Changeset 1d32326 in trunk

Timestamp:

2023-01-17T15:06:14Z (2 years ago)

Author:

Jean-Paul Calderone <exarkun@…>

Branches:

master

Children:

290bb52

Parents:

eb630c39

Message:

Simpler, more correct process lifecycle handling.

The previous version included a bogus hack where we just passed
allow_missing=True when finalization was requested of _run_node. This was
clearly wrong since if the caller asked for finalization, it's a programming
error for it to already have been done.

Fortunately we have a perfectly good finalizer already, TahoeProcess.kill,
which we can use instead of trying to craft a finalizer out of the various
pieces that make up that value.

Also, nothing seems to use the _protocol attribute set by got_proto so
let's just drop that.

File:

• integration/util.py (modified) (2 diffs)

integration/util.py ¶

@@ -255 +255 @@
         return self.transport.exited
 
-    def restart_async(self, reactor, request):
+    def restart_async(self, reactor: IReactorProcess, request: Any) -> Deferred:
+        """
+        Stop and then re-start the associated process.
+
+        :return: A Deferred that fires after the new process is ready to
+            handle requests.
+        """
         d = self.kill_async()
         d.addCallback(lambda ignored: _run_node(reactor, self.node_dir, request, None, finalize=False))
         def got_new_process(proc):
+            # Grab the new transport since the one we had before is no longer
+            # valid after the stop/start cycle.
             self._process_transport = proc.transport
         d.addCallback(got_new_process)
@@ -291 +299 @@
     transport.exited = protocol.exited
 
+    tahoe_process = TahoeProcess(
+        transport,
+        node_dir,
+    )
+
     if finalize:
-        request.addfinalizer(partial(_cleanup_tahoe_process, transport, protocol.exited, allow_missing=True))
-
-    # XXX abusing the Deferred; should use .when_magic_seen() pattern
-
-    def got_proto(proto):
-        transport._protocol = proto
-        return TahoeProcess(
-            transport,
-            node_dir,
-        )
-    protocol.magic_seen.addCallback(got_proto)
-    return protocol.magic_seen
+        request.addfinalizer(tahoe_process.kill)
+
+    d = protocol.magic_seen
+    d.addCallback(lambda ignored: tahoe_process)
+    return d