build: add --with-nt-threads and make it default on mingw

Co-authored-by: Алексей <[email protected]>
Co-authored-by: Christoph Reiter <[email protected]>

Author: Alexpux

Include/internal/pycore_condvar.h

@@ -5,6 +5,12 @@
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
+#ifdef __MINGW32__
+# if !defined(HAVE_PTHREAD_H) || defined(NT_THREADS)
+#  undef _POSIX_THREADS
+# endif
+#endif
+
 #ifndef _POSIX_THREADS
 /* This means pthreads are not implemented in libc headers, hence the macro
    not present in unistd.h. But they still can be implemented as an external
@@ -37,6 +43,10 @@
 /* include windows if it hasn't been done before */
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
+/* winpthreads are involved via windows header, so need undef _POSIX_THREADS after header include */
+#if defined(_POSIX_THREADS)
+#undef _POSIX_THREADS
+#endif
 
 /* options */
 /* non-emulated condition variables are provided for those that want

Include/pythread.h

@@ -8,6 +8,12 @@ typedef void *PyThread_type_lock;
 extern "C" {
 #endif
 
+#ifdef __MINGW32__
+# if !defined(HAVE_PTHREAD_H) || defined(NT_THREADS)
+#  undef _POSIX_THREADS
+# endif
+#endif
+
 /* Return status codes for Python lock acquisition.  Chosen for maximum
  * backwards compatibility, ie failure -> 0, success -> 1.  */
 typedef enum PyLockStatus {

Modules/_multiprocessing/multiprocessing.h

@@ -21,6 +21,9 @@
 #  endif
 #  define SEM_HANDLE HANDLE
 #  define SEM_VALUE_MAX LONG_MAX
+#  if defined(HAVE_SEM_OPEN) && defined(_POSIX_THREADS)
+#      include <semaphore.h>
+#  endif
 #else
 #  include <fcntl.h>                 /* O_CREAT and O_EXCL */
 #  if defined(HAVE_SEM_OPEN) && !defined(POSIX_SEMAPHORES_NOT_ENABLED)

configure.ac

@@ -2044,6 +2044,53 @@ then
 	BASECFLAGS="$BASECFLAGS $ac_arch_flags"
 fi
 
+dnl NOTE:
+dnl - GCC 4.4+ for mingw* require and use posix threads(pthreads-w32)
+dnl - Host may contain installed pthreads-w32.
+dnl - On windows platform only NT-thread model is supported. 
+dnl To avoid miss detection scipt first will check for NT-thread model
+dnl and if is not found will try to detect build options for pthread
+dnl model. Autodetection could be overiden if variable with_nt_threads
+dnl is set in "Site Configuration" (see autoconf manual).
+dnl If NT-thread model is enabled script skips some checks that
+dnl impact build process. When a new functionality is added, developers
+dnl are responsible to update configure script to avoid thread models
+dnl to be mixed.
+
+AC_MSG_CHECKING([for --with-nt-threads])
+AC_ARG_WITH(nt-threads,
+            AS_HELP_STRING([--with-nt-threads], [build with windows threads (default is system-dependent)]),
+[
+	case $withval in
+	no)	with_nt_threads=no;;
+	yes)	with_nt_threads=yes;;
+	*)	with_nt_threads=yes;;
+	esac
+], [
+	case $host in
+		*-*-mingw*) with_nt_threads=yes;;
+		*) with_nt_threads=no;;
+	esac
+])
+AC_MSG_RESULT([$with_nt_threads])
+
+if test $with_nt_threads = yes ; then
+AC_MSG_CHECKING([whether linking with nt-threads work])
+AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[]],[[_beginthread(0, 0, 0);]])
+  ],
+  [AC_MSG_RESULT([yes])],
+  [AC_MSG_ERROR([failed to link with nt-threads])])
+fi
+
+if test $with_nt_threads = yes ; then
+  dnl temporary default flag to avoid additional pthread checks
+  dnl and initilize other ac..thread flags to no
+  ac_cv_pthread_is_default=no
+  ac_cv_kthread=no
+  ac_cv_pthread=no
+  dnl ac_cv_kpthread is set to no if default is yes (see below)
+else
 # On some compilers, pthreads are available without further options
 # (e.g. MacOS X). On some of these systems, the compiler will not
 # complain if unaccepted options are passed (e.g. gcc on Mac OS X).
@@ -2162,6 +2209,8 @@ CC="$ac_save_cc"])
 AC_MSG_RESULT($ac_cv_pthread)
 fi
 
+fi
+
 # If we have set a CC compiler flag for thread support then
 # check if it works for CXX, too.
 ac_cv_cxx_thread=no
@@ -2182,6 +2231,10 @@ elif test "$ac_cv_pthread" = "yes"
 then
   CXX="$CXX -pthread"
   ac_cv_cxx_thread=yes
+elif test $with_nt_threads = yes
+then
+  dnl set to always to skip extra pthread check below
+  ac_cv_cxx_thread=always
 fi
 
 if test $ac_cv_cxx_thread = yes
@@ -2214,8 +2267,8 @@ dnl AC_MSG_RESULT($cpp_type)
 AC_HEADER_STDC
 AC_CHECK_HEADERS(asm/types.h crypt.h conio.h direct.h dlfcn.h errno.h \
 fcntl.h grp.h \
-ieeefp.h io.h langinfo.h libintl.h process.h pthread.h \
-sched.h shadow.h signal.h stropts.h termios.h \
+ieeefp.h io.h langinfo.h libintl.h process.h \
+shadow.h signal.h stropts.h termios.h \
 utime.h \
 poll.h sys/devpoll.h sys/epoll.h sys/poll.h \
 sys/audioio.h sys/xattr.h sys/bsdtty.h sys/event.h sys/file.h sys/ioctl.h \
@@ -2230,6 +2283,14 @@ sys/mman.h sys/eventfd.h)
 AC_HEADER_DIRENT
 AC_HEADER_MAJOR
 
