Thu, 13 Jun 2013 22:02:40 -0700
8014431: cleanup warnings indicated by the -Wunused-value compiler option on linux
Reviewed-by: dholmes, coleenp
Contributed-by: jeremymanson@google.com, calvin.cheung@oracle.com
duke@435 | 1 | /* |
coleenp@4037 | 2 | * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
trims@1907 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
trims@1907 | 20 | * or visit www.oracle.com if you need additional information or have any |
trims@1907 | 21 | * questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
stefank@2314 | 25 | #ifndef SHARE_VM_MEMORY_GENREMSET_HPP |
stefank@2314 | 26 | #define SHARE_VM_MEMORY_GENREMSET_HPP |
stefank@2314 | 27 | |
stefank@2314 | 28 | #include "oops/oop.hpp" |
stefank@2314 | 29 | |
duke@435 | 30 | // A GenRemSet provides ways of iterating over pointers accross generations. |
duke@435 | 31 | // (This is especially useful for older-to-younger.) |
duke@435 | 32 | |
duke@435 | 33 | class Generation; |
duke@435 | 34 | class BarrierSet; |
duke@435 | 35 | class OopsInGenClosure; |
duke@435 | 36 | class CardTableRS; |
duke@435 | 37 | |
coleenp@4037 | 38 | // Helper to remember modified oops in all klasses. |
coleenp@4037 | 39 | class KlassRemSet { |
coleenp@4037 | 40 | bool _accumulate_modified_oops; |
coleenp@4037 | 41 | public: |
coleenp@4037 | 42 | KlassRemSet() : _accumulate_modified_oops(false) {} |
coleenp@4037 | 43 | void set_accumulate_modified_oops(bool value) { _accumulate_modified_oops = value; } |
coleenp@4037 | 44 | bool accumulate_modified_oops() { return _accumulate_modified_oops; } |
coleenp@4037 | 45 | bool mod_union_is_clear(); |
coleenp@4037 | 46 | void clear_mod_union(); |
coleenp@4037 | 47 | }; |
coleenp@4037 | 48 | |
zgu@3900 | 49 | class GenRemSet: public CHeapObj<mtGC> { |
duke@435 | 50 | friend class Generation; |
duke@435 | 51 | |
duke@435 | 52 | BarrierSet* _bs; |
coleenp@4037 | 53 | KlassRemSet _klass_rem_set; |
duke@435 | 54 | |
duke@435 | 55 | public: |
duke@435 | 56 | enum Name { |
duke@435 | 57 | CardTable, |
duke@435 | 58 | Other |
duke@435 | 59 | }; |
duke@435 | 60 | |
duke@435 | 61 | GenRemSet(BarrierSet * bs) : _bs(bs) {} |
ysr@777 | 62 | GenRemSet() : _bs(NULL) {} |
duke@435 | 63 | |
duke@435 | 64 | virtual Name rs_kind() = 0; |
duke@435 | 65 | |
duke@435 | 66 | // These are for dynamic downcasts. Unfortunately that it names the |
duke@435 | 67 | // possible subtypes (but not that they are subtypes!) Return NULL if |
duke@435 | 68 | // the cast is invalide. |
duke@435 | 69 | virtual CardTableRS* as_CardTableRS() { return NULL; } |
duke@435 | 70 | |
duke@435 | 71 | // Return the barrier set associated with "this." |
duke@435 | 72 | BarrierSet* bs() { return _bs; } |
duke@435 | 73 | |
ysr@777 | 74 | // Set the barrier set. |
ysr@777 | 75 | void set_bs(BarrierSet* bs) { _bs = bs; } |
ysr@777 | 76 | |
coleenp@4037 | 77 | KlassRemSet* klass_rem_set() { return &_klass_rem_set; } |
coleenp@4037 | 78 | |
duke@435 | 79 | // Do any (sequential) processing necessary to prepare for (possibly |
duke@435 | 80 | // "parallel", if that arg is true) calls to younger_refs_iterate. |
duke@435 | 81 | virtual void prepare_for_younger_refs_iterate(bool parallel) = 0; |
duke@435 | 82 | |
duke@435 | 83 | // Apply the "do_oop" method of "blk" to (exactly) all oop locations |
duke@435 | 84 | // 1) that are in objects allocated in "g" at the time of the last call |
duke@435 | 85 | // to "save_Marks", and |
duke@435 | 86 | // 2) that point to objects in younger generations. |
duke@435 | 87 | virtual void younger_refs_iterate(Generation* g, OopsInGenClosure* blk) = 0; |
duke@435 | 88 | |
duke@435 | 89 | virtual void younger_refs_in_space_iterate(Space* sp, |
duke@435 | 90 | OopsInGenClosure* cl) = 0; |
duke@435 | 91 | |
duke@435 | 92 | // This method is used to notify the remembered set that "new_val" has |
duke@435 | 93 | // been written into "field" by the garbage collector. |
coleenp@548 | 94 | void write_ref_field_gc(void* field, oop new_val); |
duke@435 | 95 | protected: |
coleenp@548 | 96 | virtual void write_ref_field_gc_work(void* field, oop new_val) = 0; |
duke@435 | 97 | public: |
duke@435 | 98 | |
duke@435 | 99 | // A version of the above suitable for use by parallel collectors. |
coleenp@548 | 100 | virtual void write_ref_field_gc_par(void* field, oop new_val) = 0; |
duke@435 | 101 | |
duke@435 | 102 | // Resize one of the regions covered by the remembered set. |
duke@435 | 103 | virtual void resize_covered_region(MemRegion new_region) = 0; |
duke@435 | 104 | |
duke@435 | 105 | // If the rem set imposes any alignment restrictions on boundaries |
duke@435 | 106 | // within the heap, this function tells whether they are met. |
duke@435 | 107 | virtual bool is_aligned(HeapWord* addr) = 0; |
duke@435 | 108 | |
duke@435 | 109 | // If the RS (or BS) imposes an aligment constraint on maximum heap size. |
duke@435 | 110 | // (This must be static, and dispatch on "nm", because it is called |
duke@435 | 111 | // before an RS is created.) |
duke@435 | 112 | static uintx max_alignment_constraint(Name nm); |
duke@435 | 113 | |
duke@435 | 114 | virtual void verify() = 0; |
duke@435 | 115 | |
duke@435 | 116 | // Verify that the remembered set has no entries for |
jmasa@441 | 117 | // the heap interval denoted by mr. If there are any |
jmasa@441 | 118 | // alignment constraints on the remembered set, only the |
jmasa@441 | 119 | // part of the region that is aligned is checked. |
jmasa@441 | 120 | // |
jmasa@441 | 121 | // alignment boundaries |
jmasa@441 | 122 | // +--------+-------+--------+-------+ |
jmasa@441 | 123 | // [ region mr ) |
jmasa@441 | 124 | // [ part checked ) |
jmasa@441 | 125 | virtual void verify_aligned_region_empty(MemRegion mr) = 0; |
duke@435 | 126 | |
duke@435 | 127 | // If appropriate, print some information about the remset on "tty". |
duke@435 | 128 | virtual void print() {} |
duke@435 | 129 | |
duke@435 | 130 | // Informs the RS that the given memregion contains no references to |
duke@435 | 131 | // younger generations. |
duke@435 | 132 | virtual void clear(MemRegion mr) = 0; |
duke@435 | 133 | |
duke@435 | 134 | // Informs the RS that there are no references to generations |
duke@435 | 135 | // younger than gen from generations gen and older. |
duke@435 | 136 | // The parameter clear_perm indicates if the perm_gen's |
duke@435 | 137 | // remembered set should also be processed/cleared. |
coleenp@4037 | 138 | virtual void clear_into_younger(Generation* gen) = 0; |
duke@435 | 139 | |
duke@435 | 140 | // Informs the RS that refs in the given "mr" may have changed |
duke@435 | 141 | // arbitrarily, and therefore may contain old-to-young pointers. |
ysr@777 | 142 | // If "whole heap" is true, then this invalidation is part of an |
ysr@777 | 143 | // invalidation of the whole heap, which an implementation might |
ysr@777 | 144 | // handle differently than that of a sub-part of the heap. |
ysr@777 | 145 | virtual void invalidate(MemRegion mr, bool whole_heap = false) = 0; |
duke@435 | 146 | |
duke@435 | 147 | // Informs the RS that refs in this generation |
duke@435 | 148 | // may have changed arbitrarily, and therefore may contain |
duke@435 | 149 | // old-to-young pointers in arbitrary locations. The parameter |
duke@435 | 150 | // younger indicates if the same should be done for younger generations |
duke@435 | 151 | // as well. The parameter perm indicates if the same should be done for |
duke@435 | 152 | // perm gen as well. |
coleenp@4037 | 153 | virtual void invalidate_or_clear(Generation* gen, bool younger) = 0; |
duke@435 | 154 | }; |
stefank@2314 | 155 | |
stefank@2314 | 156 | #endif // SHARE_VM_MEMORY_GENREMSET_HPP |