DOM-object leak detection at run_webkit_tests.py

Tools/Scripts/webkitpy/layout_tests/port/driver.py

Index: Tools/Scripts/webkitpy/layout_tests/port/driver.py
diff --git a/Tools/Scripts/webkitpy/layout_tests/port/driver.py b/Tools/Scripts/webkitpy/layout_tests/port/driver.py
index e7a439d04baa9cbc547e81bcd3f8a5360751853a..b040f4e450eb2c4f67e343a7019efcacb4782b57 100644
--- a/Tools/Scripts/webkitpy/layout_tests/port/driver.py
+++ b/Tools/Scripts/webkitpy/layout_tests/port/driver.py
@@ -113,6 +113,11 @@ class Driver(object):
         # This could mean they crashed.
         self._subprocess_was_unresponsive = False
 
+        # WebKitTestRunenr can report back subprocess DOM-object leaks by printing

[Dirk Pranke, 2014/01/28 20:11:46]

WebKitTestRunner doesn't exist in Blink :) I'd probably change this to
"content_shell can report back DOM object leaks by printing".

[hajimehoshi, 2014/02/14 10:18:59]

Done.

+        # "#LEAK". This leak detection is enabled only when the flag
+        # --enable-leak-detection is passed to content_shell.
+        self._leaked = False
+
         # stderr reading is scoped on a per-test (not per-block) basis, so we store the accumulated
         # stderr output, as well as if we've seen #EOF on this driver instance.
         # FIXME: We should probably remove _read_first_block and _read_optional_image_block and
@@ -180,6 +185,8 @@ class Driver(object):
                 # If we were unresponsive append a message informing there may not have been a crash.
                 if self._subprocess_was_unresponsive:
                     crash_log += 'Process failed to become responsive before timing out.\n'
+                if self._leaked:
+                    crash_log += 'DOM-object leaking was detected.\n'

[Dirk Pranke, 2014/01/30 01:43:21]

Given that the process isn't actually crashing, it is probably wrong to be
making any changes to _check_for_driver_crash() or inside the if block that
starts on line 178.

I suggest that you add lines before line 167 that parses the stderr output, and
if it finds the '# LEAK - ' line, marks something to tell the driver code to
restart content_shell (assuming that's what you want to have happen) and
propagate the right information back up in the DriverOutput.

Let me know if the approach I describe turns out to have problems.

[hajimehoshi, 2014/02/14 10:18:59]

Done.

 
                 # Print stdout and stderr to the placeholder crash log; we want as much context as possible.
                 if self.error_from_test:
@@ -320,6 +327,8 @@ class Driver(object):
             cmd.append('--no-timeout')
         cmd.extend(self._port.get_option('additional_drt_flag', []))
         cmd.extend(self._port.additional_drt_flag())
+        if self._port.get_option('enable_leak_detection'):
+            cmd.append('--enable-leak-detection')
         cmd.extend(per_test_args)
         cmd.append('-')
         return cmd
@@ -331,9 +340,10 @@ class Driver(object):
             self._crashed_process_name = self._server_process.name()
             self._crashed_pid = self._server_process.pid()
         elif (error_line.startswith("#CRASHED - ")
-            or error_line.startswith("#PROCESS UNRESPONSIVE - ")):
+            or error_line.startswith("#PROCESS UNRESPONSIVE - ")
+            or error_line.startswith("#LEAK - ")):

[Dirk Pranke, 2014/01/30 01:43:21]

See comments above.

[hajimehoshi, 2014/02/14 10:18:59]

Done.

             # WebKitTestRunner uses this to report that the WebProcess subprocess crashed.
-            match = re.match('#(?:CRASHED|PROCESS UNRESPONSIVE) - (\S+)', error_line)
+            match = re.match('#(?:CRASHED|PROCESS UNRESPONSIVE|LEAK) - (\S+)', error_line)
             self._crashed_process_name = match.group(1) if match else 'WebProcess'
             match = re.search('pid (\d+)', error_line)
             pid = int(match.group(1)) if match else None
@@ -345,6 +355,9 @@ class Driver(object):
                 self._port.sample_process(self._crashed_process_name, self._crashed_pid)
                 # We want to show this since it's not a regular crash and probably we don't have a crash log.
                 self.error_from_test += error_line
+            elif error_line.startswith("#LEAK - "):
+                self._leaked = True
+                self.error_from_test += error_line
             return True
         return self.has_crashed()