Manpage of LINKB

LINKB

Section: Linux Fast-STREAMS DDI/DKI (9)
Updated: 2008-10-31
Index Return to Main Contents

NAME

linkb - link a message block to a STREAMS message

SYNOPSIS

#include <sys/stream.h>

void linkb(struct msgb *mp1, struct msgb *mp2);

ARGUMENTS

mp1: the message onto which to link.
mp2: the message to link.

INTERFACE

STREAMS.

DESCRIPTION

linkb() links the message pointed to by mp2 onto the end of the message pointed to by mp1.

RETURN

linkb() returns void.

ERRORS

linkb() silently fails if either mp1 or mp2 are NULL.

CONTEXT

linkb() can be called from any context, including user context, module procedures, callouts, callbacks, soft interrupts (tasklets and bottom halves), and interrupt service routines.

MP-STREAMS

linkb() is MP-safe. The caller is responsible to ensure exclusive access to the passed in messages.

NOTICES

linkb() could panic the kernel if passed an invalid pointer. linkb() is robust to being passed NULL pointers, and linkb(NULL,mp2) linkb(mp1,NULL) and linkb(NULL,NULL) are all valid (but the first form results in a memory leak of buffer mp2). Portable STREAMS drivers and modules will not pass linkb() a NULL or invalid pointer.

IMPLEMENTATION

linkb() is implemented as an extern inline function for speed. Its imlementation is as follows:


__EXTERN_INLINE void linkb(mblk_t *mp1, mblk_t *mp2)
{
    mblk_t **mpp;
    for (mpp = &mp1; *mpp; mpp = &(*mpp)->b_cont) ;
    *mpp = mp2;
}

BUGS

linkb() has no known bugs.

COMPATIBILITY

linkb() is compatible with SVR 4.2 MP DDI/DKI[1], and implementations based on SVR 4[2] with the following portability considerations:

---: linkb() is widely implmentated in a compatible fashion across many of the SVR 4 based implementations discussed here.
: Portable STREAMS drivers and modules may use this function.
---: Binary compatibility is not guaranteed.

See STREAMS(9) for additional compatibility information.

CONFORMANCE

SVR 4.2 MP DDI/DKI[1].

HISTORY

linkb() appears as part of SVR 4.0 STREAMS[3].

linkb() first appeared in SVR 3[4].

REFERENCES

[1]: USL DDI/DKI, Device Driver Interface/Driver-Kernel Interface (DDI/DKI) Reference Manual for Intel Processors, 1992, (Englewood Cliffs, New Jersey), AT&T UNIX System Laboratories, Inc., Prentice Hall.
[2]: SVR 4 DDI/DKI, UNIX® System V Release 4 Device Driver Interface/Driver-Kernel Interface (DDI/DKI) Reference Manual, 1990, (Englewood Cliffs, New Jersey), AT&T UNIX System Laboratories, Inc., Prentice Hall.
[3]: SVR 4, UNIX® System V Release 4 STREAMS Programmer's Guide, 1990, (Englewood Cliffs, New Jersey), AT&T UNIX System Laboratories, Inc., Prentice Hall.
[4]: SVR 3, UNIX® System V Release 3 STREAMS Programmer's Guide, (Englewood Cliffs, New Jersey), AT&T UNIX System Laboratories, Inc., Prentice Hall.

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

Linux Fast-STREAMS: Package streams version 0.9.2.4 released 2008-10-31.

Index

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

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Time: 22:28:29 GMT, May 23, 2013