or download this
$ perl -le "use Readonly; Readonly::Scalar $LU => 66; use threads; asy
+nc{ print join q/ /, threads->tid, $LU, \$LU } for 1..3; sleep 1; "
1 66 SCALAR(0xb84cfc)
2 66 SCALAR(0xc1bbec)
...
0 running and unjoined
3 finished and unjoined
0 running and detached