Index: generic/tcl.h
==================================================================
--- generic/tcl.h
+++ generic/tcl.h
@@ -88,10 +88,14 @@
 #ifndef JOIN
 #  define JOIN(a,b) JOIN1(a,b)
 #  define JOIN1(a,b) a##b
 #endif
 #endif /* !TCL_NO_DEPRECATED */
+
+#ifndef TCL_THREADS
+#   define TCL_THREADS 1
+#endif
 
 /*
  * A special definition used to allow this header file to be included from
  * windows resource files so that they can obtain version information.
  * RC_INVOKED is defined by default by the windows RC tool.

Index: generic/tclInt.h
==================================================================
--- generic/tclInt.h
+++ generic/tclInt.h
@@ -4195,10 +4195,14 @@
 	    TclIncrObjsFreed(); \
 	} else { \
 	    TclFreeObj(objPtr); \
 	} \
     }
+
+#if TCL_THREADS && !defined(USE_THREAD_ALLOC)
+#   define USE_THREAD_ALLOC 1
+#endif
 
 #if defined(PURIFY)
 
 /*
  * The PURIFY mode is like the regular mode, but instead of doing block

Index: unix/configure
==================================================================
--- unix/configure
+++ unix/configure
@@ -697,11 +697,10 @@
 RANLIB
 ZLIB_INCLUDE
 ZLIB_SRCS
 ZLIB_OBJS
 TCLSH_PROG
-TCL_THREADS
 EGREP
 GREP
 CPP
 OBJEXT
 EXEEXT
@@ -753,11 +752,10 @@
 ac_user_opts='
 enable_option_checking
 enable_man_symlinks
 enable_man_compression
 enable_man_suffix
-enable_threads
 with_encoding
 enable_shared
 enable_64bit
 enable_64bit_vis
 enable_rpath
@@ -1393,11 +1391,10 @@
                           compress the manpages with PROG (default: off)
   --enable-man-suffix=STRING
                           use STRING as a suffix to manpage file names
                           (default: no, tcl if enabled without
                           specifying STRING)
-  --enable-threads        build with threads (default: on)
   --enable-shared         build and link with shared libraries (default: on)
   --enable-64bit          enable 64bit support (default: off)
   --enable-64bit-vis      enable 64bit Sparc VIS support (default: off)
   --disable-rpath         disable rpath support (default: on)
   --enable-corefoundation use CoreFoundation API on MacOSX (default: on)
@@ -3907,327 +3904,10 @@
 $as_echo "$tcl_cv_cc_pipe" >&6; }
     if test $tcl_cv_cc_pipe = yes; then
 	CFLAGS="$CFLAGS -pipe"
     fi
 fi
-
-#------------------------------------------------------------------------
-# Threads support
-#------------------------------------------------------------------------
-
-
-    # Check whether --enable-threads was given.
-if test "${enable_threads+set}" = set; then :
-  enableval=$enable_threads; tcl_ok=$enableval
-else
-  tcl_ok=yes
-fi
-
-
-    if test "${TCL_THREADS}" = 1; then
-	tcl_threaded_core=1;
-    fi
-
-    if test "$tcl_ok" = "yes" -o "${TCL_THREADS}" = 1; then
-	TCL_THREADS=1
-	# USE_THREAD_ALLOC tells us to try the special thread-based
-	# allocator that significantly reduces lock contention
-
-$as_echo "#define USE_THREAD_ALLOC 1" >>confdefs.h
-
-
-$as_echo "#define _REENTRANT 1" >>confdefs.h
-
-	if test "`uname -s`" = "SunOS" ; then
-
-$as_echo "#define _POSIX_PTHREAD_SEMANTICS 1" >>confdefs.h
-
-	fi
-
-$as_echo "#define _THREAD_SAFE 1" >>confdefs.h
-
-	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_mutex_init in -lpthread" >&5
-$as_echo_n "checking for pthread_mutex_init in -lpthread... " >&6; }
-if ${ac_cv_lib_pthread_pthread_mutex_init+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lpthread  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char pthread_mutex_init ();
-int
-main ()
-{
-return pthread_mutex_init ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_lib_pthread_pthread_mutex_init=yes
-else
-  ac_cv_lib_pthread_pthread_mutex_init=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_pthread_pthread_mutex_init" >&5
-$as_echo "$ac_cv_lib_pthread_pthread_mutex_init" >&6; }
-if test "x$ac_cv_lib_pthread_pthread_mutex_init" = xyes; then :
-  tcl_ok=yes
-else
-  tcl_ok=no
-fi
-
-	if test "$tcl_ok" = "no"; then
-	    # Check a little harder for __pthread_mutex_init in the same
-	    # library, as some systems hide it there until pthread.h is
-	    # defined.  We could alternatively do an AC_TRY_COMPILE with
-	    # pthread.h, but that will work with libpthread really doesn't
-	    # exist, like AIX 4.2.  [Bug: 4359]
-	    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for __pthread_mutex_init in -lpthread" >&5
-$as_echo_n "checking for __pthread_mutex_init in -lpthread... " >&6; }
