Copilot commented on code in PR #13439:
URL: https://github.com/apache/trafficserver/pull/13439#discussion_r3714395692


##########
src/iocore/eventsystem/unit_tests/test_Lock.cc:
##########
@@ -0,0 +1,393 @@
+/** @file
+
+  Catch2 unit tests for the Lock.h mutex acquisition macros.
+
+  @section license License
+
+  Licensed to the Apache Software Foundation (ASF) under one
+  or more contributor license agreements.  See the NOTICE file
+  distributed with this work for additional information
+  regarding copyright ownership.  The ASF licenses this file
+  to you 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.
+ */
+
+#define CATCH_CONFIG_THREAD_SAFE_ASSERTIONS
+#include "inkevent_test_fixtures.h"
+
+#include <tscore/ink_assert.h>
+
+#include <cstdint>
+
+using inkevent_test::AtomicFlag;
+using inkevent_test::EventProcessorListener;
+
+CATCH_REGISTER_LISTENER(EventProcessorListener)
+
+namespace
+{
+
+class HoldOnEThread : public Continuation
+{
+public:
+  HoldOnEThread(ProxyMutex *self_mutex, Ptr<ProxyMutex> &target) : 
Continuation(self_mutex), target_mutex(target)
+  {
+    SET_HANDLER(&HoldOnEThread::on_event);
+    this->callback_action = eventProcessor.schedule_imm(this, ET_CALL);
+    ink_assert(this->callback_action != nullptr);
+  }
+
+  // In case of an exception in a thread that would have set release, we set
+  // it here in order to unfreeze any threads that may be waiting on done.
+  ~HoldOnEThread()
+  {
+    this->cancel_callback();
+    this->wait_for_callback_finish();
+  }
+
+  bool
+  wait_for_callback_start()
+  {
+    return this->held.wait_until_set();
+  }
+
+  bool
+  wait_for_callback_finish()
+  {
+    this->release.set();
+    // The callback can finish without setting done due to wait timeouts. We
+    // return false in that case.
+    return this->done.wait_until_set();
+  }
+
+private:
+  Action         *callback_action{};
+  Ptr<ProxyMutex> target_mutex;
+  AtomicFlag      held;
+  AtomicFlag      release;
+  AtomicFlag      done;
+
+  int
+  on_event(int /* event ATS_UNUSED */, void * /* data ATS_UNUSED */)
+  {
+    SCOPED_MUTEX_LOCK(guard, this->target_mutex, this_ethread());
+    this->held.set();
+    if (this->release.wait_until_set()) {
+      MUTEX_RELEASE(guard);
+      this->done.set();
+    }
+    return 0;
+  }
+
+  void
+  cancel_callback()
+  {
+    SCOPED_MUTEX_LOCK(guard, this->mutex, this_ethread());
+    if (this->is_expecting_callback()) {
+      this->callback_action->cancel(this);
+      ink_assert(this->callback_action->cancelled);
+      this->done.set();
+    }

Review Comment:
   `ink_assert(this->callback_action->cancelled);` is racy and can make the 
tests flaky/crash: the scheduled callback may already be executing (or about to 
execute) when the destructor runs, so `cancel()` may not transition `cancelled` 
to true even though the callback is in-flight. Suggestion (mandatory): remove 
the hard assert and handle both outcomes (canceled vs already-running) by 
unblocking the callback via `release.set()` and/or by waiting for a completion 
signal without assuming cancellation succeeded.



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]

Reply via email to