[webkitcorepy] Create process-like Thread object

https://bugs.webkit.org/show_bug.cgi?id=245913
<rdar://100642035>

Reviewed by Dewei Zhu and David Kilzer.

* Tools/Scripts/libraries/webkitcorepy/setup.py: Bump version.
* Tools/Scripts/libraries/webkitcorepy/webkitcorepy/__init__.py: Ditto.
* Tools/Scripts/libraries/webkitcorepy/webkitcorepy/__init__.py: Import Thread object
* Tools/Scripts/libraries/webkitcorepy/webkitcorepy/subprocess_utils.py:
(Thread):
(Thread.terminated): Check if the current thread has it's termination flag flipped.
(Thread.__init__):
(Thread.poll): Check if the Thread is running.
(Thread.terminate): Set terminate flag.
(Thread.kill): Ditto.
(Thread.__enter__): Start thread.
(Thread.__exit__): Join thread.
* Tools/Scripts/libraries/webkitcorepy/webkitcorepy/tests/subprocess_utils_unittest.py:
(SubprocessUtils.test_thread):
(SubprocessUtils.test_killed_thread):

Canonical link: https://commits.webkit.org/255370@main

Tools/Scripts/libraries/webkitcorepy/setup.py

@@ -30,7 +30,7 @@ def readme():
 
 setup(
     name='webkitcorepy',
-    version='0.13.16',
+    version='0.13.17',
     description='Library containing various Python support classes and functions.',
     long_description=readme(),
     classifiers=[

Tools/Scripts/libraries/webkitcorepy/webkitcorepy/__init__.py

@@ -32,7 +32,7 @@
 from webkitcorepy.version import Version
 from webkitcorepy.string_utils import BytesIO, StringIO, UnicodeIO, unicode
 from webkitcorepy.timeout import Timeout
-from webkitcorepy.subprocess_utils import TimeoutExpired, CompletedProcess, run
+from webkitcorepy.subprocess_utils import TimeoutExpired, CompletedProcess, run, Thread
 from webkitcorepy.output_capture import LoggerCapture, OutputCapture, OutputDuplicate
 from webkitcorepy.task_pool import TaskPool
 from webkitcorepy.terminal import Terminal
@@ -44,7 +44,7 @@
 from webkitcorepy.editor import Editor
 from webkitcorepy.file_lock import FileLock
 
-version = Version(0, 13, 16)
+version = Version(0, 13, 17)
 
 from webkitcorepy.autoinstall import Package, AutoInstall
 if sys.version_info > (3, 0):

Tools/Scripts/libraries/webkitcorepy/webkitcorepy/subprocess_utils.py

@@ -1,4 +1,4 @@
-# Copyright (C) 2020 Apple Inc. All rights reserved.
+# Copyright (C) 2020-2022 Apple Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -24,6 +24,7 @@
 import subprocess
 import sys
 import time
+import threading
 
 from webkitcorepy import Timeout, string_utils
 
@@ -146,3 +147,32 @@ def decode(string):
         if check and retcode:
             raise subprocess.CalledProcessError(retcode, popenargs[0], output=decode(stdout), stderr=decode(stderr))
         return CompletedProcess(popenargs[0], retcode, decode(stdout), decode(stderr))
+
+
+class Thread(threading.Thread):
+    @classmethod
+    def terminated(cls):
+        return getattr(threading.current_thread(), '_terminated', False)
+
+    def __init__(self, *args, **kwargs):
+        super(Thread, self).__init__(*args, **kwargs)
+        self._terminated = False
+
+    def poll(self):
+        return None if self.is_alive() else {True: 1, False: 0}.get(self._terminated, -1)
+
+    def terminate(self):
+        self._terminated = True
+
+    def kill(self):
+        self._terminated = True
+
+    def __enter__(self):
+        self.start()
+        return self
+
+    def __exit__(self, *args, **kwargs):
+        with Timeout.DisableAlarm():
+            current_time = time.time()
+            Timeout.check(current_time=current_time)
+            self.join(Timeout.difference(current_time=current_time))

Tools/Scripts/libraries/webkitcorepy/webkitcorepy/tests/subprocess_utils_unittest.py

@@ -21,9 +21,10 @@
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import sys
+import time
 import unittest
 
-from webkitcorepy import OutputCapture, run, TimeoutExpired, Timeout
+from webkitcorepy import OutputCapture, run, TimeoutExpired, Timeout, Thread
 
 
 class SubprocessUtils(unittest.TestCase):
@@ -40,6 +41,38 @@ def test_run_exit(self):
         self.assertEqual(result.stdout, None)
         self.assertEqual(result.stderr, None)
 
+    def test_thread(self):
+        data = dict()
+
+        def f():
+            data['finished'] = True
+
+        t = Thread(target=f)
+        with t:
+            pass
+
+        self.assertEqual(t.poll(), 0)
+        self.assertTrue(data.get('finished', False))
+
+    def test_killed_thread(self):
+        data = dict()
+
+        def f():
+            data['iteration'] = 0
+            for x in range(10):
+                if Thread.terminated():
+                    break
+                data['iteration'] = x
+                time.sleep(.1)
+
+        t = Thread(target=f)
+        with t:
+            self.assertIsNone(t.poll())
+            t.kill()
+
+        self.assertEqual(t.poll(), 1)
+        self.assertNotEqual(data.get('iteration', 9), 9)
+
     # Without signal.alarm, the timeout argument will not work in Python 2
     if Timeout.SIGALRM or sys.version_info > (3, 0):
         def test_run_timeout(self):