From e6ada6040b738df03c8cc6199a6375cf3aa67e44 Mon Sep 17 00:00:00 2001 From: Sven Gothel Date: Fri, 13 May 2022 01:26:43 +0200 Subject: Fix call_on_release: Skip calling `release_func` if resource has been marked orderly released, avoid use after free. Detected via valgrind. --- include/jau/basic_algos.hpp | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/jau/basic_algos.hpp b/include/jau/basic_algos.hpp index 10efa69..569f48a 100644 --- a/include/jau/basic_algos.hpp +++ b/include/jau/basic_algos.hpp @@ -49,27 +49,38 @@ namespace jau { * jau::relaxed_atomic_bool is_running = true; * * void some_thread_func() { - * thread_local jau::call_on_release lili([&]() { + * thread_local jau::call_on_release thread_cleanup([&]() { * is_running = false; * }); * ... * do some work here, which might get cancelled * .. + * thread_cleanup.set_released(); // mark orderly release * } * *

* @tparam UnaryFunction user provided function to be called @ dtor + * @see jau::service_runner */ template class call_on_release { private: UnaryFunction f; + jau::sc_atomic_bool released; public: - call_on_release(UnaryFunction release_func) noexcept : f(release_func) {} - ~call_on_release() noexcept { f(); } + call_on_release(UnaryFunction release_func) noexcept + : f(release_func), released(false) {} + ~call_on_release() noexcept { + if( !released ) { f(); } + } call_on_release(const call_on_release&) = delete; call_on_release& operator=(const call_on_release&) = delete; call_on_release& operator=(const call_on_release&) volatile = delete; + + /** Mark the resource being orderly released, `release_func()` will not be called and *use after free* avoided. */ + void set_released() noexcept { released = true; } + /** Query whethr the resource has been orderly released. */ + bool is_released() const noexcept { return released; } }; /**************************************************************************************** -- cgit v1.2.3