From a27a5dda1cb92b0eb46f41dfad596e34988737cd Mon Sep 17 00:00:00 2001 From: Mike Kaganski Date: Tue, 20 Aug 2024 11:32:03 +0500 Subject: [PATCH] Do not try to notify, if the thread is already killed On a particular system, I see unit tests reliably hung at the exit time (at a DLL unload), when it waits indefinitely in notify_all. It is the only thread in the process left; TimerManager thread was likely killed by that time. This is the call stack of the hung state: ntdll.dll!ZwReleaseKeyedEvent() ntdll.dll!string "Enabling heap debug options\n"() msvcp140d.dll!Concurrency::details::stl_condition_variable_win7::notify_all() Line 178 msvcp140d.dll!_Cnd_broadcast(_Cnd_internal_imp_t * cond) Line 93 salhelper3MSC.dll!std::condition_variable::notify_all() Line 590 salhelper3MSC.dll!salhelper::TimerManager::~TimerManager() Line 221 salhelper3MSC.dll!``anonymous namespace'::getTimerManager'::`2'::`dynamic atexit destructor for 'aManager''() ucrtbased.dll!_execute_onexit_table::__l2::() Line 206 ucrtbased.dll!__crt_seh_guarded_call::operator()(void),int (void) &,void (void)>(__acrt_lock_and_call::__l2::void (void) && setup, _execute_onexit_table::__l2::int (void) & action, __acrt_lock_and_call::__l2::void (void) && cleanup) Line 204 ucrtbased.dll!__acrt_lock_and_call(void)>(const __acrt_lock_id lock_id, _execute_onexit_table::__l2::int (void) && action) Line 974 ucrtbased.dll!_execute_onexit_table(_onexit_table_t * table) Line 231 salhelper3MSC.dll!__scrt_dllmain_uninitialize_c() Line 399 salhelper3MSC.dll!dllmain_crt_process_detach(const bool is_terminating) Line 182 salhelper3MSC.dll!dllmain_crt_dispatch(HINSTANCE__ * const instance, const unsigned long reason, void * const reserved) Line 220 salhelper3MSC.dll!dllmain_dispatch(HINSTANCE__ * const instance, const unsigned long reason, void * const reserved) Line 293 salhelper3MSC.dll!_DllMainCRTStartup(HINSTANCE__ * const instance, const unsigned long reason, void * const reserved) Line 335 ntdll.dll!LdrShutdownProcess() ntdll.dll!RtlExitUserProcess() ucrtbased.dll!exit_or_terminate_process(const unsigned int return_code) Line 144 ucrtbased.dll!common_exit(const int return_code, const _crt_exit_cleanup_mode cleanup_mode, const _crt_exit_return_mode return_mode) Line 280 ucrtbased.dll!exit(int return_code) Line 294 cppunittester.exe!__scrt_common_main_seh() Line 297 cppunittester.exe!__scrt_common_main() Line 331 cppunittester.exe!mainCRTStartup(void * __formal) Line 17 kernel32.dll!BaseThreadInitThunk() ntdll.dll!RtlUserThreadStart() This check prevents that hang. The behavior is *possibly* related to my commit 8a0c43fa86bd32b4d47fd7e46d3ed414c9282ffa (Use _beginthreadex instead of CreateThread, 2023-08-09), which put the threads under control of CRT; and also to the specific version of CRT on the affected system, which might affect the order of statics destruction and thread termination. Change-Id: I6da95ea369ac9433a426a12d62cbd2a09cb4ce4a Reviewed-on: https://gerrit.libreoffice.org/c/core/+/172093 Reviewed-by: Mike Kaganski Tested-by: Jenkins --- salhelper/source/timer.cxx | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/salhelper/source/timer.cxx b/salhelper/source/timer.cxx index 3c6c0a00d922..07510f228cde 100644 --- a/salhelper/source/timer.cxx +++ b/salhelper/source/timer.cxx @@ -215,6 +215,10 @@ TimerManager::TimerManager() : TimerManager::~TimerManager() { { std::scoped_lock g(m_Lock); + // Sometimes, the TimerManager thread gets killed before the static's destruction; + // in that case, notify_all could hang in unit tests + if (!isRunning()) + return; m_terminate = true; } m_notEmpty.notify_all();