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linkblk(D4str)


linkblk -- STREAMS multiplexor link structure

Synopsis

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

Description

The linkblk structure contains the information needed by a multiplexing driver to set up or take down a multiplexor link.

Usage

The linkblk structure is embedded in the M_DATA(D7str) portion of the M_IOCTL(D7str) messages generated from the following streamio calls: I_LINK, I_UNLINK, I_PLINK, I_PUNLINK.

Structure definitions

The linkblk structure contains the following members:
   queue_t	*l_qtop;
   queue_t	*l_qbot;
   int	l_index;

Structure members


l_qtop
pointer to the lowest write queue in the upper stream. In other words, it is the write queue of the multiplexing driver. If the link is persistent across closes of the driver, then this member is set to NULL.

l_qbot
pointer to the upper write queue in the lower stream. The lower stream is the stream being linked under the multiplexor. The topmost read and write queues in the lower stream are given to the multiplexing driver to use for the lower half of its multiplexor processing. The qinit(D4str) structures associated with these queues are those specified for the lower processing in the multiplexing driver's streamtab(D4str) structure.

l_index
unique ID that identifies the multiplexing link in the system. The driver can use this as a key on which it can multiplex or de-multiplex.

Hardware applicability

All

Version applicability

ddi: 1, 2, 3, 4, 5, 5mp, 6, 6mp, 7, 7mp, 8, 8mp
oddi: 1, 2, 2mp, 3, 3mp, 4, 4mp, 5, 5mp

References

datab(D4str), Intro(D7str), iocblk(D4str), ioctl, M_DATA(D7str), M_IOCTL(D7str), msgb(D4str), qinit(D4str), streamio, streamtab(D4str)
19 June 2005
© 2005 The SCO Group, Inc. All rights reserved.
OpenServer 6 and UnixWare (SVR5) HDK - June 2005