I am writing a C program that makes use of mmap system call, running on Linux 3.12 64-bit.
If I have two processes mmaping the same region of a disk file with read/write access, and then modify the region content from both processes at the same time...
- Can one process see (read) changed data made by the other process, before or after msync?
- If update can be seen by the other process - is there a happens-before guarantee made by Linux mmap implementation?