-if ${ac_cv_lib_pthread___pthread_mutex_init+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lpthread  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char __pthread_mutex_init ();
-int
-main ()
-{
-return __pthread_mutex_init ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_lib_pthread___pthread_mutex_init=yes
-else
-  ac_cv_lib_pthread___pthread_mutex_init=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_pthread___pthread_mutex_init" >&5
-$as_echo "$ac_cv_lib_pthread___pthread_mutex_init" >&6; }
-if test "x$ac_cv_lib_pthread___pthread_mutex_init" = xyes; then :
-  tcl_ok=yes
-else
-  tcl_ok=no
-fi
-
-	fi
-
-	if test "$tcl_ok" = "yes"; then
-	    # The space is needed
-	    THREADS_LIBS=" -lpthread"
-	else
-	    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_mutex_init in -lpthreads" >&5
-$as_echo_n "checking for pthread_mutex_init in -lpthreads... " >&6; }
-if ${ac_cv_lib_pthreads_pthread_mutex_init+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lpthreads  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char pthread_mutex_init ();
-int
-main ()
-{
-return pthread_mutex_init ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_lib_pthreads_pthread_mutex_init=yes
-else
-  ac_cv_lib_pthreads_pthread_mutex_init=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_pthreads_pthread_mutex_init" >&5
-$as_echo "$ac_cv_lib_pthreads_pthread_mutex_init" >&6; }
-if test "x$ac_cv_lib_pthreads_pthread_mutex_init" = xyes; then :
-  tcl_ok=yes
-else
-  tcl_ok=no
-fi
-
-	    if test "$tcl_ok" = "yes"; then
-		# The space is needed
-		THREADS_LIBS=" -lpthreads"
-	    else
-		{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_mutex_init in -lc" >&5
-$as_echo_n "checking for pthread_mutex_init in -lc... " >&6; }
-if ${ac_cv_lib_c_pthread_mutex_init+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lc  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char pthread_mutex_init ();
-int
-main ()
-{
-return pthread_mutex_init ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_lib_c_pthread_mutex_init=yes
-else
-  ac_cv_lib_c_pthread_mutex_init=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_c_pthread_mutex_init" >&5
-$as_echo "$ac_cv_lib_c_pthread_mutex_init" >&6; }
-if test "x$ac_cv_lib_c_pthread_mutex_init" = xyes; then :
-  tcl_ok=yes
-else
-  tcl_ok=no
-fi
-
-		if test "$tcl_ok" = "no"; then
-		    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_mutex_init in -lc_r" >&5
-$as_echo_n "checking for pthread_mutex_init in -lc_r... " >&6; }
-if ${ac_cv_lib_c_r_pthread_mutex_init+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lc_r  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char pthread_mutex_init ();
-int
-main ()
-{
-return pthread_mutex_init ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_lib_c_r_pthread_mutex_init=yes
-else
-  ac_cv_lib_c_r_pthread_mutex_init=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_c_r_pthread_mutex_init" >&5
-$as_echo "$ac_cv_lib_c_r_pthread_mutex_init" >&6; }
-if test "x$ac_cv_lib_c_r_pthread_mutex_init" = xyes; then :
-  tcl_ok=yes
-else
-  tcl_ok=no
-fi
-
-		    if test "$tcl_ok" = "yes"; then
-			# The space is needed
-			THREADS_LIBS=" -pthread"
-		    else
-			TCL_THREADS=0
-			{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Don't know how to find pthread lib on your system - you must disable thread support or edit the LIBS in the Makefile..." >&5
-$as_echo "$as_me: WARNING: Don't know how to find pthread lib on your system - you must disable thread support or edit the LIBS in the Makefile..." >&2;}
-		    fi
-		fi
-	    fi
-	fi
-
-	# Does the pthread-implementation provide
-	# 'pthread_attr_setstacksize' ?
-
-	ac_saved_libs=$LIBS
-	LIBS="$LIBS $THREADS_LIBS"
-	for ac_func in pthread_attr_setstacksize pthread_atfork
-do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
-	LIBS=$ac_saved_libs
-    else
-	TCL_THREADS=0
-    fi
-    # Do checking message here to not mess up interleaved configure output
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for building with threads" >&5
-$as_echo_n "checking for building with threads... " >&6; }
-    if test "${TCL_THREADS}" = 1; then
-
-$as_echo "#define TCL_THREADS 1" >>confdefs.h
-
-	if test "${tcl_threaded_core}" = 1; then
-	    { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes (threaded core)" >&5
-$as_echo "yes (threaded core)" >&6; }
-	else
-	    { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-	fi
-    else
-	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-    fi
-
-
-
 