+# If using nt threads, don't look for pthread.h or thread.h
+if test "x$with_nt_threads" = xno ; then
+AC_HEADER_STDC
+AC_CHECK_HEADERS(pthread.h sched.h thread.h)
+AC_HEADER_DIRENT
+AC_HEADER_MAJOR
+fi
+
 # bluetooth/bluetooth.h has been known to not compile with -std=c99.
 # http://permalink.gmane.org/gmane.linux.bluez.kernel/22294
 SAVE_CFLAGS=$CFLAGS
@@ -2429,6 +2490,10 @@ fi
 
 AC_MSG_CHECKING(for pthread_t)
 have_pthread_t=no
+if test $with_nt_threads = yes ; then
+  dnl skip check for pthread_t if NT-thread model is enabled
+  have_pthread_t=skip
+else
 AC_COMPILE_IFELSE([
   AC_LANG_PROGRAM([[#include <pthread.h>]], [[pthread_t x; x = *(pthread_t*)0;]])
 ],[have_pthread_t=yes],[])
@@ -2459,6 +2524,7 @@ if test "$ac_cv_sizeof_pthread_key_t" -eq "$ac_cv_sizeof_int" ; then
 else
   AC_MSG_RESULT(no)
 fi
+fi
 CC="$ac_save_cc"
 
 AC_SUBST(OTHER_LIBTOOL_OPT)
@@ -2949,10 +3015,15 @@ void *x = uuid_enc_be
   [AC_MSG_RESULT(no)]
 )
 
+if test $with_nt_threads = yes ; then
+  dnl do not search for sem_init if NT-thread model is enabled
+  :
+else
 # 'Real Time' functions on Solaris
 # posix4 on Solaris 2.6
 # pthread (first!) on Linux
 AC_SEARCH_LIBS(sem_init, pthread rt posix4)
+fi
 
 # check if we need libintl for locale functions
 AC_CHECK_LIB(intl, textdomain,
@@ -3252,6 +3323,11 @@ then
         CXX="$CXX -pthread"
     fi
     posix_threads=yes
+elif test $with_nt_threads = yes
+then
+    posix_threads=no
+    AC_DEFINE(NT_THREADS, 1,
+        [Define to 1 if you want to use native NT threads])
 else
     if test ! -z "$withval" -a -d "$withval"
     then LDFLAGS="$LDFLAGS -L$withval"
@@ -3706,6 +3782,15 @@ else
 fi
 
 # checks for library functions
+if test $with_nt_threads = yes ; then
+  dnl GCC(mingw) 4.4+ require and use posix threads(pthreads-w32)
+  dnl and host may contain installed pthreads-w32.
+  dnl Skip checks for some functions declared in pthreads-w32 if
+  dnl NT-thread model is enabled.
+  ac_cv_func_pthread_kill=skip
+  ac_cv_func_sem_open=skip
+  ac_cv_func_sched_setscheduler=skip
+fi
 AC_CHECK_FUNCS(alarm accept4 setitimer getitimer bind_textdomain_codeset chown \
  clock confstr close_range copy_file_range ctermid dup3 execv explicit_bzero \
  explicit_memset faccessat fchmod fchmodat fchown fchownat \
@@ -4637,6 +4722,10 @@ AC_CHECK_DECLS([isinf, isnan, isfinite], [], [], [[#include <math.h>]])
 # the kernel module that provides POSIX semaphores
 # isn't loaded by default, so an attempt to call
 # sem_open results in a 'Signal 12' error.
+if test $with_nt_threads = yes ; then
+  dnl skip posix semaphores test if NT-thread model is enabled
+  ac_cv_posix_semaphores_enabled=no
+fi
 AC_MSG_CHECKING(whether POSIX semaphores are enabled)
 AC_CACHE_VAL(ac_cv_posix_semaphores_enabled,
 AC_RUN_IFELSE([AC_LANG_SOURCE([[
@@ -4670,6 +4759,14 @@ fi
 
 # Multiprocessing check for broken sem_getvalue
 AC_MSG_CHECKING(for broken sem_getvalue)
+if test $with_nt_threads = yes ; then
+  dnl Skip test if NT-thread model is enabled.
+  dnl NOTE the test case below fail for pthreads-w32 as:
+  dnl - SEM_FAILED is not defined;
+  dnl - sem_open is a stub;
+  dnl - sem_getvalue work(!).
+  ac_cv_broken_sem_getvalue=skip
+fi
 AC_CACHE_VAL(ac_cv_broken_sem_getvalue,
 AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <unistd.h>

pyconfig.h.in

@@ -1389,6 +1389,9 @@
 /* Define if mvwdelch in curses.h is an expression. */
 #undef MVWDELCH_IS_EXPRESSION
 
+/* Define to 1 if you want to use native NT threads */
+#undef NT_THREADS
+
 /* Define to the address where bug reports for this package should be sent. */
 #undef PACKAGE_BUGREPORT