--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/interpreter/bytecodeTracer.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,58 @@
+/*
+ * Copyright 1997-2003 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// The BytecodeTracer is a helper class used by the interpreter for run-time
+// bytecode tracing. If bytecode tracing is turned on, trace() will be called
+// for each bytecode.
+//
+// By specialising the BytecodeClosure, all kinds of bytecode traces can
+// be done.
+
+#ifndef PRODUCT
+// class BytecodeTracer is only used by TraceBytecodes option
+
+class BytecodeClosure;
+class BytecodeTracer: AllStatic {
+ private:
+  static BytecodeClosure* _closure;
+
+ public:
+  static BytecodeClosure* std_closure();                        // a printing closure
+  static BytecodeClosure* closure()                                                   { return _closure; }
+  static void             set_closure(BytecodeClosure* closure) { _closure = closure; }
+
+  static void             trace(methodHandle method, address bcp, uintptr_t tos, uintptr_t tos2, outputStream* st = tty);
+  static void             trace(methodHandle method, address bcp, outputStream* st = tty);
+};
+
+
+// For each bytecode, a BytecodeClosure's trace() routine will be called.
+
+class BytecodeClosure {
+ public:
+  virtual void trace(methodHandle method, address bcp, uintptr_t tos, uintptr_t tos2, outputStream* st) = 0;
+  virtual void trace(methodHandle method, address bcp, outputStream* st) = 0;
+};
+
+#endif // !PRODUCT