c++ - 从 DLL 内部使用时，boost::interprocess::windows_shared_memory 是否需要任何特殊初始化？

Question

我之前问过一个 boost-interprocess 的问题，并发誓我会停止使用它，但是，唉，我被卡住了，我真的需要这个东西来工作。所以我仍在与之抗争。

我在分配然后立即销毁 boost::interprocess::managed_windows_shared_memory::segment_manager 时遇到奇怪的崩溃但它只发生在我正在构建的 Windows DLL 项目中。我试图在一个独立的程序中重现它作为向 Boost 报告它的一种方式，但它不会在我自己的 DLL 之外重现。

当我正常创建对象并在更理智的时间释放它时也会发生这种情况，但我想在这里展示的是 Boost 能够创建对象，并且没有时间流逝也没有状态在堆中更改，但 Boost 无法在不崩溃的情况下释放此对象。

这不会发生在一个独立的示例项目中(我构建了一个，只是为了看看它是否会)，但是，据我所知，没有其他代码正在崩溃的项目中运行。

真正奇怪的是，它是从 DLLMain 函数崩溃的，而 DLLMain 函数中的第一件事就是分配然后销毁这个 C++ boost 对象。这个 boost 对象有些奇怪，它创建了一大堆东西(红黑树)，然后甚至无法自行清理。

下面的代码几乎但还不足以重现该问题。我的 DLL 有问题，导致生成的 Boost 对象能够自行创建，但它们在关闭时崩溃:

// BoostDllMain.cpp :
//
//  Attempt to demonstrate an insane situation in my code, where
//  boost::interprocess::managed_windows_shared_memory::segment_manager 
//  can be created, but freeing it causes access violations. The context
//  for object creation and destruction is DLL load and unload time.



#include "stdafx.h"

#include <objbase.h>
#include <windows.h>



#ifdef PERSISTENT_SHARED_MEM
#include <boost/interprocess/managed_shared_memory.hpp>
#else
#include <boost/interprocess/managed_windows_shared_memory.hpp>
#endif

#include <boost/interprocess/containers/map.hpp>
#include <boost/interprocess/allocators/allocator.hpp>
#include <boost/interprocess/containers/string.hpp>
#include <functional>
#include <utility>

#define SHARED_AREA_SIZE (1024*1024*8)  // 8 megabytes of shared memory should be enough to store more than 60K data points. 
                                    // In testing using current structure sizes, allocation Failed at the 61678th 
                                    // data point item when set to this value.



#ifdef PERSISTENT_SHARED_MEM
typedef boost::interprocess::managed_shared_memory                  mgr;
typedef boost::interprocess::managed_shared_memory::segment_manager seg;
#else
typedef boost::interprocess::managed_windows_shared_memory                  mgr;
typedef boost::interprocess::managed_windows_shared_memory::segment_manager seg;
#endif

using namespace boost::interprocess;

mgr *       segment1;
mgr *       segment2;

void Init(void) {

// Tweak C Runtime Debug Heap Flags.
int tmpFlag = _CrtSetDbgFlag( _CRTDBG_REPORT_FLAG );
tmpFlag |= _CRTDBG_LEAK_CHECK_DF;
tmpFlag |= _CRTDBG_CHECK_CRT_DF;
_CrtSetDbgFlag( tmpFlag );  

      segment1 = new mgr(   open_or_create
                           , "ED3_MEMORY" // This is a global memory area name

                           , SHARED_AREA_SIZE );    
      segment2 = new mgr(   open_or_create
                           , "ED3_MEMORY" // This is a global memory area name

                           , SHARED_AREA_SIZE );  
}

void Cleanup(void) {

     delete segment1;
     segment1 = NULL;


     delete segment2;
     segment2 = NULL;


}

//
extern "C"
BOOL WINAPI DllMain(IN HANDLE hInstance, IN DWORD dwReason, IN VOID *pReserved )
{



    switch ( dwReason )
    {
    case DLL_PROCESS_ATTACH:

        Init();

        break;

    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
        break;

    case DLL_PROCESS_DETACH:

        Cleanup();


        break;

    default:
        break;
    }

    return(1);
}

简而言之，用managed_windows_shared_memory ，无论你创建什么对象，甚至不能立即彻底销毁(没有访问冲突)，这就是我在上面试图展示的，我在 DLL 加载时创建对象，并在 DLL 卸载时销毁它。

这是堆栈回溯。如果你能理解它，你可能是一个 C++ 编译器，而不是一个人，但无论如何它在这里:

