[test-runner] Move test case processing beyond the multi-process boundary.

tools/testrunner/local/testsuite.py

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 70 matching lines @@
   def GetFlagSets(self, testcase, variant):
     if testcase.outcomes and statusfile.OnlyFastVariants(testcase.outcomes):
       return FAST_VARIANT_FLAGS[variant]
     else:
       return ALL_VARIANT_FLAGS[variant]
 
 
 class TestSuite(object):
 
   @staticmethod
-  def LoadTestSuite(root):
+  def LoadTestSuite(root, global_init=True):
     name = root.split(os.path.sep)[-1]
     f = None
     try:
       (f, pathname, description) = imp.find_module("testcfg", [root])
       module = imp.load_module("testcfg", f, pathname, description)
-      return module.GetSuite(name, root)
+      suite =  module.GetSuite(name, root)
     except ImportError:
       # Use default if no testcfg is present.
-      return GoogleTestSuite(name, root)
+      suite = GoogleTestSuite(name, root)
     finally:
       if f:
         f.close()
+    if global_init:
+      suite.global_initialization()
+    return suite
 
   def __init__(self, name, root):
+    # Note: This might be called concurrently from different processes. Global
+    # state (e.g. harddisk state) should be initialized in
+    # 'global_initialization' below.
     self.name = name  # string
     self.root = root  # string containing path
     self.tests = None  # list of TestCase objects
     self.rules = None  # dictionary mapping test path to list of outcomes
     self.wildcards = None  # dictionary mapping test paths to list of outcomes
     self.total_duration = None  # float, assigned on demand
 
+  def global_initialization(self):

[Jakob Kummerow, 2015/11/27 10:09:00]

I'd keep the original LoadTestSuite and __init__ without any modifications, make
this a standalone method "SetupWorkingDirectory()", and call it from
run-tests.py around line 605:

    suite = testsuite.TestSuite.LoadTestSuite(
        os.path.join(BASE_DIR, "test", root))
    if suite:
+     suite.SetupWorkingDirectory()
      suites.append(suite)

[Michael Achenbach, 2015/11/27 10:31:21]

Method name ack. Regarding calling: I'll have to add it to three different
places then: run-test, run-deopt and network_execution endpoint. Is that ok? It
would be a bit scattered.

[Jakob Kummerow, 2015/11/27 10:34:41]

Hm... that's a bit less elegant than I was hoping, but I'd still prefer an
explicit call over an implicit side effect.

[Michael Achenbach, 2015/11/27 10:58:29]

Done.

+    # This is called once per test suite object in a multi-process setting.
+    # Logic that is not multi-process-safe can go here, e.g. set up of a
+    # working directory for the suite.
+    pass
+
   def shell(self):
     return "d8"
 
   def suffix(self):
     return ".js"
 
   def status_file(self):
     return "%s/%s.status" % (self.root, self.name)
 
   # Used in the status file and for stdout printing.
@@ skipping 209 matching lines @@
     return (testcase.flags + ["--gtest_filter=" + testcase.path] +
             ["--gtest_random_seed=%s" % context.random_seed] +
             ["--gtest_print_time=0"] +
             context.mode_flags)
 
   def _VariantGeneratorFactory(self):
     return StandardVariantGenerator
 
   def shell(self):
     return self.name