "Timestamp.h"

/**
 * epoll的使用:
 * 1. epoll_create
 * 2. epoll_ctl (add, mod, del)
 * 3. epoll_wait
 **/

class Channel;

class EPollPoller : public Poller
{
public:
    EPollPoller(EventLoop *loop);
    ~EPollPoller() override;

    // 重写基类Poller的抽象方法
    Timestamp poll(int timeoutMs, ChannelList *activeChannels) override;
    void updateChannel(Channel *channel) override;
    void removeChannel(Channel *channel) override;

private:
    static const int kInitEventListSize = 16;

    // 填写活跃的连接
    void fillActiveChannels(int numEvents, ChannelList *activeChannels) const;
    // 更新channel通道 其实就是调用epoll_ctl
    void update(int operation, Channel *channel);

    using EventList = std::vector<epoll_event>; // C++中可以省略struct 直接写epoll_event即可

    int epollfd_;      // epoll_create创建返回的fd保存在epollfd_中
    EventList events_; // 用于存放epoll_wait返回的所有发生的事件的文件描述符事件集
};

================================================
FILE: EventLoop.cc
================================================
#include <sys/eventfd.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <memory>

#include "EventLoop.h"
#include "Logger.h"
#include "Channel.h"
#include "Poller.h"

// 防止一个线程创建多个EventLoop
__thread EventLoop *t_loopInThisThread = nullptr;

// 定义默认的Poller IO复用接口的超时时间
const int kPollTimeMs = 10000; // 10000毫秒 = 10秒钟

/* 创建线程之后主线程和子线程谁先运行是不确定的。
 * 通过一个eventfd在线程之间传递数据的好处是多个线程无需上锁就可以实现同步。
 * eventfd支持的最低内核版本为Linux 2.6.27,在2.6.26及之前的版本也可以使用eventfd，但是flags必须设置为0。
 * 函数原型：
 *     #include <sys/eventfd.h>
 *     int eventfd(unsigned int initval, int flags);
 * 参数说明：
 *      initval,初始化计数器的值。
 *      flags, EFD_NONBLOCK,设置socket为非阻塞。
 *             EFD_CLOEXEC，执行fork的时候，在父进程中的描述符会自动关闭，子进程中的描述符保留。
 * 场景：
 *     eventfd可以用于同一个进程之中的线程之间的通信。
 *     eventfd还可以用于同亲缘关系的进程之间的通信。
 *     eventfd用于不同亲缘关系的进程之间通信的话需要把eventfd放在几个进程共享的共享内存中（没有测试过）。
 */
// 创建wakeupfd 用来notify唤醒subReactor处理新来的channel
int createEventfd()
{
    int evtfd = ::eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
    if (evtfd < 0)
    {
        LOG_FATAL("eventfd error:%d\n", errno);
    }
    return evtfd;
}

EventLoop::EventLoop()
    : looping_(false)
    , quit_(false)
    , callingPendingFunctors_(false)
    , threadId_(CurrentThread::tid())
    , poller_(Poller::newDefaultPoller(this))
    , wakeupFd_(createEventfd())
    , wakeupChannel_(new Channel(this, wakeupFd_))
{
    LOG_DEBUG("EventLoop created %p in thread %d\n", this, threadId_);
    if (t_loopInThisThread)
    {
        LOG_FATAL("Another EventLoop %p exists in this thread %d\n", t_loopInThisThread, threadId_);
    }
    else
    {
        t_loopInThisThread = this;
    }
    
    wakeupChannel_->setReadCallback(
        std::bind(&EventLoop::handleRead, this)); // 设置wakeupfd的事件类型以及发生事件后的回调操作
    
    wakeupChannel_->enableReading(); // 每一个EventLoop都将监听wakeupChannel_的EPOLL读事件了
}
EventLoop::~EventLoop()
{
    wakeupChannel_->disableAll(); // 给Channel移除所有感兴趣的事件
    wakeupChannel_->remove();     // 把Channel从EventLoop上删除掉
    ::close(wakeupFd_);
    t_loopInThisThread = nullptr;
}

// 开启事件循环
void EventLoop::loop()
{
    looping_ = true;
    quit_ = false;

    LOG_INFO("EventLoop %p start looping\n", this);

    while (!quit_)
    {
        activeChannels_.clear();
        pollRetureTime_ = poller_->poll(kPollTimeMs, &activeChannels_);
        for (Channel *channel : activeChannels_)
        {
            // Poller监听哪些channel发生了事件 然后上报给EventLoop 通知channel处理相应的事件
            channel->handleEvent(pollRetureTime_);
        }
        /**
         * 执行当前EventLoop事件循环需要处理的回调操作 对于线程数 >=2 的情况 IO线程 mainloop(mainReactor) 主要工作：
         * accept接收连接 => 将accept返回的connfd打包为Channel => TcpServer::newConnection通过轮询将TcpConnection对象分配给subloop处理
         *
         * mainloop调用queueInLoop将回调加入subloop（该回调需要subloop执行 但subloop还在poller_->poll处阻塞） queueInLoop通过wakeup将subloop唤醒
         **/
        doPendingFunctors();
    }
    LOG_INFO("EventLoop %p stop looping.\n", this);
    looping_ = false;
}

/**
 * 退出事件循环
 * 1. 如果loop在自己的线程中调用quit成功了 说明当前线程已经执行完毕了loop()函数的poller_->poll并退出
 * 2. 如果不是当前EventLoop所属线程中调用quit退出EventLoop 需要唤醒EventLoop所属线程的epoll_wait
 *
 * 比如在一个subloop(worker)中调用mainloop(IO)的quit时 需要唤醒mainloop(IO)的poller_->poll 让其执行完loop()函数
 *
 * ！！！ 注意： 正常情况下 mainloop负责请求连接 将回调写入subloop中 通过生产者消费者模型即可实现线程安全的队列
 * ！！！       但是muduo通过wakeup()机制 使用eventfd创建的wakeupFd_ notify 使得mainloop和subloop之间能够进行通信
 **/
void EventLoop::quit()
{
    quit_ = true;

    if (!isInLoopThread())
    {
        wakeup();
    }
}

// 在当前loop中执行cb
void EventLoop::runInLoop(Functor cb)
{
    if (isInLoopThread()) // 当前EventLoop中执行回调
    {
        cb();
    }
    else // 在非当前EventLoop线程中执行cb，就需要唤醒EventLoop所在线程执行cb
    {
        queueInLoop(cb);
    }
}

// 把cb放入队列中 唤醒loop所在的线程执行cb
void EventLoop::queueInLoop(Functor cb)
{
    {
        std::unique_lock<std::mutex> lock(mutex_);
        pendingFunctors_.emplace_back(cb);
    }

    /**
     * || callingPendingFunctors的意思是 当前loop正在执行回调中 但是loop的pendingFunctors_中又加入了新的回调 需要通过wakeup写事件
     * 唤醒相应的需要执行上面回调操作的loop的线程 让loop()下一次poller_->poll()不再阻塞（阻塞的话会延迟前一次新加入的回调的执行），然后
     * 继续执行pendingFunctors_中的回调函数
     **/
    if (!isInLoopThread() || callingPendingFunctors_)
    {
        wakeup(); // 唤醒loop所在线程
    }
}

void EventLoop::handleRead()
{
    uint64_t one = 1;
    ssize_t n = read(wakeupFd_, &one, sizeof(one));
    if (n != sizeof(one))
    {
        LOG_ERROR("EventLoop::handleRead() reads %lu bytes instead of 8\n", n);
    }
}

