src/share/vm/gc_implementation/parNew/parGCAllocBuffer.hpp

Tue, 23 Nov 2010 13:22:55 -0800

author
stefank
date
Tue, 23 Nov 2010 13:22:55 -0800
changeset 2314
f95d63e2154a
parent 1907
c18cbe5936b8
child 2325
c760f78e0a53
permissions
-rw-r--r--

6989984: Use standard include model for Hospot
Summary: Replaced MakeDeps and the includeDB files with more standardized solutions.
Reviewed-by: coleenp, kvn, kamg

duke@435 1 /*
stefank@2314 2 * Copyright (c) 2001, 2010, 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_GC_IMPLEMENTATION_PARNEW_PARGCALLOCBUFFER_HPP
stefank@2314 26 #define SHARE_VM_GC_IMPLEMENTATION_PARNEW_PARGCALLOCBUFFER_HPP
stefank@2314 27
stefank@2314 28 #include "memory/allocation.hpp"
stefank@2314 29 #include "memory/threadLocalAllocBuffer.hpp"
stefank@2314 30 #include "utilities/globalDefinitions.hpp"
stefank@2314 31
duke@435 32 // Forward decl.
duke@435 33
duke@435 34 class PLABStats;
duke@435 35
duke@435 36 // A per-thread allocation buffer used during GC.
duke@435 37 class ParGCAllocBuffer: public CHeapObj {
duke@435 38 protected:
duke@435 39 char head[32];
duke@435 40 size_t _word_sz; // in HeapWord units
duke@435 41 HeapWord* _bottom;
duke@435 42 HeapWord* _top;
duke@435 43 HeapWord* _end; // last allocatable address + 1
duke@435 44 HeapWord* _hard_end; // _end + AlignmentReserve
duke@435 45 bool _retained; // whether we hold a _retained_filler
duke@435 46 MemRegion _retained_filler;
duke@435 47 // In support of ergonomic sizing of PLAB's
duke@435 48 size_t _allocated; // in HeapWord units
duke@435 49 size_t _wasted; // in HeapWord units
duke@435 50 char tail[32];
coleenp@548 51 static size_t FillerHeaderSize;
coleenp@548 52 static size_t AlignmentReserve;
duke@435 53
duke@435 54 public:
duke@435 55 // Initializes the buffer to be empty, but with the given "word_sz".
duke@435 56 // Must get initialized with "set_buf" for an allocation to succeed.
duke@435 57 ParGCAllocBuffer(size_t word_sz);
duke@435 58
duke@435 59 static const size_t min_size() {
duke@435 60 return ThreadLocalAllocBuffer::min_size();
duke@435 61 }
duke@435 62
duke@435 63 static const size_t max_size() {
duke@435 64 return ThreadLocalAllocBuffer::max_size();
duke@435 65 }
duke@435 66
duke@435 67 // If an allocation of the given "word_sz" can be satisfied within the
duke@435 68 // buffer, do the allocation, returning a pointer to the start of the
duke@435 69 // allocated block. If the allocation request cannot be satisfied,
duke@435 70 // return NULL.
duke@435 71 HeapWord* allocate(size_t word_sz) {
duke@435 72 HeapWord* res = _top;
ysr@1069 73 if (pointer_delta(_end, _top) >= word_sz) {
ysr@1069 74 _top = _top + word_sz;
duke@435 75 return res;
duke@435 76 } else {
duke@435 77 return NULL;
duke@435 78 }
duke@435 79 }
duke@435 80
duke@435 81 // Undo the last allocation in the buffer, which is required to be of the
duke@435 82 // "obj" of the given "word_sz".
duke@435 83 void undo_allocation(HeapWord* obj, size_t word_sz) {
ysr@1069 84 assert(pointer_delta(_top, _bottom) >= word_sz, "Bad undo");
ysr@1069 85 assert(pointer_delta(_top, obj) == word_sz, "Bad undo");
ysr@1069 86 _top = obj;
duke@435 87 }
duke@435 88
