tiny.simd.thread.wait

1pub const wait = @import("wait.zig");

1const std = @import("std");2const sys = @import("sys");34pub const WaitWord = std.atomic.Value(u32);56pub fn nanoSleep(nanoseconds: u64) bool {7    if (!sys.time.supportsAwakeClock()) return false;8    sys.time.sleepNanoseconds(nanoseconds);9    return true;10}1112pub fn blockUntilDifferent(13    previous: u32,14    word: *const WaitWord,15) u32 {16    return sys.thread.blockUntilDifferent(previous, word);17}1819pub fn wakeAll(word: *WaitWord) void {20    sys.thread.wakeAll(word);21}2223const WakeContext = struct {24    word: *WaitWord,25    observed: *u32,2627    fn wait(self: WakeContext) void {28        self.observed.* = blockUntilDifferent(7, self.word);29    }30};3132test "Highway wait word blocks until storage changes and wakes" {33    if (!sys.thread.threadsSupported()) return error.SkipZigTest;34    var word = WaitWord.init(7);35    var observed: u32 = 0;36    const handle = try sys.thread.spawn(WakeContext.wait, .{37        WakeContext{ .word = &word, .observed = &observed },38    });39    _ = nanoSleep(std.time.ns_per_ms);40    word.store(11, .release);41    wakeAll(&word);42    handle.join();43    try std.testing.expectEqual(@as(u32, 11), observed);44    try std.testing.expectEqual(@as(u32, 11), blockUntilDifferent(7, &word));45}