boost :: asio tcp async_read永远不会返回
我想转换一些现有的代码来使用boost的asio tcp套接字,而不是我们当前的实现。我可以从boost网站获得一个非常类似的示例(of a chat client/server),但是当我尝试将代码放入我自己的程序中时,它停止工作。boost :: asio tcp async_read永远不会返回
我在做什么:
- 启动一个服务器进程
- 服务器进程,使闲置插槽,并用它来听(使用TCP ::受体)的端口上的TCP连接(10010例如)
- 启动客户端进程
- 在客户端过程中创建一个套接字连接到服务器的端口
- 当服务器看到一个客户端连接,它开始侦听数据(与async_read )并创建另一个空的套接字来侦听端口上的另一个TCP连接
- 当客户端发现服务器已连接时,它会发送100个字节的数据(使用async_write)并等待套接字告诉它发送完毕......这种情况发生时它打印一条消息,并关闭
- 当服务器被通知其具有已被读取数据时,它显示一条消息,并关闭
很显然,我有从我试图实现的内容中大大削减了这些代码,这只是我能够做出重现问题的事情的一小部分。我在Windows上运行,并有一个视觉演播室解决方案文件,您可以get。有一些内存泄漏,线程安全问题等等,但那是因为我正在从现有的代码中取出东西,所以不要担心它们。
无论如何,这里的文件是一个包含一些常见东西,服务器和客户端的头文件。
Connection.hpp:
#ifndef CONNECTION_HPP
#define CONNECTION_HPP
#include
#include
#include
class ConnectionTransfer
{
public:
ConnectionTransfer(char* buffer, unsigned int size) :
buffer_(buffer), size_(size) {
}
virtual ~ConnectionTransfer(void){}
char* GetBuffer(){return buffer_;}
unsigned int GetSize(){return size_;}
virtual void CallbackForFinished() = 0;
protected:
char* buffer_;
unsigned int size_;
};
class ConnectionTransferInProgress
{
public:
ConnectionTransferInProgress(ConnectionTransfer* ct):
ct_(ct)
{}
~ConnectionTransferInProgress(void){}
void operator()(const boost::system::error_code& error){Other(error);}
void Other(const boost::system::error_code& error){
if(!error)
ct_->CallbackForFinished();
}
private:
ConnectionTransfer* ct_;
};
class Connection
{
public:
Connection(boost::asio::io_service& io_service):
sock_(io_service)
{}
~Connection(void){}
void AsyncSend(ConnectionTransfer* ct){
ConnectionTransferInProgress tip(ct);
//sock_->async_send(boost::asio::buffer(ct->GetBuffer(),
// static_cast(ct->GetSize())), tip);
boost::asio::async_write(sock_, boost::asio::buffer(ct->GetBuffer(),
static_cast(ct->GetSize())), boost::bind(
&ConnectionTransferInProgress::Other, tip, boost::asio::placeholders::error));
}
void AsyncReceive(ConnectionTransfer* ct){
ConnectionTransferInProgress tip(ct);
//sock_->async_receive(boost::asio::buffer(ct->GetBuffer(),
// static_cast(ct->GetSize())), tip);
boost::asio::async_read(sock_, boost::asio::buffer(ct->GetBuffer(),
static_cast(ct->GetSize())), boost::bind(
&ConnectionTransferInProgress::Other, tip, boost::asio::placeholders::error));
}
boost::asio::ip::tcp::socket& GetSocket(){return sock_;}
private:
boost::asio::ip::tcp::socket sock_;
};
#endif //CONNECTION_HPP
BoostConnectionClient.cpp:
#include "Connection.hpp"
#include
#include
#include
#include
using namespace boost::asio::ip;
bool connected;
bool gotTransfer;
class FakeTransfer : public ConnectionTransfer
{
public:
FakeTransfer(char* buffer, unsigned int size) : ConnectionTransfer(buffer, size)
{
}
void CallbackForFinished()
{
gotTransfer = true;
}
};
void ConnectHandler(const boost::system::error_code& error)
{
if(!error)
connected = true;
}
int main(int argc, char* argv[])
{
connected = false;
gotTransfer = false;
boost::asio::io_service io_service;
Connection* conn = new Connection(io_service);
tcp::endpoint ep(address::from_string("127.0.0.1"), 10011);
conn->GetSocket().async_connect(ep, ConnectHandler);
