> could you please refresh/recheck your patch for the current gcc master > and solve the objections noted in the thread? is it possible? I have attached a revised version of the original patch at: https://gcc.gnu.org/legacy-ml/gcc-patches/2019-06/msg01840.html This reimplements the GNU threads library on native Windows (except for the Objective-C specific subset) using direct Win32 API calls, in lieu of the implementation based on semaphores. This base implementations requires Windows XP/Server 2003, which was the default minimal setting of MinGW-W64 until end of 2020. This also adds the support required for the C++11 threads, using again direct Win32 API calls; this additional layer requires Windows Vista/Server 2008 and is enabled only if _WIN32_WINNT >= 0x0600. This also changes libstdc++ to pass -D_WIN32_WINNT=0x0600 but only when the switch --enable-libstdcxx-threads is passed, which means that C++11 threads are still disabled by default *unless* MinGW-W64 itself is configured for Windows Vista/Server 2008 or later by default (this has been the case in the development version since end of 2020, for earlier versions you can configure it --with-default-win32-winnt=0x0600 to get the same effect). I only manually tested it on i686-w64-mingw32 and x86_64-w64-mingw32 but AdaCore has used it in their C/C++/Ada compilers for 3 years now and the 30_threads chapter of the libstdc++ testsuite was clean at the time. 2022-10-31 Eric Botcazou libgcc/ * config.host (i[34567]86-*-mingw*): Add thread fragment after EH one as well as new i386/t-slibgcc-mingw fragment. (x86_64-*-mingw*): Likewise. * config/i386/gthr-win32.h: If _WIN32_WINNT is at least 0x0600, define both __GTHREAD_HAS_COND and __GTHREADS_CXX0X to 1. Error out if _GTHREAD_USE_MUTEX_TIMEDLOCK is 1. Include stdlib.h instead of errno.h and do not include _mingw.h. (CONST_CAST2): Add specific definition for C++. (ATTRIBUTE_UNUSED): New macro. (__UNUSED_PARAM): Delete. Define WIN32_LEAN_AND_MEAN before including windows.h. (__gthread_objc_data_tls): Use TLS_OUT_OF_INDEXES instead of (DWORD)-1. (__gthread_objc_init_thread_system): Likewise. (__gthread_objc_thread_get_data): Minor tweak. (__gthread_objc_condition_allocate): Use ATTRIBUTE_UNUSED. (__gthread_objc_condition_deallocate): Likewise. (__gthread_objc_condition_wait): Likewise. (__gthread_objc_condition_broadcast): Likewise. (__gthread_objc_condition_signal): Likewise. Include sys/time.h. (__gthr_win32_DWORD): New typedef. (__gthr_win32_HANDLE): Likewise. (__gthr_win32_CRITICAL_SECTION): Likewise. (__gthr_win32_CONDITION_VARIABLE): Likewise. (__gthread_t): Adjust. (__gthread_key_t): Likewise. (__gthread_mutex_t): Likewise. (__gthread_recursive_mutex_t): Likewise. (__gthread_cond_t): New typedef. (__gthread_time_t): Likewise. (__GTHREAD_MUTEX_INIT_DEFAULT): Delete. (__GTHREAD_RECURSIVE_MUTEX_INIT_DEFAULT): Likewise. (__GTHREAD_COND_INIT_FUNCTION): Define. (__GTHREAD_TIME_INIT): Likewise. (__gthr_i486_lock_cmp_xchg): Delete. (__gthr_win32_create): Declare. (__gthr_win32_join): Likewise. (__gthr_win32_self): Likewise. (__gthr_win32_detach): Likewise. (__gthr_win32_equal): Likewise. (__gthr_win32_yield): Likewise. (__gthr_win32_mutex_destroy): Likewise. (__gthr_win32_cond_init_function): Likewise if __GTHREADS_HAS_COND is 