MUTEX_OWNED(D3)

NAME
     MUTEX_OWNED - query whether a mutual exclusion lock is available

SYNOPSIS
     #include <sys/types.h>
     #include <sys/ksynch.h>
     #include <sys/ddi.h>
     boolean_t MUTEX_OWNED(mutex_t *lockp);

   Arguments
     lockp     Pointer to the mutual exclusion lock to be queried.

DESCRIPTION
     MUTEX_OWNED returns an indication of whether the mutual exclusion lock
     specified by lockp is currently available.

   Return Values
     MUTEX_OWNED returns TRUE (a non-zero value) if the lock was available or
     FALSE (zero) if the lock was not available.

USAGE
     The state of the lock may change and the value returned may no longer be
     valid by the time the caller sees it.  The caller is expected to
     understand that this is ``stale data'' and is either using it as a
     heuristic or has arranged for the return value to be meaningful by other
     means.

   Level
     Base or Interrupt.

   Synchronization Constraints
     Does not sleep.

     Driver-defined basic locks, read/write locks, and sleep locks may be held
     across calls to this function.

REFERENCES
     MUTEX_ALLOC(D3), MUTEX_INIT(D3), MUTEX_DEALLOC(D3), MUTEX_DESTROY(D3),
     MUTEX_LOCK(D3), MUTEX_TRYLOCK(D3), MUTEX_UNLOCK(D3), MUTEX_MINE(D3).