From 4b245fce7366fbd38d4fe812873c3a0e7594f29e Mon Sep 17 00:00:00 2001
From: Josh Durgin <josh.durgin@dreamhost.com>
Date: Wed, 22 Jun 2011 10:50:09 -0700
Subject: [PATCH] Add a utility for running functions in parallel.

---
 teuthology/parallel.py | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 teuthology/parallel.py

diff --git a/teuthology/parallel.py b/teuthology/parallel.py
new file mode 100644
index 00000000000..1e5b02245c9
--- /dev/null
+++ b/teuthology/parallel.py
@@ -0,0 +1,27 @@
+import gevent
+import logging
+
+log = logging.getLogger(__name__)
+
+def run(func, all_args):
+    tasks = []
+    for args in all_args:
+        assert isinstance(args, list), 'args must be a list of lists'
+        tasks.append(gevent.spawn(func, *args))
+    gevent.sleep(0)
+
+    try:
+        while tasks:
+            task = tasks[-1]
+            try:
+                task.get(block=True, timeout=5)
+            except gevent.Timeout:
+                continue
+            else:
+                tasks.pop()
+    except:
+        log.exception('Exception from parallel greenlet')
+        for task in tasks:
+            log.error('KILLING TASK')
+            task.kill(block=True)
+        raise