duke@435 89 // The total (word) size of the buffer, including both allocated and
duke@435 90 // unallocted space.
duke@435 91 size_t word_sz() { return _word_sz; }
duke@435 92
duke@435 93 // Should only be done if we are about to reset with a new buffer of the
duke@435 94 // given size.
duke@435 95 void set_word_size(size_t new_word_sz) {
duke@435 96 assert(new_word_sz > AlignmentReserve, "Too small");
duke@435 97 _word_sz = new_word_sz;
duke@435 98 }
duke@435 99
duke@435 100 // The number of words of unallocated space remaining in the buffer.
duke@435 101 size_t words_remaining() {
duke@435 102 assert(_end >= _top, "Negative buffer");
duke@435 103 return pointer_delta(_end, _top, HeapWordSize);
duke@435 104 }
duke@435 105
duke@435 106 bool contains(void* addr) {
duke@435 107 return (void*)_bottom <= addr && addr < (void*)_hard_end;
duke@435 108 }
duke@435 109
duke@435 110 // Sets the space of the buffer to be [buf, space+word_sz()).
duke@435 111 void set_buf(HeapWord* buf) {
duke@435 112 _bottom = buf;
duke@435 113 _top = _bottom;
duke@435 114 _hard_end = _bottom + word_sz();
duke@435 115 _end = _hard_end - AlignmentReserve;
duke@435 116 assert(_end >= _top, "Negative buffer");
duke@435 117 // In support of ergonomic sizing
duke@435 118 _allocated += word_sz();
duke@435 119 }
duke@435 120
duke@435 121 // Flush the stats supporting ergonomic sizing of PLAB's
duke@435 122 void flush_stats(PLABStats* stats);
duke@435 123 void flush_stats_and_retire(PLABStats* stats, bool retain) {
duke@435 124 // We flush the stats first in order to get a reading of
duke@435 125 // unused space in the last buffer.
duke@435 126 if (ResizePLAB) {
duke@435 127 flush_stats(stats);
duke@435 128 }
duke@435 129 // Retire the last allocation buffer.
duke@435 130 retire(true, retain);
duke@435 131 }
duke@435 132
duke@435 133 // Force future allocations to fail and queries for contains()
duke@435 134 // to return false
duke@435 135 void invalidate() {
duke@435 136 assert(!_retained, "Shouldn't retain an invalidated buffer.");
duke@435 137 _end = _hard_end;
duke@435 138 _wasted += pointer_delta(_end, _top); // unused space
duke@435 139 _top = _end; // force future allocations to fail
duke@435 140 _bottom = _end; // force future contains() queries to return false
duke@435 141 }
duke@435 142
duke@435 143 // Fills in the unallocated portion of the buffer with a garbage object.
duke@435 144 // If "end_of_gc" is TRUE, is after the last use in the GC. IF "retain"
duke@435 145 // is true, attempt to re-use the unused portion in the next GC.
duke@435 146 void retire(bool end_of_gc, bool retain);
duke@435 147
duke@435 148 void print() PRODUCT_RETURN;
duke@435 149 };
duke@435 150
duke@435 151 // PLAB stats book-keeping
duke@435 152 class PLABStats VALUE_OBJ_CLASS_SPEC {
duke@435 153 size_t _allocated; // total allocated
duke@435 154 size_t _wasted; // of which wasted (internal fragmentation)
duke@435 155 size_t _unused; // Unused in last buffer
duke@435 156 size_t _used; // derived = allocated - wasted - unused
duke@435 157 size_t _desired_plab_sz;// output of filter (below), suitably trimmed and quantized
duke@435 158 AdaptiveWeightedAverage
duke@435 159 _filter; // integrator with decay
duke@435 160
duke@435 161 public:
duke@435 162 PLABStats(size_t desired_plab_sz_, unsigned wt) :
duke@435 163 _allocated(0),
duke@435 164 _wasted(0),
duke@435 165 _unused(0),
duke@435 166 _used(0),
duke@435 167 _desired_plab_sz(desired_plab_sz_),
duke@435 168 _filter(wt)
duke@435 169 {
duke@435 170 size_t min_sz = min_size();
duke@435 171 size_t max_sz = max_size();
duke@435 172 size_t aligned_min_sz = align_object_size(min_sz);
duke@435 173 size_t aligned_max_sz = align_object_size(max_sz);
duke@435 174 assert(min_sz <= aligned_min_sz && max_sz >= aligned_max_sz &&
duke@435 175 min_sz <= max_sz,
duke@435 176 "PLAB clipping computation in adjust_desired_plab_sz()"
duke@435 177 " may be incorrect");
duke@435 178 }
duke@435 179
duke@435 180 static const size_t min_size() {
duke@435 181 return ParGCAllocBuffer::min_size();
duke@435 182 }
duke@435 183
duke@435 184 static const size_t max_size() {
duke@435 185 return ParGCAllocBuffer::max_size();
duke@435 186 }
duke@435 187
duke@435 188 size_t desired_plab_sz() {
duke@435 189 return _desired_plab_sz;
duke@435 190 }
duke@435 191
duke@435 192 void adjust_desired_plab_sz(); // filter computation, latches output to
duke@435 193 // _desired_plab_sz, clears sensor accumulators
duke@435 194
duke@435 195 void add_allocated(size_t v) {
duke@435 196 Atomic::add_ptr(v, &_allocated);
duke@435 197 }
duke@435 198
duke@435 199 void add_unused(size_t v) {
duke@435 200 Atomic::add_ptr(v, &_unused);
duke@435 201 }
duke@435 202
duke@435 203 void add_wasted(size_t v) {
duke@435 204 Atomic::add_ptr(v, &_wasted);
duke@435 205 }
duke@435 206 };
duke@435 207
duke@435 208 class ParGCAllocBufferWithBOT: public ParGCAllocBuffer {
duke@435 209 BlockOffsetArrayContigSpace _bt;
duke@435 210 BlockOffsetSharedArray* _bsa;
duke@435 211 HeapWord* _true_end; // end of the whole ParGCAllocBuffer
duke@435 212
duke@435 213 static const size_t ChunkSizeInWords;
duke@435 214 static const size_t ChunkSizeInBytes;
duke@435 215 HeapWord* allocate_slow(size_t word_sz);
duke@435 216
duke@435 217 void fill_region_with_block(MemRegion mr, bool contig);
duke@435 218
duke@435 219 public:
duke@435 220 ParGCAllocBufferWithBOT(size_t word_sz, BlockOffsetSharedArray* bsa);
duke@435 221
duke@435 222 HeapWord* allocate(size_t word_sz) {
duke@435 223 HeapWord* res = ParGCAllocBuffer::allocate(word_sz);
duke@435 224 if (res != NULL) {
duke@435 225 _bt.alloc_block(res, word_sz);
duke@435 226 } else {
duke@435 227 res = allocate_slow(word_sz);
duke@435 228 }
duke@435 229 return res;
duke@435 230 }
duke@435 231
duke@435 232 void undo_allocation(HeapWord* obj, size_t word_sz);
duke@435 233
duke@435 234 void set_buf(HeapWord* buf_start) {
duke@435 235 ParGCAllocBuffer::set_buf(buf_start);
duke@435 236 _true_end = _hard_end;
duke@435 237 _bt.set_region(MemRegion(buf_start, word_sz()));
duke@435 238 _bt.initialize_threshold();
duke@435 239 }
duke@435 240
duke@435 241 void retire(bool end_of_gc, bool retain);
duke@435 242
duke@435 243 MemRegion range() {
duke@435 244 return MemRegion(_top, _true_end);
duke@435 245 }
duke@435 246 };
stefank@2314 247
stefank@2314 248 #endif // SHARE_VM_GC_IMPLEMENTATION_PARNEW_PARGCALLOCBUFFER_HPP

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