Windows® via C/C++, Fifth Edition

Implementation Details of Memory-Mapped Files

Windows requires a process to call MapViewOfFile before the file’s data is accessible in the process’ address space. If one process calls MapViewOfFile, the system reserves a region of address space for the view in the calling process’ address space—no other process can see the view. If another process wants to access the data in the same file-mapping object, a thread in the second process must call MapViewOfFile, and the system will reserve a region for the view in the second process’ address space.

It is important to note that the memory address returned by the first process’ call to MapViewOfFile will most likely not be the same memory address returned by the second process’ call to MapViewOfFile ...