1 /* 2 * Copyright (c) 2001, 2010, 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 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_BUFFERINGOOPCLOSURE_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_BUFFERINGOOPCLOSURE_HPP 27 28 #include "memory/genOopClosures.hpp" 29 #include "memory/generation.hpp" 30 #include "runtime/os.hpp" 31 #include "utilities/taskqueue.hpp" 32 33 // A BufferingOops closure tries to separate out the cost of finding roots 34 // from the cost of applying closures to them. It maintains an array of 35 // ref-containing locations. Until the array is full, applying the closure 36 // to an oop* merely records that location in the array. Since this 37 // closure app cost is small, an elapsed timer can approximately attribute 38 // all of this cost to the cost of finding the roots. When the array fills 39 // up, the wrapped closure is applied to all elements, keeping track of 40 // this elapsed time of this process, and leaving the array empty. 41 // The caller must be sure to call "done" to process any unprocessed 42 // buffered entriess. 43 44 class Generation; 45 class HeapRegion; 46 47 class BufferingOopClosure: public OopClosure { 48 protected: 49 enum PrivateConstants { 50 BufferLength = 1024 51 }; 52 53 StarTask _buffer[BufferLength]; 54 StarTask* _buffer_top; 55 StarTask* _buffer_curr; 56 57 OopClosure* _oc; 58 double _closure_app_seconds; 59 60 void process_buffer () { 61 double start = os::elapsedTime(); 62 for (StarTask* curr = _buffer; curr < _buffer_curr; ++curr) { 63 if (curr->is_narrow()) { 64 assert(UseCompressedOops, "Error"); 65 _oc->do_oop((narrowOop*)(*curr)); 66 } else { 67 _oc->do_oop((oop*)(*curr)); 68 } 69 } 70 _buffer_curr = _buffer; 71 _closure_app_seconds += (os::elapsedTime() - start); 72 } 73 74 template <class T> inline void do_oop_work(T* p) { 75 if (_buffer_curr == _buffer_top) { 76 process_buffer(); 77 } 78 StarTask new_ref(p); 79 *_buffer_curr = new_ref; 80 ++_buffer_curr; 81 } 82 83 public: 84 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 85 virtual void do_oop(oop* p) { do_oop_work(p); } 86 87 void done () { 88 if (_buffer_curr > _buffer) { 89 process_buffer(); 90 } 91 } 92 double closure_app_seconds () { 93 return _closure_app_seconds; 94 } 95 BufferingOopClosure (OopClosure *oc) : 96 _oc(oc), 97 _buffer_curr(_buffer), _buffer_top(_buffer + BufferLength), 98 _closure_app_seconds(0.0) { } 99 }; 100 101 class BufferingOopsInGenClosure: public OopsInGenClosure { 102 BufferingOopClosure _boc; 103 OopsInGenClosure* _oc; 104 protected: 105 template <class T> inline void do_oop_work(T* p) { 106 assert(generation()->is_in_reserved((void*)p), "Must be in!"); 107 _boc.do_oop(p); 108 } 109 public: 110 BufferingOopsInGenClosure(OopsInGenClosure *oc) : 111 _boc(oc), _oc(oc) {} 112 113 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 114 virtual void do_oop(oop* p) { do_oop_work(p); } 115 116 void done() { 117 _boc.done(); 118 } 119 120 double closure_app_seconds () { 121 return _boc.closure_app_seconds(); 122 } 123 124 void set_generation(Generation* gen) { 125 OopsInGenClosure::set_generation(gen); 126 _oc->set_generation(gen); 127 } 128 129 void reset_generation() { 130 // Make sure we finish the current work with the current generation. 131 _boc.done(); 132 OopsInGenClosure::reset_generation(); 133 _oc->reset_generation(); 134 } 135 136 }; 137 138 139 class BufferingOopsInHeapRegionClosure: public OopsInHeapRegionClosure { 140 private: 141 enum PrivateConstants { 142 BufferLength = 1024 143 }; 144 145 StarTask _buffer[BufferLength]; 146 StarTask* _buffer_top; 147 StarTask* _buffer_curr; 148 149 HeapRegion* _hr_buffer[BufferLength]; 150 HeapRegion** _hr_curr; 151 152 OopsInHeapRegionClosure* _oc; 153 double _closure_app_seconds; 154 155 void process_buffer () { 156 157 assert((_hr_curr - _hr_buffer) == (_buffer_curr - _buffer), 158 "the two lengths should be the same"); 159 160 double start = os::elapsedTime(); 161 HeapRegion** hr_curr = _hr_buffer; 162 HeapRegion* hr_prev = NULL; 163 for (StarTask* curr = _buffer; curr < _buffer_curr; ++curr) { 164 HeapRegion* region = *hr_curr; 165 if (region != hr_prev) { 166 _oc->set_region(region); 167 hr_prev = region; 168 } 169 if (curr->is_narrow()) { 170 assert(UseCompressedOops, "Error"); 171 _oc->do_oop((narrowOop*)(*curr)); 172 } else { 173 _oc->do_oop((oop*)(*curr)); 174 } 175 ++hr_curr; 176 } 177 _buffer_curr = _buffer; 178 _hr_curr = _hr_buffer; 179 _closure_app_seconds += (os::elapsedTime() - start); 180 } 181 182 public: 183 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 184 virtual void do_oop( oop* p) { do_oop_work(p); } 185 186 template <class T> void do_oop_work(T* p) { 187 if (_buffer_curr == _buffer_top) { 188 assert(_hr_curr > _hr_buffer, "_hr_curr should be consistent with _buffer_curr"); 189 process_buffer(); 190 } 191 StarTask new_ref(p); 192 *_buffer_curr = new_ref; 193 ++_buffer_curr; 194 *_hr_curr = _from; 195 ++_hr_curr; 196 } 197 void done () { 198 if (_buffer_curr > _buffer) { 199 assert(_hr_curr > _hr_buffer, "_hr_curr should be consistent with _buffer_curr"); 200 process_buffer(); 201 } 202 } 203 double closure_app_seconds () { 204 return _closure_app_seconds; 205 } 206 BufferingOopsInHeapRegionClosure (OopsInHeapRegionClosure *oc) : 207 _oc(oc), 208 _buffer_curr(_buffer), _buffer_top(_buffer + BufferLength), 209 _hr_curr(_hr_buffer), 210 _closure_app_seconds(0.0) { } 211 }; 212 213 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_BUFFERINGOOPCLOSURE_HPP