>   mydll.dll!boost::interprocess::offset_ptr<boost::intrusive::compact_rbtree_node<boost::interprocess::offset_ptr<void,int,unsigned int,0> >,int,unsigned int,0>::offset_ptr<boost::intrusive::compact_rbtree_node<boost::interprocess::offset_ptr<void,int,unsigned int,0> >,int,unsigned int,0>(const boost::interprocess::offset_ptr<boost::intrusive::compact_rbtree_node<boost::interprocess::offset_ptr<void,int,unsigned int,0> >,int,unsigned int,0> & ptr={...})  Line 272 + 0xf bytes   C++
    mydll.dll!boost::intrusive::compact_rbtree_node_traits_impl<boost::interprocess::offset_ptr<void,int,unsigned int,0> >::get_left(const boost::interprocess::offset_ptr<boost::intrusive::compact_rbtree_node<boost::interprocess::offset_ptr<void,int,unsigned int,0> >,int,unsigned int,0> & n={...})  Line 142 + 0x1d bytes   C++
    mydll.dll!boost::intrusive::detail::tree_algorithms<boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1> >::dispose_subtree<boost::intrusive::detail::node_disposer<boost::intrusive::detail::null_disposer,boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> > > >(boost::interprocess::offset_ptr<boost::intrusive::compact_rbtree_node<boost::interprocess::offset_ptr<void,int,unsigned int,0> >,int,unsigned int,0> x={...}, boost::intrusive::detail::node_disposer<boost::intrusive::detail::null_disposer,boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> > > disposer={...})  Line 1298 + 0xd bytes  C++
    mydll.dll!boost::intrusive::detail::tree_algorithms<boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1> >::clear_and_dispose<boost::intrusive::detail::node_disposer<boost::intrusive::detail::null_disposer,boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> > > >(const boost::interprocess::offset_ptr<boost::intrusive::compact_rbtree_node<boost::interprocess::offset_ptr<void,int,unsigned int,0> >,int,unsigned int,0> & header={...}, boost::intrusive::detail::node_disposer<boost::intrusive::detail::null_disposer,boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> > > disposer={...})  Line 577 + 0x15 bytes   C++
    mydll.dll!boost::intrusive::rbtree_algorithms<boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1> >::clear_and_dispose<boost::intrusive::detail::node_disposer<boost::intrusive::detail::null_disposer,boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> > > >(const boost::interprocess::offset_ptr<boost::intrusive::compact_rbtree_node<boost::interprocess::offset_ptr<void,int,unsigned int,0> >,int,unsigned int,0> & header={...}, boost::intrusive::detail::node_disposer<boost::intrusive::detail::null_disposer,boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> > > disposer={...})  Line 451 + 0x16 bytes C++
    mydll.dll!boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> >::clear_and_dispose<boost::intrusive::detail::null_disposer>(boost::intrusive::detail::null_disposer disposer={...})  Line 1006 + 0x26 bytes C++
    mydll.dll!boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> >::clear()  Line 987  C++
    mydll.dll!boost::intrusive::detail::clear_on_destructor_base<boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> > >::~clear_on_destructor_base<boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> > >()  Line 27  C++
    mydll.dll!boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> >::~rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> >()  Line 284 + 0x14 bytes  C++
    mydll.dll!boost::intrusive::set_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> >::~set_impl<boost::intrusive::setopt<boost::intrusive::detail::base_hook_traits<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int>,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,1,boost::intrusive::default_tag,3>,std::less<boost::interprocess::ipcdetail::intrusive_value_type_impl<boost::intrusive::detail::generic_hook<boost::intrusive::get_set_node_algo<boost::interprocess::offset_ptr<void,int,unsigned int,0>,1>,boost::intrusive::default_tag,1,3>,char,unsigned int> >,unsigned int,1> >()  Line 139 + 0x14 bytes    C++
    mydll.dll!boost::interprocess::iset_index<boost::interprocess::ipcdetail::index_config<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,int,unsigned int,0>,0> > >::~iset_index<boost::interprocess::ipcdetail::index_config<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,int,unsigned int,0>,0> > >()  + 0x14 bytes    C++
    mydll.dll!boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,int,unsigned int,0>,0>,boost::interprocess::iset_index>::header_t::~header_t()  + 0x3d bytes    C++
    mydll.dll!boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,int,unsigned int,0>,0>,boost::interprocess::iset_index>::~segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,int,unsigned int,0>,0>,boost::interprocess::iset_index>()  + 0x3d bytes  C++
    mydll.dll!boost::interprocess::segment_manager<char,boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,boost::interprocess::offset_ptr<void,int,unsigned int,0>,0>,boost::interprocess::iset_index>::`scalar deleting destructor'()  + 0x14 bytes   C++

总之我有

一个。从我编写的代码中排除了堆损坏，因为还没有其他代码在此 DLL 的上下文中运行。可以创建和释放其他对象，没问题，只有这个 Boost 对象无法在此 DLL 中创建或销毁。

B. DLL 项目正在编译，代码生成设置为“多线程调试 DLL”。

C. boost::interprocess::managed_windows_shared_memory::segment_manager 的析构函数总是在同一个地方崩溃，它不是随机的。那个地方是mydll.dll!boost::interprocess::offset_ptr<boost::intrusive::compact_rbtree_node<... .

D.如果我在此 DLL 上下文中从 Windows 共享内存切换到另一个选项，仅称为 shared_memory , 它在 get_last_bootup_time 中卡住/死锁在 WMI 调用中。这是来自 win32_api.hpp 的一个函数，它执行 Window WMI 函数调用并试图读取类 Win32_OperatingSystem属性(property)LastBootUpTime .

E.我开始认为 DLL 和 Boost 不喜欢对方，原因很奇怪，可能涉及 CoInitialize , 和黑暗的黑魔法。

你如何调试这么疯狂的东西？

Answer 1

DllMain 有一些非常严格的限制，因为您在进入此函数时持有加载器锁，如果您在 DllMain 中加载库，库加载器将无法正确计算库依赖性。

关于所有这一切的真正棘手的部分是你不能直接或间接持有加载程序锁。例如:你不能调用 LoadLibrary，不能与其他线程同步，不能调用 CreateThread，不能从 CRT 调用内存管理函数，不能从 User32 调用任何东西。请阅读 DLL 最佳实践指南 here (Microsoft) ，并查看文档末尾的引用资料。

简短回答:不要在 DllMain 中加载这些东西。