 #------------------------------------------------------------------------
 # Embedded configuration information, encoding to use for the values, TIP #59
 #------------------------------------------------------------------------
 
@@ -4451,10 +4131,273 @@
 fi
 
 fi
 
 
+
+$as_echo "#define _REENTRANT 1" >>confdefs.h
+
+
+$as_echo "#define _THREAD_SAFE 1" >>confdefs.h
+
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_mutex_init in -lpthread" >&5
+$as_echo_n "checking for pthread_mutex_init in -lpthread... " >&6; }
+if ${ac_cv_lib_pthread_pthread_mutex_init+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lpthread  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char pthread_mutex_init ();
+int
+main ()
+{
+return pthread_mutex_init ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_pthread_pthread_mutex_init=yes
+else
+  ac_cv_lib_pthread_pthread_mutex_init=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_pthread_pthread_mutex_init" >&5
+$as_echo "$ac_cv_lib_pthread_pthread_mutex_init" >&6; }
+if test "x$ac_cv_lib_pthread_pthread_mutex_init" = xyes; then :
+  tcl_ok=yes
+else
+  tcl_ok=no
+fi
+
+    if test "$tcl_ok" = "no"; then
+	# Check a little harder for __pthread_mutex_init in the same
+	# library, as some systems hide it there until pthread.h is
+	# defined.  We could alternatively do an AC_TRY_COMPILE with
+	# pthread.h, but that will work with libpthread really doesn't
+	# exist, like AIX 4.2.  [Bug: 4359]
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for __pthread_mutex_init in -lpthread" >&5
+$as_echo_n "checking for __pthread_mutex_init in -lpthread... " >&6; }
+if ${ac_cv_lib_pthread___pthread_mutex_init+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lpthread  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char __pthread_mutex_init ();
+int
+main ()
+{
+return __pthread_mutex_init ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_pthread___pthread_mutex_init=yes
+else
+  ac_cv_lib_pthread___pthread_mutex_init=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_pthread___pthread_mutex_init" >&5
+$as_echo "$ac_cv_lib_pthread___pthread_mutex_init" >&6; }
+if test "x$ac_cv_lib_pthread___pthread_mutex_init" = xyes; then :
+  tcl_ok=yes
+else
+  tcl_ok=no
+fi
+
+    fi
+
+    if test "$tcl_ok" = "yes"; then
+	# The space is needed
+	THREADS_LIBS=" -lpthread"
+    else
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_mutex_init in -lpthreads" >&5
+$as_echo_n "checking for pthread_mutex_init in -lpthreads... " >&6; }
+if ${ac_cv_lib_pthreads_pthread_mutex_init+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lpthreads  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char pthread_mutex_init ();
+int
+main ()
+{
+return pthread_mutex_init ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_pthreads_pthread_mutex_init=yes
+else
+  ac_cv_lib_pthreads_pthread_mutex_init=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_pthreads_pthread_mutex_init" >&5
+$as_echo "$ac_cv_lib_pthreads_pthread_mutex_init" >&6; }
+if test "x$ac_cv_lib_pthreads_pthread_mutex_init" = xyes; then :
+  _ok=yes
+else
+  tcl_ok=no
+fi
+
+	if test "$tcl_ok" = "yes"; then
+	    # The space is needed
+	    THREADS_LIBS=" -lpthreads"
+	else
+	    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_mutex_init in -lc" >&5
+$as_echo_n "checking for pthread_mutex_init in -lc... " >&6; }
+if ${ac_cv_lib_c_pthread_mutex_init+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lc  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char pthread_mutex_init ();
+int
+main ()
+{
+return pthread_mutex_init ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_c_pthread_mutex_init=yes
+else
+  ac_cv_lib_c_pthread_mutex_init=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_c_pthread_mutex_init" >&5
+$as_echo "$ac_cv_lib_c_pthread_mutex_init" >&6; }
+if test "x$ac_cv_lib_c_pthread_mutex_init" = xyes; then :
+  tcl_ok=yes
+else
+  tcl_ok=no
+fi
+
+	    if test "$tcl_ok" = "no"; then
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_mutex_init in -lc_r" >&5
+$as_echo_n "checking for pthread_mutex_init in -lc_r... " >&6; }
+if ${ac_cv_lib_c_r_pthread_mutex_init+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lc_r  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char pthread_mutex_init ();
+int
+main ()
+{
+return pthread_mutex_init ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_c_r_pthread_mutex_init=yes
+else
+  ac_cv_lib_c_r_pthread_mutex_init=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_c_r_pthread_mutex_init" >&5
+$as_echo "$ac_cv_lib_c_r_pthread_mutex_init" >&6; }
+if test "x$ac_cv_lib_c_r_pthread_mutex_init" = xyes; then :
+  tcl_ok=yes
+else
+  tcl_ok=no
+fi
+
+		if test "$tcl_ok" = "yes"; then
+		    # The space is needed
+		    THREADS_LIBS=" -pthread"
+		else
+		    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Don't know how to find pthread lib on your system - you must edit the LIBS in the Makefile..." >&5
+$as_echo "$as_me: WARNING: Don't know how to find pthread lib on your system - you must edit the LIBS in the Makefile..." >&2;}
+		fi
+	    fi
+	fi
+    fi
+
+    # Does the pthread-implementation provide
+    # 'pthread_attr_setstacksize' ?
+
+    ac_saved_libs=$LIBS
+    LIBS="$LIBS $THREADS_LIBS"
+    for ac_func in pthread_attr_setstacksize pthread_atfork
+do :
+  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
+ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
+if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
+  cat >>confdefs.h <<_ACEOF
+#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+done
+
+    LIBS=$ac_saved_libs
+
 
