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c++ - std::list 在 boost::interprocess::managed_shared_memory 中

转载 作者:行者123 更新时间:2023-11-30 02:18:46 26 4
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最近我got schooled并学习了在 boost::interprocess::managed_shared_memory 段中使用 unordered_map 的正确方法。到目前为止一切顺利,但我需要添加更多的 STL 容器。

理想情况下,我希望能够对任何 STL 容器都遵循相同的做法。现在我需要一个 std::list .我不能让它工作。我可以做一个std::vector不过,工作。

标准::vector

以下代码有效:

#include <vector>
#include <boost/interprocess/managed_shared_memory.hpp>

namespace ipc = boost::interprocess;
using Segment = ipc::managed_shared_memory;
using Manager = Segment::segment_manager;
template <typename T> using Alloc = ipc::allocator<T, Manager>;
template <typename K> using Vector = std::vector<K, Alloc<K>>;

int main() {
boost::interprocess::shared_memory_object::remove("test");
Segment _segment{ipc::create_only, "test", 1ul<<40};
Manager *mgr = _segment.get_segment_manager();
Vector<int> *v = _segment.construct<Vector<int>>("v")(mgr);
v->emplace_back(1);
}

标准::列表

列表等效代码会导致错误。

#include <list>
#include <boost/interprocess/managed_shared_memory.hpp>

namespace ipc = boost::interprocess;
using Segment = ipc::managed_shared_memory;
using Manager = Segment::segment_manager;
template <typename T> using Alloc = ipc::allocator<T, Manager>;
template <typename K> using List = std::list<K, Alloc<K>>;

int main() {
boost::interprocess::shared_memory_object::remove("test");
Segment _segment{ipc::create_only, "test", 1ul<<40};
Manager *mgr = _segment.get_segment_manager();
List<int> *v = _segment.construct<List<int>>("v")(mgr);
v->emplace_back(1);
}

编译标志(使用 g++-7)和错误如下:

$ g++ -std=gnu++17 lol_list.cpp -lrt -pthread -rdynamic -Wfatal-errors && ./a.out && rm ./a.out
In file included from /usr/include/c++/7/list:63:0,
from lol_list.cpp:1:
/usr/include/c++/7/bits/stl_list.h: In instantiation of ‘std::__cxx11::list<_Tp, _Alloc>::_Node* std::__cxx11::list<_Tp, _Alloc>::_M_create_node(_Args&& ...) [with _Args = {int}; _Tp = int; _Alloc = boost::interprocess::allocator<int, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family>, boost::interprocess::iset_index> >; std::__cxx11::list<_Tp, _Alloc>::_Node = std::_List_node<int>]’:
/usr/include/c++/7/bits/stl_list.h:1801:32: required from ‘void std::__cxx11::list<_Tp, _Alloc>::_M_insert(std::__cxx11::list<_Tp, _Alloc>::iterator, _Args&& ...) [with _Args = {int}; _Tp = int; _Alloc = boost::interprocess::allocator<int, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family>, boost::interprocess::iset_index> >; std::__cxx11::list<_Tp, _Alloc>::iterator = std::_List_iterator<int>]’
/usr/include/c++/7/bits/stl_list.h:1133:4: required from ‘std::__cxx11::list<_Tp, _Alloc>::reference std::__cxx11::list<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {int}; _Tp = int; _Alloc = boost::interprocess::allocator<int, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family>, boost::interprocess::iset_index> >; std::__cxx11::list<_Tp, _Alloc>::reference = int&]’
lol_list.cpp:16:20: required from here
/usr/include/c++/7/bits/stl_list.h:578:11: error: cannot convert ‘boost::interprocess::offset_ptr<std::_List_node<int>, long int, long unsigned int, 0>’ to ‘std::__cxx11::list<int, boost::interprocess::allocator<int, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family>, boost::interprocess::iset_index> > >::_Node* {aka std::_List_node<int>*}’ in return
return __p;
^~~
compilation terminated due to -Wfatal-errors.

错误仍然存​​在于 g++-6g++-8 甚至 clang-6.0clang-5.0.

最佳答案

并非所有标准库实现都完全支持有状态分配器(还?)。

在这种情况下,您的 std::list<> 似乎没有。只需选择用于 Boost Container 的那个,它也可以通过 Boost Interprocess header 方便地获得:

#include <boost/interprocess/containers/list.hpp>
#include <boost/interprocess/managed_shared_memory.hpp>

namespace ipc = boost::interprocess;
using Segment = ipc::managed_shared_memory;
using Manager = Segment::segment_manager;
template <typename T> using Alloc = ipc::allocator<T, Manager>;
template <typename K> using List = ipc::list<K, Alloc<K>>;

int main() {
boost::interprocess::shared_memory_object::remove("test");
Segment _segment{ipc::create_only, "test", 1ul<<40};
Manager *mgr = _segment.get_segment_manager();
List<int> *v = _segment.construct<List<int>>("v")(mgr);
v->emplace_back(1);
}

关于c++ - std::list 在 boost::interprocess::managed_shared_memory 中,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/51883848/

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