1 /* 2 * Copyright (c) 2014, 2015, 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 25 #ifndef SHARE_VM_GC_G1_HEAPREGIONTYPE_HPP 26 #define SHARE_VM_GC_G1_HEAPREGIONTYPE_HPP 27 28 #include "gc/g1/g1HeapRegionTraceType.hpp" 29 #include "memory/allocation.hpp" 30 31 #define hrt_assert_is_valid(tag) \ 32 assert(is_valid((tag)), "invalid HR type: %u", (uint) (tag)) 33 34 class HeapRegionType VALUE_OBJ_CLASS_SPEC { 35 private: 36 // We encode the value of the heap region type so the generation can be 37 // determined quickly. The tag is split into two parts: 38 // 39 // major type (young, old, humongous, archive) : top N-1 bits 40 // minor type (eden / survivor, starts / cont hum, etc.) : bottom 1 bit 41 // 42 // If there's need to increase the number of minor types in the 43 // future, we'll have to increase the size of the latter and hence 44 // decrease the size of the former. 45 // 46 // 0000 0 [ 0] Free 47 // 48 // 0001 0 [ 2] Young Mask 49 // 0001 0 [ 2] Eden 50 // 0001 1 [ 3] Survivor 51 // 52 // 0010 0 [ 4] Humongous Mask 53 // 0100 0 [ 8] Pinned Mask 54 // 0110 0 [12] Starts Humongous 55 // 0110 1 [13] Continues Humongous 56 // 57 // 1000 0 [16] Old Mask 58 // 59 // 1100 0 [24] Archive 60 typedef enum { 61 FreeTag = 0, 62 63 YoungMask = 2, 64 EdenTag = YoungMask, 65 SurvTag = YoungMask + 1, 66 67 HumongousMask = 4, 68 PinnedMask = 8, 69 StartsHumongousTag = HumongousMask | PinnedMask, 70 ContinuesHumongousTag = HumongousMask | PinnedMask + 1, 71 72 OldMask = 16, 73 OldTag = OldMask, 74 75 ArchiveTag = PinnedMask | OldMask 76 } Tag; 77 78 volatile Tag _tag; 79 80 static bool is_valid(Tag tag); 81 82 Tag get() const { 83 hrt_assert_is_valid(_tag); 84 return _tag; 85 } 86 87 // Sets the type to 'tag'. 88 void set(Tag tag) { 89 hrt_assert_is_valid(tag); 90 hrt_assert_is_valid(_tag); 91 _tag = tag; 92 } 93 94 // Sets the type to 'tag', expecting the type to be 'before'. This 95 // is available for when we want to add sanity checking to the type 96 // transition. 97 void set_from(Tag tag, Tag before) { 98 hrt_assert_is_valid(tag); 99 hrt_assert_is_valid(before); 100 hrt_assert_is_valid(_tag); 101 assert(_tag == before, "HR tag: %u, expected: %u new tag; %u", _tag, before, tag); 102 _tag = tag; 103 } 104 105 public: 106 // Queries 107 108 bool is_free() const { return get() == FreeTag; } 109 110 bool is_young() const { return (get() & YoungMask) != 0; } 111 bool is_eden() const { return get() == EdenTag; } 112 bool is_survivor() const { return get() == SurvTag; } 113 114 bool is_humongous() const { return (get() & HumongousMask) != 0; } 115 bool is_starts_humongous() const { return get() == StartsHumongousTag; } 116 bool is_continues_humongous() const { return get() == ContinuesHumongousTag; } 117 118 bool is_archive() const { return get() == ArchiveTag; } 119 120 // is_old regions may or may not also be pinned 121 bool is_old() const { return (get() & OldMask) != 0; } 122 123 // is_pinned regions may be archive or humongous 124 bool is_pinned() const { return (get() & PinnedMask) != 0; } 125 126 // Setters 127 128 void set_free() { set(FreeTag); } 129 130 void set_eden() { set_from(EdenTag, FreeTag); } 131 void set_eden_pre_gc() { set_from(EdenTag, SurvTag); } 132 void set_survivor() { set_from(SurvTag, FreeTag); } 133 134 void set_starts_humongous() { set_from(StartsHumongousTag, FreeTag); } 135 void set_continues_humongous() { set_from(ContinuesHumongousTag, FreeTag); } 136 137 void set_old() { set(OldTag); } 138 139 void set_archive() { set_from(ArchiveTag, FreeTag); } 140 141 // Misc 142 143 const char* get_str() const; 144 const char* get_short_str() const; 145 G1HeapRegionTraceType::Type get_trace_type(); 146 147 HeapRegionType() : _tag(FreeTag) { hrt_assert_is_valid(_tag); } 148 }; 149 150 #endif // SHARE_VM_GC_G1_HEAPREGIONTYPE_HPP