// 用来唤醒loop所在线程 向wakeupFd_写一个数据 wakeupChannel就发生读事件 当前loop线程就会被唤醒
void EventLoop::wakeup()
{
    uint64_t one = 1;
    ssize_t n = write(wakeupFd_, &one, sizeof(one));
    if (n != sizeof(one))
    {
        LOG_ERROR("EventLoop::wakeup() writes %lu bytes instead of 8\n", n);
    }
}

// EventLoop的方法 => Poller的方法
void EventLoop::updateChannel(Channel *channel)
{
    poller_->updateChannel(channel);
}

void EventLoop::removeChannel(Channel *channel)
{
    poller_->removeChannel(channel);
}

bool EventLoop::hasChannel(Channel *channel)
{
    return poller_->hasChannel(channel);
}

void EventLoop::doPendingFunctors()
{
    std::vector<Functor> functors;
    callingPendingFunctors_ = true;

    {
        std::unique_lock<std::mutex> lock(mutex_);
        functors.swap(pendingFunctors_); // 交换的方式减少了锁的临界区范围 提升效率 同时避免了死锁 如果执行functor()在临界区内 且functor()中调用queueInLoop()就会产生死锁
    }

    for (const Functor &functor : functors)
    {
        functor(); // 执行当前loop需要执行的回调操作
    }

    callingPendingFunctors_ = false;
}


================================================
FILE: EventLoop.h
================================================
#pragma once

#include <functional>
#include <vector>
#include <atomic>
#include <memory>
#include <mutex>

#include "noncopyable.h"
#include "Timestamp.h"
#include "CurrentThread.h"

class Channel;
class Poller;

// 事件循环类 主要包含了两个大模块 Channel Poller(epoll的抽象)
class EventLoop : noncopyable
{
public:
    using Functor = std::function<void()>;

    EventLoop();
    ~EventLoop();

    // 开启事件循环
    void loop();
    // 退出事件循环
    void quit();

    Timestamp pollReturnTime() const { pollRetureTime_; }

    // 在当前loop中执行
    void runInLoop(Functor cb);
    // 把上层注册的回调函数cb放入队列中 唤醒loop所在的线程执行cb
    void queueInLoop(Functor cb);

    // 通过eventfd唤醒loop所在的线程
    void wakeup();

    // EventLoop的方法 => Poller的方法
    void updateChannel(Channel *channel);
    void removeChannel(Channel *channel);
    bool hasChannel(Channel *channel);

    // 判断EventLoop对象是否在自己的线程里
    bool isInLoopThread() const { return threadId_ == CurrentThread::tid(); } // threadId_为EventLoop创建时的线程id CurrentThread::tid()为当前线程id

private:
    void handleRead();        // 给eventfd返回的文件描述符wakeupFd_绑定的事件回调 当wakeup()时 即有事件发生时 调用handleRead()读wakeupFd_的8字节 同时唤醒阻塞的epoll_wait
    void doPendingFunctors(); // 执行上层回调

    using ChannelList = std::vector<Channel *>;

    std::atomic_bool looping_; // 原子操作 底层通过CAS实现
    std::atomic_bool quit_;    // 标识退出loop循环

    const pid_t threadId_; // 记录当前EventLoop是被哪个线程id创建的 即标识了当前EventLoop的所属线程id

    Timestamp pollRetureTime_; // Poller返回发生事件的Channels的时间点
    std::unique_ptr<Poller> poller_;

    int wakeupFd_; // 作用：当mainLoop获取一个新用户的Channel 需通过轮询算法选择一个subLoop 通过该成员唤醒subLoop处理Channel
    std::unique_ptr<Channel> wakeupChannel_;

    ChannelList activeChannels_; // 返回Poller检测到当前有事件发生的所有Channel列表

    std::atomic_bool callingPendingFunctors_; // 标识当前loop是否有需要执行的回调操作
    std::vector<Functor> pendingFunctors_;    // 存储loop需要执行的所有回调操作
    std::mutex mutex_;                        // 互斥锁 用来保护上面vector容器的线程安全操作
};

================================================
FILE: EventLoopThread.cc
================================================
#include "EventLoopThread.h"
#include "EventLoop.h"

EventLoopThread::EventLoopThread(const ThreadInitCallback &cb,
                                 const std::string &name)
    : loop_(nullptr)
    , exiting_(false)
    , thread_(std::bind(&EventLoopThread::threadFunc, this), name)
    , mutex_()
    , cond_()
    , callback_(cb)
{
}

EventLoopThread::~EventLoopThread()
{
    exiting_ = true;
    if (loop_ != nullptr)
    {
        loop_->quit();
        thread_.join();
    }
}

EventLoop *EventLoopThread::startLoop()
{
    thread_.start(); // 启用底层线程Thread类对象thread_中通过start()创建的线程

    EventLoop *loop = nullptr;
    {
        std::unique_lock<std::mutex> lock(mutex_);
        while(loop_ == nullptr)
        {
            cond_.wait(lock);
        }
        loop = loop_;
    }
    return loop;
}

// 下面这个方法 是在单独的新线程里运行的
void EventLoopThread::threadFunc()
{
    EventLoop loop; // 创建一个独立的EventLoop对象 和上面的线程是一一对应的 级one loop per thread

    if (callback_)
    {
        callback_(&loop);
    }

    {
        std::unique_lock<std::mutex> lock(mutex_);
        loop_ = &loop;
        cond_.notify_one();
    }
    loop.loop();    // 执行EventLoop的loop() 开启了底层的Poller的poll()
    std::unique_lock<std::mutex> lock(mutex_);
    loop_ = nullptr;
}

================================================
FILE: EventLoopThread.h
================================================
#pragma once

#include <functional>
#include <mutex>
#include <condition_variable>
#include <string>

#include "noncopyable.h"
#include "Thread.h"

class EventLoop;

class EventLoopThread : noncopyable
{
public:
    using ThreadInitCallback = std::function<void(EventLoop *)>;

    EventLoopThread(const ThreadInitCallback &cb = ThreadInitCallback(),
                    const std::string &name = std::string());
    ~EventLoopThread();

    EventLoop *startLoop();

private:
    void threadFunc();

    EventLoop *loop_;
    bool exiting_;
    Thread thread_;
    std::mutex mutex_;             // 互斥锁
    std::condition_variable cond_; // 条件变量
    ThreadInitCallback callback_;
};

================================================
FILE: EventLoopThreadPool.cc
================================================
#include <memory>

#include "EventLoopThreadPool.h"
#include "EventLoopThread.h"

EventLoopThreadPool::EventLoopThreadPool(EventLoop *baseLoop, const std::string &nameArg)
    : baseLoop_(baseLoop)
    , name_(nameArg)
    , started_(false)
    , numThreads_(0)
    , next_(0)
{
}

EventLoopThreadPool::~EventLoopThreadPool()
{
    // Don't delete loop, it's stack variable
}

void EventLoopThreadPool::start(const ThreadInitCallback &cb)
{
    started_ = true;

    for(int i = 0; i < numThreads_; ++i)
    {
        char buf[name_.size() + 32];
        snprintf(buf, sizeof buf, "%s%d", name_.c_str(), i);
        EventLoopThread *t = new EventLoopThread(cb, buf);
        threads_.push_back(std::unique_ptr<EventLoopThread>(t));
        loops_.push_back(t->startLoop());                           // 底层创建线程 绑定一个新的EventLoop 并返回该loop的地址
    }

    if(numThreads_ == 0 && cb)                                      // 整个服务端只有一个线程运行baseLoop
    {
        cb(baseLoop_);
    }
}

// 如果工作在多线程中，baseLoop_(mainLoop)会默认以轮询的方式分配Channel给subLoop
EventLoop *EventLoopThreadPool::getNextLoop()
{
    EventLoop *loop = baseLoop_;    // 如果只设置一个线程 也就是只有一个mainReactor 无subReactor 那么轮询只有一个线程 getNextLoop()每次都返回当前的baseLoop_

    if(!loops_.empty())             // 通过轮询获取下一个处理事件的loop
    {
        loop = loops_[next_];
        ++next_;
        if(next_ >= loops_.size())
        {
            next_ = 0;
        }
    }

    return loop;
}

std::vector<EventLoop *> EventLoopThreadPool::getAllLoops()
{
    if(loops_.empty())
    {
        return std::vector<EventLoop *>(1, baseLoop_);
    }
    else
    {
        return loops_;
    }
}

================================================
FILE: EventLoopThreadPool.h
================================================
#pragma once

#include <functional>
#include <string>
#include <vector>
#include <memory>

#include "noncopyable.h"

class EventLoop;
class EventLoopThread;

class EventLoopThreadPool : noncopyable
{
public:
    using ThreadInitCallback = std::function<void(EventLoop *)>;

    EventLoopThreadPool(EventLoop *baseLoop, const std::string &nameArg);
    ~EventLoopThreadPool();

    void setThreadNum(int numThreads) { numThreads_ = numThreads; }

    void start(const ThreadInitCallback &cb = ThreadInitCallback());

    // 如果工作在多线程中，baseLoop_(mainLoop)会默认以轮询的方式分配Channel给subLoop
    EventLoop *getNextLoop();

    std::vector<EventLoop *> getAllLoops();

    bool started() const { return started_; }
    const std::string name() const { return name_; }

private:
    EventLoop *baseLoop_; // 用户使用muduo创建的loop 如果线程数为1 那直接使用用户创建的loop 否则创建多EventLoop
    std::string name_;
    bool started_;
    int numThreads_;
    int next_; // 轮询的下标
    std::vector<std::unique_ptr<EventLoopThread>> threads_;
    std::vector<EventLoop *> loops_;
};

================================================
FILE: InetAddress.cc
================================================
#include <strings.h>
#include <string.h>

#include "InetAddress.h"

InetAddress::InetAddress(uint16_t port, std::string ip)
{
    ::memset(&addr_, 0, sizeof(addr_));
    addr_.sin_family = AF_INET;
    addr_.sin_port = ::htons(port); // 本地字节序转为网络字节序
    addr_.sin_addr.s_addr = ::inet_addr(ip.c_str());
}

std::string InetAddress::toIp() const
{
    // addr_
    char buf[64] = {0};
    ::inet_ntop(AF_INET, &addr_.sin_addr, buf, sizeof buf);
    return buf;
}

std::string InetAddress::toIpPort() const
{
    // ip:port
    char buf[64] = {0};
    ::inet_ntop(AF_INET, &addr_.sin_addr, buf, sizeof buf);
    size_t end = ::strlen(buf);
    uint16_t port = ::ntohs(addr_.sin_port);
    sprintf(buf+end, ":%u", port);
    return buf;
}

uint16_t InetAddress::toPort() const
{
    return ::ntohs(addr_.sin_port);
}

#if 0
#include <iostream>
int main()
{
    InetAddress addr(8080);
    std::cout << addr.toIpPort() << std::endl;
}
#endif

================================================
FILE: InetAddress.h
================================================
#pragma once

#include <arpa/inet.h>
#include <netinet/in.h>
#include <string>

// 封装socket地址类型
class InetAddress
{
public:
    explicit InetAddress(uint16_t port = 0, std::string ip = "127.0.0.1");
    explicit InetAddress(const sockaddr_in &addr)
        : addr_(addr)
    {
    }

    std::string toIp() const;
    std::string toIpPort() const;
    uint16_t toPort() const;

    const sockaddr_in *getSockAddr() const { return &addr_; }
    void setSockAddr(const sockaddr_in &addr) { addr_ = addr; }

private:
    sockaddr_in addr_;
};

================================================
FILE: Logger.cc
================================================
#include <iostream>

#include "Logger.h"
#include "Timestamp.h"

// 获取日志唯一的实例对象 单例
Logger &Logger::instance()
{
    static Logger logger;
    return logger;
}

// 设置日志级别
void Logger::setLogLevel(int level)
{
    logLevel_ = level;
}

// 写日志 [级别信息] time : msg
void Logger::log(std::string msg)
{
    std::string pre = "";
    switch (logLevel_)
    {
    case INFO:
        pre = "[INFO]";
        break;
    case ERROR:
        pre = "[ERROR]";
        break;
    case FATAL:
        pre = "[FATAL]";
        break;
    case DEBUG:
        pre = "[DEBUG]";
        break;
    default:
        break;
    }

    // 打印时间和msg
    std::cout << pre + Timestamp::now().toString() << " : " << msg << std::endl;
}

================================================
FILE: Logger.h
================================================
#pragma once

#include <string>

#include "noncopyable.h"

// LOG_INFO("%s %d", arg1, arg2)
#define LOG_INFO(logmsgFormat, ...)                       \
    do                                                    \
    {                                                     \
        Logger &logger = Logger::instance();              \
        logger.setLogLevel(INFO);                         \
        char buf[1024] = {0};                             \
        snprintf(buf, 1024, logmsgFormat, ##__VA_ARGS__); \
        logger.log(buf);                                  \
    } while (0)

#define LOG_ERROR(logmsgFormat, ...)                      \
    do                                                    \
    {                                                     \
        Logger &logger = Logger::instance();              \
        logger.setLogLevel(ERROR);                        \
        char buf[1024] = {0};                             \
        snprintf(buf, 1024, logmsgFormat, ##__VA_ARGS__); \
        logger.log(buf);                                  \
    } while (0)

#define LOG_FATAL(logmsgFormat, ...)                      \
    do                                                    \
    {                                                     \
        Logger &logger = Logger::instance();              \
        logger.setLogLevel(FATAL);                        \
        char buf[1024] = {0};                             \
        snprintf(buf, 1024, logmsgFormat, ##__VA_ARGS__); \
        logger.log(buf);                                  \
        exit(-1);                                         \
    } while (0)

#ifdef MUDEBUG
#define LOG_DEBUG(logmsgFormat, ...)                      \
    do                                                    \
    {                                                     \
        Logger &logger = Logger::instance();              \
        logger.setLogLevel(DEBUG);                        \
        char buf[1024] = {0};                             \
        snprintf(buf, 1024, logmsgFormat, ##__VA_ARGS__); \
        logger.log(buf);                                  \
    } while (0)
#else
#define LOG_DEBUG(logmsgFormat, ...)
#endif

// 定义日志的级别 INFO ERROR FATAL DEBUG
enum LogLevel
{
    INFO,  // 普通信息
    ERROR, // 错误信息
    FATAL, // core dump信息
    DEBUG, // 调试信息
};

