ref: 770c90d4a5b16a5d598072b6983e50969151b166
dir: /lib/thread/test/waitgrp.myr/
use std use thread const Threadc = 8 var wg const main = { wg = thread.mkwg(Threadc) for var i = 0; i < Threadc; i++ thread.spawn({ std.usleep(3_000_000) thread.wgpost(&wg) thread.wgwait(&wg) }) ;; thread.wgwait(&wg) }