Question

我正在尝试使用共享内存正确地中断线程，但事情并非那么简单。我正在使用Boost.lockfree和Boost.Thread。以下是我创建的课程：

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，在主要：

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，包含仅由我的线程读取的字段，或者使用boost :: lockfree :: queue，这应该不是问题。

所以当我运行它时，valgrind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指向的对象是在堆上。我能做什么？我应该将shared_ptr<>*传递给我的主题，并在析构函数中手动调用params->reset()和sh_obj->reset()吗？

Answer 1

Interface_sniffer包含以下代码：

delete this;

main()包含此代码：

Interface_sniffer sniffer1(params, sh_obj);

所以你要删除一个堆栈分配的对象，就像valgrind所说的那样。这是未定义的行为。

由于delete this非常不寻常（虽然有时甚至是有效的），但重新考虑为什么以及是否需要它是一个好主意。从您的代码中可以看出您确实需要它。

在其他线程的堆栈中无内存

1 个答案: