Ruby sample scripts - Threads

require "thread"
require "observer"

class Tick
include Observable
def initialize
Thread.start do
loop do
sleep 0.999
now = Time.now
changed
notify_observers(now.hour, now.min, now.sec)
end
end
end
end

class Clock
def initialize(tick)
@tick = tick
@tick.add_observer(self)
end
def update(h, m, s)
printf "\e[8D%02d:%02d:%02d", h, m, s
STDOUT.flush
end
end

srand
#srand
N=9 # number of philosophers
$forks = []
for i in 0..N-1
$forks[i] = Mutex.new
end
$state = "-o"*N

def wait
sleep rand(20)/10.0
end

def think(n)
wait
end

def eat(n)
wait
end

def philosopher(n)
while true
think n
$forks[n].lock
if not $forks[(n+1)%N].try_lock
$forks[n].unlock # avoid deadlock
next
end
$state[n*2] = ?|;
$state[(n+1)%N*2] = ?|;
$state[n*2+1] = ?*;
print $state, "\n"
eat(n)
$state[n*2] = ?-;
$state[(n+1)%N*2] = ?-;
$state[n*2+1] = ?o;
print $state, "\n"
$forks[n].unlock
$forks[(n+1)%N].unlock
end
end

for n in 0..N-1
Thread.start(n){|i| philosopher(i)}
sleep 0.1
end

queue = Queue.new

producer = Thread.new do
5.times do |i|
sleep rand(i) # simulate expense
queue << i
puts "#{i} produced"
end
end

consumer = Thread.new do
5.times do |i|
value = queue.pop
sleep rand(i/2) # simulate expense
puts "consumed #{value}"
end
end

gets