其他线程堆栈上的内存无效答案

【问题标题】：invalid free of memory on other thread's stack其他线程堆栈上的内存无效
【发布时间】：2018-01-22 06:04:13
【问题描述】：

我正在尝试正确中断使用共享内存的线程，但这并不是那么简单。我正在使用 Boost.lockfree 和 Boost.Thread。以下是我创建的类：

typedef std::shared_ptr<Parameters_parser> sh_params_t;
typedef std::shared_ptr<Shared_objects> sh_obj_t;
class Abstract_thread {
    public:
        Abstract_thread(sh_params_t params, sh_obj_t sh_obj): 
            params(params), sh_obj(sh_obj) {}
        virtual ~Abstract_thread() = 0;
        virtual void launch() = 0;
     protected:
        /** The shared parameters of the execution. */
        sh_params_t params; 
        /** The Shared_objects containing all queues. */
        sh_obj_t sh_obj;
};
 inline Abstract_thread::~Abstract_thread(){
    cout << "Abstract_thread destructor with params: "
        << params.use_count() << " and sh_obj: " << 
        sh_obj.use_count() << endl;
}
class Interface_sniffer : public Abstract_thread {
    Interface_sniffer(sh_params_t params, sh_obj_t sh_obj): 
        Abstract_thread(params, sh_obj) {}
    ~Interface_sniffer(){
        cout << "Good bye from Interface_sniffer1 !" << endl;
     }
    void launch(){
        try {
            while(true)
                interruption_point();
         } catch(thread_interrupted const& e) {
             disable_interruption di;
             delete this;
         }
    }
};

然后，主要是：

void main(int argc, char* argv[]) {
    sh_obj_t sh_obj = std::make_shared<Shared_objects>();
    sh_params_t params = std::make_shared<Parameters_parser>();
    Interface_sniffer sniffer1(params, sh_obj);
    boost::thread t1(bind(&Interface_sniffer::launch, &sniffer1));
    boost::this_thread::sleep_for(boost::chrono::seconds(5));
    cout << "trying to stop 1" << endl;
    t1.interrupt();
    t1.join();
}

Parameters_parser 和 Shared_objects 是基本类，包含只能由我的线程或 boost::lockfree::queue 读取的字段，这应该不是问题。

所以当我运行它时，valgrind 会告诉我：

trying to stop 1
Good bye from Interface_sniffer1 !
Abstract_thread destructor with params: 2 and sh_obj: 2
==2095== Thread 2:
==2095== Invalid free() / delete / delete[] / realloc()
==2095==    at 0x4C2F24B: operator delete(void*) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2095==    by 0x41A1C1: Interface_sniffer::~Interface_sniffer() (interface_sniffer.cpp:34)
==2095==    by 0x41A6DC: Interface_sniffer::launch() (interface_sniffer.cpp:69)
==2095==    by 0x44D1E8: void std::_Mem_fn_base<void (Interface_sniffer::*)(), true>::operator()<, void>(Interface_sniffer*) const (in somewhere)
==2095==    by 0x44D162: void std::_Bind<std::_Mem_fn<void (Interface_sniffer::*)()> (Interface_sniffer*)>::__call<void, , 0ul>(std::tuple<>&&, std::_Index_tuple<0ul>) (in somewhere)
==2095==    by 0x44D115: void std::_Bind<std::_Mem_fn<void (Interface_sniffer::*)()> (Interface_sniffer*)>::operator()<, void>() (in somewhere)
==2095==    by 0x44CB9B: boost::detail::thread_data<std::_Bind<std::_Mem_fn<void (Interface_sniffer::*)()> (Interface_sniffer*)> >::run() (thread.hpp:116)
==2095==    by 0x50C95D4: ??? (in /usr/lib/x86_64-linux-gnu/libboost_thread.so.1.58.0)
==2095==    by 0x604D6B9: start_thread (pthread_create.c:333)
==2095==    by 0x636A3DC: clone (clone.S:109)
==2095==  Address 0xfff000240 is on thread 1's stack
==2095==  in frame #3, created by main (main.cpp:23)
==2095==

所以它假装我正在删除位于主线程堆栈上的东西（我假设 params 和 sh_obj），但它不是真的，因为 shared_ptr 指向的对象在堆上。我能做些什么？我应该将shared_ptr<>* 传递给我的线程，并在析构函数中手动调用params->reset() 和sh_obj->reset() 吗？

【问题讨论】：

标签： c++ multithreading boost valgrind shared-ptr

【解决方案1】：

Interface_sniffer 包含此代码：

delete this;

而main() 包含此代码：

Interface_sniffer sniffer1(params, sh_obj);

因此，正如 valgrind 所说，您正在删除堆栈分配的对象。这是未定义的行为。

由于delete this 非常不寻常（尽管有时有效甚至有用），因此最好重新考虑为什么以及是否需要它。从您的代码中看不出您确实需要它。

【讨论】：