boost::thread t(boost::bind(&boost::asio::io_service::run, &io_service));
while(!connected)
{
boost::this_thread::sleep(boost::posix_time::millisec(1));
}
std::cout (angle brackets here) "Connected\n";
char data[100];
FakeTransfer* ft = new FakeTransfer(data, 100);
conn->AsyncReceive(ft);
while(!gotTransfer)
{
boost::this_thread::sleep(boost::posix_time::millisec(1));
}
std::cout (angle brackets here) "Done\n";
return 0;
}
BoostConnectionServer.cpp:
#include "Connection.hpp"
#include
#include
#include
#include
using namespace boost::asio::ip;
Connection* conn1;
bool conn1Done;
bool gotTransfer;
Connection* conn2;
class FakeAcceptor
{
public:
FakeAcceptor(boost::asio::io_service& io_service, const tcp::endpoint& endpoint)
:
io_service_(io_service),
acceptor_(io_service, endpoint)
{
conn1 = new Connection(io_service_);
acceptor_.async_accept(conn1->GetSocket(),
boost::bind(&FakeAcceptor::HandleAccept, this, conn1,
boost::asio::placeholders::error));
}
void HandleAccept(Connection* conn, const boost::system::error_code& error)
{
if(conn == conn1)
conn1Done = true;
conn2 = new Connection(io_service_);
acceptor_.async_accept(conn2->GetSocket(),
boost::bind(&FakeAcceptor::HandleAccept, this, conn2,
boost::asio::placeholders::error));
}
boost::asio::io_service& io_service_;
tcp::acceptor acceptor_;
};
class FakeTransfer : public ConnectionTransfer
{
public:
FakeTransfer(char* buffer, unsigned int size) : ConnectionTransfer(buffer, size)
{
}
void CallbackForFinished()
{
gotTransfer = true;
}
};
int main(int argc, char* argv[])
{
boost::asio::io_service io_service;
conn1Done = false;
gotTransfer = false;
tcp::endpoint endpoint(tcp::v4(), 10011);
FakeAcceptor fa(io_service, endpoint);
boost::thread t(boost::bind(&boost::asio::io_service::run, &io_service));
while(!conn1Done)
{
boost::this_thread::sleep(boost::posix_time::millisec(1));
}
std::cout (angle brackets here) "Accepted incoming connection\n";
char data[100];
FakeTransfer* ft = new FakeTransfer(data, 100);
conn1->AsyncReceive(ft);
while(!gotTransfer)
{
boost::this_thread::sleep(boost::posix_time::millisec(1));
}
std::cout (angle brackets here) "Success!\n";
return 0;
}
我四处搜寻了一下,但还没有祝你好运。据我所知,我几乎完全匹配样本,所以它必须是我忽略的一些小东西。
谢谢!
在您的客户端代码中,您的ConnectHandler()
回调函数只是设置一个值然后返回,而不会将任何更多工作发布到io_service。那时,async_connect()
操作是与io_service关联的唯一工作;所以当ConnectHandler()
返回时,没有更多的工作与io_service相关联。因此后台线程调用io_service.run()
返回,线程退出。
一个潜在的选择是调用conn->AsyncReceive()
从ConnectHandler()
内,使async_read()
的ConnectHandler()
之前被调用返回,因此后台线程对io_service.run()
调用将不会返回。
另一种选择,更微不足道的,将是之前创建的线程调用io_service对象::运行(技术上实例化一个io_service对象::工作情况下,你可以这样做在前io_service.run()
调用的任何点返回):
...
// some point in the main() method, prior to creating the background thread
boost::asio::io_service::work work(io_service)
...
这是io_service对象文档中记载:
用尽工作停止io_service对象
某些应用程序可能需要防止在没有更多工作要做时返回io_service对象的run()调用。例如,io_service可能在应用程序的异步操作之前启动的后台线程中运行。运行()调用可以保持创建类型io_service对象::工作的对象中运行:
http://www.boost.org/doc/libs/1_43_0/doc/html/boost_asio/reference/io_service.html
哪一方不异步读有去无回? – ergosys 2010-05-20 19:53:08