SLEEP_ALLOC(D3)

NAME
     SLEEP_ALLOC, SLEEP_INIT - sleep lock initialization

SYNOPSIS
     #include <sys/types.h>
     #include <sys/kmem.h>
     #include <sys/ksynch.h>
     #include <sys/ddi.h>
     sleep_t *SLEEP_ALLOC(int arg, lkinfo_t *lkinfop, int flag);

     void SLEEP_INIT(sleep_t *lockp, int arg, lkinfo_t *lkinfop);

   Arguments
     lockp     Pointer to uninitialized sleep lock.

     arg       Reserved for future use (must be equal to zero).

     lkinfop   Reserved for future use (must be equal to -1).

     flag      Specifies whether the caller is willing to sleep waiting for
               memory.

DESCRIPTION
     SLEEP_ALLOC dynamically allocates and initializes an instance of a sleep
     lock.  SLEEP_INIT initializes an instance of a sleep lock.  The lock is
     initialized to the unlocked state.

     If flag is set to KM_SLEEP, the caller will sleep if necessary until
     sufficient memory is available.  If flag is set to KM_NOSLEEP, the caller
     will not sleep, but SLEEP_ALLOC will return NULL if sufficient memory is
     not immediately available.

   Return Values
     Upon successful completion, SLEEP_ALLOC returns a pointer to the newly
     allocated lock.  If KM_NOSLEEP is specified and sufficient memory is not
     immediately available, SLEEP_ALLOC returns a NULL pointer.

USAGE
   Level
     Base or Initialization.

   Synchronization Constraints
     May sleep if flag is set to KM_SLEEP.

     Driver-defined basic locks and read/write locks may be held across calls
     to this function if flag is KM_NOSLEEP but may not be held if flag is
     KM_SLEEP.

     Driver-defined sleep locks may be held across calls to this function
     regardless of the value of flag.
REFERENCES
     SLEEP_DEALLOC(D3), SLEEP_DESTROY(D3), SLEEP_LOCK(D3), SLEEP_LOCK_SIG(D3),
     SLEEP_LOCKAVAIL(D3), SLEEP_TRYLOCK(D3), SLEEP_UNLOCK(D3)