Add configure thread tests.

configure.in

 dnl Process this file with autoconf to produce a configure script.
-dnl $Header: /cvsroot/pgsql/configure.in,v 1.253 2003/05/22 16:39:28 tgl Exp $
+dnl $Header: /cvsroot/pgsql/configure.in,v 1.254 2003/05/27 16:36:50 momjian Exp $
 dnl
 dnl Developers, please strive to achieve this order:
 dnl
@@ -506,6 +506,9 @@ PGAC_ARG_BOOL(with, zlib, yes,
               [  --without-zlib          do not use Zlib])
 
 
+#
+# Elf
+#
 
 # Assume system is ELF if it predefines __ELF__ as 1,
 # otherwise believe host_os based default.
@@ -527,7 +530,31 @@ else
 fi])
 AC_SUBST(ELF_SYS)
 
+#
+# Pthreads
+#
+
+AC_CHECK_HEADER(pthread.h,
+	[AC_DEFINE(HAVE_THREADS, 1, [Define to 1 if you have the threads interface.])])
+if test ! -z "$HAVE_THREADS"
+then	
+	case $host_os in
+		# BSD/OS and NetBSD require no special libraries or flags
+		netbsd*|bsdi*) ;;
+		freebsd2*|freebsd3*|freebsd4*) THREAD_CFLAGS="-pthread" ;;
+		freebsd*) THREAD_LIBS="-lc_r" ;;
+		linux*) THREAD_LIBS="-lpthread"
+			THREAD_CFLAGS="-D_REENTRANT" ;;
+	# other operating systems might fail because they have pthread.h but need
+	# special libs we don't know about yet.
+	esac
+fi
+AC_SUBST(THREAD_LIBS)
+AC_SUBST(THREAD_CFLAGS)
 
+#
+# Assignments
+#
 
 CPPFLAGS="$CPPFLAGS $INCLUDES"
 LDFLAGS="$LDFLAGS $LIBDIRS"

src/Makefile.global.in

 # -*-makefile-*-
-# $Header: /cvsroot/pgsql/src/Makefile.global.in,v 1.162 2003/05/11 20:50:53 tgl Exp $
+# $Header: /cvsroot/pgsql/src/Makefile.global.in,v 1.163 2003/05/27 16:36:50 momjian Exp $
 
 #------------------------------------------------------------------------------
 # All PostgreSQL makefiles include this file and use the variables it sets,
@@ -152,6 +152,9 @@ TK_LIBS			= @TK_LIBS@
 TK_LIB_SPEC		= @TK_LIB_SPEC@
 TK_XINCLUDES		= @TK_XINCLUDES@
 
+THREAD_CFLAGS		= @THREAD_CFLAGS@
+THREAD_LIBS		= @THREAD_LIBS@
+
 have_docbook	= @have_docbook@
 DOCBOOKSTYLE	= @DOCBOOKSTYLE@
 COLLATEINDEX	= @COLLATEINDEX@

src/include/pg_config.h.in

@@ -465,6 +465,9 @@
 /* Define to 1 if you have the <termios.h> header file. */
 #undef HAVE_TERMIOS_H
 
+/* Define to 1 if you have the threads interface. */
+#undef HAVE_THREADS
+
 /* Define to 1 if your `struct tm' has `tm_zone'. Deprecated, use
    `HAVE_STRUCT_TM_TM_ZONE' instead. */
 #undef HAVE_TM_ZONE