Thu, 07 Aug 2014 22:28:53 +0200
8054341: Remove some obsolete code in G1CollectedHeap class
Summary: Remove dead code.
Reviewed-by: stefank, brutisso
tschatzl@6937 | 1 | /* |
tschatzl@6937 | 2 | * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. |
tschatzl@6937 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
tschatzl@6937 | 4 | * |
tschatzl@6937 | 5 | * This code is free software; you can redistribute it and/or modify it |
tschatzl@6937 | 6 | * under the terms of the GNU General Public License version 2 only, as |
tschatzl@6937 | 7 | * published by the Free Software Foundation. |
tschatzl@6937 | 8 | * |
tschatzl@6937 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
tschatzl@6937 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
tschatzl@6937 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
tschatzl@6937 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
tschatzl@6937 | 13 | * accompanied this code). |
tschatzl@6937 | 14 | * |
tschatzl@6937 | 15 | * You should have received a copy of the GNU General Public License version |
tschatzl@6937 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
tschatzl@6937 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
tschatzl@6937 | 18 | * |
tschatzl@6937 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
tschatzl@6937 | 20 | * or visit www.oracle.com if you need additional information or have any |
tschatzl@6937 | 21 | * questions. |
tschatzl@6937 | 22 | * |
tschatzl@6937 | 23 | */ |
tschatzl@6937 | 24 | |
tschatzl@6937 | 25 | #include "precompiled.hpp" |
tschatzl@6937 | 26 | #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" |
tschatzl@6937 | 27 | #include "gc_implementation/g1/g1OopClosures.inline.hpp" |
tschatzl@6937 | 28 | #include "gc_implementation/g1/g1ParScanThreadState.inline.hpp" |
tschatzl@6937 | 29 | #include "oops/oop.inline.hpp" |
tschatzl@6937 | 30 | #include "oops/oop.pcgc.inline.hpp" |
tschatzl@6937 | 31 | #include "runtime/prefetch.inline.hpp" |
tschatzl@6937 | 32 | |
tschatzl@6937 | 33 | G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp) |
tschatzl@6937 | 34 | : _g1h(g1h), |
tschatzl@6937 | 35 | _refs(g1h->task_queue(queue_num)), |
tschatzl@6937 | 36 | _dcq(&g1h->dirty_card_queue_set()), |
tschatzl@6937 | 37 | _ct_bs(g1h->g1_barrier_set()), |
tschatzl@6937 | 38 | _g1_rem(g1h->g1_rem_set()), |
tschatzl@6937 | 39 | _hash_seed(17), _queue_num(queue_num), |
tschatzl@6937 | 40 | _term_attempts(0), |
tschatzl@6937 | 41 | _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)), |
tschatzl@6937 | 42 | _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)), |
tschatzl@6939 | 43 | _age_table(false), _scanner(g1h, rp), |
tschatzl@6937 | 44 | _strong_roots_time(0), _term_time(0), |
tschatzl@6937 | 45 | _alloc_buffer_waste(0), _undo_waste(0) { |
tschatzl@6939 | 46 | _scanner.set_par_scan_thread_state(this); |
tschatzl@6937 | 47 | // we allocate G1YoungSurvRateNumRegions plus one entries, since |
tschatzl@6937 | 48 | // we "sacrifice" entry 0 to keep track of surviving bytes for |
tschatzl@6937 | 49 | // non-young regions (where the age is -1) |
tschatzl@6937 | 50 | // We also add a few elements at the beginning and at the end in |
tschatzl@6937 | 51 | // an attempt to eliminate cache contention |
tschatzl@6937 | 52 | uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length(); |
tschatzl@6937 | 53 | uint array_length = PADDING_ELEM_NUM + |
tschatzl@6937 | 54 | real_length + |
tschatzl@6937 | 55 | PADDING_ELEM_NUM; |
tschatzl@6937 | 56 | _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC); |
tschatzl@6937 | 57 | if (_surviving_young_words_base == NULL) |
tschatzl@6937 | 58 | vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR, |
tschatzl@6937 | 59 | "Not enough space for young surv histo."); |
tschatzl@6937 | 60 | _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM; |
tschatzl@6937 | 61 | memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t)); |
tschatzl@6937 | 62 | |
tschatzl@6937 | 63 | _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer; |
tschatzl@6937 | 64 | _alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer; |
tschatzl@6937 | 65 | |
tschatzl@6937 | 66 | _start = os::elapsedTime(); |
tschatzl@6937 | 67 | } |
tschatzl@6937 | 68 | |
tschatzl@6938 | 69 | G1ParScanThreadState::~G1ParScanThreadState() { |
tschatzl@6938 | 70 | retire_alloc_buffers(); |
tschatzl@6938 | 71 | FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC); |
tschatzl@6938 | 72 | } |
tschatzl@6938 | 73 | |
tschatzl@6937 | 74 | void |
tschatzl@6937 | 75 | G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st) |
tschatzl@6937 | 76 | { |
tschatzl@6937 | 77 | st->print_raw_cr("GC Termination Stats"); |
tschatzl@6937 | 78 | st->print_raw_cr(" elapsed --strong roots-- -------termination-------" |
tschatzl@6937 | 79 | " ------waste (KiB)------"); |
tschatzl@6937 | 80 | st->print_raw_cr("thr ms ms % ms % attempts" |
tschatzl@6937 | 81 | " total alloc undo"); |
tschatzl@6937 | 82 | st->print_raw_cr("--- --------- --------- ------ --------- ------ --------" |
tschatzl@6937 | 83 | " ------- ------- -------"); |
tschatzl@6937 | 84 | } |
tschatzl@6937 | 85 | |
tschatzl@6937 | 86 | void |
tschatzl@6937 | 87 | G1ParScanThreadState::print_termination_stats(int i, |
tschatzl@6937 | 88 | outputStream* const st) const |
tschatzl@6937 | 89 | { |
tschatzl@6937 | 90 | const double elapsed_ms = elapsed_time() * 1000.0; |
tschatzl@6937 | 91 | const double s_roots_ms = strong_roots_time() * 1000.0; |
tschatzl@6937 | 92 | const double term_ms = term_time() * 1000.0; |
tschatzl@6937 | 93 | st->print_cr("%3d %9.2f %9.2f %6.2f " |
tschatzl@6937 | 94 | "%9.2f %6.2f " SIZE_FORMAT_W(8) " " |
tschatzl@6937 | 95 | SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7), |
tschatzl@6937 | 96 | i, elapsed_ms, s_roots_ms, s_roots_ms * 100 / elapsed_ms, |
tschatzl@6937 | 97 | term_ms, term_ms * 100 / elapsed_ms, term_attempts(), |
tschatzl@6937 | 98 | (alloc_buffer_waste() + undo_waste()) * HeapWordSize / K, |
tschatzl@6937 | 99 | alloc_buffer_waste() * HeapWordSize / K, |
tschatzl@6937 | 100 | undo_waste() * HeapWordSize / K); |
tschatzl@6937 | 101 | } |
tschatzl@6937 | 102 | |
tschatzl@6937 | 103 | #ifdef ASSERT |
tschatzl@6937 | 104 | bool G1ParScanThreadState::verify_ref(narrowOop* ref) const { |
tschatzl@6937 | 105 | assert(ref != NULL, "invariant"); |
tschatzl@6937 | 106 | assert(UseCompressedOops, "sanity"); |
tschatzl@6937 | 107 | assert(!has_partial_array_mask(ref), err_msg("ref=" PTR_FORMAT, p2i(ref))); |
tschatzl@6937 | 108 | oop p = oopDesc::load_decode_heap_oop(ref); |
tschatzl@6937 | 109 | assert(_g1h->is_in_g1_reserved(p), |
tschatzl@6937 | 110 | err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p))); |
tschatzl@6937 | 111 | return true; |
tschatzl@6937 | 112 | } |
tschatzl@6937 | 113 | |
tschatzl@6937 | 114 | bool G1ParScanThreadState::verify_ref(oop* ref) const { |
tschatzl@6937 | 115 | assert(ref != NULL, "invariant"); |
tschatzl@6937 | 116 | if (has_partial_array_mask(ref)) { |