 # Add the threads support libraries
 LIBS="$LIBS$THREADS_LIBS"
 
 

Index: unix/configure.ac
==================================================================
--- unix/configure.ac
+++ unix/configure.ac
@@ -117,16 +117,10 @@
     if test $tcl_cv_cc_pipe = yes; then
 	CFLAGS="$CFLAGS -pipe"
     fi
 fi
 
-#------------------------------------------------------------------------
-# Threads support
-#------------------------------------------------------------------------
-
-SC_ENABLE_THREADS
-
 #------------------------------------------------------------------------
 # Embedded configuration information, encoding to use for the values, TIP #59
 #------------------------------------------------------------------------
 
 SC_TCL_CFG_ENCODING

Index: unix/tcl.m4
==================================================================
--- unix/tcl.m4
+++ unix/tcl.m4
@@ -590,117 +590,10 @@
 	    FRAMEWORK_BUILD=0
 	fi
     fi
 ])
 
-#------------------------------------------------------------------------
-# SC_ENABLE_THREADS --
-#
-#	Specify if thread support should be enabled
-#
-# Arguments:
-#	none
-#
-# Results:
-#
-#	Adds the following arguments to configure:
-#		--enable-threads
-#
-#	Sets the following vars:
-#		THREADS_LIBS	Thread library(s)
-#
-#	Defines the following vars:
-#		TCL_THREADS
-#		_REENTRANT
-#		_THREAD_SAFE
-#------------------------------------------------------------------------
-
-AC_DEFUN([SC_ENABLE_THREADS], [
-    AC_ARG_ENABLE(threads,
-	AC_HELP_STRING([--enable-threads],
-	    [build with threads (default: on)]),
-	[tcl_ok=$enableval], [tcl_ok=yes])
-
-    if test "${TCL_THREADS}" = 1; then
-	tcl_threaded_core=1;
-    fi
-
-    if test "$tcl_ok" = "yes" -o "${TCL_THREADS}" = 1; then
-	TCL_THREADS=1
-	# USE_THREAD_ALLOC tells us to try the special thread-based
-	# allocator that significantly reduces lock contention
-	AC_DEFINE(USE_THREAD_ALLOC, 1,
-	    [Do we want to use the threaded memory allocator?])
-	AC_DEFINE(_REENTRANT, 1, [Do we want the reentrant OS API?])
-	if test "`uname -s`" = "SunOS" ; then
-	    AC_DEFINE(_POSIX_PTHREAD_SEMANTICS, 1,
-		    [Do we really want to follow the standard? Yes we do!])
-	fi
-	AC_DEFINE(_THREAD_SAFE, 1, [Do we want the thread-safe OS API?])
-	AC_CHECK_LIB(pthread,pthread_mutex_init,tcl_ok=yes,tcl_ok=no)
-	if test "$tcl_ok" = "no"; then
-	    # Check a little harder for __pthread_mutex_init in the same
-	    # library, as some systems hide it there until pthread.h is
-	    # defined.  We could alternatively do an AC_TRY_COMPILE with
-	    # pthread.h, but that will work with libpthread really doesn't
-	    # exist, like AIX 4.2.  [Bug: 4359]
-	    AC_CHECK_LIB(pthread, __pthread_mutex_init,
-		tcl_ok=yes, tcl_ok=no)
-	fi
-
-	if test "$tcl_ok" = "yes"; then
-	    # The space is needed
-	    THREADS_LIBS=" -lpthread"
-	else
-	    AC_CHECK_LIB(pthreads, pthread_mutex_init,
-		tcl_ok=yes, tcl_ok=no)
-	    if test "$tcl_ok" = "yes"; then
-		# The space is needed
-		THREADS_LIBS=" -lpthreads"
-	    else
-		AC_CHECK_LIB(c, pthread_mutex_init,
-		    tcl_ok=yes, tcl_ok=no)
-		if test "$tcl_ok" = "no"; then
-		    AC_CHECK_LIB(c_r, pthread_mutex_init,
-			tcl_ok=yes, tcl_ok=no)
-		    if test "$tcl_ok" = "yes"; then
-			# The space is needed
-			THREADS_LIBS=" -pthread"
-		    else
-			TCL_THREADS=0
