Modify run_webkit_tests to run in a single thread when num-test-shells==1.

This makes debugging the test harness a lot easier.

  BUG=none
  TEST=none
  R=ojan@chromium.org

Review URL: http://codereview.chromium.org/500037

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@34753 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 35 insertions, 11 deletions

diff --git a/webkit/tools/layout_tests/layout_package/test_shell_thread.py b/webkit/tools/layout_tests/layout_package/test_shell_thread.py
index f39b453..a091062 100644
--- a/webkit/tools/layout_tests/layout_package/test_shell_thread.py
+++ b/webkit/tools/layout_tests/layout_package/test_shell_thread.py
@@ -261,7 +261,7 @@ class TestShellThread(threading.Thread):
     self._num_tests = 0
     try:
       logging.debug('thread %s starting' % (self.getName()))
-      self._Run()
+      self._Run(test_runner=None, result_summary=None)
       logging.debug('thread %s done (%d tests)' % (self.getName(),
                     self.GetNumTests()))
     except:
@@ -274,9 +274,19 @@ class TestShellThread(threading.Thread):
       raise
     self._stop_time = time.time()
 
-  def _Run(self):
+  def RunInMainThread(self, test_runner, result_summary):
+    """This hook allows us to run the tests from the main thread if
+    --num-test-shells==1, instead of having to always run two or more
+    threads. This allows us to debug the test harness without having to
+    do multi-threaded debugging."""
+    self._Run(test_runner, result_summary)
+
+  def _Run(self, test_runner, result_summary):
     """Main work entry point of the thread. Basically we pull urls from the
-    filename queue and run the tests until we run out of urls."""
+    filename queue and run the tests until we run out of urls.
+
+    If test_runner is not None, then we call test_runner.UpdateSummary()
+    with the results of each test."""
     batch_size = 0
     batch_count = 0
     if self._options.batch_size:
@@ -346,6 +356,9 @@ class TestShellThread(threading.Thread):
         self._KillTestShell()
         batch_count = 0
 
+      if test_runner:
+        test_runner.UpdateSummary(result_summary)
+
   def _RunTestSingly(self, test_info):
     """Run a test in a separate thread, enforcing a hard time limit.
 
diff --git a/webkit/tools/layout_tests/run_webkit_tests.py b/webkit/tools/layout_tests/run_webkit_tests.py
index 05d8e21..c19e524 100755
--- a/webkit/tools/layout_tests/run_webkit_tests.py
+++ b/webkit/tools/layout_tests/run_webkit_tests.py
@@ -411,7 +411,8 @@ class TestRunner:
       The Queue of lists of TestInfo objects.
     """
 
-    if self._options.experimental_fully_parallel:
+    if (self._options.experimental_fully_parallel or
+        self._IsSingleThreaded()):
       filename_queue = Queue.Queue()
       for test_file in test_files:
        filename_queue.put(('.', [self._GetTestInfoForFile(test_file)]))
@@ -481,7 +482,8 @@ class TestRunner:
         return True
     return False
 
-  def _InstantiateTestShellThreads(self, test_shell_binary, test_files):
+  def _InstantiateTestShellThreads(self, test_shell_binary, test_files,
+                                   result_summary):
     """Instantitates and starts the TestShellThread(s).
 
     Return:
@@ -515,7 +517,10 @@ class TestRunner:
                                                  test_args,
                                                  shell_args,
                                                  self._options)
-      thread.start()
+      if self._IsSingleThreaded():
+        thread.RunInMainThread(self, result_summary)
+      else:
+        thread.start()
       threads.append(thread)
 
     return threads
@@ -528,6 +533,10 @@ class TestRunner:
       proc.stdin.close()
       proc.wait()
 
+  def _IsSingleThreaded(self):
+    """Returns whether we should run all the tests in the main thread."""
+    return int(self._options.num_test_shells) == 1
+
   def _RunTests(self, test_shell_binary, file_list, result_summary):
     """Runs the tests in the file_list.
 
@@ -542,7 +551,8 @@ class TestRunner:
           {filename:filename, test_run_time:test_run_time}
         result_summary: summary object to populate with the results
     """
-    threads = self._InstantiateTestShellThreads(test_shell_binary, file_list)
+    threads = self._InstantiateTestShellThreads(test_shell_binary, file_list,
+                                                result_summary)
 
     # Wait for the threads to finish and collect test failures.
     failures = {}
@@ -557,7 +567,7 @@ class TestRunner:
           # suffices to not use an indefinite blocking join for it to
           # be interruptible by KeyboardInterrupt.
           thread.join(0.1)
-          self._UpdateSummary(result_summary)
+          self.UpdateSummary(result_summary)
         thread_timings.append({ 'name': thread.getName(),
                                 'num_tests': thread.GetNumTests(),
                                 'total_time': thread.GetTotalTime()});
@@ -578,7 +588,7 @@ class TestRunner:
         raise exception_info[0], exception_info[1], exception_info[2]
 
     # Make sure we pick up any remaining tests.
-    self._UpdateSummary(result_summary)
+    self.UpdateSummary(result_summary)
     return (thread_timings, test_timings, individual_test_timings)
 
   def Run(self, result_summary):
@@ -693,7 +703,7 @@ class TestRunner:
     # bot red for those.
     return unexpected_results['num_regressions']
 
-  def _UpdateSummary(self, result_summary):
+  def UpdateSummary(self, result_summary):
     """Update the summary while running tests."""
     while True:
       try:
@@ -702,7 +712,8 @@ class TestRunner:
         expected = self._expectations.MatchesAnExpectedResult(test, result)
         result_summary.Add(test, fail_list, result, expected)
         if (LOG_DETAILED_PROGRESS in self._options.log and
-            self._options.experimental_fully_parallel):
+            (self._options.experimental_fully_parallel or
+             self._IsSingleThreaded())):
           self._DisplayDetailedProgress(result_summary)
         else:
           if not expected and LOG_UNEXPECTED in self._options.log: