make test: improve stability

Disable automatic garbage collection and run it manually before
running each test case to minimize stalls. Improve vpp subprocess
cleanup. Reduce helper thread count to one and properly clean that
thread once it's not needed.

Change-Id: I3ea78ed9628552b5ef3ff29cc7bcf2d3fc42f2c3
Signed-off-by: Klement Sekera <ksekera@cisco.com>

1 files changed, 58 insertions, 20 deletions

diff --git a/test/framework.py b/test/framework.py
index 6a0ec965..8dd61aa1 100644
--- a/test/framework.py
+++ b/test/framework.py
@@ -1,23 +1,33 @@
 #!/usr/bin/env python
 
-import subprocess
+from __future__ import print_function
+import gc
+import sys
+import os
+import select
 import unittest
 import tempfile
 import time
 import resource
 from collections import deque
-from threading import Thread
+from threading import Thread, Event
 from inspect import getdoc
 from traceback import format_exception
+from logging import FileHandler, DEBUG, Formatter
+from scapy.packet import Raw
 from hook import StepHook, PollHook
 from vpp_pg_interface import VppPGInterface
 from vpp_sub_interface import VppSubInterface
 from vpp_lo_interface import VppLoInterface
 from vpp_papi_provider import VppPapiProvider
-from scapy.packet import Raw
-from logging import FileHandler, DEBUG
 from log import *
 from vpp_object import VppObjectRegistry
+if os.name == 'posix' and sys.version_info[0] < 3:
+    # using subprocess32 is recommended by python official documentation
+    # @ https://docs.python.org/2/library/subprocess.html
+    import subprocess32 as subprocess
+else:
+    import subprocess
 
 """
   Test framework module.
@@ -51,9 +61,21 @@ class _PacketInfo(object):
         return index and src and dst and data
 
 
-def pump_output(out, deque):
-    for line in iter(out.readline, b''):
-        deque.append(line)
+def pump_output(testclass):
+    """ pump output from vpp stdout/stderr to proper queues """
+    while not testclass.pump_thread_stop_flag.wait(0):
+        readable = select.select([testclass.vpp.stdout.fileno(),
+                                  testclass.vpp.stderr.fileno(),
+                                  testclass.pump_thread_wakeup_pipe[0]],
+                                 [], [])[0]
+        if testclass.vpp.stdout.fileno() in readable:
+            read = os.read(testclass.vpp.stdout.fileno(), 1024)
+            testclass.vpp_stdout_deque.append(read)
+        if testclass.vpp.stderr.fileno() in readable:
+            read = os.read(testclass.vpp.stderr.fileno(), 1024)
+            testclass.vpp_stderr_deque.append(read)
+        # ignoring the dummy pipe here intentionally - the flag will take care
+        # of properly terminating the loop
 
 
 class VppTestCase(unittest.TestCase):
@@ -181,10 +203,14 @@ class VppTestCase(unittest.TestCase):
         Perform class setup before running the testcase
         Remove shared memory files, start vpp and connect the vpp-api
         """
+        gc.collect()  # run garbage collection first
         cls.logger = getLogger(cls.__name__)
         cls.tempdir = tempfile.mkdtemp(
             prefix='vpp-unittest-' + cls.__name__ + '-')
         file_handler = FileHandler("%s/log.txt" % cls.tempdir)
+        file_handler.setFormatter(
+            Formatter(fmt='%(asctime)s,%(msecs)03d %(message)s',
+                      datefmt="%H:%M:%S"))
         file_handler.setLevel(DEBUG)
         cls.logger.addHandler(file_handler)
         cls.shm_prefix = cls.tempdir.split("/")[-1]
@@ -206,20 +232,18 @@ class VppTestCase(unittest.TestCase):
         try:
             cls.run_vpp()
             cls.vpp_stdout_deque = deque()
-            cls.vpp_stdout_reader_thread = Thread(target=pump_output, args=(
-                cls.vpp.stdout, cls.vpp_stdout_deque))
-            cls.vpp_stdout_reader_thread.start()
             cls.vpp_stderr_deque = deque()
-            cls.vpp_stderr_reader_thread = Thread(target=pump_output, args=(
-                cls.vpp.stderr, cls.vpp_stderr_deque))
-            cls.vpp_stderr_reader_thread.start()
+            cls.pump_thread_stop_flag = Event()
+            cls.pump_thread_wakeup_pipe = os.pipe()
+            cls.pump_thread = Thread(target=pump_output, args=(cls,))
+            cls.pump_thread.start()
             cls.vapi = VppPapiProvider(cls.shm_prefix, cls.shm_prefix, cls)
             if cls.step:
                 hook = StepHook(cls)
             else:
                 hook = PollHook(cls)
             cls.vapi.register_hook(hook)
-            time.sleep(0.1)
+            cls.sleep(0.1, "after vpp startup, before initial poll")
             hook.poll_vpp()
             try:
                 cls.vapi.connect()
@@ -251,12 +275,25 @@ class VppTestCase(unittest.TestCase):
                 raw_input("When done debugging, press ENTER to kill the "
                           "process and finish running the testcase...")
 
+        os.write(cls.pump_thread_wakeup_pipe[1], 'ding dong wake up')
+        cls.pump_thread_stop_flag.set()
+        if hasattr(cls, 'pump_thread'):
+            cls.logger.debug("Waiting for pump thread to stop")
+            cls.pump_thread.join()
+        if hasattr(cls, 'vpp_stderr_reader_thread'):
+            cls.logger.debug("Waiting for stdderr pump to stop")
+            cls.vpp_stderr_reader_thread.join()
+
         if hasattr(cls, 'vpp'):
             if hasattr(cls, 'vapi'):
                 cls.vapi.disconnect()
+                del cls.vapi
             cls.vpp.poll()
             if cls.vpp.returncode is None:
+                cls.logger.debug("Sending TERM to vpp")
                 cls.vpp.terminate()
+                cls.logger.debug("Waiting for vpp to die")
+                cls.vpp.communicate()
             del cls.vpp
 
         if hasattr(cls, 'vpp_stdout_deque'):
@@ -306,7 +343,7 @@ class VppTestCase(unittest.TestCase):
                            self._testMethodDoc))
         if self.vpp_dead:
             raise Exception("VPP is dead when setting up the test")
-        time.sleep(.1)
+        self.sleep(.1, "during setUp")
         self.vpp_stdout_deque.append(
             "--- test setUp() for %s.%s(%s) starts here ---\n" %
             (self.__class__.__name__, self._testMethodName,
@@ -351,9 +388,7 @@ class VppTestCase(unittest.TestCase):
         for stamp, cap_name in cls._zombie_captures:
             wait = stamp + capture_ttl - now
             if wait > 0:
-                cls.logger.debug("Waiting for %ss before deleting capture %s",
-                                 wait, cap_name)
-                time.sleep(wait)
+                cls.sleep(wait, "before deleting capture %s" % cap_name)
                 now = time.time()
             cls.logger.debug("Removing zombie capture %s" % cap_name)
             cls.vapi.cli('packet-generator delete %s' % cap_name)
@@ -552,8 +587,10 @@ class VppTestCase(unittest.TestCase):
                 name, real_value, expected_min, expected_max)
         self.assertTrue(expected_min <= real_value <= expected_max, msg)
 
-    def sleep(self, timeout):
-        self.logger.debug("Sleeping for %ss" % timeout)
+    @classmethod
+    def sleep(cls, timeout, remark=None):
+        if hasattr(cls, 'logger'):
+            cls.logger.debug("Sleeping for %ss (%s)" % (timeout, remark))
         time.sleep(timeout)
 
 
@@ -817,6 +854,7 @@ class VppTestRunner(unittest.TextTestRunner):
         :param test:
 
         """
+        gc.disable()  # disable garbage collection, we'll do that manually
         print("Running tests using custom test runner")  # debug message
         filter_file, filter_class, filter_func = self.parse_test_option()
         print("Active filters: file=%s, class=%s, function=%s" % (