Configure check for pthreads.

Doxyfile

@@ -313,6 +313,7 @@ INPUT                  = \
 	simgear/sg_inlines.h \
 	simgear/sg_traits.hxx \
 	simgear/sg_zlib.h \
+	simgear/threads \
 	simgear/sky \
 	simgear/timing \
 	simgear/xml

configure.in

@@ -28,6 +28,7 @@ echo CC = $CC
 dnl Checks for programs.
 AC_PROG_MAKE_SET
 AC_PROG_CC
+AC_PROG_CPP
 AC_PROG_CXX
 AC_PROG_RANLIB
 AC_PROG_INSTALL
@@ -94,6 +95,15 @@ AC_CHECK_LIB(m, cos)
 
 base_LIBS="$LIBS"
 
+dnl Thread related checks
+AC_CHECK_LIB(pthread, pthread_exit)
+AC_CHECK_HEADER(pthread.h)
+if test "x$ac_cv_lib_pthread_pthread_exit" = "xyes" -o "x$ac_cv_header_pthread_h" = "xyes"; then
+    CXXFLAGS="$CXXFLAGS -D_REENTRANT"
+    CFLAGS="$CFLAGS -D_REENTRANT"
+fi
+AM_CONDITIONAL(HAVE_THREADS, test "x$ac_cv_lib_pthread_pthread_exit" = "xyes" -o "x$ac_cv_header_pthread_h" = "xyes")
+
 AC_CHECK_LIB(socket, socket)
 AC_CHECK_LIB(X11, XCreateWindow)
 AC_CHECK_LIB(Xext, XShmCreateImage)

simgear/Makefile.am

@@ -16,6 +16,12 @@ else
 ZLIB_DIRS = zlib
 endif
 
+if HAVE_THREADS
+SGTHREAD_DIR = threads
+else
+SGTHREAD_DIR = 
+endif
+
 # METAR_DIRS =
 METAR_DIRS = metar
 
@@ -38,8 +44,7 @@ SUBDIRS = \
 	screen \
 	$(SERIAL_DIRS) \
 	sky \
-        threads \
+	$(SGTHREAD_DIR)
 	timing \
 	xgl \
 	$(ZLIB_DIRS)
-

simgear/config.h.in

@@ -197,6 +197,9 @@
 /* Define if you have the m library (-lm).  */
 #undef HAVE_LIBM
 
+/* Define if you have the pthread library (-lpthread).  */
+#undef HAVE_LIBPTHREAD
+
 /* Define if you have the socket library (-lsocket).  */
 #undef HAVE_LIBSOCKET