[stable26] Fix stopping recording service before it has fully started

recording/src/nextcloud/talk/recording/Service.py

@@ -28,7 +28,7 @@
 from datetime import datetime
 from pyvirtualdisplay import Display
 from secrets import token_urlsafe
-from threading import Thread
+from threading import Event, Thread
 
 from . import BackendNotifier
 from .Config import config
@@ -169,6 +169,9 @@ def __init__(self, backend, token, status, owner):
         self.status = status
         self.owner = owner
 
+        self._started = Event()
+        self._stopped = Event()
+
         self._display = None
         self._audioModuleIndex = None
         self._participant = None
@@ -213,10 +216,16 @@ def start(self, actorType, actorId):
             self._display = Display(size=(width, height), manage_global_env=False)
             self._display.start()
 
+            if self._stopped.is_set():
+                raise Exception("Display started after recording was stopped")
+
             # Start new audio sink for the audio output of the browser.
             self._audioModuleIndex, audioSinkIndex = newAudioSink(sanitizedBackend, self.token)
             audioSinkIndex = str(audioSinkIndex)
 
+            if self._stopped.is_set():
+                raise Exception("Audio sink started after recording was stopped")
+
             env = self._display.env()
             env['PULSE_SINK'] = audioSinkIndex
 
@@ -226,6 +235,14 @@ def start(self, actorType, actorId):
             self._logger.debug("Joining call")
             self._participant.joinCall(self.token)
 
+            if self._stopped.is_set():
+                # Not strictly needed, as if the participant is started or the
+                # call is joined after the recording was stopped there will be
+                # no display and it will automatically fail, but just in case.
+                raise Exception("Call joined after recording was stopped")
+
+            self._started.set()
+
             BackendNotifier.started(self.backend, self.token, self.status, actorType, actorId)
 
             extensionlessFileName = f'{fullDirectory}/recording-{datetime.now().strftime("%Y%m%d-%H%M%S")}'
@@ -240,6 +257,12 @@ def start(self, actorType, actorId):
             # Log recorder output.
             Thread(target=recorderLog, args=[self.backend, self.token, self._process.stdout], daemon=True).start()
 
+            if self._stopped.is_set():
+                # Not strictly needed, as if the recorder is started after the
+                # recording was stopped there will be no display and it will
+                # automatically fail, but just in case.
+                raise Exception("Call joined after recording was stopped")
+
             returnCode = self._process.wait()
 
             # recorder process will be explicitly terminated when needed, which
@@ -250,6 +273,14 @@ def start(self, actorType, actorId):
         except Exception as exception:
             self._stopHelpers()
 
+            if self._stopped.is_set() and not self._started.is_set():
+                # If the service fails before being started but it was already
+                # stopped the error does not need to be notified; the error was
+                # probably caused by stopping the helpers, and even if it was
+                # something else it does not need to be notified either given
+                # that the recording was not started yet.
+                raise
+
             try:
                 BackendNotifier.failed(self.backend, self.token)
             except:
@@ -271,6 +302,8 @@ def stop(self, actorType, actorId):
         :raise Exception: if the file could not be uploaded.
         """
 
+        self._stopped.set()
+
         self._stopHelpers()
 
         BackendNotifier.stopped(self.backend, self.token, actorType, actorId)