From 02a1c40051e4d4ad081c38a368fd87da89ede5ac Mon Sep 17 00:00:00 2001
From: Guido van Rossum <guido@python.org>
Date: Fri, 25 Feb 2000 19:26:31 +0000
Subject: [PATCH] Pat Knight:

Solaris 2 has stub implementations of the POSIX thread functions such as
pthread_detach in libc. This means that configure tries to use them without
-lpthread, then the test of pthread_create fails and the configuration
falls back to the Solaris thread library. This patch moves the test for
pthread_create in -lpthread ahead of the test for pthread_detach in libc.
The patch also ensures that -lpthread is at the start of the library list
when linking, to pick up POSIX thread semantics for fork (see below).

Justification.
Use of POSIX threads on Solaris ensures that the fork() call only runs the
thread that called fork() in the child. This is desirable to prevent (for
example) parent server or database threads running in the child. Sun's
-lthread library uses a traditional fork() which replicates all the
parent's threads in the child. I find this undesirable.

Digression.
The configure.in seems to always test for -lthread even if a POSIX library
is found. I'm not enough of a configure.in wizard to decide whether this is
desirable or how to fix it. It is also irrelevant to this patch - I just
spotted it while testing.
End of Digression.
---
 configure    | 114 +++++++++++++++++++++++++--------------------------
 configure.in |   8 ++--
 2 files changed, 61 insertions(+), 61 deletions(-)

diff --git a/configure b/configure
index c6ad7a5a7dc..28cf1a2b097 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# From configure.in Revision: 1.115 
+# From configure.in Revision: 1.116 
 
 # Guess values for system-dependent variables and create Makefiles.
 # Generated automatically using autoconf version 2.13 
@@ -2728,17 +2728,65 @@ cat >> confdefs.h <<\EOF
 #define C_THREADS 1
 EOF
 
+LIBOBJS="$LIBOBJS thread.o"
+else
+  echo "$ac_t""no" 1>&6
+
+echo $ac_n "checking for pthread_create in -lpthread""... $ac_c" 1>&6
+echo "configure:2737: checking for pthread_create in -lpthread" >&5
+ac_lib_var=`echo pthread'_'pthread_create | sed 'y%./+-%__p_%'`
+if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
+  echo $ac_n "(cached) $ac_c" 1>&6
+else
+  ac_save_LIBS="$LIBS"
+LIBS="-lpthread  $LIBS"
+cat > conftest.$ac_ext <<EOF
+#line 2745 "configure"
+#include "confdefs.h"
+/* Override any gcc2 internal prototype to avoid an error.  */
+/* We use char because int might match the return type of a gcc2
+    builtin and then its argument prototype would still apply.  */
+char pthread_create();
+
+int main() {
+pthread_create()
+; return 0; }
+EOF
+if { (eval echo configure:2756: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+  rm -rf conftest*
+  eval "ac_cv_lib_$ac_lib_var=yes"
+else
+  echo "configure: failed program was:" >&5
+  cat conftest.$ac_ext >&5
+  rm -rf conftest*
+  eval "ac_cv_lib_$ac_lib_var=no"
+fi
+rm -f conftest*
+LIBS="$ac_save_LIBS"
+
+fi
+if eval "test \"`echo '$ac_cv_lib_'$ac_lib_var`\" = yes"; then
+  echo "$ac_t""yes" 1>&6
+  cat >> confdefs.h <<\EOF
+#define WITH_THREAD 1
+EOF
+
+cat >> confdefs.h <<\EOF
+#define _POSIX_THREADS 1
+EOF
+
+LIBS="-lpthread $LIBS"
 LIBOBJS="$LIBOBJS thread.o"
 else
   echo "$ac_t""no" 1>&6
 
 echo $ac_n "checking for pthread_detach""... $ac_c" 1>&6
-echo "configure:2737: checking for pthread_detach" >&5
+echo "configure:2785: checking for pthread_detach" >&5
 if eval "test \"`echo '$''{'ac_cv_func_pthread_detach'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 2742 "configure"
+#line 2790 "configure"
 #include "confdefs.h"
 /* System header to define __stub macros and hopefully few prototypes,
     which can conflict with char pthread_detach(); below.  */
@@ -2761,7 +2809,7 @@ pthread_detach();
 