-			AC_MSG_WARN([Don't know how to find pthread lib on your system - you must disable thread support or edit the LIBS in the Makefile...])
-		    fi
-		fi
-	    fi
-	fi
-
-	# Does the pthread-implementation provide
-	# 'pthread_attr_setstacksize' ?
-
-	ac_saved_libs=$LIBS
-	LIBS="$LIBS $THREADS_LIBS"
-	AC_CHECK_FUNCS(pthread_attr_setstacksize pthread_atfork)
-	LIBS=$ac_saved_libs
-    else
-	TCL_THREADS=0
-    fi
-    # Do checking message here to not mess up interleaved configure output
-    AC_MSG_CHECKING([for building with threads])
-    if test "${TCL_THREADS}" = 1; then
-	AC_DEFINE(TCL_THREADS, 1, [Are we building with threads enabled?])
-	if test "${tcl_threaded_core}" = 1; then
-	    AC_MSG_RESULT([yes (threaded core)])
-	else
-	    AC_MSG_RESULT([yes])
-	fi
-    else
-	AC_MSG_RESULT([no])
-    fi
-
-    AC_SUBST(TCL_THREADS)
-])
-
 #------------------------------------------------------------------------
 # SC_ENABLE_SYMBOLS --
 #
 #	Specify if debugging symbols should be used.
 #	Memory (TCL_MEM_DEBUG) and compile (TCL_COMPILE_DEBUG) debugging
@@ -2348,16 +2241,24 @@
 #--------------------------------------------------------------------
 # SC_TCL_LINK_LIBS
 #
 #	Search for the libraries needed to link the Tcl shell.
 #	Things like the math library (-lm) and socket stuff (-lsocket vs.
-#	-lnsl) are dealt with here.
+#	-lnsl) or thread library (-lpthread) are dealt with here.
 #
 # Arguments:
 #	None.
 #
 # Results:
+#
+#	Sets the following vars:
+#		THREADS_LIBS	Thread library(s)
+#
+#	Defines the following vars:
+#		TCL_THREADS
+#		_REENTRANT
+#		_THREAD_SAFE
 #
 #	Might append to the following vars:
 #		LIBS
 #		MATH_LIBS
 #
@@ -2412,10 +2313,56 @@
 	LIBS="$LIBS -lsocket -lnsl"
 	AC_CHECK_FUNC(accept, tcl_checkNsl=0, [LIBS=$tk_oldLibs])
     fi
     AC_CHECK_FUNC(gethostbyname, , [AC_CHECK_LIB(nsl, gethostbyname,
 	    [LIBS="$LIBS -lnsl"])])
+
+    AC_DEFINE(_REENTRANT, 1, [Do we want the reentrant OS API?])
+    AC_DEFINE(_THREAD_SAFE, 1, [Do we want the thread-safe OS API?])
+    AC_CHECK_LIB(pthread,pthread_mutex_init,tcl_ok=yes,tcl_ok=no)
+    if test "$tcl_ok" = "no"; then
+	# Check a little harder for __pthread_mutex_init in the same
+	# library, as some systems hide it there until pthread.h is
+	# defined.  We could alternatively do an AC_TRY_COMPILE with
+	# pthread.h, but that will work with libpthread really doesn't
+	# exist, like AIX 4.2.  [Bug: 4359]
+	AC_CHECK_LIB(pthread, __pthread_mutex_init,
+		tcl_ok=yes, tcl_ok=no)
+    fi
+
+    if test "$tcl_ok" = "yes"; then
+	# The space is needed
+	THREADS_LIBS=" -lpthread"
+    else
+	AC_CHECK_LIB(pthreads, pthread_mutex_init,
+	_ok=yes, tcl_ok=no)
+	if test "$tcl_ok" = "yes"; then
+	    # The space is needed
+	    THREADS_LIBS=" -lpthreads"
+	else
+	    AC_CHECK_LIB(c, pthread_mutex_init,
+		    tcl_ok=yes, tcl_ok=no)
+	    if test "$tcl_ok" = "no"; then
+		AC_CHECK_LIB(c_r, pthread_mutex_init,
+			tcl_ok=yes, tcl_ok=no)
+		if test "$tcl_ok" = "yes"; then
+		    # The space is needed
+		    THREADS_LIBS=" -pthread"
+		else
+		    AC_MSG_WARN([Don't know how to find pthread lib on your system - you must edit the LIBS in the Makefile...])
+		fi
+	    fi
+	fi
+    fi
+
+    # Does the pthread-implementation provide
+    # 'pthread_attr_setstacksize' ?
+
+    ac_saved_libs=$LIBS
+    LIBS="$LIBS $THREADS_LIBS"
+    AC_CHECK_FUNCS(pthread_attr_setstacksize pthread_atfork)
+    LIBS=$ac_saved_libs
 ])
 
