Changeset 136314 in webkit

Timestamp:

Dec 1, 2012 11:06:01 PM (11 years ago)

Author:

zandobersek@gmail.com

Message:

[XvfbDriver] XvfbDriverTest.test_next_free_display is flaky on builders using XvfbDriver
​https://bugs.webkit.org/show_bug.cgi?id=103806

Reviewed by Dirk Pranke.

There are occasional mishaps on builders where XvfbDriver doesn't properly
clean up the Xvfb instance it was managing so the related guard lock files
are still existing when the webkitpy unit tests are run. This can cause failures
in XvfbDriverTest.test_next_free_display as the test tries to acquire displays
with a specific number but is unable to due to the stale locks.

The solution to this is to use MockFileLock when inside unit test. This is achievable
by creating a file lock through the SystemHost instance connected to the Port object,
the latter available to the Driver.

• Scripts/webkitpy/common/system/file_lock_mock.py:

(MockFileLock.acquire_lock): Return True to signal lock acquiring succeeded.
(MockFileLock.release_lock): Return True to signal lock releasing succeeded.

• Scripts/webkitpy/layout_tests/port/xvfbdriver.py:

(XvfbDriver._next_free_display): Create the file lock through a mockable way.

• Scripts/webkitpy/layout_tests/port/xvfbdriver_unittest.py:

(XvfbDriverTest.test_next_free_display): Enable back the unit test.

Location:

trunk/Tools

Files:

• ChangeLog (modified) (1 diff)
• Scripts/webkitpy/common/system/file_lock_mock.py (modified) (1 diff)
• Scripts/webkitpy/layout_tests/port/xvfbdriver.py (modified) (1 diff)
• Scripts/webkitpy/layout_tests/port/xvfbdriver_unittest.py (modified) (1 diff)

trunk/Tools/ChangeLog

@@ +1 @@
+2012-12-01  Zan Dobersek  <zandobersek@gmail.com>
+
+        [XvfbDriver] XvfbDriverTest.test_next_free_display is flaky on builders using XvfbDriver
+        https://bugs.webkit.org/show_bug.cgi?id=103806
+
+        Reviewed by Dirk Pranke.
+
+        There are occasional mishaps on builders where XvfbDriver doesn't properly
+        clean up the Xvfb instance it was managing so the related guard lock files
+        are still existing when the webkitpy unit tests are run. This can cause failures
+        in XvfbDriverTest.test_next_free_display as the test tries to acquire displays
+        with a specific number but is unable to due to the stale locks.
+
+        The solution to this is to use MockFileLock when inside unit test. This is achievable
+        by creating a file lock through the SystemHost instance connected to the Port object,
+        the latter available to the Driver.
+
+        * Scripts/webkitpy/common/system/file_lock_mock.py:
+        (MockFileLock.acquire_lock): Return True to signal lock acquiring succeeded.
+        (MockFileLock.release_lock): Return True to signal lock releasing succeeded.
+        * Scripts/webkitpy/layout_tests/port/xvfbdriver.py:
+        (XvfbDriver._next_free_display): Create the file lock through a mockable way.
+        * Scripts/webkitpy/layout_tests/port/xvfbdriver_unittest.py:
+        (XvfbDriverTest.test_next_free_display): Enable back the unit test.
+
 2012-12-01  Zan Dobersek  <zandobersek@gmail.com>
 

trunk/Tools/Scripts/webkitpy/common/system/file_lock_mock.py

@@ -31 +31 @@
 
     def acquire_lock(self):
-        pass
+        return True
 
     def release_lock(self):
-        pass
+        return True

trunk/Tools/Scripts/webkitpy/layout_tests/port/xvfbdriver.py

@@ -55 +55 @@
             if i not in reserved_screens:
                 _guard_lock_file = self._port.host.filesystem.join('/tmp', 'WebKitXvfb.lock.%i' % i)
-                self._guard_lock = FileLock(_guard_lock_file)
+                self._guard_lock = self._port.host.make_file_lock(_guard_lock_file)
                 if self._guard_lock.acquire_lock():
                     return i

trunk/Tools/Scripts/webkitpy/layout_tests/port/xvfbdriver_unittest.py

@@ -83 +83 @@
         self.cleanup_driver(driver)
 
-    def disabled_test_next_free_display(self):
+    def test_next_free_display(self):
         output = "Xorg            /usr/bin/X :0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch -background none\nXvfb            Xvfb :1 -screen 0 800x600x24 -nolisten tcp"
         executive = MockExecutive2(output)