From 0a0440a6e869e8d8791608f14fb55f37f323a23e Mon Sep 17 00:00:00 2001
From: hikari <ftphikari@gmail.com>
Date: Sat, 16 Apr 2022 14:08:37 +0300
Subject: [PATCH] time: yield accurate_sleep instead of relaxing the cpu

---
 core/time/time.odin         | 10 ++++++++--
 core/time/time_unix.odin    |  6 ++++++
 core/time/time_windows.odin |  4 ++++
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/core/time/time.odin b/core/time/time.odin
index 7056f83f8..f2e974647 100644
--- a/core/time/time.odin
+++ b/core/time/time.odin
@@ -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
 	}
 }
 
diff --git a/core/time/time_unix.odin b/core/time/time_unix.odin
index 37fc1fd3e..db15a824a 100644
--- a/core/time/time_unix.odin
+++ b/core/time/time_unix.odin
@@ -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 */
diff --git a/core/time/time_windows.odin b/core/time/time_windows.odin
index 0fb9eaa0f..397741126 100644
--- a/core/time/time_windows.odin
+++ b/core/time/time_windows.odin
@@ -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()
+}