tschatzl@6937 | 117 | // Must be in the collection set--it's already been copied. |
tschatzl@6937 | 118 | oop p = clear_partial_array_mask(ref); |
tschatzl@6937 | 119 | assert(_g1h->obj_in_cs(p), |
tschatzl@6937 | 120 | err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p))); |
tschatzl@6937 | 121 | } else { |
tschatzl@6937 | 122 | oop p = oopDesc::load_decode_heap_oop(ref); |
tschatzl@6937 | 123 | assert(_g1h->is_in_g1_reserved(p), |
tschatzl@6937 | 124 | err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p))); |
tschatzl@6937 | 125 | } |
tschatzl@6937 | 126 | return true; |
tschatzl@6937 | 127 | } |
tschatzl@6937 | 128 | |
tschatzl@6937 | 129 | bool G1ParScanThreadState::verify_task(StarTask ref) const { |
tschatzl@6937 | 130 | if (ref.is_narrow()) { |
tschatzl@6937 | 131 | return verify_ref((narrowOop*) ref); |
tschatzl@6937 | 132 | } else { |
tschatzl@6937 | 133 | return verify_ref((oop*) ref); |
tschatzl@6937 | 134 | } |
tschatzl@6937 | 135 | } |
tschatzl@6937 | 136 | #endif // ASSERT |
tschatzl@6937 | 137 | |
tschatzl@6937 | 138 | void G1ParScanThreadState::trim_queue() { |
tschatzl@6937 | 139 | assert(_evac_failure_cl != NULL, "not set"); |
tschatzl@6937 | 140 | |
tschatzl@6937 | 141 | StarTask ref; |
tschatzl@6937 | 142 | do { |
tschatzl@6937 | 143 | // Drain the overflow stack first, so other threads can steal. |
tschatzl@6938 | 144 | while (_refs->pop_overflow(ref)) { |
tschatzl@6938 | 145 | dispatch_reference(ref); |
tschatzl@6937 | 146 | } |
tschatzl@6937 | 147 | |
tschatzl@6938 | 148 | while (_refs->pop_local(ref)) { |
tschatzl@6938 | 149 | dispatch_reference(ref); |
tschatzl@6937 | 150 | } |
tschatzl@6938 | 151 | } while (!_refs->is_empty()); |
tschatzl@6937 | 152 | } |
tschatzl@6937 | 153 | |
tschatzl@6937 | 154 | oop G1ParScanThreadState::copy_to_survivor_space(oop const old) { |
tschatzl@6937 | 155 | size_t word_sz = old->size(); |
tschatzl@6937 | 156 | HeapRegion* from_region = _g1h->heap_region_containing_raw(old); |
tschatzl@6937 | 157 | // +1 to make the -1 indexes valid... |
tschatzl@6937 | 158 | int young_index = from_region->young_index_in_cset()+1; |
tschatzl@6937 | 159 | assert( (from_region->is_young() && young_index > 0) || |
tschatzl@6937 | 160 | (!from_region->is_young() && young_index == 0), "invariant" ); |
tschatzl@6937 | 161 | G1CollectorPolicy* g1p = _g1h->g1_policy(); |
tschatzl@6937 | 162 | markOop m = old->mark(); |
tschatzl@6937 | 163 | int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age() |
tschatzl@6937 | 164 | : m->age(); |
tschatzl@6937 | 165 | GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age, |
tschatzl@6937 | 166 | word_sz); |
tschatzl@6937 | 167 | HeapWord* obj_ptr = allocate(alloc_purpose, word_sz); |
tschatzl@6937 | 168 | #ifndef PRODUCT |
tschatzl@6937 | 169 | // Should this evacuation fail? |
tschatzl@6937 | 170 | if (_g1h->evacuation_should_fail()) { |
tschatzl@6937 | 171 | if (obj_ptr != NULL) { |
tschatzl@6937 | 172 | undo_allocation(alloc_purpose, obj_ptr, word_sz); |
tschatzl@6937 | 173 | obj_ptr = NULL; |
tschatzl@6937 | 174 | } |
tschatzl@6937 | 175 | } |
tschatzl@6937 | 176 | #endif // !PRODUCT |
tschatzl@6937 | 177 | |
tschatzl@6937 | 178 | if (obj_ptr == NULL) { |
tschatzl@6937 | 179 | // This will either forward-to-self, or detect that someone else has |
tschatzl@6937 | 180 | // installed a forwarding pointer. |
tschatzl@6937 | 181 | return _g1h->handle_evacuation_failure_par(this, old); |
tschatzl@6937 | 182 | } |
tschatzl@6937 | 183 | |
tschatzl@6937 | 184 | oop obj = oop(obj_ptr); |
tschatzl@6937 | 185 | |
tschatzl@6937 | 186 | // We're going to allocate linearly, so might as well prefetch ahead. |
tschatzl@6937 | 187 | Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes); |
tschatzl@6937 | 188 | |
tschatzl@6937 | 189 | oop forward_ptr = old->forward_to_atomic(obj); |
tschatzl@6937 | 190 | if (forward_ptr == NULL) { |
tschatzl@6937 | 191 | Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz); |
tschatzl@6937 | 192 | |
tschatzl@6937 | 193 | // alloc_purpose is just a hint to allocate() above, recheck the type of region |
tschatzl@6937 | 194 | // we actually allocated from and update alloc_purpose accordingly |
tschatzl@6937 | 195 | HeapRegion* to_region = _g1h->heap_region_containing_raw(obj_ptr); |
tschatzl@6937 | 196 | alloc_purpose = to_region->is_young() ? GCAllocForSurvived : GCAllocForTenured; |
tschatzl@6937 | 197 | |
tschatzl@6937 | 198 | if (g1p->track_object_age(alloc_purpose)) { |
tschatzl@6937 | 199 | // We could simply do obj->incr_age(). However, this causes a |
tschatzl@6937 | 200 | // performance issue. obj->incr_age() will first check whether |
tschatzl@6937 | 201 | // the object has a displaced mark by checking its mark word; |
tschatzl@6937 | 202 | // getting the mark word from the new location of the object |
tschatzl@6937 | 203 | // stalls. So, given that we already have the mark word and we |
tschatzl@6937 | 204 | // are about to install it anyway, it's better to increase the |
tschatzl@6937 | 205 | // age on the mark word, when the object does not have a |
tschatzl@6937 | 206 | // displaced mark word. We're not expecting many objects to have |
tschatzl@6937 | 207 | // a displaced marked word, so that case is not optimized |
tschatzl@6937 | 208 | // further (it could be...) and we simply call obj->incr_age(). |
tschatzl@6937 | 209 | |
tschatzl@6937 | 210 | if (m->has_displaced_mark_helper()) { |
tschatzl@6937 | 211 | // in this case, we have to install the mark word first, |
tschatzl@6937 | 212 | // otherwise obj looks to be forwarded (the old mark word, |
tschatzl@6937 | 213 | // which contains the forward pointer, was copied) |
tschatzl@6937 | 214 | obj->set_mark(m); |
tschatzl@6937 | 215 | obj->incr_age(); |
tschatzl@6937 | 216 | } else { |
tschatzl@6937 | 217 | m = m->incr_age(); |
tschatzl@6937 | 218 | obj->set_mark(m); |
tschatzl@6937 | 219 | } |
tschatzl@6937 | 220 | age_table()->add(obj, word_sz); |
tschatzl@6937 | 221 | } else { |
tschatzl@6937 | 222 | obj->set_mark(m); |
tschatzl@6937 | 223 | } |
tschatzl@6937 | 224 | |
tschatzl@6937 | 225 | if (G1StringDedup::is_enabled()) { |
tschatzl@6937 | 226 | G1StringDedup::enqueue_from_evacuation(from_region->is_young(), |
tschatzl@6937 | 227 | to_region->is_young(), |
tschatzl@6937 | 228 | queue_num(), |
tschatzl@6937 | 229 | obj); |
tschatzl@6937 | 230 | } |
tschatzl@6937 | 231 | |
tschatzl@6937 | 232 | size_t* surv_young_words = surviving_young_words(); |
tschatzl@6937 | 233 | surv_young_words[young_index] += word_sz; |
tschatzl@6937 | 234 | |
tschatzl@6937 | 235 | if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) { |
tschatzl@6937 | 236 | // We keep track of the next start index in the length field of |
tschatzl@6937 | 237 | // the to-space object. The actual length can be found in the |
tschatzl@6937 | 238 | // length field of the from-space object. |
tschatzl@6937 | 239 | arrayOop(obj)->set_length(0); |
tschatzl@6937 | 240 | oop* old_p = set_partial_array_mask(old); |
tschatzl@6937 | 241 | push_on_queue(old_p); |
tschatzl@6937 | 242 | } else { |
