muduo用TcpClient发起连接，TcpClient有一个Connector连接器，TCPClient使用Conneccor发起连接, 连接建立成功后, 用socket创建TcpConnection来管理连接, 每个TcpClient class只管理一个TcpConnecction，连接建立成功后设置相应的回调函数。很显然，TcpClient用来管理客户端连接，真正连接交给Connector。
TcpClient.h
// 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 a public header file, it must only include public header files.
#ifndef MUDUO_NET_TCPCLIENT_H
#define MUDUO_NET_TCPCLIENT_H
#include "muduo/base/Mutex.h"
#include "muduo/net/TcpConnection.h"
namespace muduo
{
namespace net
{
class Connector;
typedef std::shared_ptr<Connector> ConnectorPtr;
//TCPClient使用Conneccor发起连接, 连接建立成功后, 用socket创建TcpConnection来管理连接, 每个TcpClient class只管理一个TcpConnecction
class TcpClient : noncopyable
{
public:
// TcpClient(EventLoop* loop);
// TcpClient(EventLoop* loop, const string& host, uint16_t port);
TcpClient(EventLoop* loop,
const InetAddress& serverAddr,
const string& nameArg);
~TcpClient(); // force out-line dtor, for std::unique_ptr members.
void connect();
void disconnect();
void stop();
TcpConnectionPtr connection() const
{
MutexLockGuard lock(mutex_);
return connection_;
}
EventLoop* getLoop() const { return loop_; }
bool retry() const { return retry_; }
void enableRetry() { retry_ = true; }
const string& name() const
{ return name_; }
/// Set connection callback.
/// Not thread safe.
void setConnectionCallback(ConnectionCallback cb)
{ connectionCallback_ = std::move(cb); }
/// Set message callback.
/// Not thread safe.
void setMessageCallback(MessageCallback cb)
{ messageCallback_ = std::move(cb); }
/// Set write complete callback.
/// Not thread safe.
void setWriteCompleteCallback(WriteCompleteCallback cb)
{ writeCompleteCallback_ = std::move(cb); }
private:
/// Not thread safe, but in loop
void newConnection(int sockfd);
/// Not thread safe, but in loop
void removeConnection(const TcpConnectionPtr& conn);
EventLoop* loop_; //用户创建传入的EventLoop
ConnectorPtr connector_; // avoid revealing Connector //指向Connector的shared_ptr
const string name_; //用户指定的名字
//这些回调函数都需要显示设置
ConnectionCallback connectionCallback_; //连接建立回调函数
MessageCallback messageCallback_; //消息到来回调函数
WriteCompleteCallback writeCompleteCallback_; //数据发送完毕回调函数
bool retry_; // atomic //连接断开后是否重连
bool connect_; // atomic
// always in loop thread
int nextConnId_; //name_+nextConnId_用于标识一个连接
mutable MutexLock mutex_;
TcpConnectionPtr connection_ GUARDED_BY(mutex_);
};
} // namespace net
} // namespace muduo
#endif // MUDUO_NET_TCPCLIENT_H
TcpClient.cc
// 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 "muduo/net/TcpClient.h"
#include "muduo/base/Logging.h"
#include "muduo/net/Connector.h"
#include "muduo/net/EventLoop.h"
#include "muduo/net/SocketsOps.h"
#include <stdio.h> // snprintf
using namespace muduo;
using namespace muduo::net;
// TcpClient::TcpClient(EventLoop* loop)
// : loop_(loop)
// {
// }
// TcpClient::TcpClient(EventLoop* loop, const string& host, uint16_t port)
// : loop_(CHECK_NOTNULL(loop)),
// serverAddr_(host, port)
// {
// }
namespace muduo
{
namespace net
{
namespace detail
{
void removeConnection(EventLoop* loop, const TcpConnectionPtr& conn)
{
loop->queueInLoop(std::bind(&TcpConnection::connectDestroyed, conn));
}
void removeConnector(const ConnectorPtr& connector)
{
//connector->
}
} // namespace detail
