WR(9F) Kernel Functions for Drivers WR(9F)NAME
WR, wr - get pointer to the write queue for this module or driver
SYNOPSIS
#include <sys/stream.h>
#include <sys/ddi.h>
queue_t *WR(queue_t *q);
INTERFACE LEVEL
Architecture independent level 1 (DDI/DKI).
PARAMETERS
q Pointer to the read queue whose write queue is to be returned.
DESCRIPTION
The WR() function accepts a read queue pointer as an argument and
returns a pointer to the write queue of the same module.
CAUTION: Make sure the argument to this function is a pointer to a read
queue. WR() will not check for queue type, and a system panic could
result if the pointer is not to a read queue.
RETURN VALUES
The pointer to the write queue.
CONTEXT
The WR() function can be called from user, interrupt, or kernel con‐
text.
EXAMPLES
Example 1 Using WR()
In a STREAMS close(9E) routine, the driver or module is passed a
pointer to the read queue. These usually are set to the address of the
module-specific data structure for the minor device.
1 xxxclose(q, flag)
2 queue_t *q;
3 int flag;
4 {
5 q->q_ptr = NULL;
6 WR(q)->q_ptr = NULL;
. . .
7 }
SEE ALSOclose(9E), OTHERQ(9F), RD(9F)SunOS 5.10 16 Jan 2006 WR(9F)
