ref: a8e7cff8503ba81955e63546e7c4328cee5490c6
dir: /lib/thread/test/mutex.myr/
use std
use thread
use "test/util.use"
const Nherd = 20
var val : uint64 = 0
var done : uint32 = 0
var mtx : thread.mutex
const main = {
	done = 0
	val = 0
	mtx = thread.mkmtx()
	mkherd(Nherd, incvar)
	while thread.xget(&done) != Nherd
		/* nothing */
	;;
	if val != 1000 * 20
		std.fatal("mutexes are broken, got {}\n", val)
	;;
}
const incvar = {
	for var i = 0; i < 1000; i++
		thread.mtxlock(&mtx)
		val++
		std.put("val: {}\n", val)
		thread.mtxunlock(&mtx)
	;;
	thread.xadd(&done, 1)
}