<feed xmlns='http://www.w3.org/2005/Atom'>
<title>openbsd/src/regress/lib/libc/timekeep, branch libressl-v3.8.2</title>
<subtitle>A mirror of https://github.com/libressl/openbsd.git
</subtitle>
<id>https://git.lua4.win/openbsd/atom?h=libressl-v3.8.2</id>
<link rel='self' href='https://git.lua4.win/openbsd/atom?h=libressl-v3.8.2'/>
<link rel='alternate' type='text/html' href='https://git.lua4.win/openbsd/'/>
<updated>2020-07-06T13:33:06+00:00</updated>
<entry>
<title>Add support for timeconting in userland.</title>
<updated>2020-07-06T13:33:06+00:00</updated>
<author>
<name>pirofti</name>
<email></email>
</author>
<published>2020-07-06T13:33:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.lua4.win/openbsd/commit/?id=0320e8b397405d62725b086d54c65caf0669f919'/>
<id>urn:sha1:0320e8b397405d62725b086d54c65caf0669f919</id>
<content type='text'>
This diff exposes parts of clock_gettime(2) and gettimeofday(2) to
userland via libc eliberating processes from the need for a context
switch everytime they want to count the passage of time.

If a timecounter clock can be exposed to userland than it needs to set
its tc_user member to a non-zero value. Tested with one or multiple
counters per architecture.

The timing data is shared through a pointer found in the new ELF
auxiliary vector AUX_openbsd_timekeep containing timehands information
that is frequently updated by the kernel.

Timing differences between the last kernel update and the current time
are adjusted in userland by the tc_get_timecount() function inside the
MD usertc.c file.

This permits a much more responsive environment, quite visible in
browsers, office programs and gaming (apparently one is are able to fly
in Minecraft now).

Tested by robert@, sthen@, naddy@, kmos@, phessler@, and many others!

OK from at least kettenis@, cheloha@, naddy@, sthen@
</content>
</entry>
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