1 /*
   2  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright 2007, 2008, 2010 Red Hat, Inc.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  *
  24  */
  25 
  26 #ifndef CPU_ZERO_VM_JAVAFRAMEANCHOR_ZERO_HPP
  27 #define CPU_ZERO_VM_JAVAFRAMEANCHOR_ZERO_HPP
  28 
  29  private:
  30   ZeroFrame* volatile _last_Java_fp;
  31 
  32  public:
  33   // Each arch must define reset, save, restore
  34   // These are used by objects that only care about:
  35   //  1 - initializing a new state (thread creation, javaCalls)
  36   //  2 - saving a current state (javaCalls)
  37   //  3 - restoring an old state (javaCalls)
  38   // Note that whenever _last_Java_sp != NULL other anchor fields
  39   // must be valid.  The profiler apparently depends on this.
  40 
  41   void clear() {
  42     // clearing _last_Java_sp must be first
  43     _last_Java_sp = NULL;
  44     // fence?
  45     _last_Java_fp = NULL;
  46     _last_Java_pc = NULL;
  47   }
  48 
  49   void copy(JavaFrameAnchor* src) {
  50     set(src->_last_Java_sp, src->_last_Java_pc, src->_last_Java_fp);
  51   }
  52 
  53   void set(intptr_t* sp, address pc, ZeroFrame* fp) {
  54     // In order to make sure the transition state is valid for "this"
  55     // We must clear _last_Java_sp before copying the rest of the new
  56     // data
  57     //
  58     // Hack Alert: Temporary bugfix for 4717480/4721647 To act like
  59     // previous version (pd_cache_state) don't NULL _last_Java_sp
  60     // unless the value is changing
  61     //
  62     if (_last_Java_sp != sp)
  63       _last_Java_sp = NULL;
  64 
  65     _last_Java_fp = fp;
  66     _last_Java_pc = pc;
  67     // Must be last so profiler will always see valid frame if
  68     // has_last_frame() is true
  69     _last_Java_sp = sp;
  70   }
  71 
  72   bool walkable() {
  73     return true;
  74   }
  75 
  76   void make_walkable(JavaThread* thread) {
  77     // nothing to do
  78   }
  79 
  80   intptr_t* last_Java_sp() const {
  81     return _last_Java_sp;
  82   }
  83 
  84   ZeroFrame* last_Java_fp() const {
  85     return _last_Java_fp;
  86   }
  87 
  88   address last_Java_pc() const {
  89     return _last_Java_pc;
  90   }
  91 
  92   static ByteSize last_Java_fp_offset() {
  93     return byte_offset_of(JavaFrameAnchor, _last_Java_fp);
  94   }
  95 
  96 #endif // CPU_ZERO_VM_JAVAFRAMEANCHOR_ZERO_HPP