_lwp_mutex_lock, _lwp_mutex_unlock, _lwp_mutex_trylock -
int _lwp_mutex_lock(lwp_mutex_t *mp);
int _lwp_mutex_trylock(lwp_mutex_t *mp);
int _lwp_mutex_unlock(lwp_mutex_t *mp);
These functions serialize the execution of lightweight
processes. They are useful for ensuring that only one light-
weight process can execute a critical section of code at any
one time (mutual exclusion). LWP mutexes must be initial-
ized to 0 before use.
The _lwp_mutex_lock() function locks the LWP mutex pointed
to by mp. If the mutex is already locked, the calling LWP
blocks until the mutex becomes available. When
_lwp_mutex_lock() returns, the mutex is locked and the cal-
ling LWP is the "owner".
The _lwp_mutex_trylock() function attempts to lock the
mutex. If the mutex is already locked it returns with an
error. If the mutex is unlocked, it is locked and
The _lwp_mutex_unlock() function unlocks a locked mutex. The
mutex must be locked and the calling LWP must be the one
that last locked the mutex (the owner). If any other LWPs
are waiting for the mutex to become available, one of them
Upon successful completion, 0 is returned. A non-zero value
indicates an error.
If any of the following conditions are detected,
_lwp_mutex_lock(), _lwp_mutex_trylock(), and
_lwp_mutex_unlock() fail and return the corresponding value:
The mp argument points to an invalid LWP mutex.
The mp argument points to an illegal address.
If any of the following conditions occur,
_lwp_mutex_trylock() fails and returns the corresponding
EBUSY The mp argument points to a locked mutex.
Man(1) output converted with