Manpage of MI_SET_STH_HIWAT

MI_SET_STH_HIWAT

Section: OpenSS7 STREAMS Compatibility DDI/DKI (9)
Updated: 2008-10-31
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NAME

mi_set_sth_hiwat - set the Stream head high water mark

SYNOPSIS

#define _MPS_SOURCE
#include <sys/stream.h>
#include <sys/ddi.h>
#include <sys/mpsddi.h>

int mi_set_sth_hiwat(queue_t *q, size_t hiwat);

ARGUMENTS

q: the read queue of the current queue pair.
hiwat: the high water mark to set.

INTERFACE

MPS®-specific DDI.

DESCRIPTION

mi_set_sth_hiwat() is one of a group of helper functions, mi_set_sth_copyopt(9), mi_set_sth_lowat(9), mi_set_sth_maxblk(9), mi_set_sth_wroff(9), that are used to set characteristics of the Stream head. mi_set_sth_hiwat() sets the high water mark to hiwat for the Stream head belonging to the Stream containing queue pair, q.

USAGE

mi_set_sth_hiwat() is normally be called from within a STREAMS driver or module's qi_qopen(9) routine to adjust characteristics of the Stream head.

RETURN

When mi_set_sth_hiwat() succeeds, it returns true (1); when it fails, it returns false (0).

ERRORS

mi_set_sth_hiwat() fails when it cannot allocate a message block to hold the M_SETOPTS(9) message.

CONTEXT

mi_set_sth_hiwat() can be called from any context; however, it is intended to be called from a STREAMS driver or module's qi_qopen(9) routine.

MP-STREAMS

mi_set_sth_hiwat() is MP-safe.

NOTICES

mi_set_sth_hiwat() is an MPS®-specific function: _MPS_SOURCE, _AIX_SOURCE or _MAC_SOURCE must be defined before including DDI/DKI include files to expose this symbol. OpenSS7 STREAMS Compatibility must also have been compiled with CONFIG_STREAMS_COMPAT_MPS, CONFIG_STREAMS_COMPAT_MPS_MODULE, CONFIG_STREAMS_COMPAT_AIX, CONFIG_STREAMS_COMPAT_AIX_MODULE, CONFIG_STREAMS_COMPAT_MAC or CONFIG_STREAMS_COMPAT_MAC_MODULE defined.

IMPLEMENTATION

mi_set_sth_hiwat() is implemented by formulating a M_SETOPTS(9) message with stroptions(9) structure with SO_HIWAT set in so_flags and the hiwat argument copied to the so_hiwat member. The resulting M_SETOPTS(9) message is passed along queue, q, using putnext(9).

BUGS

mi_set_sth_hiwat() has no known bugs.

COMPATIBILITY

mi_set_sth_hiwat() is compatible with MPS®, AIX®, MacOT®, and Solaris®, with the following portability considerations:

---: mi_set_sth_hiwat() is an MPS®-specific function and should not be used by portable STREAMS drivers and modules. The more common zzz() function should be used in its stead.
---: mi_set_sth_hiwat() is provided for source level compatibility with MPS® for the purpose of porting MPS® drivers to Linux. Because internal structures and definitions for OpenSS7 STREAMS Compatibility[1] differ from that of MPS®, binaries are incompatible.
---: mi_set_sth_hiwat() only provides functionality comparable to MPS® for use by STREAMS drivers and modules. Any and all functionality provided by mi_set_sth_hiwat() in support of non-STREAMS devices are not supported.

See mpscompat(9), aixcompat(9), maccompat(9), and STREAMS(9) for additional compatibility considerations.

CONFORMANCE

MPS® DDI documentation, MacOT® DDI documentation[2, 3], AIX® documentation[4].

HISTORY

mi_set_sth_hiwat() first appeared in MPS®. mi_set_sth_hiwat() is a Mentat, Inc. function that goes all the way back to the pre-OSF/1 Mentat implementations. mi_set_sth_hiwat() appears in MacOT®[3] and AIX®[4]. An undocumented version of mi_set_sth_hiwat() appears in Solaris®.

REFERENCES

[1]: strcompat-0.9.2, STREAMS Compatibility Modules (strcompat) 0.9.2 Source Code, Brian Bidulock, ed., OpenSS7 Corporation. <http://www.openss7.org/>
[2]: Mac OS 9, Open Transport Reference, 2003, (Cupertino, California), Apple Computer, Inc., Apple. <http://developer.apple.com/macros/opentransport/>
[3]: Revision 1.5d2, Open Transport Module Developer Note, June 18, 1996, (Cupertino, California), Apple Computer, Inc., Apple. <http://developer.apple.com/macos/opentransport/>
[4]: AIX® 5L Version 5.1, AIX Communications Programming Concepts, 2001, (Boulder, Colorado), Internatonal Business Machines Corp., IBM. <http://publibn.boulder.ibm.com/>

TRADEMARKS

OpenSS7tm: is a trademark of OpenSS7 Corporation.
Linux®: is a registered trademark of Linus Torvalds.
UNIX®: is a registered trademark of The Open Group.
Solaris®: is a registered trademark of Sun Microsystems.

Other trademarks are the property of their respective owners.

IDENTIFICATION

OpenSS7 STREAMS Compatibility: Package strcompat version 0.9.2.7 released 2008-10-31.

Index

NAME
SYNOPSIS
ARGUMENTS
INTERFACE
DESCRIPTION
USAGE
RETURN
ERRORS
CONTEXT
MP-STREAMS
NOTICES
IMPLEMENTATION
SEE ALSO
BUGS
COMPATIBILITY
CONFORMANCE
HISTORY
REFERENCES
TRADEMARKS
IDENTIFICATION

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Time: 01:10:55 GMT, May 20, 2013