I created and initialized System V semaphores with semget() and semctl() in the main function, but the semop() function is called in a different function. I simply passed the ids of the semaphores as parameters to that function. It looks something like this:

int manageProcesses(int* data, int* numProcesses, int semId, int mutex, int time)
{
    semop(mutex, &semwait, 1);
    ...
}

Does this work or should semop() be called in the same function as semget() and semctl()?

CodePudding user response：

Does this work or should semop() be called in the same function as semget() and semctl()?

The id of a semaphore set, as obtained from semget(), is a process-scoped handle on an object (the semaphore set) with kernel persistence. Once you obtain one, you can use that anywhere in the program in conjunction with semctl() and / or semop(), until and unless you remove the semaphore set via semctl(..., IPC_RMID), or some other process removes it.