 ; return 0; }
 EOF
-if { (eval echo configure:2765: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:2813: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_func_pthread_detach=yes"
 else
@@ -2789,17 +2837,17 @@ else
 
 ac_safe=`echo "kernel/OS.h" | sed 'y%./+-%__p_%'`
 echo $ac_n "checking for kernel/OS.h""... $ac_c" 1>&6
-echo "configure:2793: checking for kernel/OS.h" >&5
+echo "configure:2841: checking for kernel/OS.h" >&5
 if eval "test \"`echo '$''{'ac_cv_header_$ac_safe'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 2798 "configure"
+#line 2846 "configure"
 #include "confdefs.h"
 #include <kernel/OS.h>
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:2803: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:2851: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   rm -rf conftest*
@@ -2828,7 +2876,7 @@ else
   echo "$ac_t""no" 1>&6
 
 echo $ac_n "checking for pthread_create in -lpthreads""... $ac_c" 1>&6
-echo "configure:2832: checking for pthread_create in -lpthreads" >&5
+echo "configure:2880: checking for pthread_create in -lpthreads" >&5
 ac_lib_var=`echo pthreads'_'pthread_create | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -2836,54 +2884,6 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-lpthreads  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 2840 "configure"
-#include "confdefs.h"
-/* Override any gcc2 internal prototype to avoid an error.  */
-/* We use char because int might match the return type of a gcc2
-    builtin and then its argument prototype would still apply.  */
-char pthread_create();
-
-int main() {
-pthread_create()
-; return 0; }
-EOF
-if { (eval echo configure:2851: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
-  rm -rf conftest*
-  eval "ac_cv_lib_$ac_lib_var=yes"
-else
-  echo "configure: failed program was:" >&5
-  cat conftest.$ac_ext >&5
-  rm -rf conftest*
-  eval "ac_cv_lib_$ac_lib_var=no"
-fi
-rm -f conftest*
-LIBS="$ac_save_LIBS"
-
-fi
-if eval "test \"`echo '$ac_cv_lib_'$ac_lib_var`\" = yes"; then
-  echo "$ac_t""yes" 1>&6
-  cat >> confdefs.h <<\EOF
-#define WITH_THREAD 1
-EOF
-
-cat >> confdefs.h <<\EOF
-#define _POSIX_THREADS 1
-EOF
-
-LIBS="$LIBS -lpthreads"
-LIBOBJS="$LIBOBJS thread.o"
-else
-  echo "$ac_t""no" 1>&6
-
-echo $ac_n "checking for pthread_create in -lpthread""... $ac_c" 1>&6
-echo "configure:2880: checking for pthread_create in -lpthread" >&5
-ac_lib_var=`echo pthread'_'pthread_create | sed 'y%./+-%__p_%'`
-if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
-  echo $ac_n "(cached) $ac_c" 1>&6
-else
-  ac_save_LIBS="$LIBS"
-LIBS="-lpthread  $LIBS"
-cat > conftest.$ac_ext <<EOF
 #line 2888 "configure"
 #include "confdefs.h"
 /* Override any gcc2 internal prototype to avoid an error.  */
@@ -2918,7 +2918,7 @@ cat >> confdefs.h <<\EOF
 #define _POSIX_THREADS 1
 EOF
 
-LIBS="$LIBS -lpthread"
+LIBS="$LIBS -lpthreads"
 LIBOBJS="$LIBOBJS thread.o"
 else
   echo "$ac_t""no" 1>&6
diff --git a/configure.in b/configure.in
index 789eaace661..8fa23958129 100644
--- a/configure.in
+++ b/configure.in
@@ -647,6 +647,10 @@ AC_DEFINE(_REENTRANT)
 AC_CHECK_HEADER(mach/cthreads.h, [AC_DEFINE(WITH_THREAD)
 AC_DEFINE(C_THREADS)
 LIBOBJS="$LIBOBJS thread.o"],[
+AC_CHECK_LIB(pthread, pthread_create, [AC_DEFINE(WITH_THREAD)
+AC_DEFINE(_POSIX_THREADS)
+LIBS="-lpthread $LIBS"
+LIBOBJS="$LIBOBJS thread.o"],[
 AC_CHECK_FUNC(pthread_detach, [AC_DEFINE(WITH_THREAD)
 AC_DEFINE(_POSIX_THREADS)
 LIBOBJS="$LIBOBJS thread.o"],[
@@ -657,10 +661,6 @@ AC_CHECK_LIB(pthreads, pthread_create, [AC_DEFINE(WITH_THREAD)
 AC_DEFINE(_POSIX_THREADS)
 LIBS="$LIBS -lpthreads"
 LIBOBJS="$LIBOBJS thread.o"], [
-AC_CHECK_LIB(pthread, pthread_create, [AC_DEFINE(WITH_THREAD)
-AC_DEFINE(_POSIX_THREADS)
-LIBS="$LIBS -lpthread"
-LIBOBJS="$LIBOBJS thread.o"], [
 AC_CHECK_LIB(c_r, pthread_create, [AC_DEFINE(WITH_THREAD)
 AC_DEFINE(_POSIX_THREADS)
 LIBS="$LIBS -lc_r"