deinit

pub fn deinit(k: *Kqueue) void {
    const active_threads = @atomicLoad(u32, &k.threads.active, .acquire);
    for (k.threads.allocated[0..active_threads]) |*thread| {
        const ready_fiber = @atomicLoad(?*Fiber, &thread.ready_queue, .monotonic);
        assert(ready_fiber == null or ready_fiber == Fiber.finished); // pending async
    }
    k.yield(null, .exit);
    const main_thread = &k.threads.allocated[0];
    const gpa = k.gpa;
    main_thread.deinit(gpa);
    const allocated_ptr: [*]align(@alignOf(Thread)) u8 = @ptrCast(@alignCast(k.threads.allocated.ptr));
    const idle_stack_end_offset = std.mem.alignForward(usize, k.threads.allocated.len * @sizeOf(Thread) + idle_stack_size, std.heap.page_size_max);
    for (k.threads.allocated[1..active_threads]) |*thread| thread.thread.join();
    gpa.free(allocated_ptr[0..idle_stack_end_offset]);
    k.* = undefined;
}