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Java example source code file (stack_zero.hpp)

This example Java source code file (stack_zero.hpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bytesize, cpu_zero_vm_stack_zero_hpp, entry_frame, entryframe, fake_stub_frame, fakestubframe, frametype, interpreter_frame, interpreterframe, logbytesperword, null, sharkframe, zeroframe, zerostack

The stack_zero.hpp Java example source code

/*
 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 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 CPU_ZERO_VM_STACK_ZERO_HPP
#define CPU_ZERO_VM_STACK_ZERO_HPP

#include "utilities/sizes.hpp"

class ZeroStack {
 private:
  intptr_t *_base; // the last available word
  intptr_t *_top;  // the word past the end of the stack
  intptr_t *_sp;   // the top word on the stack

 private:
  int _shadow_pages_size; // how much ABI stack must we keep free?

 public:
  ZeroStack()
    : _base(NULL), _top(NULL), _sp(NULL) {
    _shadow_pages_size = StackShadowPages * os::vm_page_size();
  }

  bool needs_setup() const {
    return _base == NULL;
  }

  int suggest_size(Thread *thread) const;

  void setup(void *mem, size_t size) {
    assert(needs_setup(), "already set up");
    assert(!(size & WordAlignmentMask), "unaligned");

    _base = (intptr_t *) mem;
    _top  = _base + (size >> LogBytesPerWord);
    _sp   = _top;
  }
  void teardown() {
    assert(!needs_setup(), "not set up");
    assert(_sp == _top, "stuff on stack at teardown");

    _base = NULL;
    _top  = NULL;
    _sp   = NULL;
  }

  intptr_t *sp() const {
    return _sp;
  }
  void set_sp(intptr_t *new_sp) {
    assert(_top >= new_sp && new_sp >= _base, "bad stack pointer");
    _sp = new_sp;
  }

  int total_words() const {
    return _top - _base;
  }
  int available_words() const {
    return _sp - _base;
  }

  void push(intptr_t value) {
    assert(_sp > _base, "stack overflow");
    *(--_sp) = value;
  }
  intptr_t pop() {
    assert(_sp < _top, "stack underflow");
    return *(_sp++);
  }

  void *alloc(size_t size) {
    int count = align_size_up(size, wordSize) >> LogBytesPerWord;
    assert(count <= available_words(), "stack overflow");
    return _sp -= count;
  }

  int shadow_pages_size() const {
    return _shadow_pages_size;
  }
  int abi_stack_available(Thread *thread) const;

 public:
  void overflow_check(int required_words, TRAPS);
  static void handle_overflow(TRAPS);

 public:
  void zap(int c) PRODUCT_RETURN;

 public:
  static ByteSize base_offset() {
    return byte_offset_of(ZeroStack, _base);
  }
  static ByteSize top_offset() {
    return byte_offset_of(ZeroStack, _top);
  }
  static ByteSize sp_offset() {
    return byte_offset_of(ZeroStack, _sp);
  }
};


class EntryFrame;
class InterpreterFrame;
class SharkFrame;
class FakeStubFrame;

//
// |  ...               |
// +--------------------+  ------------------
// |  ...               |       low addresses
// | frame_type         |
// | next_frame         |      high addresses
// +--------------------+  ------------------
// |  ...               |

class ZeroFrame {
  friend class frame;
  friend class ZeroStackPrinter;

 protected:
  ZeroFrame() {
    ShouldNotCallThis();
  }

  enum Layout {
    next_frame_off,
    frame_type_off,
    jf_header_words
  };

  enum FrameType {
    ENTRY_FRAME = 1,
    INTERPRETER_FRAME,
    SHARK_FRAME,
    FAKE_STUB_FRAME
  };

 protected:
  intptr_t *addr_of_word(int offset) const {
    return (intptr_t *) this - offset;
  }
  intptr_t value_of_word(int offset) const {
    return *addr_of_word(offset);
  }

 public:
  ZeroFrame *next() const {
    return (ZeroFrame *) value_of_word(next_frame_off);
  }

 protected:
  FrameType type() const {
    return (FrameType) value_of_word(frame_type_off);
  }

 public:
  bool is_entry_frame() const {
    return type() == ENTRY_FRAME;
  }
  bool is_interpreter_frame() const {
    return type() == INTERPRETER_FRAME;
  }
  bool is_shark_frame() const {
    return type() == SHARK_FRAME;
  }
  bool is_fake_stub_frame() const {
    return type() == FAKE_STUB_FRAME;
  }

 public:
  EntryFrame *as_entry_frame() const {
    assert(is_entry_frame(), "should be");
    return (EntryFrame *) this;
  }
  InterpreterFrame *as_interpreter_frame() const {
    assert(is_interpreter_frame(), "should be");
    return (InterpreterFrame *) this;
  }
  SharkFrame *as_shark_frame() const {
    assert(is_shark_frame(), "should be");
    return (SharkFrame *) this;
  }
  FakeStubFrame *as_fake_stub_frame() const {
    assert(is_fake_stub_frame(), "should be");
    return (FakeStubFrame *) this;
  }

 public:
  void identify_word(int   frame_index,
                     int   offset,
                     char* fieldbuf,
                     char* valuebuf,
                     int   buflen) const;

 protected:
  void identify_vp_word(int       frame_index,
                        intptr_t* addr,
                        intptr_t* monitor_base,
                        intptr_t* stack_base,
                        char*     fieldbuf,
                        int       buflen) const;
};

#endif // CPU_ZERO_VM_STACK_ZERO_HPP

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