1 /* 2 * Copyright (c) 2012, 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 #include "precompiled.hpp" 26 #include "gc_implementation/concurrentMarkSweep/adaptiveFreeList.hpp" 27 #include "gc_implementation/concurrentMarkSweep/freeChunk.hpp" 28 #include "memory/freeBlockDictionary.hpp" 29 #include "memory/sharedHeap.hpp" 30 #include "runtime/globals.hpp" 31 #include "runtime/mutex.hpp" 32 #include "runtime/vmThread.hpp" 33 34 template <> 35 void AdaptiveFreeList<FreeChunk>::print_on(outputStream* st, const char* c) const { 36 if (c != NULL) { 37 st->print("%16s", c); 38 } else { 39 st->print(SIZE_FORMAT_W(16), size()); 40 } 41 st->print("\t" 42 SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" 43 SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\n", 44 bfr_surp(), surplus(), desired(), prev_sweep(), before_sweep(), 45 count(), coal_births(), coal_deaths(), split_births(), split_deaths()); 46 } 47 48 template <class Chunk> 49 AdaptiveFreeList<Chunk>::AdaptiveFreeList() : FreeList<Chunk>(), _hint(0) { 50 init_statistics(); 51 } 52 53 template <class Chunk> 54 void AdaptiveFreeList<Chunk>::initialize() { 55 FreeList<Chunk>::initialize(); 56 set_hint(0); 57 init_statistics(true /* split_birth */); 58 } 59 60 template <class Chunk> 61 void AdaptiveFreeList<Chunk>::reset(size_t hint) { 62 FreeList<Chunk>::reset(); 63 set_hint(hint); 64 } 65 66 #ifndef PRODUCT 67 template <class Chunk> 68 void AdaptiveFreeList<Chunk>::assert_proper_lock_protection_work() const { 69 assert(protecting_lock() != NULL, "Don't call this directly"); 70 assert(ParallelGCThreads > 0, "Don't call this directly"); 71 Thread* thr = Thread::current(); 72 if (thr->is_VM_thread() || thr->is_ConcurrentGC_thread()) { 73 // assert that we are holding the freelist lock 74 } else if (thr->is_GC_task_thread()) { 75 assert(protecting_lock()->owned_by_self(), "FreeList RACE DETECTED"); 76 } else if (thr->is_Java_thread()) { 77 assert(!SafepointSynchronize::is_at_safepoint(), "Should not be executing"); 78 } else { 79 ShouldNotReachHere(); // unaccounted thread type? 80 } 81 } 82 #endif 83 template <class Chunk> 84 void AdaptiveFreeList<Chunk>::init_statistics(bool split_birth) { 85 _allocation_stats.initialize(split_birth); 86 } 87 88 template <class Chunk> 89 size_t AdaptiveFreeList<Chunk>::get_better_size() { 90 91 // A candidate chunk has been found. If it is already under 92 // populated and there is a hinT, REturn the hint(). Else 93 // return the size of this chunk. 94 if (surplus() <= 0) { 95 if (hint() != 0) { 96 return hint(); 97 } else { 98 return size(); 99 } 100 } else { 101 // This list has a surplus so use it. 102 return size(); 103 } 104 } 105 106 107 template <class Chunk> 108 void AdaptiveFreeList<Chunk>::return_chunk_at_head(Chunk* chunk) { 109 assert_proper_lock_protection(); 110 return_chunk_at_head(chunk, true); 111 } 112 113 template <class Chunk> 114 void AdaptiveFreeList<Chunk>::return_chunk_at_head(Chunk* chunk, bool record_return) { 115 FreeList<Chunk>::return_chunk_at_head(chunk, record_return); 116 #ifdef ASSERT 117 if (record_return) { 118 increment_returned_bytes_by(size()*HeapWordSize); 119 } 120 #endif 121 } 122 123 template <class Chunk> 124 void AdaptiveFreeList<Chunk>::return_chunk_at_tail(Chunk* chunk) { 125 return_chunk_at_tail(chunk, true); 126 } 127 128 template <class Chunk> 129 void AdaptiveFreeList<Chunk>::return_chunk_at_tail(Chunk* chunk, bool record_return) { 130 FreeList<Chunk>::return_chunk_at_tail(chunk, record_return); 131 #ifdef ASSERT 132 if (record_return) { 133 increment_returned_bytes_by(size()*HeapWordSize); 134 } 135 #endif 136 } 137 138 #ifndef PRODUCT 139 template <class Chunk> 140 void AdaptiveFreeList<Chunk>::verify_stats() const { 141 // The +1 of the LH comparand is to allow some "looseness" in 142 // checking: we usually call this interface when adding a block 143 // and we'll subsequently update the stats; we cannot update the 144 // stats beforehand because in the case of the large-block BT 145 // dictionary for example, this might be the first block and 146 // in that case there would be no place that we could record 147 // the stats (which are kept in the block itself). 148 assert((_allocation_stats.prev_sweep() + _allocation_stats.split_births() 149 + _allocation_stats.coal_births() + 1) // Total Production Stock + 1 150 >= (_allocation_stats.split_deaths() + _allocation_stats.coal_deaths() 151 + (ssize_t)count()), // Total Current Stock + depletion 152 err_msg("FreeList " PTR_FORMAT " of size " SIZE_FORMAT 153 " violates Conservation Principle: " 154 "prev_sweep(" SIZE_FORMAT ")" 155 " + split_births(" SIZE_FORMAT ")" 156 " + coal_births(" SIZE_FORMAT ") + 1 >= " 157 " split_deaths(" SIZE_FORMAT ")" 158 " coal_deaths(" SIZE_FORMAT ")" 159 " + count(" SSIZE_FORMAT ")", 160 this, size(), _allocation_stats.prev_sweep(), _allocation_stats.split_births(), 161 _allocation_stats.split_births(), _allocation_stats.split_deaths(), 162 _allocation_stats.coal_deaths(), count())); 163 } 164 #endif 165 166 // Needs to be after the definitions have been seen. 167 template class AdaptiveFreeList<FreeChunk>;