Detecter sigwait pour les threads POSIX (Cygwin ne l'a pas)

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@5759 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

configure

@@ -1067,6 +1067,10 @@ if ./hasgot -i pthread.h $pthread_link pthread_self; then
   esac
   echo "Options for linking with POSIX threads: $pthread_link"
   echo "PTHREAD_LINK=$pthread_link" >> Makefile
+  if sh ./hasgot $pthread_link sigwait; then
+    echo "sigwait() found"
+    echo "#define HAS_SIGWAIT" >> s.h
+  fi
 else
   echo "POSIX threads not found."
 fi

otherlibs/systhreads/posix.c

@@ -779,6 +779,7 @@ int caml_threadstatus_wait (value wrapper)
 
 value caml_wait_signal(value sigs) /* ML */
 {
+#ifdef HAS_SIGWAIT
   sigset_t set;
   int retcode, signo;
 
@@ -793,6 +794,10 @@ value caml_wait_signal(value sigs) /* ML */
   leave_blocking_section();
   caml_pthread_check(retcode, "Thread.wait_signal");
   return Val_int(signo);
+#else
+  invalid_argument("Thread.wait_signal not implemented");
+  return Val_int(0);		/* not reached */
+#endif
 }
 
 /* Error report */