#include <sys/locking.h>
Remarks
The mode argument in the call to the _locking function specifies the locking action to be performed.
The mode argument must be one of the following manifest constants:
_LK_LOCK
Locks the specified bytes. If the bytes cannot be locked, the function tries again after one second. If, after ten attempts, the bytes cannot be locked, the function returns an error.
_LK_RLCK
Same as _LK_LOCK.
_LK_NBLCK
Locks the specified bytes. If bytes cannot be locked, the function returns an error.
_LK_NBRLCK
Same as _LK_NBLCK.
_LK_UNLCK
Unlocks the specified bytes. (The bytes must have been previously locked.)
See Also _locking