 #--------------------------------------------------------------------
 # SC_TCL_EARLY_FLAGS
 #

Index: unix/tclUnixPort.h
==================================================================
--- unix/tclUnixPort.h
+++ unix/tclUnixPort.h
@@ -600,14 +600,12 @@
 #	    undef HAVE_OSSPINLOCKLOCK
 #	    undef HAVE_PTHREAD_ATFORK
 #	    undef HAVE_COPYFILE
 #	endif
 #	if MAC_OS_X_VERSION_MAX_ALLOWED < 1030
-#	    ifdef TCL_THREADS
-		/* prior to 10.3, realpath is not threadsafe, c.f. bug 711232 */
-#		define NO_REALPATH 1
-#	    endif
+	    /* prior to 10.3, realpath is not threadsafe, c.f. bug 711232 */
+#	    define NO_REALPATH 1
 #	    undef HAVE_LANGINFO
 #	endif
 #   endif /* MAC_OS_X_VERSION_MAX_ALLOWED */
 #   if defined(HAVE_COREFOUNDATION) && defined(__LP64__) && \
 	    defined(HAVE_WEAK_IMPORT) && MAC_OS_X_VERSION_MIN_REQUIRED < 1050
@@ -676,11 +674,11 @@
  *---------------------------------------------------------------------------
  */
 
 #define TclpExit	exit
 
-#ifdef TCL_THREADS
+#if !defined(TCL_THREADS) || TCL_THREADS
 #   include <pthread.h>
 #endif /* TCL_THREADS */
 
 /* FIXME - Hyper-enormous platform assumption! */
 #ifndef AF_INET6

Index: win/configure
==================================================================
--- win/configure
+++ win/configure
@@ -705,11 +705,10 @@
 CFLAGS_WARNING
 CFLAGS_OPTIMIZE
 CFLAGS_DEBUG
 DL_LIBS
 CYGPATH
-TCL_THREADS
 SET_MAKE
 RC
 RANLIB
 AR
 EGREP
@@ -761,11 +760,10 @@
 PATH_SEPARATOR
 SHELL'
 ac_subst_files=''
 ac_user_opts='
 enable_option_checking
-enable_threads
 with_encoding
 enable_shared
 enable_64bit
 enable_symbols
 enable_embedded_manifest
@@ -1384,11 +1382,10 @@
 
 Optional Features:
   --disable-option-checking  ignore unrecognized --enable/--with options
   --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
-  --enable-threads        build with threads (default: on)
   --enable-shared         build and link with shared libraries (default: on)
   --enable-64bit          enable 64bit support (where applicable)
   --enable-symbols        build with debugging symbols (default: off)
   --enable-embedded-manifest
                           embed manifest if possible (default: yes)
@@ -3669,43 +3666,10 @@
 #--------------------------------------------------------------------
 # Determines the correct binary file extension (.o, .obj, .exe etc.)
 #--------------------------------------------------------------------
 
 
-
-
-#--------------------------------------------------------------------
-# Check whether --enable-threads or --disable-threads was given.
-#--------------------------------------------------------------------
-
-
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for building with threads" >&5
-$as_echo_n "checking for building with threads... " >&6; }
-    # Check whether --enable-threads was given.
-if test "${enable_threads+set}" = set; then :
-  enableval=$enable_threads; tcl_ok=$enableval
-else
-  tcl_ok=yes
-fi
-
-
-    if test "$tcl_ok" = "yes"; then
-	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes (default)" >&5
-$as_echo "yes (default)" >&6; }
-	TCL_THREADS=1
-	$as_echo "#define TCL_THREADS 1" >>confdefs.h
-
-	# USE_THREAD_ALLOC tells us to try the special thread-based
-	# allocator that significantly reduces lock contention
-	$as_echo "#define USE_THREAD_ALLOC 1" >>confdefs.h
-
-    else
-	TCL_THREADS=0
-	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-    fi
-
 
 
 #------------------------------------------------------------------------
 # Embedded configuration information, encoding to use for the values, TIP #59
 #------------------------------------------------------------------------

Index: win/configure.ac
==================================================================
--- win/configure.ac
+++ win/configure.ac
@@ -76,16 +76,10 @@
 #--------------------------------------------------------------------
 
 AC_OBJEXT
 AC_EXEEXT
 
-#--------------------------------------------------------------------
-# Check whether --enable-threads or --disable-threads was given.
-#--------------------------------------------------------------------
-
-SC_ENABLE_THREADS
-
 #------------------------------------------------------------------------
 # Embedded configuration information, encoding to use for the values, TIP #59
 #------------------------------------------------------------------------
 