} // namespace net
} // namespace muduo
TcpClient::TcpClient(EventLoop* loop,
const InetAddress& serverAddr,
const string& nameArg)
: loop_(CHECK_NOTNULL(loop)),
connector_(new Connector(loop, serverAddr)),
name_(nameArg),
connectionCallback_(defaultConnectionCallback),
messageCallback_(defaultMessageCallback),
retry_(false),
connect_(true),
nextConnId_(1)
{
//将Connector的连接回调函数设置为TcpClient::newConnection
//该函数在Connector::handleWrite中被调用
connector_->setNewConnectionCallback(
std::bind(&TcpClient::newConnection, this, _1));
// FIXME setConnectFailedCallback
LOG_INFO << "TcpClient::TcpClient[" << name_
<< "] - connector " << get_pointer(connector_);
}
TcpClient::~TcpClient()
{
LOG_INFO << "TcpClient::~TcpClient[" << name_
<< "] - connector " << get_pointer(connector_);
TcpConnectionPtr conn;
bool unique = false;
{
MutexLockGuard lock(mutex_);
unique = connection_.unique();
conn = connection_;
}
if (conn)
{
assert(loop_ == conn->getLoop());
// FIXME: not 100% safe, if we are in different thread
CloseCallback cb = std::bind(&detail::removeConnection, loop_, _1);
loop_->runInLoop(
std::bind(&TcpConnection::setCloseCallback, conn, cb));
if (unique)
{
conn->forceClose();
}
}
else
{
connector_->stop();
// FIXME: HACK
loop_->runAfter(1, std::bind(&detail::removeConnector, connector_));
}
}
void TcpClient::connect()
{
// FIXME: check state
LOG_INFO << "TcpClient::connect[" << name_ << "] - connecting to "
<< connector_->serverAddress().toIpPort();
connect_ = true;
//调用Connector::start,发起连接
connector_->start();
}
void TcpClient::disconnect()
{
connect_ = false;
{
MutexLockGuard lock(mutex_);
if (connection_)
{
connection_->shutdown();
}
}
}
void TcpClient::stop()
{
connect_ = false;
connector_->stop();
}
//新连接的回调函数,将新连接封装为TcpConnection交给TcpClient来管理
void TcpClient::newConnection(int sockfd)
{
loop_->assertInLoopThread();
InetAddress peerAddr(sockets::getPeerAddr(sockfd));
char buf[32];
snprintf(buf, sizeof buf, ":%s#%d", peerAddr.toIpPort().c_str(), nextConnId_);
++nextConnId_;
string connName = name_ + buf;
InetAddress localAddr(sockets::getLocalAddr(sockfd));
// FIXME poll with zero timeout to double confirm the new connection
// FIXME use make_shared if necessary
//创建一个堆上局部TcpConnection对象，并用TcpClient的智能指针connection_保存起来
TcpConnectionPtr conn(new TcpConnection(loop_,
connName,
sockfd,
localAddr,
peerAddr));
//设置各种回调函数
conn->setConnectionCallback(connectionCallback_); //连接建立
conn->setMessageCallback(messageCallback_); //可读
conn->setWriteCompleteCallback(writeCompleteCallback_); //可写
conn->setCloseCallback(
std::bind(&TcpClient::removeConnection, this, _1)); // FIXME: unsafe
{
MutexLockGuard lock(mutex_);
//将新创建的TcpConnection赋给TcpClient类内成员connection_
connection_ = conn;
}
conn->connectEstablished();
}
void TcpClient::removeConnection(const TcpConnectionPtr& conn)
{
loop_->assertInLoopThread();
assert(loop_ == conn->getLoop());
{
MutexLockGuard lock(mutex_);
assert(connection_ == conn);
connection_.reset(); //重置
}
//I/O线程中销毁
loop_->queueInLoop(std::bind(&TcpConnection::connectDestroyed, conn));
if (retry_ && connect_) //是否发起重连
{
LOG_INFO << "TcpClient::connect[" << name_ << "] - Reconnecting to "
<< connector_->serverAddress().toIpPort();
//这里的重连是连接成功后断开的重连，所以实际上是重启
connector_->restart();
}
}
