safety fix for Inotify#dup

We do not want to share buffers between inotify descriptors.

2 files changed, 24 insertions, 0 deletions

diff --git a/ext/sleepy_penguin/inotify.c b/ext/sleepy_penguin/inotify.c
index 76082f7..f3a07d9 100644
--- a/ext/sleepy_penguin/inotify.c
+++ b/ext/sleepy_penguin/inotify.c
@@ -213,6 +213,16 @@ static VALUE events(VALUE self)
         return rv;
 }
 
+static VALUE init_copy(VALUE dest, VALUE orig)
+{
+        VALUE tmp;
+
+        dest = rb_call_super(1, &orig);
+        rb_ivar_set(dest, id_inotify_buf, rb_str_new(0, 128));
+
+        return dest;
+}
+
 void sleepy_penguin_init_inotify(void)
 {
         VALUE mSleepyPenguin, cInotify;
@@ -221,6 +231,7 @@ void sleepy_penguin_init_inotify(void)
         cInotify = rb_define_class_under(mSleepyPenguin, "Inotify", rb_cIO);
         rb_define_method(cInotify, "add_watch", add_watch, 2);
         rb_define_method(cInotify, "rm_watch", rm_watch, 1);
+        rb_define_method(cInotify, "initialize_copy", init_copy, 1);
         rb_define_method(cInotify, "take", take, -1);
         cEvent = rb_struct_define(NULL, "wd", "mask", "cookie", "name", NULL);
         rb_define_const(cInotify, "Event", cEvent);
diff --git a/test/test_inotify.rb b/test/test_inotify.rb
index f0c135b..ab52b77 100644
--- a/test/test_inotify.rb
+++ b/test/test_inotify.rb
@@ -12,6 +12,19 @@ class TestInotify < Test::Unit::TestCase
     assert_kind_of(IO, ino)
   end
 
+  def test_dup
+    a = Inotify.new
+    b = a.dup
+    assert a.fileno != b.fileno
+    abuf = a.instance_variable_get(:@inotify_buf)
+    bbuf = b.instance_variable_get(:@inotify_buf)
+    assert abuf.object_id != bbuf.object_id
+
+    atmp = a.instance_variable_get(:@inotify_tmp)
+    btmp = b.instance_variable_get(:@inotify_tmp)
+    assert_equal atmp.object_id, btmp.object_id
+  end
+
   def test_new_nonblock
     ino = Inotify.new Inotify::NONBLOCK
     flags = ino.fcntl(Fcntl::F_GETFL) & Fcntl::O_NONBLOCK