使用进程间映射提升模板错误

Question

编辑：虽然严格来说不是我正在寻找的答案，但那是因为我问错了问题。我已将此问题标记为“已回答”，因为它帮助我了解自己做错了什么（回到上下文中，类结构没有意义，需要使用类似的更改以不同方式重做），我认为海报值得修复他所说的“非标准”的代表提升。

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请花时间帮助解决这个问题。如果你对 Boost 的经验比我多，那应该不难。

我正在使用 Boost 1.57 进行 IPC。我正在尝试制作pair（void *，struct）的共享映射。这是一个完整的程序（短）。您可以将其插入 MSVC（或更改 main() 声明并将其更改为常规 managed_shared_memory、GCC 或 Clang）。

代码可以在http://pastebin.com/caNNdztt找到语法高亮显示（虽然我忘了去掉代码中不存在的#define的一种用法，它被替换为0x30000000）

#include <iostream>
#include <boost/interprocess/mapped_region.hpp>
#include <boost/interprocess/managed_shared_memory.hpp>
#include <boost/interprocess/managed_windows_shared_memory.hpp>
#include <boost/interprocess/allocators/allocator.hpp>
#include <boost/interprocess/containers/map.hpp>


using namespace boost::interprocess;

typedef void* mem_managed_type; // GLE_GLOBAL is just void *, but changing it to int doesn't work
struct global_ptr_state; // This is just a POD struct, the definition doesn't matter

//typedef managed_shared_memory mem_manager_t;
typedef managed_windows_shared_memory mem_manager_t;
typedef std::pair<const mem_managed_type, global_ptr_state> global_state_pair;
typedef mem_manager_t::segment_manager segm_t;
typedef allocator< global_state_pair, segm_t > my_global_allocator;
typedef std::less<mem_managed_type> mem_managed_type_less;
typedef mem_manager_t::segment_manager segm_manager;
typedef map<const mem_managed_type, global_ptr_state, mem_managed_type_less, my_global_allocator> global_ptr_pair_map;

int _tmain(int argc, _TCHAR* argv[])
{
    segm_manager *_segm_manager;
    my_global_allocator *_allocatr;
    global_ptr_pair_map *global_map;
    mem_manager_t managed_pool;

    managed_pool = mem_manager_t(create_only, "thisdoesntmatter", 65536, (void *)0x3C000000);
    shared_memory_object _stator_share(open_only, "thisdoesntmattereither", read_write);
    mapped_region _stator_region(_stator_share, read_write, 0, 0, (void *)0x30000000);
    _segm_manager = managed_pool.get_segment_manager();
    _allocatr = new my_global_allocator(_segm_manager);

    // This line throws the error
    global_map = new global_ptr_pair_map; // This line causes the compilation error
}

错误的简短版本是

1>c:\boost\include\boost-1_57\boost\container\map.hpp(493): error C2535: 'std::pair<boost::container::container_detail::iterator<boost::intrusive::tree_iterator<boost::intrusive::bhtraits<T,boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,ptrdiff_t,size_t,0>,true>,normal_link,boost::intrusive::default_tag,3>,false>,false>,bool> boost::container::map<const mem_managed_type,global_ptr_state,mem_managed_type_less,my_global_allocator,boost::container::tree_assoc_defaults>::insert(const std::pair<const mem_managed_type,global_ptr_state> &)'
: member function already defined or declared

可以在 Pastebin 上找到整个错误

http://pastebin.com/gjk1e1N7

据我所知，它在抱怨这个：

std::pair<iterator,bool> insert(const nonconst_value_type& x)
   { return this->base_t::insert_unique(x); }

在该标题中替换上面的语句：

   std::pair<iterator,bool> insert(const value_type& x)
   { return this->base_t::insert_unique(x); }

我无计可施。请帮忙！

Answer 1

您需要调用 construct 在 shmem 中创建地图，而不是使用 new，另外还有一些修复：

typedef void* mem_managed_type; // GLE_GLOBAL is just void *, but changing it to int doesn't work
struct global_ptr_state{}; // This is just a POD struct, the definition doesn't matter

typedef managed_windows_shared_memory mem_manager_t;
typedef std::pair<const mem_managed_type, global_ptr_state> global_state_pair;
typedef mem_manager_t::segment_manager segm_t;
typedef allocator< global_state_pair, segm_t > my_global_allocator;
typedef std::less<mem_managed_type> mem_managed_type_less;
typedef mem_manager_t::segment_manager segm_manager;
typedef map<mem_managed_type, global_ptr_state, mem_managed_type_less, my_global_allocator> global_ptr_pair_map;

int _tmain(int argc, _TCHAR* argv[])
{
    segm_manager *_segm_manager;
    global_ptr_pair_map *global_map;
    mem_manager_t managed_pool;

    managed_pool = mem_manager_t(create_only, "thisdoesntmatter", 65536, (void *)0x3C000000);
    shared_memory_object _stator_share(open_only, "thisdoesntmattereither", read_write);
    mapped_region _stator_region(_stator_share, read_write, 0, 0, (void *)0x30000000);
    _segm_manager = managed_pool.get_segment_manager();
    my_global_allocator _allocatr = _segm_manager;

    global_map = managed_pool.construct<global_ptr_pair_map>("mymap")(mem_managed_type_less(), _allocatr);
}

您正在以一种“非标准”的方式执行此操作，因此我无法确定该代码是否有效。为什么不关注 boost 进程间tutorial？