Adds a Twisted implementation of a process pool

Meant for use instead of utils.execute()

1 files changed, 115 insertions, 0 deletions

diff --git a/nova/tests/process_unittest.py b/nova/tests/process_unittest.py
new file mode 100644
index 000000000..50368dd3f
--- /dev/null
+++ b/nova/tests/process_unittest.py
@@ -0,0 +1,115 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+# Copyright [2010] [Anso Labs, LLC]
+#
+#    Licensed under the Apache License, Version 2.0 (the "License");
+#    you may not use this file except in compliance with the License.
+#    You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#    See the License for the specific language governing permissions and
+#    limitations under the License.
+
+import logging
+from xml.etree import ElementTree
+
+from nova import vendor
+from twisted.internet import defer
+from twisted.internet import reactor
+
+from nova import exception
+from nova import flags
+from nova import process
+from nova import test
+from nova import utils
+
+FLAGS = flags.FLAGS
+
+
+class ProcessTestCase(test.TrialTestCase):
+    def setUp(self):
+        logging.getLogger().setLevel(logging.DEBUG)
+        super(ProcessTestCase, self).setUp()
+
+    def test_execute_stdout(self):
+        pool = process.ProcessPool(2)
+        d = pool.simpleExecute('echo test')
+        def _check(rv):
+            self.assertEqual(rv[0], 'test\n')
+            self.assertEqual(rv[1], '')
+
+        d.addCallback(_check)
+        d.addErrback(self.fail)
+        return d
+
+    def test_execute_stderr(self):
+        pool = process.ProcessPool(2)
+        d = pool.simpleExecute('cat BAD_FILE', error_ok=1)
+        def _check(rv):
+            self.assertEqual(rv[0], '')
+            self.assert_('No such file' in rv[1])
+        
+        d.addCallback(_check)
+        d.addErrback(self.fail)
+        return d
+
+    def test_execute_unexpected_stderr(self):
+        pool = process.ProcessPool(2)
+        d = pool.simpleExecute('cat BAD_FILE')
+        d.addCallback(lambda x: self.fail('should have raised an error'))
+        d.addErrback(lambda failure: failure.trap(IOError))
+        return d
+    
+    def test_max_processes(self):
+        pool = process.ProcessPool(2)
+        d1 = pool.simpleExecute('sleep 0.01')
+        d2 = pool.simpleExecute('sleep 0.01')
+        d3 = pool.simpleExecute('sleep 0.005')
+        d4 = pool.simpleExecute('sleep 0.005')
+
+        called = []
+        def _called(rv, name):
+            called.append(name)
+    
+        d1.addCallback(_called, 'd1')
+        d2.addCallback(_called, 'd2')
+        d3.addCallback(_called, 'd3')
+        d4.addCallback(_called, 'd4')
+        
+        # Make sure that d3 and d4 had to wait on the other two and were called
+        # in order
+        # NOTE(termie): there may be a race condition in this test if for some
+        #               reason one of the sleeps takes longer to complete
+        #               than it should
+        d4.addCallback(lambda x: self.assertEqual(called[2], 'd3'))
+        d4.addCallback(lambda x: self.assertEqual(called[3], 'd4'))
+        d4.addErrback(self.fail)
+        return d4
+
+    def test_kill_long_process(self):
+        pool = process.ProcessPool(2)
+        
+        d1 = pool.simpleExecute('sleep 1')
+        d2 = pool.simpleExecute('sleep 0.005')
+
+        timeout = reactor.callLater(0.1, self.fail, 'should have been killed')
+         
+        # kill d1 and wait on it to end then cancel the timeout
+        d2.addCallback(lambda _: d1.process.signalProcess('KILL'))
+        d2.addCallback(lambda _: d1)
+        d2.addBoth(lambda _: timeout.active() and timeout.cancel())
+        d2.addErrback(self.fail)
+        return d2
+        
+    def test_process_exit_is_contained(self):
+        pool = process.ProcessPool(2)
+        
+        d1 = pool.simpleExecute('sleep 1')
+        d1.addCallback(lambda x: self.fail('should have errbacked'))
+        d1.addErrback(lambda fail: fail.trap(IOError))
+        reactor.callLater(0.05, d1.process.signalProcess, 'KILL')
+        
+        return d1