1 /*
   2  * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 #ifndef SHARE_GC_Z_ZBARRIER_HPP
  25 #define SHARE_GC_Z_ZBARRIER_HPP
  26 
  27 #include "memory/allocation.hpp"
  28 #include "oops/oop.hpp"
  29 
  30 typedef bool (*ZBarrierFastPath)(uintptr_t);
  31 typedef uintptr_t (*ZBarrierSlowPath)(uintptr_t);
  32 
  33 class ZBarrier : public AllStatic {
  34 private:
  35   static const bool Strong      = false;
  36   static const bool Finalizable = true;
  37 
  38   static const bool Publish     = true;
  39   static const bool Overflow    = false;
  40 
  41   template <ZBarrierFastPath fast_path, ZBarrierSlowPath slow_path> static oop barrier(volatile oop* p, oop o);
  42   template <ZBarrierFastPath fast_path, ZBarrierSlowPath slow_path> static oop weak_barrier(volatile oop* p, oop o);
  43   template <ZBarrierFastPath fast_path, ZBarrierSlowPath slow_path> static void root_barrier(volatile oop* p, oop o);
  44 
  45   static bool is_null_fast_path(uintptr_t addr);
  46   static bool is_good_or_null_fast_path(uintptr_t addr);
  47   static bool is_weak_good_or_null_fast_path(uintptr_t addr);
  48 
  49   static bool is_resurrection_blocked(volatile oop* p, oop* o);
  50 
  51   static bool during_mark();
  52   static bool during_relocate();
  53   template <bool finalizable> static bool should_mark_through(uintptr_t addr);
  54   template <bool finalizable, bool publish> static uintptr_t mark(uintptr_t addr);
  55   static uintptr_t remap(uintptr_t addr);
  56   static uintptr_t relocate(uintptr_t addr);
  57   static uintptr_t relocate_or_mark(uintptr_t addr);
  58   static uintptr_t relocate_or_remap(uintptr_t addr);
  59 
  60   static uintptr_t load_barrier_on_oop_slow_path(uintptr_t addr);
  61 
  62   static uintptr_t weak_load_barrier_on_oop_slow_path(uintptr_t addr);
  63   static uintptr_t weak_load_barrier_on_weak_oop_slow_path(uintptr_t addr);
  64   static uintptr_t weak_load_barrier_on_phantom_oop_slow_path(uintptr_t addr);
  65 
  66   static uintptr_t keep_alive_barrier_on_weak_oop_slow_path(uintptr_t addr);
  67   static uintptr_t keep_alive_barrier_on_phantom_oop_slow_path(uintptr_t addr);
  68 
  69   static uintptr_t mark_barrier_on_oop_slow_path(uintptr_t addr);
  70   static uintptr_t mark_barrier_on_finalizable_oop_slow_path(uintptr_t addr);
  71   static uintptr_t mark_barrier_on_root_oop_slow_path(uintptr_t addr);
  72 
  73   static uintptr_t relocate_barrier_on_root_oop_slow_path(uintptr_t addr);
  74 
  75 public:
  76   // Load barrier
  77   static  oop load_barrier_on_oop(oop o);
  78   static  oop load_barrier_on_oop_field(volatile oop* p);
  79   static  oop load_barrier_on_oop_field_preloaded(volatile oop* p, oop o);
  80   static void load_barrier_on_oop_array(volatile oop* p, size_t length);
  81   static void load_barrier_on_oop_fields(oop o);
  82   static  oop load_barrier_on_weak_oop_field_preloaded(volatile oop* p, oop o);
  83   static  oop load_barrier_on_phantom_oop_field_preloaded(volatile oop* p, oop o);
  84 
  85   // Weak load barrier
  86   static oop weak_load_barrier_on_oop_field_preloaded(volatile oop* p, oop o);
  87   static oop weak_load_barrier_on_weak_oop(oop o);
  88   static oop weak_load_barrier_on_weak_oop_field(volatile oop* p);
  89   static oop weak_load_barrier_on_weak_oop_field_preloaded(volatile oop* p, oop o);
  90   static oop weak_load_barrier_on_phantom_oop(oop o);
  91   static oop weak_load_barrier_on_phantom_oop_field(volatile oop* p);
  92   static oop weak_load_barrier_on_phantom_oop_field_preloaded(volatile oop* p, oop o);
  93 
  94   // Is alive barrier
  95   static bool is_alive_barrier_on_weak_oop(oop o);
  96   static bool is_alive_barrier_on_phantom_oop(oop o);
  97 
  98   // Keep alive barrier
  99   static void keep_alive_barrier_on_weak_oop_field(volatile oop* p);
 100   static void keep_alive_barrier_on_phantom_oop_field(volatile oop* p);
 101 
 102   // Mark barrier
 103   static void mark_barrier_on_oop_field(volatile oop* p, bool finalizable);
 104   static void mark_barrier_on_oop_array(volatile oop* p, size_t length, bool finalizable);
 105   static void mark_barrier_on_root_oop_field(volatile oop* p);
 106 
 107   // Relocate barrier
 108   static void relocate_barrier_on_root_oop_field(volatile oop* p);
 109 
 110   // Narrow oop variants, never used.
 111   static oop  load_barrier_on_oop_field(volatile narrowOop* p);
 112   static oop  load_barrier_on_oop_field_preloaded(volatile narrowOop* p, oop o);
 113   static void load_barrier_on_oop_array(volatile narrowOop* p, size_t length);
 114   static oop  load_barrier_on_weak_oop_field_preloaded(volatile narrowOop* p, oop o);
 115   static oop  load_barrier_on_phantom_oop_field_preloaded(volatile narrowOop* p, oop o);
 116   static oop  weak_load_barrier_on_oop_field_preloaded(volatile narrowOop* p, oop o);
 117   static oop  weak_load_barrier_on_weak_oop_field_preloaded(volatile narrowOop* p, oop o);
 118   static oop  weak_load_barrier_on_phantom_oop_field_preloaded(volatile narrowOop* p, oop o);
 119 };
 120 
 121 #endif // SHARE_GC_Z_ZBARRIER_HPP