crashHandler

fn crashHandler(userdata: ?*anyopaque) void {
    const ev: *Evented = @ptrCast(@alignCast(userdata));
    _ = ev;
    const thread = Thread.self orelse std.process.abort();
    if (thread.current_context == &thread.idle_context) std.process.abort();
    const fiber = thread.currentFiber();
    @atomicStore(
        Fiber.CancelStatus,
        &fiber.cancel_status,
        .{ .requested = true, .awaiting = .nothing },
        .monotonic,
    );
    fiber.cancel_protection = .{ .user = .blocked, .acknowledged = true };
}