Replace drop token mecanism on closed channel by leaving drop token active on the receiver side and closing sender side shared memory with a lower timeout

apis/rust/node/src/event_stream/thread.rs

@@ -237,13 +237,12 @@ fn report_remaining_drop_tokens(
                     drop_tokens.push(token);
                 }
                 Err(flume::RecvTimeoutError::Timeout) => {
-                    let duration = Duration::from_secs(2);
+                    let duration = Duration::from_secs(1);
                     if since.elapsed() > duration {
                         tracing::warn!(
                             "timeout: node finished, but token {token:?} was still not \
                             dropped after {duration:?} -> ignoring it"
                         );
-                        drop_tokens.push(token);
                     } else {
                         still_pending.push((token, rx, since, 0));
                     }

apis/rust/node/src/node/mod.rs

@@ -409,14 +409,14 @@ impl Drop for DoraNode {
                 );
             }
 
-            match self.drop_stream.recv_timeout(Duration::from_secs(10)) {
+            match self.drop_stream.recv_timeout(Duration::from_secs(2)) {
                 Ok(token) => {
                     self.sent_out_shared_memory.remove(&token);
                 }
                 Err(flume::RecvTimeoutError::Disconnected) => {
                     tracing::warn!(
                         "finished_drop_tokens channel closed while still waiting for drop tokens; \
-                        closing {} shared memory regions that might still be used",
+                        closing {} shared memory regions that might not yet been mapped.",
                         self.sent_out_shared_memory.len()
                     );
                     break;
@@ -424,7 +424,7 @@ impl Drop for DoraNode {
                 Err(flume::RecvTimeoutError::Timeout) => {
                     tracing::warn!(
                         "timeout while waiting for drop tokens; \
-                        closing {} shared memory regions that might still be used",
+                        closing {} shared memory regions that might not yet been mapped.",
                         self.sent_out_shared_memory.len()
                     );
                     break;