// 输出一个日志类

class Logger : noncopyable
{
public:
    // 获取日志唯一的实例对象 单例
    static Logger &instance();
    // 设置日志级别
    void setLogLevel(int level);
    // 写日志
    void log(std::string msg);

private:
    int logLevel_;
};

================================================
FILE: Poller.cc
================================================
#include "Poller.h"
#include "Channel.h"

Poller::Poller(EventLoop *loop)
    : ownerLoop_(loop)
{
}

bool Poller::hasChannel(Channel *channel) const
{
    auto it = channels_.find(channel->fd());
    return it != channels_.end() && it->second == channel;
}

================================================
FILE: Poller.h
================================================
#pragma once

#include <vector>
#include <unordered_map>

#include "noncopyable.h"
#include "Timestamp.h"

class Channel;
class EventLoop;

// muduo库中多路事件分发器的核心IO复用模块
class Poller
{
public:
    using ChannelList = std::vector<Channel *>;

    Poller(EventLoop *loop);
    virtual ~Poller() = default;

    // 给所有IO复用保留统一的接口
    virtual Timestamp poll(int timeoutMs, ChannelList *activeChannels) = 0;
    virtual void updateChannel(Channel *channel) = 0;
    virtual void removeChannel(Channel *channel) = 0;

    // 判断参数channel是否在当前的Poller当中
    bool hasChannel(Channel *channel) const;

    // EventLoop可以通过该接口获取默认的IO复用的具体实现
    static Poller *newDefaultPoller(EventLoop *loop);

protected:
    // map的key:sockfd value:sockfd所属的channel通道类型
    using ChannelMap = std::unordered_map<int, Channel *>;
    ChannelMap channels_;

private:
    EventLoop *ownerLoop_; // 定义Poller所属的事件循环EventLoop
};

================================================
FILE: README.md
================================================
# C++11 Muduo

![流程图](./img/a.png)

## 开发环境

* linux kernel version 4.4.0 (ubuntu 16.04 Server)
* gcc version 5.4.0
* cmake version 3.5.1

项目编译执行`./build.sh`即可，测试用例进入`example/`文件夹，`make`即可生成服务器测试用例

## 功能介绍

头文件生成至目录`/usr/include/mymuduo/`，`.so`库文件生成至目录`/usr/lib/`。

1. `EventLoop.*`、`Channel.*`、`Poller.*`、`EPollPoller.*`等主要用于事件轮询检测，并实现了事件分发处理的底层实现方法。`EventLoop`负责轮询执行`Poller`，要进行读、写、错误、关闭等事件时需执行哪些回调函数，均绑定至`Channel`中，只需从中调用即可，事件发生后进行相应的回调处理即可
2. `Thread.*`、`EventLoopThread.*`、`EventLoopThreadPool.*`等将线程和`EventLoop`事件轮询绑定在一起，实现真正意义上的`one loop per thread`
3. `TcpServer.*`、`TcpConnection.*`、`Acceptor.*`、`Socket.*`等是`mainloop`对网络连接的响应并轮询分发至各个`subloop`的实现，其中注册大量回调函数
4. `Buffer.*`为`muduo`网络库自行设计的自动扩容的缓冲区，保证数据有序性到达


## 技术亮点

1. `EventLoop`中使用了`eventfd`来调用`wakeup()`，让`mainloop`唤醒`subloop`的`epoll_wait`阻塞
2. 在`EventLoop`中注册回调`cb`至`pendingFunctors_`，并在`doPendingFunctors`中通过`swap()`的方式，快速换出注册的回调，只在`swap()`时加锁，减少代码临界区长度，提升效率。（若不通过`swap()`的方式去处理，而是加锁执行`pendingFunctors`中的回调，然后解锁，会出现什么问题呢？1. 临界区过大，锁降低了服务器响应效率 2. 若执行的回调中执行`queueInLoop`需要抢占锁时，会发生死锁）
3. `Logger`可以设置日志等级，调试代码时可以开启`DEBUG`打印日志；若启动服务器，由于日志会影响服务器性能，可适当关闭`DEBUG`相关日志输出
4. 在`Thread`中通过`C++lambda`表达式以及信号量机制保证线程创建时的有序性，只有当线程获取到了其自己的`tid`后，才算启动线程完毕
5. `TcpConnection`继承自`enable_shared_from_this`，`TcpConnection`对象可以调用`shared_from_this()`方法给其内部回调函数，相当于创建了一个带引用计数的`shared_ptr`，可参考链接 [link](https://blog.csdn.net/gc348342215/article/details/123215888)，同时`muduo`通过`tie()`方式解决了`TcpConnection`对象生命周期先于`Channel`结束的情况
6. `muduo`采用`Reactor`模型和多线程结合的方式，实现了高并发非阻塞网络库


## 视频介绍

* [muduo源码剖析(1)-简介](https://www.bilibili.com/video/BV1nu411Q7Gq)
* [muduo源码剖析(2)-muduo编写回射服务器实例](https://www.bilibili.com/video/BV1CY411g7AE)
* [muduo源码剖析(3)-Timestamp类日志类](https://www.bilibili.com/video/BV1dF411x7A8)
* [muduo源码剖析(4)-Channel类](https://www.bilibili.com/video/BV14a411h7JW)
* [muduo源码剖析(5)-Poller类、EPollPoller类等相关](https://www.bilibili.com/video/BV1VL4y1u714)
* [muduo源码剖析(6)-EventLoop类介绍1](https://www.bilibili.com/video/BV1aY411g7As)
* [muduo源码剖析(7)-EventLoop类介绍2](https://www.bilibili.com/video/BV1kS4y1S7DC)
* [muduo源码剖析(8)-Thread类、EventLoopThread类](https://www.bilibili.com/video/BV1GL411P73C)
* [muduo源码剖析(9)-EventLoopThreadPool类](https://www.bilibili.com/video/BV1yS4y1S7FY)
* [muduo源码剖析(10)-InetAddress类、Socket类](https://www.bilibili.com/video/BV1UU4y1o7BT)
* [muduo源码剖析(11)-Acceptor类1](https://www.bilibili.com/video/BV1q3411W79d)
* [muduo源码剖析(12)-Acceptor类2](https://www.bilibili.com/video/BV1Ua411b7aV)
* [muduo源码剖析(13)-TcpConnection类、Buffer类](https://www.bilibili.com/video/BV1hS4y137Eg)
* [muduo源码剖析(14)-TcpConnection类、Buffer类2](https://www.bilibili.com/video/BV1PS4y1D74z)
* [muduo源码剖析(15)-TcpConnection类](https://www.bilibili.com/video/BV1L3411p7jy)
* [muduo源码剖析(16)-TcpServer类](https://www.bilibili.com/video/BV13Y411u74h)

持续更新..


================================================
FILE: Socket.cc
================================================
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include <netinet/tcp.h>
#include <sys/socket.h>

#include "Socket.h"
#include "Logger.h"
#include "InetAddress.h"

Socket::~Socket()
{
    ::close(sockfd_);
}

void Socket::bindAddress(const InetAddress &localaddr)
{
    if (0 != ::bind(sockfd_, (sockaddr *)localaddr.getSockAddr(), sizeof(sockaddr_in)))
    {
        LOG_FATAL("bind sockfd:%d fail\n", sockfd_);
    }
}

void Socket::listen()
{
    if (0 != ::listen(sockfd_, 1024))
    {
        LOG_FATAL("listen sockfd:%d fail\n", sockfd_);
    }
}

int Socket::accept(InetAddress *peeraddr)
{
    /**
     * 1. accept函数的参数不合法
     * 2. 对返回的connfd没有设置非阻塞
     * Reactor模型 one loop per thread
     * poller + non-blocking IO
     **/
    sockaddr_in addr;
    socklen_t len = sizeof(addr);
    ::memset(&addr, 0, sizeof(addr));
    // fixed : int connfd = ::accept(sockfd_, (sockaddr *)&addr, &len);
    int connfd = ::accept4(sockfd_, (sockaddr *)&addr, &len, SOCK_NONBLOCK | SOCK_CLOEXEC);
    if (connfd >= 0)
    {
        peeraddr->setSockAddr(addr);
    }
    return connfd;
}

void Socket::shutdownWrite()
{
    if (::shutdown(sockfd_, SHUT_WR) < 0)
    {
        LOG_ERROR("shutdownWrite error");
    }
}

void Socket::setTcpNoDelay(bool on)
{
    int optval = on ? 1 : 0;
    ::setsockopt(sockfd_, IPPROTO_TCP, TCP_NODELAY, &optval, sizeof(optval)); // TCP_NODELAY包含头文件 <netinet/tcp.h>
}
void Socket::setReuseAddr(bool on)
{
    int optval = on ? 1 : 0;
    ::setsockopt(sockfd_, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval)); // TCP_NODELAY包含头文件 <netinet/tcp.h>
}
void Socket::setReusePort(bool on)
{
    int optval = on ? 1 : 0;
    ::setsockopt(sockfd_, SOL_SOCKET, SO_REUSEPORT, &optval, sizeof(optval)); // TCP_NODELAY包含头文件 <netinet/tcp.h>
}
void Socket::setKeepAlive(bool on)
{
    int optval = on ? 1 : 0;
    ::setsockopt(sockfd_, SOL_SOCKET, SO_KEEPALIVE, &optval, sizeof(optval)); // TCP_NODELAY包含头文件 <netinet/tcp.h>
}

================================================
FILE: Socket.h
================================================
#pragma once

#include "noncopyable.h"

class InetAddress;

// 封装socket fd
class Socket : noncopyable
{
public:
    explicit Socket(int sockfd)
        : sockfd_(sockfd)
    {
    }
    ~Socket();

    int fd() const { return sockfd_; }
    void bindAddress(const InetAddress &localaddr);
    void listen();
    int accept(InetAddress *peeraddr);

    void shutdownWrite();

    void setTcpNoDelay(bool on);
    void setReuseAddr(bool on);
    void setReusePort(bool on);
    void setKeepAlive(bool on);

private:
    const int sockfd_;
};


================================================
FILE: TcpConnection.cc
================================================
#include <functional>
#include <string>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include <netinet/tcp.h>

#include "TcpConnection.h"
#include "Logger.h"
#include "Socket.h"
#include "Channel.h"
#include "EventLoop.h"

static EventLoop *CheckLoopNotNull(EventLoop *loop)
{
    if (loop == nullptr)
    {
        LOG_FATAL("%s:%s:%d mainLoop is null!\n", __FILE__, __FUNCTION__, __LINE__);
    }
    return loop;
}

TcpConnection::TcpConnection(EventLoop *loop,
                             const std::string &nameArg,
                             int sockfd,
                             const InetAddress &localAddr,
                             const InetAddress &peerAddr)
    : loop_(CheckLoopNotNull(loop))
    , name_(nameArg)
    , state_(kConnecting)
    , reading_(true)
    , socket_(new Socket(sockfd))
    , channel_(new Channel(loop, sockfd))
    , localAddr_(localAddr)
    , peerAddr_(peerAddr)
    , highWaterMark_(64 * 1024 * 1024) // 64M
{
    // 下面给channel设置相应的回调函数 poller给channel通知感兴趣的事件发生了 channel会回调相应的回调函数
    channel_->setReadCallback(
        std::bind(&TcpConnection::handleRead, this, std::placeholders::_1));
    channel_->setWriteCallback(
        std::bind(&TcpConnection::handleWrite, this));
    channel_->setCloseCallback(
        std::bind(&TcpConnection::handleClose, this));
    channel_->setErrorCallback(
        std::bind(&TcpConnection::handleError, this));

    LOG_INFO("TcpConnection::ctor[%s] at fd=%d\n", name_.c_str(), sockfd);
    socket_->setKeepAlive(true);
}

TcpConnection::~TcpConnection()
{
    LOG_INFO("TcpConnection::dtor[%s] at fd=%d state=%d\n", name_.c_str(), channel_->fd(), (int)state_);
}

void TcpConnection::send(const std::string &buf)
{
    if (state_ == kConnected)
    {
        if (loop_->isInLoopThread()) // 这种是对于单个reactor的情况 用户调用conn->send时 loop_即为当前线程
        {
            sendInLoop(buf.c_str(), buf.size());
        }
        else
        {
            loop_->runInLoop(
                std::bind(&TcpConnection::sendInLoop, this, buf.c_str(), buf.size()));
        }
    }
}

/**
 * 发送数据 应用写的快 而内核发送数据慢 需要把待发送数据写入缓冲区，而且设置了水位回调
 **/
void TcpConnection::sendInLoop(const void *data, size_t len)
{
    ssize_t nwrote = 0;
    size_t remaining = len;
    bool faultError = false;

    if (state_ == kDisconnected) // 之前调用过该connection的shutdown 不能再进行发送了
    {
        LOG_ERROR("disconnected, give up writing");
    }

    // 表示channel_第一次开始写数据或者缓冲区没有待发送数据
    if (!channel_->isWriting() && outputBuffer_.readableBytes() == 0)
    {
        nwrote = ::write(channel_->fd(), data, len);
        if (nwrote >= 0)
        {
            remaining = len - nwrote;
            if (remaining == 0 && writeCompleteCallback_)
            {
                // 既然在这里数据全部发送完成，就不用再给channel设置epollout事件了
                loop_->queueInLoop(
                    std::bind(writeCompleteCallback_, shared_from_this()));
            }
        }
        else // nwrote < 0
        {
            nwrote = 0;
            if (errno != EWOULDBLOCK) // EWOULDBLOCK表示非阻塞情况下没有数据后的正常返回 等同于EAGAIN
            {
                LOG_ERROR("TcpConnection::sendInLoop");
                if (errno == EPIPE || errno == ECONNRESET) // SIGPIPE RESET
                {
                    faultError = true;
                }
            }
        }
    }
    /**
     * 说明当前这一次write并没有把数据全部发送出去 剩余的数据需要保存到缓冲区当中
     * 然后给channel注册EPOLLOUT事件，Poller发现tcp的发送缓冲区有空间后会通知
     * 相应的sock->channel，调用channel对应注册的writeCallback_回调方法，
     * channel的writeCallback_实际上就是TcpConnection设置的handleWrite回调，
     * 把发送缓冲区outputBuffer_的内容全部发送完成
     **/
    if (!faultError && remaining > 0)
    {
        // 目前发送缓冲区剩余的待发送的数据的长度
        size_t oldLen = outputBuffer_.readableBytes();
        if (oldLen + remaining >= highWaterMark_ && oldLen < highWaterMark_ && highWaterMarkCallback_)
        {
            loop_->queueInLoop(
                std::bind(highWaterMarkCallback_, shared_from_this(), oldLen + remaining));
        }
        outputBuffer_.append((char *)data + nwrote, remaining);
        if (!channel_->isWriting())
        {
            channel_->enableWriting(); // 这里一定要注册channel的写事件 否则poller不会给channel通知epollout
        }
    }
}

void TcpConnection::shutdown()
{
    if (state_ == kConnected)
    {
        setState(kDisconnecting);
        loop_->runInLoop(
            std::bind(&TcpConnection::shutdownInLoop, this));
    }
}

void TcpConnection::shutdownInLoop()
{
    if (!channel_->isWriting()) // 说明当前outputBuffer_的数据全部向外发送完成
    {
        socket_->shutdownWrite();
    }
}

