require 'thread'
m,n = Mutex.new, Mutex.new
t = Thread.new {
m.lock
puts "Thread t locked Mutex m"
sleep 1
puts "Thread t waiting to lock Mutex n"
n.lock
}
s = Thread.new {
n.lock
puts "Thread s locked Mutex n"
sleep 1
puts "Thread s waiting to lock Mutex m"
m.lock
}
t.join
s.join