qprocson

, qprocsoff

- enable, disable put and service routines

Synopsis

#include <sys/stream.h> 
#include <sys/ddi.h> 

void qprocson(queue_t *q);

void qprocsoff(queue_t *q);

Interface Level

Architecture independent level 1 (DDI/DKI).

Parameters

q

Pointer to the RD side of a streams queue pair.

Description

The qprocson() enables the put and service routines of the driver or module whose read queue is pointed to by q. Threads cannot enter the module instance through the put and service routines while they are disabled.

The qprocson() function must be called by the open routine of a driver or module before returning, and after any initialization necessary for the proper functioning of the put and service routines.

The qprocson() function must be called before calling put(9F), putnext(9F), qbufcall(9F), qtimeout(9F), qwait(9F), or qwait_sig(9F).

The qprocsoff() function must be called by the close routine of a driver or module before returning, and before deallocating any resources necessary for the proper functioning of the put and service routines. It also removes the queue's service routines from the service queue, and blocks until any pending service processing completes.

The module or driver instance is guaranteed to be single-threaded before qprocson() is called and after qprocsoff() is called, except for threads executing asynchronous events such as interrupt handlers and callbacks, which must be handled separately.

Context

These routines can be called from user, interrupt, or kernel context.

See Also

close(9E), open(9E), put(9E), srv(9E), put(9F), putnext(9F), qbufcall(9F), qtimeout(9F), qwait(9F), qwait_sig(9F)

Writing Device Drivers

STREAMS Programming Guide

Notes

The caller may not have the stream frozen during either of these calls.