view src/share/vm/interpreter/bytecodeTracer.hpp @ 1716:be3f9c242c9d

6948538: CMS: BOT walkers can fall into object allocation and initialization cracks Summary: GC workers now recognize an intermediate transient state of blocks which are allocated but have not yet completed initialization. blk_start() calls do not attempt to determine the size of a block in the transient state, rather waiting for the block to become initialized so that it is safe to query its size. Audited and ensured the order of initialization of object fields (klass, free bit and size) to respect block state transition protocol. Also included some new assertion checking code enabled in debug mode. Reviewed-by: chrisphi, johnc, poonam
author ysr
date Mon, 16 Aug 2010 15:58:42 -0700
parents c18cbe5936b8
children f95d63e2154a
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/*
 * Copyright (c) 1997, 2003, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.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