1 files changed, 54 insertions, 0 deletions
diff --git a/sample/philos.rb b/sample/philos.rb
new file mode 100644
index 0000000000..ee0a8cd5fc
--- /dev/null
+++ b/sample/philos.rb
@@ -0,0 +1,54 @@
+#
+# The Dining Philosophers - thread example
+#
+require "thread"
+
+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
+      continue
+    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 i in 0..N-1
+  Thread.start{philosopher(i)}
+  sleep 0.1
+end
+
+sleep