Content-type: text/html Man page of WR

WR

Section: Kernel Functions for Drivers (9F)
Updated: 16 Jan 2006
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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 context.  

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 ALSO

close(9E), OTHERQ(9F), RD(9F)


 

Index

NAME
SYNOPSIS
INTERFACE LEVEL
PARAMETERS
DESCRIPTION
RETURN VALUES
CONTEXT
EXAMPLES
SEE ALSO

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Time: 02:39:40 GMT, October 02, 2010