solaris Man Page: WR(9f)

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WR(9F) manual page Table of Contents

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).

Arguments

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

WR() can be called from user or interrupt context.

Examples

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  }