Deadlocks

The following program will be deadlock-ed unless one of the threads acquires both locks first.

use threads;
use threads::shared;

my @a : shared = (1, 2);
my %b : shared = ("foo" => "bar");
my $thr1 = threads->new(sub {
	lock(@a);
	print "Thread 1: got lock on 'a'\n";
	threads->yield;
	sleep 5;
	lock(%b);
	print "Thread 1: got lock on 'b'\n";
});
my $thr2 = threads->new(sub {
	lock(%b);
	print "Thread 2: got lock on 'b'\n";
	threads->yield;
	sleep 5;
	lock(@a);
	print "Thread 2: got lock on 'a'\n";
});
sleep 8;

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