time: yield accurate_sleep instead of relaxing the cpu

This commit is contained in:
hikari
2022-04-16 14:08:37 +03:00
parent b9dc81d808
commit 0a0440a6e8
3 changed files with 18 additions and 2 deletions

View File

@@ -213,6 +213,10 @@ time_add :: proc(t: Time, d: Duration) -> Time {
return Time{t._nsec + i64(d)}
}
yield :: proc "contextless" () {
_yield()
}
// Accurate sleep borrowed from: https://blat-blatnik.github.io/computerBear/making-accurate-sleep-function/
accurate_sleep :: proc(d: Duration) {
to_sleep, estimate, mean, m2, count: Duration
@@ -240,8 +244,10 @@ accurate_sleep :: proc(d: Duration) {
start := tick_now()
for to_sleep > tick_since(start) {
intrinsics.cpu_relax() // prevent the spinlock from taking the thread hostage, still accurate enough
// NOTE: it is possible that sometimes cpu can relax a bit too much, in that case it should spinlock freely for a while (TODO)
// prevent the spinlock from taking the thread hostage, still accurate enough
yield()
// NOTE: it might be possible that it yields for too long, in that case it should spinlock freely for a while
// TODO: needs actual testing done to check if that's the case
}
}

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@@ -1,6 +1,8 @@
//+build linux, darwin, freebsd, openbsd
package time
import "core:sys/unix"
IS_SUPPORTED :: true // NOTE: Times on Darwin are UTC.
when ODIN_OS == .Darwin {
@@ -17,6 +19,10 @@ foreign libc {
@(link_name="nanosleep") _unix_nanosleep :: proc(requested: ^TimeSpec, remaining: ^TimeSpec) -> i32 ---
}
_yield :: proc "contextless" () {
unix.sched_yield()
}
TimeSpec :: struct {
tv_sec : i64, /* seconds */
tv_nsec : i64, /* nanoseconds */

View File

@@ -35,3 +35,7 @@ _tick_now :: proc "contextless" () -> Tick {
_nsec := mul_div_u64(i64(now), 1e9, i64(qpc_frequency))
return Tick{_nsec = _nsec}
}
_yield :: proc "contextless" () {
win32.SwitchToThread()
}