diff options
| author |   pirofti <pirofti@openbsd.org> | 2020-07-06 13:33:05 +0000 |
|---|---|---|
| committer | pirofti <pirofti@openbsd.org> | 2020-07-06 13:33:05 +0000 |
| commit | d82e6535c6efd8305182f77041b2246ccfae1196 (patch) | |
| tree | d28dc130334c17949d90330ecbb2121294b899ff /lib/libc/thread/synch.h | |
| parent | sync (diff) | |
| download | wireguard-openbsd-d82e6535c6efd8305182f77041b2246ccfae1196.tar.xz wireguard-openbsd-d82e6535c6efd8305182f77041b2246ccfae1196.zip | |
Add support for timeconting in userland.
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@
Diffstat (limited to 'lib/libc/thread/synch.h')
| -rw-r--r-- | lib/libc/thread/synch.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/libc/thread/synch.h b/lib/libc/thread/synch.h index 788890add89..aaeb965956a 100644 --- a/lib/libc/thread/synch.h +++ b/lib/libc/thread/synch.h @@ -1,4 +1,4 @@ -/* $OpenBSD: synch.h,v 1.4 2019/10/21 10:04:19 mpi Exp $ */ +/* $OpenBSD: synch.h,v 1.5 2020/07/06 13:33:06 pirofti Exp $ */ /* * Copyright (c) 2017 Martin Pieuchot * @@ -33,7 +33,7 @@ _twait(volatile uint32_t *p, int val, clockid_t clockid, const struct timespec * if (abs == NULL) return futex(p, FUTEX_WAIT_PRIVATE, val, NULL, NULL); - if (abs->tv_nsec >= 1000000000 || clock_gettime(clockid, &rel)) + if (abs->tv_nsec >= 1000000000 || WRAP(clock_gettime)(clockid, &rel)) return (EINVAL); rel.tv_sec = abs->tv_sec - rel.tv_sec; |