Question

我正在尝试使用Boost共享内存分配器在共享内存上分配Folly Concurrent Hash Map。

#include <boost/interprocess/allocators/allocator.hpp>
#include <boost/interprocess/managed_shared_memory.hpp>
#include <folly/concurrency/ConcurrentHashMap.h>

template<class T>
using ShmAlloc = boost::interprocess::allocator<T, 
boost::interprocess::managed_shared_memory::segment_manager>;

using Key = int;
using Value = int;
using Table = folly::ConcurrentHashMap<Key, Value, std::hash<Key>, 
std::equal_to<Key>, ShmAlloc<uint8_t >>;

int main()
{
    //Create a new segment with given name and size
    managed_shared_memory segment(create_only, "SharedTable", 65536);

    //Initialize shared memory STL-compatible allocator
    ShmAlloc<uint8_t> alloc_inst (segment.get_segment_manager());

    Table* table = segment.construct<Table>("t1")(alloc_inst);

    // In another process I want to find it
    auto res = segment.find<Table>("t1");
    Table* found_table = res.first;


}

但出现以下错误：

ConcurrentHashMap.h:496:74: error: no matching function for call to ‘boost::interprocess::allocator<unsigned char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family>, boost::interprocess::iset_index> >::allocator()’
       SegmentT* newseg = (SegmentT*)Allocator().allocate(sizeof(SegmentT));

我尝试用具有默认构造函数和存储Boost共享内存实例的静态成员的分配器包装Boost共享内存分配器。这样可以解决编译错误，但会引起严重的以下问题：由于并发哈希映射未使用Allocator :: pointer（使用Boost分配器时为offset_ptr）。

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有人可以帮助我吗？

在共享内存上分配Folly ConcurrentHashMap

0 个答案: