_lwp_sema_trywait --
conditionally acquire the semaphore
Synopsis
#include <synch.h>
int _lwp_sema_trywait(_lwp_sema_t *sema);
Parameters
sema
Description
_lwp_sema_trywait makes a single attempt to acquire the semaphore sema,
but does not block in the case of a failure.
sema parameter
sema must have been previously initialized,
either by _lwp_sema_init or statically (see _lwp_sema_init).
Return values
_lwp_sema_trywait returns zero for success
and an error number for failure, as described below.
Errors
If any of the following conditions is detected,
_lwp_sema_trywait fails and returns the corresponding value:
EBUSY
The semaphore is in the locked state.
EFAULT
The sema parameter points to an illegal address.
(This error may not be detected; a SIGSEGV signal may be posted to the
faulting lightweight processs (LWP) if an illegal address is used.)