tschatzl@6937 | 243 | // No point in using the slower heap_region_containing() method, |
tschatzl@6937 | 244 | // given that we know obj is in the heap. |
tschatzl@6937 | 245 | _scanner.set_region(_g1h->heap_region_containing_raw(obj)); |
tschatzl@6937 | 246 | obj->oop_iterate_backwards(&_scanner); |
tschatzl@6937 | 247 | } |
tschatzl@6937 | 248 | } else { |
tschatzl@6937 | 249 | undo_allocation(alloc_purpose, obj_ptr, word_sz); |
tschatzl@6937 | 250 | obj = forward_ptr; |
tschatzl@6937 | 251 | } |
tschatzl@6937 | 252 | return obj; |
tschatzl@6937 | 253 | } |
tschatzl@6938 | 254 | |
tschatzl@6938 | 255 | HeapWord* G1ParScanThreadState::allocate_slow(GCAllocPurpose purpose, size_t word_sz) { |
tschatzl@6938 | 256 | HeapWord* obj = NULL; |
tschatzl@6938 | 257 | size_t gclab_word_size = _g1h->desired_plab_sz(purpose); |
tschatzl@6938 | 258 | if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) { |
tschatzl@6938 | 259 | G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose); |
tschatzl@6938 | 260 | add_to_alloc_buffer_waste(alloc_buf->words_remaining()); |
tschatzl@6938 | 261 | alloc_buf->retire(false /* end_of_gc */, false /* retain */); |
tschatzl@6938 | 262 | |
tschatzl@6938 | 263 | HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size); |
tschatzl@6938 | 264 | if (buf == NULL) { |
tschatzl@6938 | 265 | return NULL; // Let caller handle allocation failure. |
tschatzl@6938 | 266 | } |
tschatzl@6938 | 267 | // Otherwise. |
tschatzl@6938 | 268 | alloc_buf->set_word_size(gclab_word_size); |
tschatzl@6938 | 269 | alloc_buf->set_buf(buf); |
tschatzl@6938 | 270 | |
tschatzl@6938 | 271 | obj = alloc_buf->allocate(word_sz); |
tschatzl@6938 | 272 | assert(obj != NULL, "buffer was definitely big enough..."); |
tschatzl@6938 | 273 | } else { |
tschatzl@6938 | 274 | obj = _g1h->par_allocate_during_gc(purpose, word_sz); |
tschatzl@6938 | 275 | } |
tschatzl@6938 | 276 | return obj; |
tschatzl@6938 | 277 | } |
tschatzl@6938 | 278 | |
tschatzl@6938 | 279 | void G1ParScanThreadState::undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) { |
tschatzl@6938 | 280 | if (alloc_buffer(purpose)->contains(obj)) { |
tschatzl@6938 | 281 | assert(alloc_buffer(purpose)->contains(obj + word_sz - 1), |
tschatzl@6938 | 282 | "should contain whole object"); |
tschatzl@6938 | 283 | alloc_buffer(purpose)->undo_allocation(obj, word_sz); |
tschatzl@6938 | 284 | } else { |
tschatzl@6938 | 285 | CollectedHeap::fill_with_object(obj, word_sz); |
tschatzl@6938 | 286 | add_to_undo_waste(word_sz); |
tschatzl@6938 | 287 | } |
tschatzl@6938 | 288 | } |
tschatzl@6938 | 289 | |
tschatzl@6938 | 290 | HeapWord* G1ParScanThreadState::allocate(GCAllocPurpose purpose, size_t word_sz) { |
tschatzl@6938 | 291 | HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz); |
tschatzl@6938 | 292 | if (obj != NULL) { |
tschatzl@6938 | 293 | return obj; |
tschatzl@6938 | 294 | } |
tschatzl@6938 | 295 | return allocate_slow(purpose, word_sz); |
tschatzl@6938 | 296 | } |
tschatzl@6938 | 297 | |
tschatzl@6938 | 298 | void G1ParScanThreadState::retire_alloc_buffers() { |
tschatzl@6938 | 299 | for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { |
tschatzl@6938 | 300 | size_t waste = _alloc_buffers[ap]->words_remaining(); |
tschatzl@6938 | 301 | add_to_alloc_buffer_waste(waste); |
tschatzl@6938 | 302 | _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap), |
tschatzl@6938 | 303 | true /* end_of_gc */, |
tschatzl@6938 | 304 | false /* retain */); |
tschatzl@6938 | 305 | } |
tschatzl@6938 | 306 | } |