在另一个进程中销毁共享的std :: vector

Question

我正在尝试std::vector<std::string>通过Boost.Interprocess 将a转移到新分叉的进程,以便子进程获取它的所有权并将其销毁.检索和读取矢量有效,但是我在破坏它时会遇到访问冲突.我认为分配器开始使用一些指向父母地址空间的指针,并且在孩子的地址空间中没有任何意义.

我应该如何在父母中创建该向量并在孩子中正确销毁？

父流程代码:

namespace ip = boost::interprocess;

template <class T>
using ip_allocator = ip::allocator<T, ip::managed_shared_memory::segment_manager>;

template <class T>
using ip_vector = std::vector<T, ip_allocator<T>>;

int CALLBACK WinMain(
    _In_ HINSTANCE,
    _In_ HINSTANCE,
    _In_ LPSTR,
    _In_ int
) {
    ip::shared_memory_object::remove("MyTestShm");
    ip::managed_shared_memory mshm{ ip::open_or_create, "MyTestShm", 1024 * 1024 };

    ip_allocator<int> intAlloc{ mshm.get_segment_manager() };

    mshm.construct<ip_vector<int>>("ForkData")(
        ip_vector<int>{ {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}, intAlloc}
    );

    boost::process::spawn(L"Executor.exe", L"ForkData");
}

子进程(Executor.exe)代码:

int wmain(int argc, wchar_t **argv) try {
    namespace ip = boost::interprocess;

    // Kludge to attach the debugger and force continuation
    bool volatile coin = true;
    while (coin)
        ::Sleep(1000);

    ip::managed_shared_memory mshm{ ip::open_only, "MyTestShm" };
    auto const * const fd = mshm.find<ip_vector<int>>("ForkData").first;

    if(!fd)
        return 1;

    for (int i : *fd)
        std::cout << i << ' ';
    std::cout << '\n';

    mshm.destroy_ptr(fd); // Crashing line
}
catch (std::exception const &exc) {
    std::cerr
        << "Unhandled " << boost::typeindex::type_id_runtime(exc).pretty_name() << ":\n"
        << exc.what() << '\n';
    return 1;
}

错误和callstack:

抛出异常:读取访问冲突. _Pnext是的0x21FE21200B0.发生了

Executor.exe!std::_Container_base12::_Orphan_all() Line 221
Executor.exe!std::_Vector_alloc<std::_Vec_base_types<int,boost::interprocess::allocator<int,boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index> > > >::_Orphan_all() Line 536
Executor.exe!std::vector<int,boost::interprocess::allocator<int,boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index> > >::_Tidy() Line 1913
Executor.exe!std::vector<int,boost::interprocess::allocator<int,boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index> > >::~vector<int,boost::interprocess::allocator<int,boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index> > >() Line 894
Executor.exe!std::vector<int,boost::interprocess::allocator<int,boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index> > >::`scalar deleting destructor'(unsigned int)   Executor.exe!boost::interprocess::ipcdetail::placement_destroy<std::vector<int,boost::interprocess::allocator<int,boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index> > > >::destroy_n(void * mem, unsigned __int64 num, unsigned __int64 & destroyed) Line 61
Executor.exe!boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index>::priv_generic_named_destroy<char>(const char * name, boost::interprocess::iset_index<boost::interprocess::ipcdetail::index_config<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0> > > & index, boost::interprocess::ipcdetail::in_place_interface & table, boost::interprocess::ipcdetail::bool_<1> is_intrusive_index) Line 976
Executor.exe!boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index>::priv_generic_named_destroy<char>(boost::interprocess::ipcdetail::block_header<unsigned __int64> * block_header, boost::interprocess::iset_index<boost::interprocess::ipcdetail::index_config<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0> > > & index, boost::interprocess::ipcdetail::in_place_interface & table, boost::interprocess::ipcdetail::bool_<0> is_node_index) Line 929
Executor.exe!boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index>::priv_destroy_ptr(const void * ptr, boost::interprocess::ipcdetail::in_place_interface & dtor) Line 777
Executor.exe!boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index>::destroy_ptr<std::vector<int,boost::interprocess::allocator<int,boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index> > > >(const std::vector<int,boost::interprocess::allocator<int,boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index> > > * p) Line 550
Executor.exe!boost::interprocess::ipcdetail::basic_managed_memory_impl<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index,8>::destroy_ptr<std::vector<int,boost::interprocess::allocator<int,boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index> > > >(const std::vector<int,boost::interprocess::allocator<int,boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0>,boost::interprocess::iset_index> > > * ptr) Line 608
Executor.exe!wmain(int argc, wchar_t * * argv) Line 31
Executor.exe!invoke_main() Line 91
Executor.exe!__scrt_common_main_seh() Line 288
Executor.exe!__scrt_common_main() Line 331
Executor.exe!wmainCRTStartup() Line 17
kernel32.dll!BaseThreadInitThunk()
ntdll.dll!RtlUserThreadStart()

Answer 1

感谢Passer By促使我再次浏览 Boost.Interprocess 文档，我偶然发现了这个示例，幸运的是，这正是我想要做的。在确认它对我有效（确实有效）后，我开始逐渐将其改造成我自己的程序的副本，并发现了问题。

区别在于选择 或std::vector（boost::interprocess::vector也称为boost::container::vector）。std::vector应该可以与自定义分配器一起正常工作，但问题在于 Microsoft 的实现：_Orphan_all发生访问冲突的函数是调试迭代器功能的一部分。该系统跟踪哪个迭代器属于哪个容器，但通过存储原始指针来实现这一点，当向量更改地址空间时，原始指针会变得陈旧，并在向量尝试在销毁时更新簿记数据时最终导致崩溃。

事实上，在发布模式（其中_ITERATOR_DEBUG_LEVEL == 0迭代器和调试迭代​​器被停用）下编译或使用 Boost 的vector实现都可以完美地工作。