From 8f3f3991023702d597728be7e37b1e46b3ad7e46 Mon Sep 17 00:00:00 2001 From: pirofti <> Date: Mon, 6 Jul 2020 13:33:06 +0000 Subject: 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@ --- src/lib/libc/net/res_random.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'src/lib/libc/net/res_random.c') diff --git a/src/lib/libc/net/res_random.c b/src/lib/libc/net/res_random.c index 763e420bb8..b7036815c9 100644 --- a/src/lib/libc/net/res_random.c +++ b/src/lib/libc/net/res_random.c @@ -1,4 +1,4 @@ -/* $OpenBSD: res_random.c,v 1.24 2016/04/05 04:29:21 guenther Exp $ */ +/* $OpenBSD: res_random.c,v 1.25 2020/07/06 13:33:06 pirofti Exp $ */ /* * Copyright 1997 Niels Provos @@ -219,7 +219,7 @@ res_initid(void) if (ru_prf != NULL) arc4random_buf(ru_prf, sizeof(*ru_prf)); - clock_gettime(CLOCK_MONOTONIC, &ts); + WRAP(clock_gettime)(CLOCK_MONOTONIC, &ts); ru_reseed = ts.tv_sec + RU_OUT; ru_msb = ru_msb == 0x8000 ? 0 : 0x8000; } @@ -232,7 +232,7 @@ __res_randomid(void) u_int r; static void *randomid_mutex; - clock_gettime(CLOCK_MONOTONIC, &ts); + WRAP(clock_gettime)(CLOCK_MONOTONIC, &ts); pid = getpid(); _MUTEX_LOCK(&randomid_mutex); -- cgit v1.2.3-55-g6feb