C++ 32位和64位进程之间共享的MapViewOfFile

我试图在64位进程中对已映射到另一个32位进程内存的文件使用MapViewOfFile。它失败并给我一个“拒绝访问”错误。这是已知的Windows限制还是我做错了什么？同样的代码适用于2个32位进程

代码有点像这样：

hMapFile = OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, szShmName);
if (NULL == hMapFile)
{   /* failed to open - create new (this happens in the 32 bit app) */
   SECURITY_ATTRIBUTES  sa;
   sa.nLength = sizeof(SECURITY_ATTRIBUTES);
   sa.bInheritHandle = FALSE;  
   /* give access to members of administrators group */
   BOOL success = ConvertStringSecurityDescriptorToSecurityDescriptor(
            "D:(A;OICI;GA;;;BA)",
            SDDL_REVISION_1,
            &(sa.lpSecurityDescriptor),
            NULL);
   HANDLE hShmFile = CreateFile(FILE_XXX_SHM, 
            FILE_ALL_ACCESS, 0, 
            &sa, 
            OPEN_ALWAYS, 0, NULL);

   hMapFile = CreateFileMapping(hShmFile, &sa, PAGE_READWRITE, 
            0, 
            SHM_SIZE, 
            szShmName);

   CloseHandle(hShmFile);
}

// this one fails in 64 bit app
pShm = MapViewOfFile(hMapFile, FILE_MAP_ALL_ACCESS, 0, 0, SHM_SIZE); 

---

当您在32位应用程序中调用CreateFile时，您正在为sharing参数传递

0

，这意味着不允许共享。将其更改为

FILE\u SHARE\u READ | FILE\u SHARE\u WRITE

可能是正确的一步

编辑：我刚刚制作了一个演示（至少对我来说）：

#包括
#包括
静态常量char map_name[]=“FileMapping1”；
静态常量char event1_name[]=“EventName1”；
静态常量char event2_name[]=“EventName2”；
int main（）{
HANDLE mapping=OpenFileMapping（FILE\u MAP\u ALL\u ACCESS，FALSE，MAP\u name）；
if（NULL==映射）{
std：：你能检查路径是否被重定向到VirtualStore目录吗？Process Monitor可能会有所帮助。谢谢Jerry，它对你有用很有趣。不过我不认为这是我的问题，因为no sharing标志只传递给CreateFile；该文件会立即关闭，因此不应该应用。而且它在r在多个32位应用程序之间共享，仅当其中一个应用程序为64位时才会出现故障。不过，我会尝试运行您的代码。我想我已经找到了答案。文件大小是根据结构的大小确定的，在64位系统上，结构的大小更大，因为时间是64位的，而在32位版本上，我们强制我们的时间仍然是32位的。对于some指定大于MapViewOfFile上现有区域大小的原因失败，访问被拒绝。谢谢！
#include <windows.h>
#include <iostream>

static const char map_name[] = "FileMapping1";
static const char event1_name[] = "EventName1";
static const char event2_name[] = "EventName2";

int main() { 
    HANDLE mapping = OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, map_name);

    if (NULL == mapping) {
        std::cout << "Calling CreateFile\n";
        HANDLE file = CreateFile("MappedFile", 
            FILE_ALL_ACCESS, 
            FILE_SHARE_READ | FILE_SHARE_WRITE,
            NULL, 
            OPEN_ALWAYS, 
            0, 
            NULL);
        std::cout << "Creating File mapping\n";
        mapping = CreateFileMapping(file, NULL, PAGE_READWRITE, 0, 65536, map_name);

        std::cout << "Closing file handle\n";
        CloseHandle(file);
    }

    std::cout << "Mapping view of file\n";
    char *memory = (char *)MapViewOfFile(mapping, FILE_MAP_ALL_ACCESS, 0, 0, 65536);
    if (memory == NULL) {
        std::cerr << "Mapping Failed.\n";
        return 1;
    }
    std::cout << "Mapping succeeded\n";

    HANDLE event = CreateEvent(NULL, false, false, event1_name);

    if (GetLastError()==ERROR_ALREADY_EXISTS) {
        std::cout <<"Waiting to receive string:\n";
        WaitForSingleObject(event, INFINITE);
        std::cout << "Received: " << memory;
        HANDLE event2 = CreateEvent(NULL, false, false, event2_name);
        SetEvent(event2);
    }
    else {
        char string[] = "This is the shared string";
        std::cout << "Sending string: " << string << "\n";
        strncpy(memory, string, sizeof(string));
        SetEvent(event);
        HANDLE event2 = CreateEvent(NULL, false, false, event2_name);
        WaitForSingleObject(event2, INFINITE);
    }   
    return 0;
}