// 连接建立
void TcpConnection::connectEstablished()
{
    setState(kConnected);
    channel_->tie(shared_from_this());
    channel_->enableReading(); // 向poller注册channel的EPOLLIN读事件

    // 新连接建立 执行回调
    connectionCallback_(shared_from_this());
}
// 连接销毁
void TcpConnection::connectDestroyed()
{
    if (state_ == kConnected)
    {
        setState(kDisconnected);
        channel_->disableAll(); // 把channel的所有感兴趣的事件从poller中删除掉
        connectionCallback_(shared_from_this());
    }
    channel_->remove(); // 把channel从poller中删除掉
}

// 读是相对服务器而言的 当对端客户端有数据到达 服务器端检测到EPOLLIN 就会触发该fd上的回调 handleRead取读走对端发来的数据
void TcpConnection::handleRead(Timestamp receiveTime)
{
    int savedErrno = 0;
    ssize_t n = inputBuffer_.readFd(channel_->fd(), &savedErrno);
    if (n > 0) // 有数据到达
    {
        // 已建立连接的用户有可读事件发生了 调用用户传入的回调操作onMessage shared_from_this就是获取了TcpConnection的智能指针
        messageCallback_(shared_from_this(), &inputBuffer_, receiveTime);
    }
    else if (n == 0) // 客户端断开
    {
        handleClose();
    }
    else // 出错了
    {
        errno = savedErrno;
        LOG_ERROR("TcpConnection::handleRead");
        handleError();
    }
}

void TcpConnection::handleWrite()
{
    if (channel_->isWriting())
    {
        int savedErrno = 0;
        ssize_t n = outputBuffer_.writeFd(channel_->fd(), &savedErrno);
        if (n > 0)
        {
            outputBuffer_.retrieve(n);
            if (outputBuffer_.readableBytes() == 0)
            {
                channel_->disableWriting();
                if (writeCompleteCallback_)
                {
                    // TcpConnection对象在其所在的subloop中 向pendingFunctors_中加入回调
                    loop_->queueInLoop(
                        std::bind(writeCompleteCallback_, shared_from_this()));
                }
                if (state_ == kDisconnecting)
                {
                    shutdownInLoop(); // 在当前所属的loop中把TcpConnection删除掉
                }
            }
        }
        else
        {
            LOG_ERROR("TcpConnection::handleWrite");
        }
    }
    else
    {
        LOG_ERROR("TcpConnection fd=%d is down, no more writing", channel_->fd());
    }
}

void TcpConnection::handleClose()
{
    LOG_INFO("TcpConnection::handleClose fd=%d state=%d\n", channel_->fd(), (int)state_);
    setState(kDisconnected);
    channel_->disableAll();

    TcpConnectionPtr connPtr(shared_from_this());
    connectionCallback_(connPtr); // 执行连接关闭的回调
    closeCallback_(connPtr);      // 执行关闭连接的回调 执行的是TcpServer::removeConnection回调方法   // must be the last line
}

void TcpConnection::handleError()
{
    int optval;
    socklen_t optlen = sizeof optval;
    int err = 0;
    if (::getsockopt(channel_->fd(), SOL_SOCKET, SO_ERROR, &optval, &optlen) < 0)
    {
        err = errno;
    }
    else
    {
        err = optval;
    }
    LOG_ERROR("TcpConnection::handleError name:%s - SO_ERROR:%d\n", name_.c_str(), err);
}

================================================
FILE: TcpConnection.h
================================================
#pragma once

#include <memory>
#include <string>
#include <atomic>

#include "noncopyable.h"
#include "InetAddress.h"
#include "Callbacks.h"
#include "Buffer.h"
#include "Timestamp.h"

class Channel;
class EventLoop;
class Socket;

/**
 * TcpServer => Acceptor => 有一个新用户连接，通过accept函数拿到connfd
 * => TcpConnection设置回调 => 设置到Channel => Poller => Channel回调
 **/

class TcpConnection : noncopyable, public std::enable_shared_from_this<TcpConnection>
{
public:
    TcpConnection(EventLoop *loop,
                  const std::string &nameArg,
                  int sockfd,
                  const InetAddress &localAddr,
                  const InetAddress &peerAddr);
    ~TcpConnection();

    EventLoop *getLoop() const { return loop_; }
    const std::string &name() const { return name_; }
    const InetAddress &localAddress() const { return localAddr_; }
    const InetAddress &peerAddress() const { return peerAddr_; }

    bool connected() const { return state_ == kConnected; }

    // 发送数据
    void send(const std::string &buf);
    // 关闭连接
    void shutdown();

    void setConnectionCallback(const ConnectionCallback &cb)
    { connectionCallback_ = cb; }
    void setMessageCallback(const MessageCallback &cb)
    { messageCallback_ = cb; }
    void setWriteCompleteCallback(const WriteCompleteCallback &cb)
    { writeCompleteCallback_ = cb; }
    void setCloseCallback(const CloseCallback &cb)
    { closeCallback_ = cb; }
    void setHighWaterMarkCallback(const HighWaterMarkCallback &cb, size_t highWaterMark)
    { highWaterMarkCallback_ = cb; highWaterMark_ = highWaterMark; }

    // 连接建立
    void connectEstablished();
    // 连接销毁
    void connectDestroyed();

private:
    enum StateE
    {
        kDisconnected, // 已经断开连接
        kConnecting,   // 正在连接
        kConnected,    // 已连接
        kDisconnecting // 正在断开连接
    };
    void setState(StateE state) { state_ = state; }

    void handleRead(Timestamp receiveTime);
    void handleWrite();
    void handleClose();
    void handleError();

    void sendInLoop(const void *data, size_t len);
    void shutdownInLoop();

    EventLoop *loop_; // 这里是baseloop还是subloop由TcpServer中创建的线程数决定 若为多Reactor 该loop_指向subloop 若为单Reactor 该loop_指向baseloop
    const std::string name_;
    std::atomic_int state_;
    bool reading_;

    // Socket Channel 这里和Acceptor类似    Acceptor => mainloop    TcpConnection => subloop
    std::unique_ptr<Socket> socket_;
    std::unique_ptr<Channel> channel_;

    const InetAddress localAddr_;
    const InetAddress peerAddr_;

