SV_ALLOC(D3)

NAME
     SV_ALLOC, SV_INIT - synchronization variable initialization

SYNOPSIS
     #include <sys/types.h>
     #include <sys/kmem.h>
     #include <sys/ksynch.h>
     #include <sys/ddi.h>
     #include <sys/sema.h>
     sv_t *SV_ALLOC(int type, int flag, char *name);

     void SV_INIT(sv_t *svp, int type, char *name);

   Arguments
     svp       Pointer to uninitialized synchronization variable.

     type      Specifies the order in which threads of execution that are
               waiting on the synchronization variable are dequeued when
               SV_SIGNAL or SV_BROADCAST are called.

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

     name      Ascii string associated with the synchronization object.

DESCRIPTION
     SV_ALLOC dynamically allocates and initializes an instance of a
     synchronization variable.  SV_INIT initializes an instance of a
     synchronization variable.

     If type is set to either SV_DEFAULT or SV_FIFO, waiting threads of
     execution are wakened in first-in, first-out order; if the type is
     SV_LIFO, they are dequeued in first-in, last-out order.  If the
     synchronization variable is of type SV_PRIO, waiters will be processed in
     priority order.

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

     The name argument is only used if the metering sleep-locks package is
     installed.  A null name is ignored.

   Return Values
     Upon successful completion, SV_ALLOC returns a pointer to the newly
     allocated lock.  If KM_NOSLEEP is specified and sufficient memory is not
     immediately available, SV_ALLOC returns a NULL pointer.
USAGE
   Level
     Base or Initialization.

   Synchronization Constraints
     SV_ALLOC 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
     SV_DEALLOC(D3), SV_DESTROY(D3), SV_WAIT(D3), SV_WAIT_SIG(D3),
     SV_SIGNAL(D3), SV_BROADCAST(D3).