 SC_TCL_CFG_ENCODING

Index: win/rules.vc
==================================================================
--- win/rules.vc
+++ win/rules.vc
@@ -728,19 +728,10 @@
 TCL_USE_STATIC_PACKAGES	= 1
 !else
 TCL_USE_STATIC_PACKAGES	= 0
 !endif
 
-!if [nmakehlp -f $(OPTS) "nothreads"]
-!message *** Compile explicitly for non-threaded tcl
-TCL_THREADS	= 0
-USE_THREAD_ALLOC= 0
-!else
-TCL_THREADS	= 1
-USE_THREAD_ALLOC= 1
-!endif
-
 !if [nmakehlp -f $(OPTS) "symbols"]
 !message *** Doing symbols
 DEBUG		= 1
 !else
 DEBUG		= 0
@@ -772,16 +763,10 @@
 
 !if [nmakehlp -f $(OPTS) "loimpact"]
 !message *** Warning: ignoring option "loimpact" - deprecated on modern Windows.
 !endif
 
-# TBD - should get rid of this option
-!if [nmakehlp -f $(OPTS) "thrdalloc"]
-!message *** Doing thrdalloc
-USE_THREAD_ALLOC = 1
-!endif
-
 !if [nmakehlp -f $(OPTS) "tclalloc"]
 USE_THREAD_ALLOC = 0
 !endif
 
 !if [nmakehlp -f $(OPTS) "unchecked"]
@@ -968,11 +953,11 @@
 # Figure-out how to name our intermediate and output directories.
 # In order to avoid inadvertent mixing of object files built using
 # different compilers, build configurations etc.,
 #
 # Naming convention (suffixes):
-#   t = full thread support.
+#   t = full thread support. (Not used for Tcl >= 8.7)
 #   s = static library (as opposed to an import library)
 #   g = linked to the debug enabled C run-time.
 #   x = special static build when it links to the dynamic C run-time.
 #
 # The following macros are set in this section:
@@ -1026,11 +1011,11 @@
 TMP_DIRFULL = $(TMP_DIRFULL:X=)
 SUFX	    = $(SUFX:x=)
 !endif
 !endif
 
-!if !$(TCL_THREADS)
+!if !$(TCL_THREADS) || $(TCL_VERSION) > 86
 TMP_DIRFULL = $(TMP_DIRFULL:Threaded=)
 SUFX	    = $(SUFX:t=)
 !endif
 
 !ifndef TMP_DIR
@@ -1077,13 +1062,10 @@
 
 # When building extensions, we need to locate tclsh. Depending on version
 # of Tcl we are building against, this may or may not have a "t" suffix.
 # Try various possibilities in turn.
 TCLSH		= $(_TCLDIR)\bin\tclsh$(TCL_VERSION)$(SUFX).exe
-!if !exist("$(TCLSH)") && $(TCL_THREADS)
-TCLSH           = $(_TCLDIR)\bin\tclsh$(TCL_VERSION)t$(SUFX).exe
-!endif
 !if !exist("$(TCLSH)")
 TCLSH           = $(_TCLDIR)\bin\tclsh$(TCL_VERSION)$(SUFX:t=).exe
 !endif
 
 TCLSTUBLIB	= $(_TCLDIR)\lib\tclstub$(TCL_VERSION).lib
@@ -1100,13 +1082,10 @@
 TCL_INCLUDES    = -I"$(_TCLDIR)\include"
 
 !else # Building against Tcl sources
 
 TCLSH		= $(_TCLDIR)\win\$(BUILDDIRTOP)\tclsh$(TCL_VERSION)$(SUFX).exe
-!if !exist($(TCLSH)) && $(TCL_THREADS)
-TCLSH		= $(_TCLDIR)\win\$(BUILDDIRTOP)\tclsh$(TCL_VERSION)t$(SUFX).exe
-!endif
 !if !exist($(TCLSH))
 TCLSH		= $(_TCLDIR)\win\$(BUILDDIRTOP)\tclsh$(TCL_VERSION)$(SUFX:t=).exe
 !endif
 TCLSTUBLIB	= $(_TCLDIR)\win\$(BUILDDIRTOP)\tclstub$(TCL_VERSION).lib
 TCLIMPLIB	= $(_TCLDIR)\win\$(BUILDDIRTOP)\tcl$(TCL_VERSION)$(SUFX).lib
@@ -1262,11 +1241,11 @@
 OPTDEFINES	= $(OPTDEFINES) -DTCL_MEM_DEBUG
 !endif
 !if $(TCL_COMPILE_DEBUG)
 OPTDEFINES	= $(OPTDEFINES) -DTCL_COMPILE_DEBUG -DTCL_COMPILE_STATS
 !endif
-!if $(TCL_THREADS)
+!if $(TCL_THREADS) && $(TCL_VERSION) < 86
 OPTDEFINES	= $(OPTDEFINES) -DTCL_THREADS=1
 !if $(USE_THREAD_ALLOC)
 OPTDEFINES	= $(OPTDEFINES) -DUSE_THREAD_ALLOC=1
 !endif
 !endif
@@ -1706,13 +1685,10 @@
 !include $(TCLNMAKECONFIG)
 
