1 /*
   2  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
   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_AARCH64_VM_JAVAFRAMEANCHOR_AARCH64_HPP
  27 #define CPU_AARCH64_VM_JAVAFRAMEANCHOR_AARCH64_HPP
  28 
  29 private:
  30 
  31   // FP value associated with _last_Java_sp:
  32   intptr_t* volatile        _last_Java_fp;           // pointer is volatile not what it points to
  33 
  34 public:
  35   // Each arch must define reset, save, restore
  36   // These are used by objects that only care about:
  37   //  1 - initializing a new state (thread creation, javaCalls)
  38   //  2 - saving a current state (javaCalls)
  39   //  3 - restoring an old state (javaCalls)
  40 
  41   void clear(void) {
  42     // clearing _last_Java_sp must be first
  43     _last_Java_sp = NULL;
  44     OrderAccess::release();
  45     _last_Java_fp = NULL;
  46     _last_Java_pc = NULL;
  47   }
  48 
  49   void copy(JavaFrameAnchor* src) {
  50     // In order to make sure the transition state is valid for "this"
  51     // We must clear _last_Java_sp before copying the rest of the new data
  52     //
  53     // Hack Alert: Temporary bugfix for 4717480/4721647
  54     // To act like previous version (pd_cache_state) don't NULL _last_Java_sp
  55     // unless the value is changing
  56     //
  57     if (_last_Java_sp != src->_last_Java_sp) {
  58       _last_Java_sp = NULL;
  59       OrderAccess::release();
  60     }
  61     _last_Java_fp = src->_last_Java_fp;
  62     _last_Java_pc = src->_last_Java_pc;
  63     // Must be last so profiler will always see valid frame if has_last_frame() is true
  64     _last_Java_sp = src->_last_Java_sp;
  65   }
  66 
  67   // Always walkable
  68   bool walkable(void)                            { return _last_Java_sp != NULL && _last_Java_pc != NULL; }
  69   void make_walkable(JavaThread* thread);
  70   void capture_last_Java_pc(void);
  71 
  72   intptr_t* last_Java_sp(void) const             { return _last_Java_sp; }
  73 
  74   address last_Java_pc(void)                     { return _last_Java_pc; }
  75 
  76 private:
  77 
  78   static ByteSize last_Java_fp_offset()          { return byte_offset_of(JavaFrameAnchor, _last_Java_fp); }
  79 
  80 public:
  81 
  82   void set_last_Java_sp(intptr_t* sp)            { _last_Java_sp = sp; OrderAccess::release(); }
  83 
  84   intptr_t*   last_Java_fp(void)                     { return _last_Java_fp; }
  85   // Assert (last_Java_sp == NULL || fp == NULL)
  86   void set_last_Java_fp(intptr_t* fp)                { OrderAccess::release(); _last_Java_fp = fp; }
  87 
  88 #endif // CPU_AARCH64_VM_JAVAFRAMEANCHOR_AARCH64_HPP