端點上的數據損壞

Question

在循環調用asio :: async_write（）數據在接收點損壞。

但是，如果在調用asio :: async_write（）之間插入1 ms的暫停，那麼數據將被正確讀取。

例這樣的問題：http://rghost.ru/4908432

#ifndef _header_hpp_included_ 
#define _header_hpp_included_ 

#include <iostream> 
#include <sstream> 
#include <cstdio> 
#include <boost/bind.hpp> 
#include <boost/asio.hpp> 
#include <boost/thread.hpp> 
#include <boost/shared_ptr.hpp> 
#include <boost/shared_array.hpp> 
#include <boost/lexical_cast.hpp> 

enum { recv_buffer_size = 13 }; 
enum { send_buffer_size = 13 }; 

volatile size_t counter = 0; 

/***************************************************************************/ 

void client_readed(boost::asio::ip::tcp::socket&, boost::shared_array<char>, const boost::system::error_code&); 

/** client read the reply from the server */ 

void client_read(boost::asio::ip::tcp::socket& sock) { 
    boost::shared_array<char> buf(new char[recv_buffer_size]); 
    boost::asio::async_read(
     sock, 
     boost::asio::buffer(buf.get(), recv_buffer_size), 
     boost::bind(
     &client_readed, 
     boost::ref(sock), 
     buf, 
     boost::asio::placeholders::error 
    ) 
    ); 
} 

/** when the whole packet is read client check it's index */ 

void client_readed(boost::asio::ip::tcp::socket& sock, boost::shared_array<char> buf, const boost::system::error_code& e) { 
    if (e) { 
     if (!counter) return; 
     std::cout << "read handler: " << e.message() << std::endl; 
     return; 
    } 

    counter--; 

#ifdef _my_debug_ 
    printf("client_readed(): %s", buf.get()); 
    fflush(stdout); 
#endif 

    static size_t idx = 0; 
    size_t tmp = 0; 
    char* p = strchr(buf.get(), ':'); 
    if (p) { 
     p++; 
     sscanf(p, "%8d", &tmp); 
    } else { 
     throw std::runtime_error("input data error!"); 
    } 
    if (idx != tmp) { 
     std::ostringstream os; 
     os << "read error. expected " << idx << " get " << tmp; 
     throw std::runtime_error(os.str()); 
    } 
    idx++; 
    client_read(sock); 
} 

/***************************************************************************/ 

void writen(boost::shared_array<char>, const boost::system::error_code&); 

/** client send the packet to the server */ 

void start_write(boost::asio::ip::tcp::socket& sock, boost::shared_array<char> buf) { 
    counter++; 
    boost::asio::async_write(
     sock, 
     boost::asio::buffer(buf.get(), send_buffer_size), 
     boost::bind(
     &writen, 
     buf, 
     boost::asio::placeholders::error 
    ) 
    ); 
} 

void writen(boost::shared_array<char> buf, const boost::system::error_code& e) { 
    if (e) { 
     std::cout << "writen(): " << e.message() << std::endl; 
    } 
} 

/***************************************************************************/ 

void server_readed(boost::asio::ip::tcp::socket&, boost::shared_array<char>, const boost::system::error_code&); 

/** async reading incoming packet at the server side */ 
void server_read(boost::asio::ip::tcp::socket& sock) { 
    boost::shared_array<char> buf(new char[recv_buffer_size]); 
    boost::asio::async_read(
     sock, 
     boost::asio::buffer(buf.get(), recv_buffer_size), 
     boost::bind(
     &server_readed, 
     boost::ref(sock), 
     buf, 
     boost::asio::placeholders::error 
    ) 
    ); 
} 

/** when the whole packet is read send it back to the client */ 

void server_readed(boost::asio::ip::tcp::socket& sock, boost::shared_array<char> buf, const boost::system::error_code& e) { 
    if (e) { 
     std::cout << "read handler: " << e.message() << std::endl; 
     return; 
    } 

#ifdef _my_debug_ 
    printf("server_readed(): %s", buf.get()); 
#endif 

    static const char* ptr = "sc:"; 
    memcpy(buf.get(), ptr, strlen(ptr)); 
    start_write(sock, buf); 
    server_read(sock); 
} 

/***************************************************************************/ 
/** this functional object execute in the boost::thread at the client side */ 

struct async_test { 
    async_test(boost::asio::ip::tcp::socket& sock, volatile bool& run) 
    :_sock(sock), 
    _run(run) 
    {} 

    void operator()() { 
     for (size_t idx = 0; _run; ++idx) { 
     boost::shared_array<char> buf(new char[send_buffer_size]); 
     sprintf(buf.get(), "cs:%8d\n", idx); 
     start_write(_sock, buf); 
     } 
    } 

private: 
    boost::asio::ip::tcp::socket& _sock; 
    volatile bool& _run; 
}; 


/***************************************************************************/ 

#endif // _header_hpp_included_ 

Answer 1

你的例子並不表明頂級用法，線程等

檢查，如果你從不同的線程同時發送到同一個插座，這樣可以成爲一個問題。按順序執行

Answer 2

這種情況下的數據損壞很可能是因爲您正在使用async_read，並且在async_read處理程序內部再次調用async_read（在處理程序後沒有時間清理）。

相關：boost::asio : data corruption