 !if defined(CORE_MACHINE) && "$(CORE_MACHINE)" != "$(MACHINE)"
 !error ERROR: Build target ($(MACHINE)) does not match the Tcl library architecture ($(CORE_MACHINE)).
 !endif
-!if defined(CORE_USE_THREAD_ALLOC) && $(CORE_USE_THREAD_ALLOC) != $(USE_THREAD_ALLOC)
-!message WARNING: Value of USE_THREAD_ALLOC ($(USE_THREAD_ALLOC)) does not match its Tcl core value ($(CORE_USE_THREAD_ALLOC)).
-!endif
 !if defined(CORE_DEBUG) && $(CORE_DEBUG) != $(DEBUG)
 !message WARNING: Value of DEBUG ($(DEBUG)) does not match its Tcl library configuration ($(DEBUG)).
 !endif
 !endif
 

Index: win/tcl.m4
==================================================================
--- win/tcl.m4
+++ win/tcl.m4
@@ -380,46 +380,10 @@
 	SHARED_BUILD=0
 	AC_DEFINE(STATIC_BUILD, 1, [Is this a static build?])
     fi
 ])
 
-#------------------------------------------------------------------------
-# SC_ENABLE_THREADS --
-#
-#	Specify if thread support should be enabled
-#
-# Arguments:
-#	none
-#
-# Results:
-#
-#	Adds the following arguments to configure:
-#		--enable-threads=yes|no
-#
-#	Defines the following vars:
-#		TCL_THREADS
-#------------------------------------------------------------------------
-
-AC_DEFUN([SC_ENABLE_THREADS], [
-    AC_MSG_CHECKING(for building with threads)
-    AC_ARG_ENABLE(threads, [  --enable-threads        build with threads (default: on)],
-	[tcl_ok=$enableval], [tcl_ok=yes])
-
-    if test "$tcl_ok" = "yes"; then
-	AC_MSG_RESULT([yes (default)])
-	TCL_THREADS=1
-	AC_DEFINE(TCL_THREADS)
-	# USE_THREAD_ALLOC tells us to try the special thread-based
-	# allocator that significantly reduces lock contention
-	AC_DEFINE(USE_THREAD_ALLOC)
-    else
-	TCL_THREADS=0
-	AC_MSG_RESULT(no)
-    fi
-    AC_SUBST(TCL_THREADS)
-])
-
 #------------------------------------------------------------------------
 # SC_ENABLE_SYMBOLS --
 #
 #	Specify if debugging symbols should be used.
 #	Memory (TCL_MEM_DEBUG) and compile (TCL_COMPILE_DEBUG) debugging

Index: win/tcl.rc
==================================================================
--- win/tcl.rc
+++ win/tcl.rc
@@ -5,23 +5,17 @@
 #include <tcl.h>
 
 //
 // build-up the name suffix that defines the type of build this is.
 //
-#if TCL_THREADS
-#define SUFFIX_THREADS	    "t"
-#else
-#define SUFFIX_THREADS	    ""
-#endif
-
 #if DEBUG && !UNCHECKED
 #define SUFFIX_DEBUG	    "g"
 #else
 #define SUFFIX_DEBUG	    ""
 #endif
 
-#define SUFFIX		    SUFFIX_THREADS SUFFIX_DEBUG
+#define SUFFIX		    SUFFIX_DEBUG
 
 
 LANGUAGE 0x9, 0x1	/* LANG_ENGLISH, SUBLANG_DEFAULT */
 
 VS_VERSION_INFO VERSIONINFO

Index: win/tclsh.rc
==================================================================
--- win/tclsh.rc
+++ win/tclsh.rc
@@ -6,16 +6,10 @@
 #include <tcl.h>
 
 //
 // build-up the name suffix that defines the type of build this is.
 //
-#if TCL_THREADS
-#define SUFFIX_THREADS	    "t"
-#else
-#define SUFFIX_THREADS	    ""
-#endif
-
 #if STATIC_BUILD
 #define SUFFIX_STATIC	    "s"
 #else
 #define SUFFIX_STATIC	    ""
 #endif
@@ -24,11 +18,11 @@
 #define SUFFIX_DEBUG	    "g"
 #else
 #define SUFFIX_DEBUG	    ""
 #endif
 
-#define SUFFIX		    SUFFIX_THREADS SUFFIX_STATIC SUFFIX_DEBUG
+#define SUFFIX		    SUFFIX_STATIC SUFFIX_DEBUG
 
 
 LANGUAGE 0x9, 0x1	/* LANG_ENGLISH, SUBLANG_DEFAULT */
 
 VS_VERSION_INFO VERSIONINFO