内存映射文件 - 映射结构而不是文件？
我对内存映射文件非常陌生，我对某些东西有点迷失。
我知道如果我有一个文件，我可以加载它并使用 MMap 立即从各个进程访问它。
但在我的情况下，我正在创建一个附加到进程 A 的 DLL，并且该 DLL 已被赋予一个指向进程 A 准备的 cSurface 的指针。我需要与进程B共享cSurface的数据。我真的不想调用一个空白的MMap并将我的进程A的表面复制到其中，只是在进程B中再次将其复制出来。
是否可以映射我的Surface 就好像它是一个文件一样，因此 MMap 在创建时已经指向表面数据（就像我加载 SomeTextFile.txt 一样）？
理论上，我的计划是在 Proc A 中接收指向表面的指针，告诉窗口以给定名称共享该表面的内存，并使用互斥体来协调访问 - 其想法是两个进程读取相同的物理副本表面没有繁琐的复制。
这可能吗？
I'm very new to Memory Mapped Files, and I'm a little lost on something.
I know that if I had a file, I could load it and access it from various processes at once using MMaps.
But in my situation, I'm creating a DLL attached to Process A, and that DLL has been given a pointer to a cSurface which Process A has prepared. I need to share that cSurface's data with Process B. I really don't want to have to call up a blank MMap and copy my Process A's surface into it, only to copy it out again in process B.
Is it possible to map my surface as if it were a file so the MMap already points to the surface data when it's created (as it would were I loading SomeTextFile.txt)?
My plan, in theory, would be to receive a pointer to the surface in Proc A, tell windows to share that surface's memory with a given name, and use Mutexes to coordinate access - the idea being that both processes read the same physical copy of the surface with no cumbersome copying.
Is that possible?
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是的，这一切都在 CreateFileMapping 的文档中。
您可以为内存映射文件命名。如果另一个进程打开同名的 mmap，它将指向相同的内存。如果 CreateFileMapping 中的句柄被放入 INVALID_HANDLE_VALUE 中，它将纯粹保留在内存中。查看CreateFileMapping
Yes, it's all there in the documentation of CreateFileMapping.
You can give your memory mapped file a name. If another process open a mmap with the same name it will point to the same memory. It the handle in CreateFileMapping is put to INVALID_HANDLE_VALUE it keeps it purely in memory. Check the documentation of CreateFileMapping
感谢您的所有评论。
我做了一些进一步的研究并找到了答案。
您可以使用内存映射文件来共享文件或空白内存空间。如果您想在设置地图之前共享内存中已初始化的数据，则必须创建一个空白地图，然后将数据复制到其中。
Thanks for all your comments.
I did some further research and found the answer.
You can use Memory Mapped Files to share either a file, or a blank memory space. If you want to share data already initialised in memory prior to setting up the map, you have to create a blank map and subsequently copy your data into it.