WR(D3)

NAME
     WR - get a pointer to the write queue

SYNOPSIS
     #include <sys/stream.h>
     #include <sys/ddi.h>
     queue_t *WR(queue_t *q);

   Arguments
     q         Pointer to the queue whose write queue is to be returned.

DESCRIPTION
     The WR function accepts a queue pointer as an argument and returns a
     pointer to the write queue of the same module.

   Return Values
     The pointer to the write queue.

USAGE
     Note that when WR is passed a write queue pointer as an argument, it
     returns a pointer to this write queue.

   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.

   Examples
     In a STREAMS open(D2) routine, the driver or module is passed a pointer
     to the read queue.  The driver or module can store a pointer to a private
     data structure in the q_ptr field of both the read and write queues if it
     needs to identify the data structures from its put(D2) or srv(D2)
     routines.

      1  extern struct xxx_dev[];
         ...
      2  xxxopen(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *crp)
      3  {
          ...
      3   q->q_ptr = (caddr_t)&xxx_dev[getminor(*devp)];
      4   WR(q)->q_ptr = (caddr_t)&xxx_dev[getminor(*devp)];
          ...
      5  }
REFERENCES
     OTHERQ(D3), RD(D3)