    // 这些回调TcpServer也有 用户通过写入TcpServer注册 TcpServer再将注册的回调传递给TcpConnection TcpConnection再将回调注册到Channel中
    ConnectionCallback connectionCallback_;       // 有新连接时的回调
    MessageCallback messageCallback_;             // 有读写消息时的回调
    WriteCompleteCallback writeCompleteCallback_; // 消息发送完成以后的回调
    HighWaterMarkCallback highWaterMarkCallback_;
    CloseCallback closeCallback_;
    size_t highWaterMark_;

    // 数据缓冲区
    Buffer inputBuffer_;    // 接收数据的缓冲区
    Buffer outputBuffer_;   // 发送数据的缓冲区 用户send向outputBuffer_发
};


================================================
FILE: TcpServer.cc
================================================
#include <functional>
#include <string.h>

#include "TcpServer.h"
#include "Logger.h"
#include "TcpConnection.h"

static EventLoop *CheckLoopNotNull(EventLoop *loop)
{
    if (loop == nullptr)
    {
        LOG_FATAL("%s:%s:%d mainLoop is null!\n", __FILE__, __FUNCTION__, __LINE__);
    }
    return loop;
}

TcpServer::TcpServer(EventLoop *loop,
                     const InetAddress &listenAddr,
                     const std::string &nameArg,
                     Option option)
    : loop_(CheckLoopNotNull(loop))
    , ipPort_(listenAddr.toIpPort())
    , name_(nameArg)
    , acceptor_(new Acceptor(loop, listenAddr, option == kReusePort))
    , threadPool_(new EventLoopThreadPool(loop, name_))
    , connectionCallback_()
    , messageCallback_()
    , nextConnId_(1)
    , started_(0)
{
    // 当有新用户连接时，Acceptor类中绑定的acceptChannel_会有读事件发生，执行handleRead()调用TcpServer::newConnection回调
    acceptor_->setNewConnectionCallback(
        std::bind(&TcpServer::newConnection, this, std::placeholders::_1, std::placeholders::_2));
}

TcpServer::~TcpServer()
{
    for(auto &item : connections_)
    {
        TcpConnectionPtr conn(item.second);
        item.second.reset();    // 把原始的智能指针复位 让栈空间的TcpConnectionPtr conn指向该对象 当conn出了其作用域 即可释放智能指针指向的对象
        // 销毁连接
        conn->getLoop()->runInLoop(
            std::bind(&TcpConnection::connectDestroyed, conn));
    }
}

// 设置底层subloop的个数
void TcpServer::setThreadNum(int numThreads)
{
    threadPool_->setThreadNum(numThreads);
}

// 开启服务器监听
void TcpServer::start()
{
    if (started_++ == 0)    // 防止一个TcpServer对象被start多次
    {
        threadPool_->start(threadInitCallback_);    // 启动底层的loop线程池
        loop_->runInLoop(std::bind(&Acceptor::listen, acceptor_.get()));
    }
}

// 有一个新用户连接，acceptor会执行这个回调操作，负责将mainLoop接收到的请求连接(acceptChannel_会有读事件发生)通过回调轮询分发给subLoop去处理
void TcpServer::newConnection(int sockfd, const InetAddress &peerAddr)
{
    // 轮询算法 选择一个subLoop 来管理connfd对应的channel
    EventLoop *ioLoop = threadPool_->getNextLoop();
    char buf[64] = {0};
    snprintf(buf, sizeof buf, "-%s#%d", ipPort_.c_str(), nextConnId_);
    ++nextConnId_;  // 这里没有设置为原子类是因为其只在mainloop中执行 不涉及线程安全问题
    std::string connName = name_ + buf;

    LOG_INFO("TcpServer::newConnection [%s] - new connection [%s] from %s\n",
             name_.c_str(), connName.c_str(), peerAddr.toIpPort().c_str());
    
    // 通过sockfd获取其绑定的本机的ip地址和端口信息
    sockaddr_in local;
    ::memset(&local, 0, sizeof(local));
    socklen_t addrlen = sizeof(local);
    if(::getsockname(sockfd, (sockaddr *)&local, &addrlen) < 0)
    {
        LOG_ERROR("sockets::getLocalAddr");
    }

    InetAddress localAddr(local);
    TcpConnectionPtr conn(new TcpConnection(ioLoop,
                                            connName,
                                            sockfd,
                                            localAddr,
                                            peerAddr));
    connections_[connName] = conn;
    // 下面的回调都是用户设置给TcpServer => TcpConnection的，至于Channel绑定的则是TcpConnection设置的四个，handleRead,handleWrite... 这下面的回调用于handlexxx函数中
    conn->setConnectionCallback(connectionCallback_);
    conn->setMessageCallback(messageCallback_);
    conn->setWriteCompleteCallback(writeCompleteCallback_);

    // 设置了如何关闭连接的回调
    conn->setCloseCallback(
        std::bind(&TcpServer::removeConnection, this, std::placeholders::_1));

    ioLoop->runInLoop(
        std::bind(&TcpConnection::connectEstablished, conn));
}

void TcpServer::removeConnection(const TcpConnectionPtr &conn)
{
    loop_->runInLoop(
        std::bind(&TcpServer::removeConnectionInLoop, this, conn));
}

void TcpServer::removeConnectionInLoop(const TcpConnectionPtr &conn)
{
    LOG_INFO("TcpServer::removeConnectionInLoop [%s] - connection %s\n",
             name_.c_str(), conn->name().c_str());

    connections_.erase(conn->name());
    EventLoop *ioLoop = conn->getLoop();
    ioLoop->queueInLoop(
        std::bind(&TcpConnection::connectDestroyed, conn));
}

================================================
FILE: TcpServer.h
================================================
#pragma once

/**
 * 用户使用muduo编写服务器程序
 **/

#include <functional>
#include <string>
#include <memory>
#include <atomic>
#include <unordered_map>

#include "EventLoop.h"
#include "Acceptor.h"
#include "InetAddress.h"
#include "noncopyable.h"
#include "EventLoopThreadPool.h"
#include "Callbacks.h"
#include "TcpConnection.h"
#include "Buffer.h"

// 对外的服务器编程使用的类
class TcpServer
{
public:
    using ThreadInitCallback = std::function<void(EventLoop *)>;

    enum Option
    {
        kNoReusePort,
        kReusePort,
    };

    TcpServer(EventLoop *loop,
              const InetAddress &listenAddr,
              const std::string &nameArg,
              Option option = kNoReusePort);
    ~TcpServer();

    void setThreadInitCallback(const ThreadInitCallback &cb) { threadInitCallback_ = cb; }
    void setConnectionCallback(const ConnectionCallback &cb) { connectionCallback_ = cb; }
    void setMessageCallback(const MessageCallback &cb) { messageCallback_ = cb; }
    void setWriteCompleteCallback(const WriteCompleteCallback &cb) { writeCompleteCallback_ = cb; }

    // 设置底层subloop的个数
    void setThreadNum(int numThreads);

    // 开启服务器监听
    void start();

private:
    void newConnection(int sockfd, const InetAddress &peerAddr);
    void removeConnection(const TcpConnectionPtr &conn);
    void removeConnectionInLoop(const TcpConnectionPtr &conn);

    using ConnectionMap = std::unordered_map<std::string, TcpConnectionPtr>;

    EventLoop *loop_; // baseloop 用户自定义的loop

    const std::string ipPort_;
    const std::string name_;

    std::unique_ptr<Acceptor> acceptor_; // 运行在mainloop 任务就是监听新连接事件

    std::shared_ptr<EventLoopThreadPool> threadPool_; // one loop per thread

    ConnectionCallback connectionCallback_;       //有新连接时的回调
    MessageCallback messageCallback_;             // 有读写事件发生时的回调
    WriteCompleteCallback writeCompleteCallback_; // 消息发送完成后的回调

