* thread.c (ruby_thread_stack_overflow): call rb_exc_raise() on

stack overflows in the signal handler, if sigaltstack is
  available.  On stack overflow (and with sigaltstack), the signal
  handler is more likely to have room to create an exception
  object.  [ruby-core:23813]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@23720 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,11 @@
+Wed Jun 17 12:37:37 2009  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* thread.c (ruby_thread_stack_overflow): call rb_exc_raise() on
+	  stack overflows in the signal handler, if sigaltstack is
+	  available.  On stack overflow (and with sigaltstack), the signal
+	  handler is more likely to have room to create an exception
+	  object.  [ruby-core:23813]
+
 Wed Jun 17 08:10:38 2009  Koichi Sasada  <ko1@atdot.net>
 
 	* ext/objspace: added.  objspace library extends some methods to

thread.c

@@ -1300,12 +1300,21 @@ rb_threadptr_signal_exit(rb_thread_t *th)
     rb_threadptr_raise(th->vm->main_thread, 2, argv);
 }
 
+#if defined(POSIX_SIGNAL) && defined(SIGSEGV) && defined(HAVE_SIGALTSTACK)
+#define USE_SIGALTSTACK
+#endif
+
 void
 ruby_thread_stack_overflow(rb_thread_t *th)
 {
-    th->errinfo = sysstack_error;
     th->raised_flag = 0;
+#ifdef USE_SIGALTSTACK
+    th->raised_flag = 0;
+    rb_exc_raise(sysstack_error);
+#else
+    th->errinfo = sysstack_error;
     TH_JUMP_TAG(th, TAG_RAISE);
+#endif
 }
 
 int