PPT Slide
Memory-mapped File I/O
- File mapping: extension of the VM system that allows the mapping of file I/O into the virtual address space.
- Once the mapping is established then file I/O is done through standard memory operations (notice the similarity to memory-mapped I/O). No explicit file I/O system calls are needed!
- Mapping a file to a memory address involves a new system call to create the mapping (MapFile()) and one to disconnect the mapping (UnMapFile()).
- Most UNIXes provide a file mapping mechanism via the mmap() and munmap().