static VALUE e_Error; /* used for all errors */
static void ruby_event_callback_wrapper (guestfs_h *g, void *data, uint64_t event, int event_handle, int flags, const char *buf, size_t buf_len, const uint64_t *array, size_t array_len);
+static VALUE ruby_event_callback_wrapper_wrapper (VALUE argv);
+static VALUE ruby_event_callback_handle_exception (VALUE not_used, VALUE exn);
static VALUE **get_all_event_callbacks (guestfs_h *g, size_t *len_rtn);
static void
const uint64_t *array, size_t array_len)
{
size_t i;
- VALUE eventv, event_handlev, bufv, arrayv;
+ VALUE eventv, event_handlev, bufv, arrayv, argv;
eventv = ULL2NUM (event);
event_handlev = INT2NUM (event_handle);
for (i = 0; i < array_len; ++i)
rb_ary_push (arrayv, ULL2NUM (array[i]));
- /* XXX If the Ruby callback raises any sort of exception then
- * it causes the process to segfault. I don't understand how
- * to catch exceptions here.
+ /* Wrap up the arguments in an array which will be unpacked
+ * and passed as multiple arguments. This is a crap limitation
+ * of rb_rescue.
+ * http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/~poffice/mail/ruby-talk/65698
*/
- rb_funcall (*(VALUE *) data, rb_intern (\"call\"), 4,
+ argv = rb_ary_new2 (5);
+ rb_ary_store (argv, 0, * (VALUE *) data /* function */);
+ rb_ary_store (argv, 1, eventv);
+ rb_ary_store (argv, 2, event_handlev);
+ rb_ary_store (argv, 3, bufv);
+ rb_ary_store (argv, 4, arrayv);
+
+ rb_rescue (ruby_event_callback_wrapper_wrapper, argv,
+ ruby_event_callback_handle_exception, Qnil);
+}
+
+static VALUE
+ruby_event_callback_wrapper_wrapper (VALUE argv)
+{
+ VALUE fn, eventv, event_handlev, bufv, arrayv;
+
+ fn = rb_ary_entry (argv, 0);
+ eventv = rb_ary_entry (argv, 1);
+ event_handlev = rb_ary_entry (argv, 2);
+ bufv = rb_ary_entry (argv, 3);
+ arrayv = rb_ary_entry (argv, 4);
+
+ rb_funcall (fn, rb_intern (\"call\"), 4,
eventv, event_handlev, bufv, arrayv);
+
+ return Qnil;
+}
+
+static VALUE
+ruby_event_callback_handle_exception (VALUE not_used, VALUE exn)
+{
+ /* Callbacks aren't supposed to throw exceptions. The best we
+ * can do is to print the error.
+ */
+ fprintf (stderr, \"libguestfs: exception in callback: %%s\",
+ StringValueCStr (exn));
+
+ return Qnil;
}
static VALUE **
--- /dev/null
+# libguestfs Ruby bindings -*- ruby -*-
+# Copyright (C) 2011 Red Hat Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+# Test that throwing an exception in a callback doesn't cause
+# the interpreter to segfault. See:
+# https://bugzilla.redhat.com/show_bug.cgi?id=664558#c6
+
+require 'test/unit'
+$:.unshift(File::join(File::dirname(__FILE__), "..", "lib"))
+$:.unshift(File::join(File::dirname(__FILE__), "..", "ext", "guestfs"))
+require 'guestfs'
+
+class TestLoad < Test::Unit::TestCase
+ def test_rhbz664558c6
+ g = Guestfs::create()
+
+ close_invoked = 0
+ close = Proc.new {| event, event_handle, buf, array |
+ close_invoked += 1
+ # Raising an exception used to cause the interpreter to
+ # segfault. It should just cause an error message to be
+ # printed on stderr.
+ raise "ignore this error"
+ }
+ g.set_event_callback(close, Guestfs::EVENT_CLOSE)
+
+ # This should call the close callback.
+ g.close()
+
+ if close_invoked != 1
+ raise "close_invoked should be 1"
+ end
+ end
+end