Mercurial > hg > truffle
annotate src/share/vm/gc_implementation/parNew/parGCAllocBuffer.hpp @ 113:ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
Summary: Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv
Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold
| author | coleenp |
|---|---|
| date | Sun, 13 Apr 2008 17:43:42 -0400 |
| parents | a61af66fc99e |
| children | d1605aabd0a1 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 * Copyright 2001-2006 Sun Microsystems, Inc. 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 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 // Forward decl. | |
| 26 | |
| 27 class PLABStats; | |
| 28 | |
| 29 // A per-thread allocation buffer used during GC. | |
| 30 class ParGCAllocBuffer: public CHeapObj { | |
| 31 protected: | |
| 32 char head[32]; | |
| 33 size_t _word_sz; // in HeapWord units | |
| 34 HeapWord* _bottom; | |
| 35 HeapWord* _top; | |
| 36 HeapWord* _end; // last allocatable address + 1 | |
| 37 HeapWord* _hard_end; // _end + AlignmentReserve | |
| 38 bool _retained; // whether we hold a _retained_filler | |
| 39 MemRegion _retained_filler; | |
| 40 // In support of ergonomic sizing of PLAB's | |
| 41 size_t _allocated; // in HeapWord units | |
| 42 size_t _wasted; // in HeapWord units | |
| 43 char tail[32]; | |
|
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ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
44 static size_t FillerHeaderSize; |
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ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
45 static size_t AlignmentReserve; |
| 0 | 46 |
| 47 public: | |
| 48 // Initializes the buffer to be empty, but with the given "word_sz". | |
| 49 // Must get initialized with "set_buf" for an allocation to succeed. | |
| 50 ParGCAllocBuffer(size_t word_sz); | |
| 51 | |
| 52 static const size_t min_size() { | |
| 53 return ThreadLocalAllocBuffer::min_size(); | |
| 54 } | |
| 55 | |
| 56 static const size_t max_size() { | |
| 57 return ThreadLocalAllocBuffer::max_size(); | |
| 58 } | |
| 59 | |
| 60 // If an allocation of the given "word_sz" can be satisfied within the | |
| 61 // buffer, do the allocation, returning a pointer to the start of the | |
| 62 // allocated block. If the allocation request cannot be satisfied, | |
| 63 // return NULL. | |
| 64 HeapWord* allocate(size_t word_sz) { | |
| 65 HeapWord* res = _top; | |
| 66 HeapWord* new_top = _top + word_sz; | |
| 67 if (new_top <= _end) { | |
| 68 _top = new_top; | |
| 69 return res; | |
| 70 } else { | |
| 71 return NULL; | |
| 72 } | |
| 73 } | |
| 74 | |
| 75 // Undo the last allocation in the buffer, which is required to be of the | |
| 76 // "obj" of the given "word_sz". | |
| 77 void undo_allocation(HeapWord* obj, size_t word_sz) { | |
| 78 assert(_top - word_sz >= _bottom | |
| 79 && _top - word_sz == obj, | |
| 80 "Bad undo_allocation"); | |
| 81 _top = _top - word_sz; | |
| 82 } | |
| 83 | |
| 84 // The total (word) size of the buffer, including both allocated and | |
| 85 // unallocted space. | |
| 86 size_t word_sz() { return _word_sz; } | |
| 87 | |
| 88 // Should only be done if we are about to reset with a new buffer of the | |
| 89 // given size. | |
| 90 void set_word_size(size_t new_word_sz) { | |
| 91 assert(new_word_sz > AlignmentReserve, "Too small"); | |
| 92 _word_sz = new_word_sz; | |
| 93 } | |
| 94 | |
| 95 // The number of words of unallocated space remaining in the buffer. | |
| 96 size_t words_remaining() { | |
| 97 assert(_end >= _top, "Negative buffer"); | |
| 98 return pointer_delta(_end, _top, HeapWordSize); | |
| 99 } | |
| 100 | |
| 101 bool contains(void* addr) { | |
| 102 return (void*)_bottom <= addr && addr < (void*)_hard_end; | |
| 103 } | |
| 104 | |
| 105 // Sets the space of the buffer to be [buf, space+word_sz()). | |
| 106 void set_buf(HeapWord* buf) { | |
| 107 _bottom = buf; | |
| 108 _top = _bottom; | |
| 109 _hard_end = _bottom + word_sz(); | |
| 110 _end = _hard_end - AlignmentReserve; | |
| 111 assert(_end >= _top, "Negative buffer"); | |
| 112 // In support of ergonomic sizing | |
| 113 _allocated += word_sz(); | |
| 114 } | |
| 115 | |
| 116 // Flush the stats supporting ergonomic sizing of PLAB's | |
| 117 void flush_stats(PLABStats* stats); | |
| 118 void flush_stats_and_retire(PLABStats* stats, bool retain) { | |
| 119 // We flush the stats first in order to get a reading of | |
| 120 // unused space in the last buffer. | |
| 121 if (ResizePLAB) { | |
| 122 flush_stats(stats); | |
| 123 } | |
| 124 // Retire the last allocation buffer. | |
| 125 retire(true, retain); | |
| 126 } | |
| 127 | |
| 128 // Force future allocations to fail and queries for contains() | |
| 129 // to return false | |
| 130 void invalidate() { | |
| 131 assert(!_retained, "Shouldn't retain an invalidated buffer."); | |
| 132 _end = _hard_end; | |
| 133 _wasted += pointer_delta(_end, _top); // unused space | |
| 134 _top = _end; // force future allocations to fail | |
| 135 _bottom = _end; // force future contains() queries to return false | |
| 136 } | |
| 137 | |
| 138 // Fills in the unallocated portion of the buffer with a garbage object. | |
| 139 // If "end_of_gc" is TRUE, is after the last use in the GC. IF "retain" | |
| 140 // is true, attempt to re-use the unused portion in the next GC. | |
| 141 void retire(bool end_of_gc, bool retain); | |
| 142 | |
| 143 void print() PRODUCT_RETURN; | |
| 144 }; | |
| 145 | |
| 146 // PLAB stats book-keeping | |
| 147 class PLABStats VALUE_OBJ_CLASS_SPEC { | |
| 148 size_t _allocated; // total allocated | |
| 149 size_t _wasted; // of which wasted (internal fragmentation) | |
| 150 size_t _unused; // Unused in last buffer | |
| 151 size_t _used; // derived = allocated - wasted - unused | |
| 152 size_t _desired_plab_sz;// output of filter (below), suitably trimmed and quantized | |
| 153 AdaptiveWeightedAverage | |
| 154 _filter; // integrator with decay | |
| 155 | |
| 156 public: | |
| 157 PLABStats(size_t desired_plab_sz_, unsigned wt) : | |
| 158 _allocated(0), | |
| 159 _wasted(0), | |
| 160 _unused(0), | |
| 161 _used(0), | |
| 162 _desired_plab_sz(desired_plab_sz_), | |
| 163 _filter(wt) | |
| 164 { | |
| 165 size_t min_sz = min_size(); | |
| 166 size_t max_sz = max_size(); | |
| 167 size_t aligned_min_sz = align_object_size(min_sz); | |
| 168 size_t aligned_max_sz = align_object_size(max_sz); | |
| 169 assert(min_sz <= aligned_min_sz && max_sz >= aligned_max_sz && | |
| 170 min_sz <= max_sz, | |
| 171 "PLAB clipping computation in adjust_desired_plab_sz()" | |
| 172 " may be incorrect"); | |
| 173 } | |
| 174 | |
| 175 static const size_t min_size() { | |
| 176 return ParGCAllocBuffer::min_size(); | |
| 177 } | |
| 178 | |
| 179 static const size_t max_size() { | |
| 180 return ParGCAllocBuffer::max_size(); | |
| 181 } | |
| 182 | |
| 183 size_t desired_plab_sz() { | |
| 184 return _desired_plab_sz; | |
| 185 } | |
| 186 | |
| 187 void adjust_desired_plab_sz(); // filter computation, latches output to | |
| 188 // _desired_plab_sz, clears sensor accumulators | |
| 189 | |
| 190 void add_allocated(size_t v) { | |
| 191 Atomic::add_ptr(v, &_allocated); | |
| 192 } | |
| 193 | |
| 194 void add_unused(size_t v) { | |
| 195 Atomic::add_ptr(v, &_unused); | |
| 196 } | |
| 197 | |
| 198 void add_wasted(size_t v) { | |
| 199 Atomic::add_ptr(v, &_wasted); | |
| 200 } | |
| 201 }; | |
| 202 | |
| 203 class ParGCAllocBufferWithBOT: public ParGCAllocBuffer { | |
| 204 BlockOffsetArrayContigSpace _bt; | |
| 205 BlockOffsetSharedArray* _bsa; | |
| 206 HeapWord* _true_end; // end of the whole ParGCAllocBuffer | |
| 207 | |
| 208 static const size_t ChunkSizeInWords; | |
| 209 static const size_t ChunkSizeInBytes; | |
| 210 HeapWord* allocate_slow(size_t word_sz); | |
| 211 | |
| 212 void fill_region_with_block(MemRegion mr, bool contig); | |
| 213 | |
| 214 public: | |
| 215 ParGCAllocBufferWithBOT(size_t word_sz, BlockOffsetSharedArray* bsa); | |
| 216 | |
| 217 HeapWord* allocate(size_t word_sz) { | |
| 218 HeapWord* res = ParGCAllocBuffer::allocate(word_sz); | |
| 219 if (res != NULL) { | |
| 220 _bt.alloc_block(res, word_sz); | |
| 221 } else { | |
| 222 res = allocate_slow(word_sz); | |
| 223 } | |
| 224 return res; | |
| 225 } | |
| 226 | |
| 227 void undo_allocation(HeapWord* obj, size_t word_sz); | |
| 228 | |
| 229 void set_buf(HeapWord* buf_start) { | |
| 230 ParGCAllocBuffer::set_buf(buf_start); | |
| 231 _true_end = _hard_end; | |
| 232 _bt.set_region(MemRegion(buf_start, word_sz())); | |
| 233 _bt.initialize_threshold(); | |
| 234 } | |
| 235 | |
| 236 void retire(bool end_of_gc, bool retain); | |
| 237 | |
| 238 MemRegion range() { | |
| 239 return MemRegion(_top, _true_end); | |
| 240 } | |
| 241 }; |