1 /*
   2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2016 SAP SE. 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_S390_VM_JAVAFRAMEANCHOR_S390_HPP
  27 #define CPU_S390_VM_JAVAFRAMEANCHOR_S390_HPP
  28 
  29  public:
  30 
  31   // Each arch must define reset, save, restore.
  32   // These are used by objects that only care about:
  33   //  1 - initializing a new state (thread creation, javaCalls)
  34   //  2 - saving a current state (javaCalls)
  35   //  3 - restoring an old state (javaCalls).
  36 
  37   inline void clear(void) {
  38     // Clearing _last_Java_sp must be first.
  39     OrderAccess::release();
  40     _last_Java_sp = NULL;
  41     // Fence?
  42     OrderAccess::fence();
  43 
  44     _last_Java_pc = NULL;
  45   }
  46 
  47   inline void set(intptr_t* sp, address pc) {
  48     _last_Java_pc = pc;
  49 
  50     OrderAccess::release();
  51     _last_Java_sp = sp;
  52   }
  53 
  54   void copy(JavaFrameAnchor* src) {
  55     // In order to make sure the transition state is valid for "this"
  56     // we must clear _last_Java_sp before copying the rest of the new data.
  57     // Hack Alert: Temporary bugfix for 4717480/4721647
  58     // To act like previous version (pd_cache_state) don't NULL _last_Java_sp
  59     // unless the value is changing.
  60     //
  61     if (_last_Java_sp != src->_last_Java_sp) {
  62       OrderAccess::release();
  63       _last_Java_sp = NULL;
  64       OrderAccess::fence();
  65     }
  66     _last_Java_pc = src->_last_Java_pc;
  67     // Must be last so profiler will always see valid frame if has_last_frame() is true.
  68 
  69     OrderAccess::release();
  70     _last_Java_sp = src->_last_Java_sp;
  71   }
  72 
  73   // We don't have to flush registers, so the stack is always walkable.
  74   inline bool walkable(void) { return true; }
  75   inline void make_walkable(JavaThread* thread) { }
  76 
  77  public:
  78 
  79   // We don't have a frame pointer.
  80   intptr_t* last_Java_fp(void)        { return NULL; }
  81 
  82   intptr_t* last_Java_sp() const      { return _last_Java_sp; }
  83   void set_last_Java_sp(intptr_t* sp) { OrderAccess::release(); _last_Java_sp = sp; }
  84 
  85   address last_Java_pc(void)          { return _last_Java_pc; }
  86 
  87 #endif // CPU_S390_VM_JAVAFRAMEANCHOR_S390_HPP