我试图制作简单的服务器,记住并操作一些带有接收短指令的变量。我没有完成这个服务器,我正在尝试测试连接到服务器。但是当我尝试连接服务器时,会发生分段故障。它似乎发生在io_context.run()函数中。尽管阅读了asio的参考页面,但我不知道这个错误的确切原因。请帮我..
我认为你不必阅读数据代码(data.hpp)。这是服务器代码。
//server.cpp
#include <iostream>
#include "network/sc_network.hpp"
int main(int argc, char *argv[])
{
try
{
if(argc != 2)
{
std::cerr << "Usage: server <port>\n";
return 1;
}
boost::asio::io_context io_context;
tcp::endpoint endpoint(tcp::v4(), std::atoi(argv[1]));
server server(io_context, endpoint);
io_context.run();
}
catch (std::exception& e)
{
std::cerr << "Exception: " << e.what() << "\n";
}
return 0;
}
这是客户端代码。
//client.cpp
#include <iostream>
#include <thread>
#include <cstdlib>
#include <boost/asio.hpp>
#include "network/data/data.hpp"
using boost::asio::ip::tcp;
class client{
private:
boost::asio::io_context& io_context_;
tcp::socket socket_;
oper_data *data_;
void do_connect(const tcp::resolver::results_type& endpoints)
{
boost::asio::async_connect(socket_, endpoints,
[this](boost::system::error_code ec, tcp::endpoint)
{
if(!ec)
{
boost::asio::async_read(socket_,
boost::asio::buffer(data_, sizeof(oper_data)),
[this](boost::system::error_code ec, std::size_t)
{
if(!ec)
{
boost::asio::async_write(socket_,
boost::asio::buffer(data_,sizeof(oper_data)),
[this](boost::system::error_code ec, std::size_t)
{
});
}
else
{
socket_.close();
}
});
}
else
{
socket_.close();
}
});
}
public:
client(boost::asio::io_context& io_context,
const tcp::resolver::results_type& endpoints)
: io_context_(io_context),
socket_(io_context)
{
do_connect(endpoints);
}
void write(const oper_data& data)
{
boost::asio::post(io_context_,
[this, data]()
{
});
}
};
int main(int argc, char *argv[])
{
try
{
if(argc != 3)
{
std::cerr << "Usage: client <host> <port>\n";
return 1;
}
boost::asio::io_context io_context;
tcp::resolver resolver(io_context);
auto endpoints = resolver.resolve(argv[1], argv[2]);
client c(io_context, endpoints);
std::thread t([&io_context](){ io_context.run(); });
char line[128];
while (std::cin.getline(line, 128))
{
oper_data data;
//processing the line with deviding in 3 words.
}
}
catch (std::exception& e)
{
std::cerr << "Exception: " << e.what() << "\n";
}
return 0;
}
这是sc_network.hpp
//sc_network.hpp
#include <boost/asio.hpp>
#include <memory>
#include <utility>
#include "data/data.hpp"
using boost::asio::ip::tcp;
class session
: public std::enable_shared_from_this<session>
{
private:
tcp::socket socket_;
data_proc data_proc_;
public:
session(tcp::socket socket)
: socket_(std::move(socket)){}
void start()
{
oper_data *input_data;
boost::asio::async_read(socket_,
boost::asio::buffer(input_data, sizeof(oper_data)),
[this, input_data](boost::system::error_code ec, std::size_t)
{
if(!ec)
{
data_proc_.set_data(*input_data);
data_proc_.oper_process();
start();
}
else
{
return;
}
});
}
};
class server
{
private:
tcp::acceptor acceptor_;
void do_accept()
{
acceptor_.async_accept(
[this](boost::system::error_code ec, tcp::socket socket)
{
if(!ec)
{
session ex_session(std::move(socket));
}
do_accept();
});
}
public:
server(boost::asio::io_context& io_context,
const tcp::endpoint& endpoint)
: acceptor_(io_context, endpoint)
{
do_accept();
}
};
这是data.hpp。
//data.hpp
#include <deque>
#include <cstring>
#include "favdew_utility.hpp"
#define max_oper_size 5
#define max_oper_buf max_oper_size + 1
struct oper_data {
char oper_[max_oper_buf] = "\0";
char *operand_;
char *oper_num_;
};
typedef struct oper_data oper_data;
class data_store {
private:
char *var_name_;
char *var_value_;
public:
data_store()
: var_name_(NULL), var_value_(NULL) {}
data_store(const char *var_name, const char *var_value)
{
std::size_t var_name_size = strlen(var_name) + 1;
var_name_ = new char[var_name_size];
strncpy(var_name_, var_name, strlen(var_name));
std::size_t var_value_size = strlen(var_value) + 1;
var_value_ = new char[var_value_size];
strncpy(var_value_, var_value, strlen(var_value));
}
char *var_name() { return var_name_; }
char *var_value() { return var_value_; }
void set_value(const char *var_value) {
var_value_ = new char[strlen(var_value) + 1];
strncpy(var_value_, var_value, strlen(var_value));
}
};
typedef std::deque<data_store> data_queue;
class data_proc {
private:
oper_data data_;
data_queue proc_queue;
void var()
{
if (data_store *var = this->get_var(data_.operand_)) {
var->set_value(data_.oper_num_);
}
else {
data_store input_data(data_.operand_, data_.oper_num_);
this->proc_queue.push_back(input_data);
}
}
bool sum()
{
data_store *var = this->get_var(data_.operand_);
if ( (var) && isNumber(var->var_value()))
{
const int input_data = std::atoi(var->var_value()) +
std::atoi(this->data_.oper_num_);
var->set_value(std::to_string(input_data).c_str());
return true;
}
else
return false;
}
bool dif()
{
data_store *var = this->get_var(data_.operand_);
if ((var) && isNumber(var->var_value()))
{
const int input_data = std::atoi(var->var_value()) -
std::atoi(this->data_.oper_num_);
var->set_value(std::to_string(input_data).c_str());
return true;
}
else
return false;
}
public:
data_proc()
{
oper_data input_data;
//<input_data.oper_> is already initialized with "\0"
std::memset(input_data.operand_, 0, sizeof(char *));
std::memset(input_data.oper_num_, 0, sizeof(char *));
}
data_proc(const char *oper, const char *operand, const char *oper_num)
{
strncpy(data_.oper_, oper, max_oper_size);
std::size_t operand_size = strlen(operand) + 1;
data_.operand_ = new char[operand_size];
strncpy(data_.operand_, operand, strlen(operand));
std::size_t oper_num_size = strlen(oper_num) + 1;
data_.oper_num_ = new char[oper_num_size];
strncpy(data_.oper_num_, oper_num, strlen(oper_num));
}
inline void set_data(oper_data data)
{
this->data_ = data;
}
void set_data(const char *oper, const char *operand, const char *oper_num)
{
strncpy(data_.oper_, oper, max_oper_size);
std::size_t operand_size = strlen(operand) + 1;
data_.operand_ = new char[operand_size];
strncpy(data_.operand_, operand, strlen(operand));
std::size_t oper_num_size = strlen(oper_num) + 1;
data_.oper_num_ = new char[oper_num_size];
strncpy(data_.oper_num_, oper_num, strlen(oper_num));
}
data_store *get_var(const char *var_name)
{
const std::size_t queue_size = this->proc_queue.size();
for (std::size_t i=0; i < queue_size; i++) {
if (!strcmp(this->proc_queue[i].var_name(), var_name)) {
return &proc_queue[i];
}
}
return NULL;
}
bool oper_process()
{
const char *oper = this->data_.oper_;
if (!strcmp(oper, "var")) {
var();
return true;
}
else if (!strcmp(oper, "sum")) {
sum();
return true;
}
else if (!strcmp(oper, "dif")) {
dif();
return true;
}
else {
return false;
}
}
};
这是favdew_utility.hpp
#include <string>
#include <cstdlib>
bool isNumber(const char *str)
{
std::size_t length = strlen(str);
for (std::size_t i = 0; i < length; i++)
{
if (!('0' < str[i] && str[i] < '9'))
return false;
continue;
}
return true;
}
bool isEmpty(void *buffer)
{
if (!buffer || *(char *)buffer == '\0')
return true;
else
return false;
}
有很多问题,只需指出几点:
session ex_session(std::move(socket));
这将创建一个继承自enable_shared_from_this
的本地(堆栈)变量。使用shared_from_this
将是Undefined Behaviour
会话立即被破坏,start()
似乎从未被调用过session::start()
,它将失败,因为它在不保护session
实例的生命周期的情况下启动异步操作:
boost::asio::async_read(socket_,
boost::asio::buffer(input_data, sizeof(oper_data)),
[this, input_data](boost::system::error_code ec, std::size_t) { ....
至少你需要捕获到会话的共享指针:
auto self = shared_from_this();
boost::asio::async_read(socket_,
boost::asio::buffer(input_data, sizeof(oper_data)),
[this, self, input_data](boost::system::error_code ec, std::size_t)
input_data
从未被初始化。再次:Undefined Behaviour。即使你做了初始化,你也必须管理一生;为什么不让它成为会话的成员,而不是动态分配(或忘记,如你所知)?
警告:不,即使你在lambda中捕获它也不能在start()
中进行堆栈分配,因为在start()
退出之前异步操作不会完成。client
:data_
永远不会被初始化。繁荣。asio::buffer()
将其视为POD。
然而,因为data_proc
愉快地聚集了一个data_queue
,这是std::deque<>
,它显然不是POD。更多Undefined Behaviour。
你可能需要的是序列化你的数据结构,而不是希望复制一些字节的内存将神奇地“工作”。它不会!
参见例如sending/receiving a struct in boost::asio
注意当你在,是,使用C ++而不是C?所有的原始指针和char*
都是你不需要的复杂性,并且它会递给你几十个脚趾或两端或绳索,你会更加伤害自己。client.cpp
线程需要加入(std::thread t([&io_context](){ io_context.run(); });
char line[128];
while (std::cin.getline(line, 128))
{
oper_data data;
//processing the line with deviding in 3 words.
}
)
如果您只是阻止输入,为什么有线程?
std::getline
std::istream::getline
也不是POD,但它也是一个活的内存泄漏。所有https://en.cppreference.com/w/cpp/thread/thread/~thread-ed内存永远不会被释放。
请注意,它的编写方式,结构可能看起来是POD,但逻辑上它不是(Rule Of Three)。基本上,你用C语言编写,而不是用C ++编写。这放弃了C ++所有的抽象,现在编译器无法判断结构是指非自有资源。
请注意,这让我觉得 io_context.run(); // replaces all of the above
可能有类似的问题(虽然起初我认为data_store
和new
应该指向固定大小的缓冲区oper_data
)你领先于自己。开始简单得多。使用C ++(operand_
,从不使用_oper_num
/ oper_[]
,如果你想使用std::string
,实际上使用new
)。
你会更开心。当你遇到困难时,请随意回答更简单的问题,理想情况下,SSCCE将是(少数)十几行。