对于p2p应用程序的异步网络编程工作,我遇到了麻烦。 我的应用程序必须是服务器和客户端。当服务器收到 请求时,它必须将其广播到其他服务器的k
。我认为boost :: asio示例的HTTP Server 3 Example可以很好地工作,并在其中实现异步客户端(作为类)。 上述(从升压:: ASIO客户端的例子),客户端类如下:客户端的C++ boost/asio服务器
ClientIO::ClientIO(boost::asio::io_service& io_service, tcp::resolver::iterator endpoint_iterator)
: _io_service(io_service),
strand_(io_service),
resolver_(io_service),
socket_(io_service)
{
tcp::endpoint endpoint = *endpoint_iterator;
socket_.async_connect(endpoint,
boost::bind(&ClientIO::handle_after_connect, this,
boost::asio::placeholders::error, ++endpoint_iterator));
}
void ClientIO::write(G3P mex)
{
_io_service.post(boost::bind(&ClientIO::writeMessage, this, mex));
}
void ClientIO::writeMessage(G3P mex)
{
bool write_in_progress = !messages_queue_.empty();
messages_queue_.push_back(mex);
if (!write_in_progress)
{
char* message=NULL;
boost::system::error_code ec;
if (messages_queue_.front().opcode == DATA)
{
message=(char*)malloc((10800)*sizeof(char));
}
else
message=(char*)malloc(1024*sizeof(char));
boost::asio::streambuf request;
std::ostream request_stream(&request);
serializeMessage(message, messages_queue_.front());
request_stream << message;
boost::asio::async_write(socket_, boost::asio::buffer(message, strlen(message)),
strand_.wrap(
boost::bind(&ClientIO::handle_after_write, this,
boost::asio::placeholders::error)));
free(message);
}
}
void ClientIO::readMessage()
{
boost::asio::async_read(socket_, data_,
boost::bind(&ClientIO::handle_after_read, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred
));
}
void ClientIO::stop()
{
socket_.shutdown(tcp::socket::shutdown_both);
socket_.close();
}
void ClientIO::handle_after_connect(const boost::system::error_code& error,
tcp::resolver::iterator endpoint_iterator)
{
if (error)
{
if (endpoint_iterator != tcp::resolver::iterator())
{
socket_.close();
tcp::endpoint endpoint = *endpoint_iterator;
socket_.async_connect(endpoint,
boost::bind(&ClientIO::handle_after_connect,this,
boost::asio::placeholders::error, ++endpoint_iterator));
}
}
else
{
}
}
void ClientIO::handle_after_read(const boost::system::error_code& error, std::size_t bytes_transferred)
{
if (bytes_transferred > 0)
{
std::istream response_stream(&data_);
std::string mex="";
std::getline(response_stream, mex);
deserializeMessage(&reply_,mex);
if (reply_.opcode == REPL)
{
cout << "ack received" << endl;
}
}
if (error)
{
ERROR_MSG(error.message());
}
}
void ClientIO::handle_after_write(const boost::system::error_code& error)
{
if (error)
{
// ERROR_MSG("Error in write: " << error.message());
}
else
{
messages_queue_.pop_front();
if (!messages_queue_.empty())
{
cout << "[w] handle after write" << endl;
char* message;
if (messages_queue_.front().opcode == DATA)
{
message=(char*)malloc((10800)*sizeof(char));
}
else
message=(char*)malloc(1024*sizeof(char));
boost::asio::streambuf request;
std::ostream request_stream(&request);
serializeMessage(message, messages_queue_.front());
request_stream << message;
boost::asio::async_write(socket_, boost::asio::buffer(message, strlen(message)),
strand_.wrap(
boost::bind(&ClientIO::handle_after_write, this,
boost::asio::placeholders::error)));
}
boost::asio::async_read_until(socket_, data_,"\r\n",
strand_.wrap(
boost::bind(&ClientIO::handle_after_read, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred)));
}
}
ClientIO::~ClientIO()
{
cout << "service stopped" << endl;
}
}
当一个新的请求是由服务器接收时,它启动一个新的数据管理类形式的连接和一些计算后,写一个队列 用上面的类中的其他服务器(这里只有一个),并在每一个写有对应的ACK
client --write-> server ---write->\
|--server1
server <--ACK----</
为了实现这一目标,我创建了一个用一个io_service姿态(io_service_test),为类变量,随着数据管理构造以下实例它:
DataManagement::DataManagement(){
tcp::resolver resolver(io_service_test);
tcp::resolver::query query(remotehost, remoteport);
tcp::resolver::iterator iterator = resolver.resolve(query);
cluster = new cluster_head::ClusterIO(io_service_test,iterator);
io_service_test.run_one();
}
然后,在计算后,发送数据:
void DataManagement::sendTuple(. . .){
. . .
io_service_test.reset();
io_service_test.run();
for (size_t i=0; i<ready_queue.size() ;i++)
{
cluster->write(fragTuple);
}
}
相对应的是相同的HTTP Proxy3将例子以相同的方式修改(没有客户端类)。问题是有时候一切都很好,有时会失败,我得到一个堆栈跟踪,有时它不会停止,甚至是分段错误。 我认为这个问题是关闭的io_service管理和类方法的生活,但我无法弄清楚。
- 任何想法?
- 你有适合这种情况的一些例子,还是一个实现它的虚拟类?
你可以提供回溯? – tr9sh 2012-02-16 09:27:41