shithub: mc

ref: 74d91a0021de012908cfdb35fb61a1473a376130
dir: /lib/thread/test/rwlock.myr/

use std
use thread

use thrtestutil

const Nherd = 20
const Nloops = 100_000

var val : uint64
var nreaders : uint32
var nwriters : uint32
var rw
var done

const main = {
	rw = thread.mkrwlock()
	done = thread.mkwg(Nherd)

	thrtestutil.mkherd(Nherd, read)
	thrtestutil.mkherd(Nherd, incvar)
	thread.wgwait(&done)
	if val != Nloops * (Nherd : uint64)
		std.fatal("rwlocks are broken, got {}\n", val)
	;;
}

const incvar = {
	for var i = 0; i < Nloops; i++
		thread.wrlock(&rw)
		thread.xadd(&nwriters, 1)
		std.assert(thread.xget(&nreaders) == 0, "incvar: rwlocks are broken\n")
		val++
		thread.xadd(&nwriters, -1)
		thread.wrunlock(&rw)
	;;
	thread.wgpost(&done)
}

const read = {
	/* Linux seems to not want to end the process when there are still running threads. */
	while thread.xget(&done._val) != 0
		thread.rdlock(&rw)
		thread.xadd(&nreaders, 1)
		std.assert(thread.xget(&nwriters) == 0, "read: rwlocks are broken\n")
		thread.xadd(&nreaders, -1)
		thread.rdunlock(&rw)
		std.usleep(1000)
	;;
}