Question

我正在尝试在共享内存中创建一个int数组和一个bool数组。到目前为止，我有以下代码运行没有错误，“显然”创建内存，但我不确定我可以使用LPCTSTR访问像数组一样的数据？有人可以解释一下最好的解决方法，因为我发现MSDN非常缺乏和痛苦。

void createSharedMemory()
{
    const char slotsName[]="Slots";
    const char flagsName[]="Flags";

    const LONG BufferSize = sizeof(int);
    const LONG Buffers = 10;
    const LONG FlagSize = sizeof(bool); 

    HANDLE hSlots = CreateFileMapping((HANDLE)0xFFFFFFFF, NULL, PAGE_READWRITE, 0, BufferSize * Buffers, SLOTSNAME);
    assert(hSlots != NULL);

    HANDLE hFlags = CreateFileMapping((HANDLE)0xFFFFFFFF, NULL, PAGE_READWRITE, 0, FlagSize * Buffers, flagsName);
    assert(hSlots != NULL);

    std::cout << "Created shared memory!" << std::endl;
}


int main(int argc, char* argv[])
{
    createSharedMemory();

    HANDLE hSlots;
    LPCTSTR pSlots;

    hSlots = OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, SLOTSNAME);

    if(hSlots == NULL)
    {
        std::cout << "Could not open slots file mapping object:" << GetLastError() << std::endl;
        getchar();
        return 0;
    }

    pSlots = (LPTSTR) MapViewOfFile(hSlots, FILE_MAP_ALL_ACCESS, 0, 0, 10 * sizeof(int));

    if(pSlots == NULL)
    {
        std::cout << "Could not map view of slots file:" << GetLastError() << std::endl;
        CloseHandle(hSlots);
        getchar();
        return 0;
    }

    std::cout << "Mapped slots correctly!" << std::endl;

    HANDLE hFlags;
    LPCTSTR pFlags;

    hFlags = OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, FLAGSNAME);

    if(hFlags == NULL)
    {
        std::cout << "Could not open flags file mapping object:" << GetLastError() << std::endl;
        getchar();
        return 0;
    }

    pFlags = (LPTSTR) MapViewOfFile(hFlags, FILE_MAP_ALL_ACCESS, 0, 0, 10 * sizeof(bool));

    if(pFlags == NULL)
    {
        std::cout << "Could not map view of flags file:" << GetLastError() << std::endl;
        CloseHandle(hFlags);
        getchar();
        return 0;
    }

    std::cout << "Mapped flags correctly!" << std::endl;

    //Access the data here

    getchar();

    UnmapViewOfFile(pSlots);
    CloseHandle(hSlots);

    UnmapViewOfFile(pFlags);
    CloseHandle(hFlags);

    return 0;
}

Answer 1

MapViewOfFile()将共享内存映射到进程的地址空间。从那时起（直到它被取消映射），您可以将其视为您分配（或在堆栈中声明）的本地内存块。

共享内存句柄hSlots的大小为10 * sizeof(int)个字节，如果你真的在这个内存中存储了int，那么最简单的方法是将pSlots声明为{{ 1}}：

int*

C ++ WIN32在共享内存中创建整数和布尔数组

1 个答案: