我指的是Chat Client
我的写操作是:
void CSession::beginWrite(const Buffer & message)
{
//Check if the socket is open or not?
bool writeInProgress = !writeQueue_.empty();
writeQueue_.push_back(message);
if (!writeInProgress) //Exception Thrown here
{
asio::async_write(socket_, asio::buffer(writeQueue_.front().received_, writeQueue_.front().buffsize),
std::bind(&CSession::handle_write, this,
std::placeholders::_1, std::placeholders::_2));
}
}
void CSession::handle_write(const asio::error_code& error /*error*/, size_t bytes_transferred /*bytes_transferred*/)
{
//std::cout << "CSession::handle_write() Called" << "(" << __FILE__ << " : " << __LINE__ << ")" << std::endl;
if (!error)
{
//std::cout << bytes_transferred << " bytes written to the socket." << std::endl;
writeQueue_.pop_front();
if (!writeQueue_.empty())
{
asio::async_write(socket_, asio::buffer(writeQueue_.front().received_, writeQueue_.front().buffsize),
std::bind(&CSession::handle_write, this,
std::placeholders::_1, std::placeholders::_2));
}
}
else
{
std::cout << "Write Error Detected" << std::endl;
std::cout << error.message() << std::endl;
state_ = false;
doClose();
return;
}
}
工作正常。然后我尝试通过让客户端连续11分钟向服务器写入消息Client 2
来加载测试,如下所示:
bool flag = false;
void setFlag(const asio::error_code& /*e*/)
{
flag = true;
}
void Client(std::string IP, std::string port)
{
CSession Session(IP, port);
Session.initSession();
asio::thread t(boost::bind(&asio::io_service::run, &(*CIOService::fetchIOService().getIO())));
asio::deadline_timer timer(*CIOService::fetchIOService().getIO(), boost::posix_time::seconds(675));
timer.async_wait(&setFlag);
while (!flag)
{
Session.write("Client 2");
}
Session.close();
t.join();
}
void main()
{
Client("localhost", "8974");
system("Pause");
}
成功写入操作2-3分钟后,代码会在行
处抛出异常Unhandled exception at 0x75B7C42D in NetworkComponentsClient.exe: Microsoft C++ exception: std::bad_alloc at memory location 0x026DE87C.
if (!writeInProgress) //Exception Thrown here
{
asio::async_write(socket_, asio::buffer(writeQueue_.front().received_, writeQueue_.front().buffsize),
std::bind(&CSession::handle_write, this,
std::placeholders::_1, std::placeholders::_2));
}
调试显示:
- writeQueue_ { size=16777215 } std::deque<channel::Buffer,std::allocator<channel::Buffer> >
+ [0] {received_=0x052a0ac8 "Client 2" } channel::Buffer
+ [1] {received_=0x052a0b28 "Client 2" } channel::Buffer
+ [2] {received_=0x052a0b88 "Client 2" } channel::Buffer
....
....
我可以看到writeQueue_ { size=16777215 }
的大小非常大,因此std::bad_alloc
。
为什么会出现这种行为?我可以看到来自deque的代码弹出消息,如下所示:
if (!error)
{
writeQueue_.pop_front();
if (!writeQueue_.empty())
{
asio::async_write(socket_, asio::buffer(writeQueue_.front().received_, writeQueue_.front().buffsize),
std::bind(&CSession::handle_write, this,
std::placeholders::_1, std::placeholders::_2));
}
}
所以write deque
不应该变得那么大。
我的客户端应该运行数天,并且应该涉及大量连续数据写入。如何确保平滑的长写操作?
答案 0 :(得分:0)
您的消费者(CSession
)远远低于您的消费者(Client
)。
您的生产者通过尽可能快地生成消息来进行拒绝服务攻击。这是一个很好的测试。
您的消费者应该(至少一个,最好是所有人):
我的客户应该运行数天并且应该参与其中 连续数据写入。如何确保平滑的长写操作?
然后你需要比在网上找到的例子更好的代码。