I have a bunch of processes forked from the same parent processes. And they need to read the same large file during initialization. Unfortunately, I do not have any control over the parent process.
Is it possible that one process open the file, read contents and save the trouble of other brother processes from opening and reading?
- mmap does not seem to work, because I need to mmap the file before forking processes.
- Simple shmget/shmat is not a good idea for the needed synchronization.
- Use another separate process to load the file into shared memory, so the working processes no longer need to read file. It works although a little troublesome.
Is there any other way?