posix: add package

core/time/time_linux.odin

@@ -0,0 +1,38 @@
+package time
+
+import "core:sys/linux"
+
+_IS_SUPPORTED :: true
+
+_now :: proc "contextless" () -> Time {
+	time_spec_now, _ := linux.clock_gettime(.REALTIME)
+	ns := time_spec_now.time_sec * 1e9 + time_spec_now.time_nsec
+	return Time{_nsec=i64(ns)}
+}
+
+_sleep :: proc "contextless" (d: Duration) {
+	ds := duration_seconds(d)
+	seconds := uint(ds)
+	nanoseconds := uint((ds - f64(seconds)) * 1e9)
+
+	ts := linux.Time_Spec{
+		time_sec  = seconds,
+		time_nsec = nanoseconds,
+	}
+
+	for {
+		if linux.nanosleep(&ts, &ts) != .EINTR {
+			break
+		}
+	}
+}
+
+_tick_now :: proc "contextless" () -> Tick {
+	t, _ := linux.clock_gettime(.MONOTONIC_RAW)
+	return Tick{_nsec = i64(t.time_sec*1e9 + t.time_nsec)}
+}
+
+_yield :: proc "contextless" () {
+	linux.sched_yield()
+}
+