C/C++编程：终止程序

叁歲伎倆 2022-10-23 08:19 186阅读 0赞

# std::atexit #

![在这里插入图片描述][20210310195205115.png]

*  注册 func 所指向的函数，使得在正常程序中止（通过 std::exit() 或从 main 函数返回）时调用它。
 *  可以多次注册同一函数
 *  保证实现支持注册至少 32 个函数。准确限制是实现定义的。
 *  若函数通过异常退出，则调用 std::terminate 。
 *  atexit 是线程安全的：从数个线程调用函数不引入数据竞争。

#include <iostream>
    #include <cstdlib>
     
    void atexit_handler_1() 
    {
        
        std::cout << "at exit #1\n";
    }
     
    void atexit_handler_2() 
    {
        
        std::cout << "at exit #2\n";
    }
     
    int main() 
    {
        
        const int result_1 = std::atexit(atexit_handler_1);
        const int result_2 = std::atexit(atexit_handler_2);
     
        if ((result_1 != 0) || (result_2 != 0)) {
        
            std::cerr << "Registration failed\n";
            return EXIT_FAILURE;
        }
     
        std::cout << "returning from main\n";
        return EXIT_SUCCESS;
    }

![在这里插入图片描述][20210310195410282.png]

# std::exit #

导致正常程序终止发生

#include <iostream>
    #include <cstdlib>
    
    class Static {
        
    public:
        ~Static()
        {
        
            std::cout << "Static dtor\n";
        }
    };
    
    class Local {
        
    public:
        ~Local()
        {
        
            std::cout << "Local dtor\n";
        }
    };
    
    Static static_variable;  // *将*调用此对象的析构函数
    void atexit_handler()
    {
        
        std::cout << "atexit handler\n";
    }
    int main()
    {
        
        Local local_variable; // // 将*不*调用此对象的析构函数
        const int result = std::atexit(atexit_handler); // 将调用处理函数
    
        if (result != 0) {
        
            std::cerr << "atexit registration failed\n";
            return EXIT_FAILURE;
        }
        
        std::cout << "test\n";
        std::exit(EXIT_SUCCESS);
    }

![在这里插入图片描述][20210310200538961.png]

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70 1]

# std::abort #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70 2]

#include <iostream>
    #include <csignal>
    #include <cstdlib>
    
    class Tester{
        
    public:
        Tester(){
        std::cout << "Tester contruction\n";}
        ~Tester(){
        std::cout << "Tester dectruction\n";}
    };
    
    Tester static_tester;  // 不调用析构函数
    
    void signal_handler(int signal){
        
        if(signal == SIGABRT){
        
            std::cerr << "SIGABRT received\n";
        }else{
        
            std::cerr << "Unexpected signal " << signal << " received\n";
        }
        std::_Exit(EXIT_FAILURE);
    }
    
    int main() {
        
        Tester automatic_tester; // 不调用析构函数
    
        // 安装处理函数
        auto previous_handler = std::signal(SIGABRT, signal_handler);
        if (previous_handler == SIG_ERR) {
        
            std::cerr << "Setup failed\n";
            return EXIT_FAILURE;
        }
    
        std::abort();  // 引发 SIGABRT
        std::cout << "This code is unreachable\n";
    }

![在这里插入图片描述][20210309180017911.png]

[20210310195205115.png]: /images/20221023/20e4c4b53b8b4911937d60c65cb2567c.png
[20210310195410282.png]: /images/20221023/a4c6013a3fdd4270bdf6c34e6ca5e9d0.png
[20210310200538961.png]: /images/20221023/b18cead4c6dc41d9aa5682386ca50657.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70]: /images/20221023/611ca18591c24ce4a55b2f04f0f5ec90.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70 1]: /images/20221023/14ee30ab7827471c8097702855b46070.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70 2]: /images/20221023/6fdaa9541d2e40209f7b3697416ff21b.png
[20210309180017911.png]: /images/20221023/1eb044b4064b4dd0873952ddd40e52ea.png