Copilot commented on code in PR #13439: URL: https://github.com/apache/trafficserver/pull/13439#discussion_r3683899159
########## src/iocore/eventsystem/unit_tests/test_Lock.cc: ########## @@ -0,0 +1,351 @@ +/** @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. + */ + +#include "inkevent_test_fixtures.h" + +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); + } + + Ptr<ProxyMutex> target_mutex; + AtomicFlag held; + AtomicFlag release; + AtomicFlag done; + +private: + int + on_event(int /* event ATS_UNUSED */, void * /* data ATS_UNUSED */) + { + { + SCOPED_MUTEX_LOCK(guard, target_mutex, this_ethread()); + held.set(); + release.wait_until_set(); + } + done.set(); + return 0; + } +}; + +} // namespace + +TEST_CASE("MUTEX_TRY_LOCK on an unheld ProxyMutex constructs a guard whose is_locked() reports the successful acquisition", + "[inkevent][lock]") +{ + Ptr<ProxyMutex> m{new_ProxyMutex()}; + EThread *t = this_ethread(); + + MUTEX_TRY_LOCK(guard, m, t); + + REQUIRE(guard.is_locked()); + REQUIRE(m->thread_holding == t); + REQUIRE(m->nthread_holding == 1); +} + +TEST_CASE("MUTEX_TRY_LOCK against a contended ProxyMutex constructs a guard whose is_locked() reports the failed acquisition", + "[inkevent][lock][multithread]") +{ + Ptr<ProxyMutex> contended{new_ProxyMutex()}; + Ptr<ProxyMutex> cont_self{new_ProxyMutex()}; + HoldOnEThread holder{cont_self.get(), contended}; + + REQUIRE(eventProcessor.schedule_imm(&holder, ET_CALL) != nullptr); + REQUIRE(holder.held.wait_until_set()); + + EThread *t = this_ethread(); + MUTEX_TRY_LOCK(guard, contended, t); + + REQUIRE_FALSE(guard.is_locked()); + + holder.release.set(); + REQUIRE(holder.done.wait_until_set()); +} Review Comment: The `HoldOnEThread holder` continuation is stack-allocated but scheduled asynchronously. If any `REQUIRE(...)` throws before `holder.release.set()` / `holder.done.wait_until_set()` runs, the scheduled EThread can block forever on `release.wait_until_set()` and/or continue executing after `holder` has been destroyed during stack unwinding (use-after-free). To make the test exception-safe, add an unconditional cleanup mechanism immediately after scheduling (e.g., a scope-exit guard) that always signals `release` and waits for `done`, or allocate the continuation with a lifetime that extends until completion and ensure it self-owns / is joined before scope exit. Same pattern appears in the other `[multithread]` test cases using `HoldOnEThread`. -- 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]
