/*

 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.

 * Copyright 2007, 2008, 2009, 2010 Red Hat, Inc.

 * 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.

 *

 */

#ifndef OS_CPU_LINUX_ZERO_VM_THREAD_LINUX_ZERO_HPP

#define OS_CPU_LINUX_ZERO_VM_THREAD_LINUX_ZERO_HPP

 private:

  ZeroStack  _zero_stack;

  ZeroFrame* _top_zero_frame;

  void pd_initialize() {

    _top_zero_frame = NULL;

  }

 public:

  ZeroStack *zero_stack() {

    return &_zero_stack;

  }

 public:

  ZeroFrame *top_zero_frame() {

    return _top_zero_frame;

  }

  void push_zero_frame(ZeroFrame *frame) {

    *(ZeroFrame **) frame = _top_zero_frame;

    _top_zero_frame = frame;

  }

  void pop_zero_frame() {

    zero_stack()->set_sp((intptr_t *) _top_zero_frame + 1);

    _top_zero_frame = *(ZeroFrame **) _top_zero_frame;

  }

 public:

  static ByteSize zero_stack_offset() {

    return byte_offset_of(JavaThread, _zero_stack);

  }

  static ByteSize top_zero_frame_offset() {

    return byte_offset_of(JavaThread, _top_zero_frame);

  }

 public:

  void record_base_of_stack_pointer() {

    assert(top_zero_frame() == NULL, "junk on stack prior to Java call");

  }

  void set_base_of_stack_pointer(intptr_t* base_sp) {

    assert(base_sp == NULL, "should be");

    assert(top_zero_frame() == NULL, "junk on stack after Java call");

  }

 public:

  void set_last_Java_frame() {

    set_last_Java_frame(top_zero_frame(), zero_stack()->sp());

  }

  void reset_last_Java_frame() {

    frame_anchor()->zap();

  }

  void set_last_Java_frame(ZeroFrame* fp, intptr_t* sp) {

    frame_anchor()->set(sp, NULL, fp);

  }

 public:

  ZeroFrame* last_Java_fp() {

    return frame_anchor()->last_Java_fp();

  }

 private:

  frame pd_last_frame() {

    assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");

    return frame(last_Java_fp(), last_Java_sp());

  }

 public:

  static ByteSize last_Java_fp_offset() {

    return byte_offset_of(JavaThread, _anchor) +

      JavaFrameAnchor::last_Java_fp_offset();

  }

 public:

  // Check for pending suspend requests and pending asynchronous

  // exceptions.  There are separate accessors for these, but

  // _suspend_flags is volatile so using them would be unsafe.

  bool has_special_condition_for_native_trans() {

    return _suspend_flags != 0;

  }

 public:

  bool pd_get_top_frame_for_signal_handler(frame* fr_addr,

                                           void* ucontext,

                                           bool isInJava) {

    ShouldNotCallThis();

  }

  // These routines are only used on cpu architectures that

  // have separate register stacks (Itanium).

  static bool register_stack_overflow() { return false; }

  static void enable_register_stack_guard() {}

  static void disable_register_stack_guard() {}

#endif // OS_CPU_LINUX_ZERO_VM_THREAD_LINUX_ZERO_HPP