Semaphores in C Linux Programming -

i'm taking on c code running in linux (centos) extensive use of semaphores. way code written :

./program1

this program launches bunch of processes makes use of mutexes , semaphores.

./program2

this program launches bunch of processes makes use of mutexes , semaphores.

i've realised program1 , program2, make use of semaphores same names. in linux c programming, can different programs use same semaphores? guess no, same naming confusing hell out of me. using same source code launch , handle semaphores.

the semaphores invoked using following commands:

semget semctl semop i've read these called processes semaphores.. if program1 creates semaphore1, can program2 access semaphore1?

appreciate here, thanks!

assuming mean named semaphores (or unnamed semaphores stored in shared memory, both can created sem_open), are shared amongst processes.

semaphores using semget , related calls use id key rather name usage patterns similar.

semaphores 1 of ipc (inter-process communication) methods.

you can create one-process-only semaphore using unnamed variant in non-shared memory , accessible threads of given process but, in experience, that's not common use case. semget family of calls can give process-private semaphores.

mutexes, on other hand, tend more used within single process inter-thread communication there variant of them can work inter-process.

you create pthread_mutexattr (attribute) allows sharing of mutexes , use attribute when initialising mutex want share. obviously, mutex needs in shared memory multiple processes can @ it.