implement manual multiprocessing pools for the runner.

this fixes the ctrl-c not-working problem.

implemented this solution: http://www.bryceboe.com/2010/08/26/python-multiprocessing-and-keyboardinterrupt/#georges

also add hosts which do not get a chance to return results to the 'dark' results.

lib/ansible/runner.py

@@ -21,16 +21,23 @@
 
 import fnmatch
 import multiprocessing
+import signal
 import os
 import json
 import traceback
 import paramiko # non-core dependency
 import ansible.constants as C 
 
-def _executor_hook(x):
+def _executor_hook(job_queue, result_queue):
     ''' callback used by multiprocessing pool '''
-    (runner, host) = x
-    return runner._executor(host)
+    signal.signal(signal.SIGINT, signal.SIG_IGN)
+    while not job_queue.empty():
+        try:
+            job = job_queue.get(block=False)
+            runner, host = job
+            result_queue.put(runner._executor(host))
+        except Queue.Empty:
+            pass
 
 class Runner(object):
 
@@ -296,10 +303,34 @@ class Runner(object):
         # _executor_hook does all of the work
         hosts = [ (self,x) for x in hosts ]
         if self.forks > 1:
-            pool = multiprocessing.Pool(self.forks)
-            results = pool.map(_executor_hook, hosts)
+            job_queue = multiprocessing.Queue()
+            result_queue = multiprocessing.Queue()
+ 
+            for i in hosts:
+                job_queue.put(i)
+ 
+            workers = []
+            for i in range(self.forks):
+                tmp = multiprocessing.Process(target=_executor_hook,
+                                      args=(job_queue, result_queue))
+                tmp.start()
+                workers.append(tmp)
+ 
+            try:
+                for worker in workers:
+                    worker.join()
+            except KeyboardInterrupt:
+                print 'parent received ctrl-c'
+                for worker in workers:
+                    worker.terminate()
+                    worker.join()
+            
+            results = []
+            while not result_queue.empty():
+                results.append(result_queue.get(block=False))
+ 
         else:
-            results = [ _executor_hook(x) for x in hosts ]
+            results = [ x._executor(h) for (x,h) in hosts ]
 
         # sort hosts by ones we successfully contacted
         # and ones we did not so that we can return a 
@@ -309,12 +340,21 @@ class Runner(object):
           "contacted" : {},
           "dark"      : {}
         }
+        hosts_with_results = []
         for x in results:
             (host, is_ok, result) = x
+            hosts_with_results.append(host)
             if not is_ok:
                 results2["dark"][host] = result
             else:
                 results2["contacted"][host] = result
+        # hosts which were contacted but never got a chance
+        # to return a result before we exited/ctrl-c'd
+        # perhaps these shouldn't be 'dark' but I'm not sure if they fit
+        # anywhere else.
+        for host in self.match_hosts(self.pattern):
+            if host not in hosts_with_results:
+                results2["dark"][host] = {}
                 
         return results2