Mercurial > hg > truffle
annotate src/share/vm/memory/barrierSet.hpp @ 196:d1605aabd0a1 jdk7-b30
6719955: Update copyright year
Summary: Update copyright year for files that have been modified in 2008
Reviewed-by: ohair, tbell
| author | xdono |
|---|---|
| date | Wed, 02 Jul 2008 12:55:16 -0700 |
| parents | ba764ed4b6f2 |
| children | 1ee8caae33af |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 196 | 2 * Copyright 2000-2008 Sun Microsystems, Inc. All Rights Reserved. |
| 0 | 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
| 20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
| 21 * have any questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 // This class provides the interface between a barrier implementation and | |
| 26 // the rest of the system. | |
| 27 | |
| 28 class BarrierSet: public CHeapObj { | |
| 29 friend class VMStructs; | |
| 30 public: | |
| 31 enum Name { | |
| 32 ModRef, | |
| 33 CardTableModRef, | |
| 34 CardTableExtension, | |
| 35 Other, | |
| 36 Uninit | |
| 37 }; | |
| 38 | |
| 39 protected: | |
| 40 int _max_covered_regions; | |
| 41 Name _kind; | |
| 42 | |
| 43 public: | |
| 44 | |
| 45 // To get around prohibition on RTTI. | |
| 46 virtual BarrierSet::Name kind() { return _kind; } | |
| 47 virtual bool is_a(BarrierSet::Name bsn) = 0; | |
| 48 | |
| 49 // These operations indicate what kind of barriers the BarrierSet has. | |
| 50 virtual bool has_read_ref_barrier() = 0; | |
| 51 virtual bool has_read_prim_barrier() = 0; | |
| 52 virtual bool has_write_ref_barrier() = 0; | |
| 53 virtual bool has_write_prim_barrier() = 0; | |
| 54 | |
| 55 // These functions indicate whether a particular access of the given | |
| 56 // kinds requires a barrier. | |
|
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57 virtual bool read_ref_needs_barrier(void* field) = 0; |
| 0 | 58 virtual bool read_prim_needs_barrier(HeapWord* field, size_t bytes) = 0; |
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59 virtual bool write_ref_needs_barrier(void* field, oop new_val) = 0; |
| 0 | 60 virtual bool write_prim_needs_barrier(HeapWord* field, size_t bytes, juint val1, juint val2) = 0; |
| 61 | |
| 62 // The first four operations provide a direct implementation of the | |
| 63 // barrier set. An interpreter loop, for example, could call these | |
| 64 // directly, as appropriate. | |
| 65 | |
| 66 // Invoke the barrier, if any, necessary when reading the given ref field. | |
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67 virtual void read_ref_field(void* field) = 0; |
| 0 | 68 |
| 69 // Invoke the barrier, if any, necessary when reading the given primitive | |
| 70 // "field" of "bytes" bytes in "obj". | |
| 71 virtual void read_prim_field(HeapWord* field, size_t bytes) = 0; | |
| 72 | |
| 73 // Invoke the barrier, if any, necessary when writing "new_val" into the | |
| 74 // ref field at "offset" in "obj". | |
| 75 // (For efficiency reasons, this operation is specialized for certain | |
| 76 // barrier types. Semantically, it should be thought of as a call to the | |
| 77 // virtual "_work" function below, which must implement the barrier.) | |
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78 inline void write_ref_field(void* field, oop new_val); |
| 0 | 79 protected: |
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80 virtual void write_ref_field_work(void* field, oop new_val) = 0; |
| 0 | 81 public: |
| 82 | |
| 83 // Invoke the barrier, if any, necessary when writing the "bytes"-byte | |
| 84 // value(s) "val1" (and "val2") into the primitive "field". | |
| 85 virtual void write_prim_field(HeapWord* field, size_t bytes, | |
| 86 juint val1, juint val2) = 0; | |
| 87 | |
| 88 // Operations on arrays, or general regions (e.g., for "clone") may be | |
| 89 // optimized by some barriers. | |
| 90 | |
| 91 // The first six operations tell whether such an optimization exists for | |
| 92 // the particular barrier. | |
| 93 virtual bool has_read_ref_array_opt() = 0; | |
| 94 virtual bool has_read_prim_array_opt() = 0; | |
| 95 virtual bool has_write_ref_array_opt() = 0; | |
| 96 virtual bool has_write_prim_array_opt() = 0; | |
| 97 | |
| 98 virtual bool has_read_region_opt() = 0; | |
| 99 virtual bool has_write_region_opt() = 0; | |
| 100 | |
| 101 // These operations should assert false unless the correponding operation | |
| 102 // above returns true. Otherwise, they should perform an appropriate | |
| 103 // barrier for an array whose elements are all in the given memory region. | |
| 104 virtual void read_ref_array(MemRegion mr) = 0; | |
| 105 virtual void read_prim_array(MemRegion mr) = 0; | |
| 106 | |
| 107 inline void write_ref_array(MemRegion mr); | |
| 108 protected: | |
| 109 virtual void write_ref_array_work(MemRegion mr) = 0; | |
| 110 public: | |
| 111 virtual void write_prim_array(MemRegion mr) = 0; | |
| 112 | |
| 113 virtual void read_region(MemRegion mr) = 0; | |
| 114 | |
| 115 // (For efficiency reasons, this operation is specialized for certain | |
| 116 // barrier types. Semantically, it should be thought of as a call to the | |
| 117 // virtual "_work" function below, which must implement the barrier.) | |
| 118 inline void write_region(MemRegion mr); | |
| 119 protected: | |
| 120 virtual void write_region_work(MemRegion mr) = 0; | |
| 121 public: | |
| 122 | |
| 123 // The remaining sets of operations are called by compilers or other code | |
| 124 // generators to insert barriers into generated code. There may be | |
| 125 // several such code generators; the signatures of these | |
| 126 // barrier-generating functions may differ from generator to generator. | |
| 127 // There will be a set of four function signatures for each code | |
| 128 // generator, which accomplish the generation of barriers of the four | |
| 129 // kinds listed above. | |
| 130 | |
| 131 #ifdef TBD | |
| 132 // Generates code to invoke the barrier, if any, necessary when reading | |
| 133 // the ref field at "offset" in "obj". | |
| 134 virtual void gen_read_ref_field() = 0; | |
| 135 | |
| 136 // Generates code to invoke the barrier, if any, necessary when reading | |
| 137 // the primitive field of "bytes" bytes at offset" in "obj". | |
| 138 virtual void gen_read_prim_field() = 0; | |
| 139 | |
| 140 // Generates code to invoke the barrier, if any, necessary when writing | |
| 141 // "new_val" into the ref field at "offset" in "obj". | |
| 142 virtual void gen_write_ref_field() = 0; | |
| 143 | |
| 144 // Generates code to invoke the barrier, if any, necessary when writing | |
| 145 // the "bytes"-byte value "new_val" into the primitive field at "offset" | |
| 146 // in "obj". | |
| 147 virtual void gen_write_prim_field() = 0; | |
| 148 #endif | |
| 149 | |
| 150 // Some barrier sets create tables whose elements correspond to parts of | |
| 151 // the heap; the CardTableModRefBS is an example. Such barrier sets will | |
| 152 // normally reserve space for such tables, and commit parts of the table | |
| 153 // "covering" parts of the heap that are committed. The constructor is | |
| 154 // passed the maximum number of independently committable subregions to | |
| 155 // be covered, and the "resize_covoered_region" function allows the | |
| 156 // sub-parts of the heap to inform the barrier set of changes of their | |
| 157 // sizes. | |
| 158 BarrierSet(int max_covered_regions) : | |
| 159 _max_covered_regions(max_covered_regions) {} | |
| 160 | |
| 161 // Inform the BarrierSet that the the covered heap region that starts | |
| 162 // with "base" has been changed to have the given size (possibly from 0, | |
| 163 // for initialization.) | |
| 164 virtual void resize_covered_region(MemRegion new_region) = 0; | |
| 165 | |
| 166 // If the barrier set imposes any alignment restrictions on boundaries | |
| 167 // within the heap, this function tells whether they are met. | |
| 168 virtual bool is_aligned(HeapWord* addr) = 0; | |
| 169 | |
| 170 }; |