queue(9S)

NAME

queue − STREAMS queue structure

SYNOPSIS

#include <sys/stream.h>

INTERFACE LEVEL

Architecture independent level 1 (DDI/DKI).

DESCRIPTION

A STREAMS driver or module consists of two queue structures, one for upstream processing (read) and one for downstream processing (write). This structure is the major building block of a stream. It contains pointers to the processing procedures, pointers to the next and previous queues in the stream, flow control parameters, and a pointer defining the position of its messages on the STREAMS scheduler list.

The queue structure is defined as type queue_t.

STRUCTURE MEMBERS

struct qinit	∗q_qinfo;	/∗ module or driver entry points ∗/
struct msgb	∗q_first;	/∗ first message in queue ∗/
struct msgb	∗q_last;	/∗ last message in queue ∗/
struct queue	∗q_next;	/∗ next queue in stream ∗/
void	∗q_ptr;	/∗ pointer to private data structure ∗/
ulong	q_count;	/∗ approximate size of message queue ∗/
ulong	q_flag;	/∗ status of queue ∗/
long	q_minpsz;	/∗ smallest packet accepted by QUEUE ∗/
long	q_maxpsz;	/∗ largest packet accepted by QUEUE ∗/
ulong	q_hiwat;	/∗ high water mark ∗/
ulong	q_lowat;	/∗ low water mark ∗/
struct qband	∗q_bandp;	/∗ separate flow info ∗/

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