Handle restarting logcat thread processing if non-alive after env reset

PiperOrigin-RevId: 864898141

Author: gabrielle-lau

android_env/components/logcat_thread.py

@@ -77,6 +77,12 @@ def pause(self):
     self._log_stream.pause_stream()
 
   def resume(self):
+    """Resume or restart the thread if it's dead after resetting environment."""
+    if not self._thread.is_alive():
+      self._should_stop.clear()
+      self._thread = threading.Thread(target=self._process_logs)
+      self._thread.daemon = True
+      self._thread.start()
     self._log_stream.resume_stream()
 
   def kill(self):

android_env/components/logcat_thread_test.py

@@ -42,6 +42,9 @@ def has_next_value(self):
   def kill(self):
     self._kill = True
 
+  def reset(self):
+    self._kill = False
+
   def __iter__(self):
     while True:
       if self._kill:
@@ -74,6 +77,10 @@ def stop_stream(self):
     self.stream_is_alive = False
     self.logs.kill()
 
+  def reset(self):
+    self.stream_is_alive = True
+    self.logs.reset()
+
 
 class LogcatThreadTest(absltest.TestCase):
 
@@ -135,6 +142,27 @@ def my_handler(event: re.Pattern[str], match: re.Match[str]):
     some_state.wait(timeout=1.0)
     self.assertFalse(some_state.is_set())
 
+  def test_resume_does_not_recreate_alive_thread(self):
+    logcat = logcat_thread.LogcatThread(log_stream=self.fake_log_stream)
+    thread_before = logcat._thread
+    self.assertTrue(thread_before.is_alive())
+    logcat.resume()
+    thread_after = logcat._thread
+    self.assertTrue(thread_after.is_alive())
+    self.assertIs(thread_before, thread_after)
+
+  def test_resume_recreates_thread(self):
+    logcat = logcat_thread.LogcatThread(log_stream=self.fake_log_stream)
+    self.assertTrue(logcat._thread.is_alive())
+    logcat.kill()
+    self.assertFalse(logcat._thread.is_alive())
+    self.assertTrue(logcat._should_stop.is_set())
+    self.fake_log_stream.reset()
+    logcat.resume()
+    self.assertTrue(logcat._thread.is_alive())
+    self.assertFalse(logcat._should_stop.is_set())
+    self.assertTrue(logcat._thread.daemon)
+
 
 if __name__ == '__main__':
   absltest.main()