53.6. Semaphore Limits

SUSv3 defines two limits applying to semaphores:

SEM_NSEMS_MAX

This is the maximum number of POSIX semaphores that a process may have. SUSv3 requires that this limit be at least 256. On Linux, the number of POSIX semaphores is effectively limited only by available memory.

SEM_VALUE_MAX

This is the maximum value that a POSIX semaphore may reach. Semaphores may assume any value from 0 up to this limit. SUSv3 requires this limit to be at least 32,767; the Linux implementation allows values up to INT_MAX (2,147,483,647 on Linux/x86-32).