CVS commit: src

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Mon May 22 14:07:24 UTC 2023

Modified Files:
        src/share/man/man9: uiomove.9
        src/sys/kern: subr_copy.c
        src/sys/sys: systm.h

Log Message:
uiomove(9): Add uiopeek/uioskip operations.

This allows a caller to grab some data, consume part of it, and
atomically update the uio with only the amount it consumed.  This
way, the caller can use a buffer of a size that doesn't depend on how
much it will actually consume, which it may not know in advance --
e.g., because it depends on how much an underlying hardware tty
device will accept before it decides it has had too much.

Proposed on tech-kern:
https://mail-index.netbsd.org/tech-kern/2023/05/09/msg028883.html

(Opinions were divided between `uioadvance' and `uioskip'.  I stuck
with `uioskip' because that was less work for me.)


To generate a diff of this commit:
cvs rdiff -u -r1.20 -r1.21 src/share/man/man9/uiomove.9
cvs rdiff -u -r1.18 -r1.19 src/sys/kern/subr_copy.c
cvs rdiff -u -r1.301 -r1.302 src/sys/sys/systm.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.