    ThreadInitCallback threadInitCallback_; // loop线程初始化的回调

    std::atomic_int started_;

    int nextConnId_;
    ConnectionMap connections_; // 保存所有的连接
};

================================================
FILE: Thread.cc
================================================
#include "Thread.h"
#include "CurrentThread.h"

#include <semaphore.h>

std::atomic_int Thread::numCreated_(0);

Thread::Thread(ThreadFunc func, const std::string &name)
    : started_(false)
    , joined_(false)
    , tid_(0)
    , func_(std::move(func))
    , name_(name)
{
    setDefaultName();
}

Thread::~Thread()
{
    if (started_ && !joined_)
    {
        thread_->detach();                                                  // thread类提供了设置分离线程的方法 线程运行后自动销毁（非阻塞）
    }
}

void Thread::start()                                                        // 一个Thread对象 记录的就是一个新线程的详细信息
{
    started_ = true;
    sem_t sem;
    sem_init(&sem, false, 0);                                               // false指的是 不设置进程间共享
    // 开启线程
    thread_ = std::shared_ptr<std::thread>(new std::thread([&]() {
        tid_ = CurrentThread::tid();                                        // 获取线程的tid值
        sem_post(&sem);
        func_();                                                            // 开启一个新线程 专门执行该线程函数
    }));

    // 这里必须等待获取上面新创建的线程的tid值
    sem_wait(&sem);
}

// C++ std::thread 中join()和detach()的区别：https://blog.nowcoder.net/n/8fcd9bb6e2e94d9596cf0a45c8e5858a
void Thread::join()
{
    joined_ = true;
    thread_->join();
}

void Thread::setDefaultName()
{
    int num = ++numCreated_;
    if (name_.empty())
    {
        char buf[32] = {0};
        snprintf(buf, sizeof buf, "Thread%d", num);
        name_ = buf;
    }
}

================================================
FILE: Thread.h
================================================
#pragma once

#include <functional>
#include <thread>
#include <memory>
#include <unistd.h>
#include <string>
#include <atomic>

#include "noncopyable.h"

class Thread : noncopyable
{
public:
    using ThreadFunc = std::function<void()>;

    explicit Thread(ThreadFunc, const std::string &name = std::string());
    ~Thread();

    void start();
    void join();

    bool started() { return started_; }
    pid_t tid() const { return tid_; }
    const std::string &name() const { return name_; }

    static int numCreated() { return numCreated_; }

private:
    void setDefaultName();

    bool started_;
    bool joined_;
    std::shared_ptr<std::thread> thread_;
    pid_t tid_;       // 在线程创建时再绑定
    ThreadFunc func_; // 线程回调函数
    std::string name_;
    static std::atomic_int numCreated_;
};

================================================
FILE: Timestamp.cc
================================================
#include <time.h>

#include "Timestamp.h"

Timestamp::Timestamp() : microSecondsSinceEpoch_(0)
{
}

Timestamp::Timestamp(int64_t microSecondsSinceEpoch)
    : microSecondsSinceEpoch_(microSecondsSinceEpoch)
{
}

Timestamp Timestamp::now()
{
    return Timestamp(time(NULL));
}
std::string Timestamp::toString() const
{
    char buf[128] = {0};
    tm *tm_time = localtime(&microSecondsSinceEpoch_);
    snprintf(buf, 128, "%4d/%02d/%02d %02d:%02d:%02d",
             tm_time->tm_year + 1900,
             tm_time->tm_mon + 1,
             tm_time->tm_mday,
             tm_time->tm_hour,
             tm_time->tm_min,
             tm_time->tm_sec);
    return buf;
}

// #include <iostream>
// int main() {
//     std::cout << Timestamp::now().toString() << std::endl;
//     return 0;
// }

================================================
FILE: Timestamp.h
================================================
#pragma once

#include <iostream>
#include <string>

class Timestamp
{
public:
    Timestamp();
    explicit Timestamp(int64_t microSecondsSinceEpoch);
    static Timestamp now();
    std::string toString() const;

private:
    int64_t microSecondsSinceEpoch_;
};

================================================
FILE: build.sh
================================================
#!/bin/bash

set -e

# 如果没有build目录 创建该目录
if [ ! -d `pwd`/build ]; then
    mkdir `pwd`/build
fi

rm -fr `pwd`/build/*
cd `pwd`/build &&
    cmake .. &&
    make

# 回到项目根目录
cd ..

# 把头文件拷贝到 /usr/include/mymuduo       .so库拷贝到 /usr/lib
if [ ! -d /usr/include/mymuduo ]; then
    mkdir /usr/include/mymuduo
fi

for header in `ls *.h`
do
    cp $header /usr/include/mymuduo
done

cp `pwd`/lib/libmymuduo.so /usr/lib

ldconfig

================================================
FILE: example/Makefile
================================================
testserver :
	g++ -g -o testserver testserver.cc -lmymuduo -lpthread -std=c++11

clean :
	rm -f testserver

================================================
FILE: example/testserver.cc
================================================
#include <string>

#include <mymuduo/TcpServer.h>
#include <mymuduo/Logger.h>

class EchoServer
{
public:
    EchoServer(EventLoop *loop, const InetAddress &addr, const std::string &name)
        : server_(loop, addr, name)
        , loop_(loop)
    {
        // 注册回调函数
        server_.setConnectionCallback(
            std::bind(&EchoServer::onConnection, this, std::placeholders::_1));
        
        server_.setMessageCallback(
            std::bind(&EchoServer::onMessage, this, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3));

        // 设置合适的subloop线程数量
        server_.setThreadNum(3);
    }
    void start()
    {
        server_.start();
    }

private:
    // 连接建立或断开的回调函数
    void onConnection(const TcpConnectionPtr &conn)   
    {
        if (conn->connected())
        {
            LOG_INFO("Connection UP : %s", conn->peerAddress().toIpPort().c_str());
        }
        else
        {
            LOG_INFO("Connection DOWN : %s", conn->peerAddress().toIpPort().c_str());
        }
    }

    // 可读写事件回调
    void onMessage(const TcpConnectionPtr &conn, Buffer *buf, Timestamp time)
    {
        std::string msg = buf->retrieveAllAsString();
        conn->send(msg);
        // conn->shutdown();   // 关闭写端 底层响应EPOLLHUP => 执行closeCallback_
    }

    EventLoop *loop_;
    TcpServer server_;
};

int main() {
    EventLoop loop;
    InetAddress addr(8002);
    EchoServer server(&loop, addr, "EchoServer");
    server.start();
    loop.loop();
    return 0;
}

================================================
FILE: noncopyable.h
================================================
#pragma once // 防止头文件重复包含

/**
 * noncopyable被继承后 派生类对象可正常构造和析构 但派生类对象无法进行拷贝构造和赋值构造
 **/
class noncopyable
{
public:
    noncopyable(const noncopyable &) = delete;
    noncopyable &operator=(const noncopyable &) = delete;
    // void operator=(const noncopyable &) = delete;    // muduo将返回值变为void 这其实无可厚非
protected:
    noncopyable() = default;
    ~noncopyable() = default;
};