Decompose idf_monitor.py

tools/idf_monitor_base/stoppable_thread.py

@@ -0,0 +1,68 @@
+# Copyright 2015-2021 Espressif Systems (Shanghai) CO LTD
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import threading
+from typing import Optional
+
+
+class StoppableThread(object):
+    """
+    Provide a Thread-like class which can be 'cancelled' via a subclass-provided
+    cancellation method.
+
+    Can be started and stopped multiple times.
+
+    Isn't an instance of type Thread because Python Thread objects can only be run once
+    """
+
+    def __init__(self):
+        #  type: () -> None
+        self._thread = None  # type: Optional[threading.Thread]
+
+    @property
+    def alive(self):
+        #  type: () -> bool
+        """
+        Is 'alive' whenever the internal thread object exists
+        """
+        return self._thread is not None
+
+    def start(self):
+        #  type: () -> None
+        if self._thread is None:
+            self._thread = threading.Thread(target=self._run_outer)
+            self._thread.start()
+
+    def _cancel(self):
+        #  type: () -> None
+        pass  # override to provide cancellation functionality
+
+    def run(self):
+        #  type: () -> None
+        pass  # override for the main thread behaviour
+
+    def _run_outer(self):
+        #  type: () -> None
+        try:
+            self.run()
+        finally:
+            self._thread = None
+
+    def stop(self):
+        #  type: () -> None
+        if self._thread is not None:
+            old_thread = self._thread
+            self._thread = None
+            self._cancel()
+            old_thread.join()