File segment/section/record locks in Linux threads

Question

I have a multi-threaded process where a file is shared (read and written) by multiple threads. Is there any way a thread can lock one file segment so that other threads cannot a

Answer 1

If you don't need file locks between different processes, avoid the file locks (which are one of the worst designed parts of the POSIX API) and just use mutexes or other shared memory concurrency primitives.