1. (__gthr_win32_cond_broadcast): Likewise. (__gthr_win32_cond_signal): Likewise. (__gthr_win32_cond_wait): Likewise. (__gthr_win32_cond_timedwait): Likewise. (__gthr_win32_recursive_mutex_init_function): Delete. (__gthr_win32_recursive_mutex_lock): Likewise. (__gthr_win32_recursive_mutex_unlock): Likewise. (__gthr_win32_recursive_mutex_destroy): Likewise. (__gthread_create): New inline function. (__gthread_join): Likewise. (__gthread_self): Likewise. (__gthread_detach): Likewise. (__gthread_equal): Likewise. (__gthread_yield): Likewise. (__gthread_cond_init_function): Likewise if __GTHREADS_HAS_COND is 1. (__gthread_cond_broadcast): Likewise. (__gthread_cond_signal): Likewise. (__gthread_cond_wait): Likewise. (__gthread_cond_timedwait): Likewise. (__GTHREAD_WIN32_INLINE): New macro. (__GTHREAD_WIN32_COND_INLINE): Likewise. (__GTHREAD_WIN32_ACTIVE_P): Likewise. Define WIN32_LEAN_AND_MEAN before including windows.h. (__gthread_once): Minor tweaks. (__gthread_key_create): Use ATTRIBUTE_UNUSED and TLS_OUT_OF_INDEXES. (__gthread_key_delete): Minor tweak. (__gthread_getspecific): Likewise. (__gthread_setspecific): Likewise. (__gthread_mutex_init_function): Reimplement. (__gthread_mutex_destroy): Likewise. (__gthread_mutex_lock): Likewise. (__gthread_mutex_trylock): Likewise. (__gthread_mutex_unlock): Likewise. (__gthr_win32_abs_to_rel_time): Declare. (__gthread_recursive_mutex_init_function): Reimplement. (__gthread_recursive_mutex_destroy): Likewise. (__gthread_recursive_mutex_lock): Likewise. (__gthread_recursive_mutex_trylock): Likewise. (__gthread_recursive_mutex_unlock): Likewise. (__gthread_cond_destroy): New inline function. (__gthread_cond_wait_recursive): Likewise. * config/i386/gthr-win32.c: Delete everything. Include gthr-win32.h to get the out-of-line version of inline routines. Add compile-time checks for the local version of the Win32 types. * config/i386/gthr-win32-cond.c: New file. * config/i386/gthr-win32-thread.c: Likewise. * config/i386/t-gthr-win32: Add config/i386/gthr-win32-thread.c to the EH part, config/i386/gthr-win32-cond.c and config/i386/gthr-win32.c to the static version of libgcc. * config/i386/t-slibgcc-mingw: New file. * config/i386/libgcc-mingw.ver: Likewise. libstdc++-v3/ * acinclude.m4 (GLIBCXX_EXPORT_FLAGS): Substitute CPPFLAGS. (GLIBCXX_ENABLE_LIBSTDCXX_TIME): Set ac_has_sched_yield and ac_has_win32_sleep to yes for MinGW. Change HAVE_WIN32_SLEEP into _GLIBCXX_USE_WIN32_SLEEP. (GLIBCXX_CHECK_GTHREADS): Add _WIN32_THREADS to compilation flags for Win32 threads and force _GTHREAD_USE_MUTEX_TIMEDLOCK to 0 for them. Add -D_WIN32_WINNT=0x0600 to compilation flags if yes was configured and add it to CPPFLAGS on success. * config.h.in: Regenerate. * configure: Likewise. * config/os/mingw32-w64/os_defines.h (_GLIBCXX_USE_GET_NPROCS_WIN32): Define to 1. * config/os/mingw32/os_defines.h (_GLIBCXX_USE_GET_NPROCS_WIN32): Ditto * src/c++11/thread.cc (get_nprocs): Provide Win32 implementation if _GLIBCXX_USE_GET_NPROCS_WIN32 is defined. Replace HAVE_WIN32_SLEEP with USE_WIN32_SLEEP. * testsuite/19_diagnostics/headers/system_error/errc_std_c++0x.cc: Add missing conditional compilation. * testsuite/lib/libstdc++.exp (check_v3_target_sleep): Add support for _GLIBCXX_USE_WIN32_SLEEP. (check_v3_target_nprocs): Likewise for _GLIBCXX_USE_GET_NPROCS_WIN32. -- Eric Botcazou