hotspot/src/cpu/s390/vm/metaspaceShared_s390.cpp
author coleenp
Thu, 01 Dec 2016 14:21:31 -0500
changeset 44738 11431bbc9549
parent 42065 6032b31e3719
permissions -rw-r--r--
8168699: Validate special case invocations Reviewed-by: acorn, kvn, lfoltan, ctornqvi, ahgross, vlivanov

/*
 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2016 SAP SE. 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.
 *
 */

#include "precompiled.hpp"
#include "asm/codeBuffer.hpp"
#include "asm/macroAssembler.inline.hpp"
#include "memory/metaspaceShared.hpp"

// Generate the self-patching vtable method:
//
// This method will be called (as any other Klass virtual method) with
// the Klass itself as the first argument. Example:
//
//   oop obj;
//   int size = obj->klass()->klass_part()->oop_size(this);
//
// for which the virtual method call is Klass::oop_size();.
//
// The dummy method is called with the Klass object as the first
// operand, and an object as the second argument.
//

//=====================================================================

// All of the dummy methods in the vtable are essentially identical,
// differing only by an ordinal constant, and they bear no releationship
// to the original method which the caller intended. Also, there needs
// to be 'vtbl_list_size' instances of the vtable in order to
// differentiate between the 'vtable_list_size' original Klass objects.

#undef __
#define __ masm->

void MetaspaceShared::generate_vtable_methods(void** vtbl_list,
                                              void** vtable,
                                              char** md_top,
                                              char* md_end,
                                              char** mc_top,
                                              char* mc_end) {

  intptr_t vtable_bytes = (num_virtuals * vtbl_list_size) * sizeof(void*);
  *(intptr_t *)(*md_top) = vtable_bytes;
  *md_top += sizeof(intptr_t);
  void** dummy_vtable = (void**)*md_top;
  *vtable = dummy_vtable;
  *md_top += vtable_bytes;

  // Get ready to generate dummy methods.

  CodeBuffer cb((unsigned char*)*mc_top, mc_end - *mc_top);
  MacroAssembler* masm = new MacroAssembler(&cb);

  __ unimplemented();
}