Introduce Kernel#callback; Mark struct members for GC

bench/raggi_bench.rb

@@ -8,6 +8,7 @@ def me; @s.to_s; end
 cb = Callback &ld
 c2 = Callback( @s, :to_s )
 rb = RubyCallback { @s.to_s }
+farm = @s.callback(:to_s)
 
 tests = 100_000
 puts "# Calling"
@@ -17,4 +18,5 @@ def me; @s.to_s; end
   results.report("callback:") { tests.times { cb.call } }
   results.report("callbak2:") { tests.times { c2.call } }
   results.report("rubyback:") { tests.times { rb.call } }
+  results.report("farm:") { tests.times { farm.call } }
 end

ext/callback/callback.c

@@ -11,20 +11,24 @@ VALUE rb_cCallback;
 
 static ID id_call;
 
+static void mark_callback(RCallback* cb)
+{
+     rb_gc_mark(cb->method);
+     rb_gc_mark(cb->object);
+}
+
 static void free_callback(RCallback* cb)
 {
     xfree(cb);
 }
 
-
 static VALUE callback_alloc _((VALUE));
 static VALUE
 callback_alloc( VALUE klass )
 {
 	VALUE cb;
 	RCallback* cbs;
-	cb = Data_Make_Struct(klass, RCallback, 0, free_callback, cbs);
-
+	cb = Data_Make_Struct(klass, RCallback, mark_callback, free_callback, cbs);
     cbs->object = Qnil;
 	cbs->method = 0;
 
@@ -57,7 +61,7 @@ static VALUE rb_callback_initialize( int argc, VALUE *argv, VALUE cb )
 	return cb;
 }
 
-static VALUE rb_callback_call( VALUE cb, VALUE args )
+static VALUE rb_callback_call( VALUE cb, VALUE *args )
 {
 	RCallback* cbs = GetCallbackStruct(cb);
 	return rb_funcall2(cbs->object, cbs->method, -1, &args); 
@@ -68,6 +72,15 @@ static VALUE rb_f_callback( int argc, VALUE *argv )
 	return rb_callback_initialize( argc, argv, rb_callback_new() );
 }
 
+static VALUE
+rb_obj_callback( VALUE obj, VALUE mid)
+{
+	VALUE args[2];
+	args[0] = obj;
+	args[1] = mid; 
+	return rb_f_callback( 2, (VALUE *)args );
+}
+
 void
 Init_callback()
 {
@@ -80,4 +93,5 @@ Init_callback()
     rb_define_method(rb_cCallback,"call", rb_callback_call, -2);
 
     rb_define_global_function("Callback", rb_f_callback, -1);
+    rb_define_method(rb_mKernel, "callback", rb_obj_callback, 1);
 }	

test/test_callback.rb

@@ -17,10 +17,22 @@ def test_init_object_call_with_args
     assert_equal 'hai', cb.call( 'b', 'h' )
   end
 
+  def test_many_calls
+    cb = Callback { :foo }
+    100_000.times { cb.call }
+  end  
+
   def test_arguments
     assert_raises ArgumentError do
       Callback( 'hai' ){}
     end
   end
 
+  def test_farmed_from_object
+    cb = 'hai'.callback(:to_s)
+    assert_equal 'hai', cb.call
+    ocb = 'bai'.callback(:gsub)
+    assert_equal 'hai', ocb.call('b', 'h')
+  end  
+
 end