--- /dev/null 2014-07-16 10:04:12.054455181 +0200 +++ new/src/share/vm/gc_implementation/g1/g1ParScanThreadState.cpp 2014-07-16 15:29:35.027194383 +0200 @@ -0,0 +1,251 @@ +/* + * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" +#include "gc_implementation/g1/g1CollectedHeap.inline.hpp" +#include "gc_implementation/g1/g1OopClosures.inline.hpp" +#include "gc_implementation/g1/g1ParScanThreadState.inline.hpp" +#include "oops/oop.inline.hpp" +#include "oops/oop.pcgc.inline.hpp" +#include "runtime/prefetch.inline.hpp" + +#ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away +#pragma warning( disable:4355 ) // 'this' : used in base member initializer list +#endif // _MSC_VER + +G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp) + : _g1h(g1h), + _refs(g1h->task_queue(queue_num)), + _dcq(&g1h->dirty_card_queue_set()), + _ct_bs(g1h->g1_barrier_set()), + _g1_rem(g1h->g1_rem_set()), + _hash_seed(17), _queue_num(queue_num), + _term_attempts(0), + _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)), + _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)), + _age_table(false), _scanner(g1h, this, rp), + _strong_roots_time(0), _term_time(0), + _alloc_buffer_waste(0), _undo_waste(0) { + // we allocate G1YoungSurvRateNumRegions plus one entries, since + // we "sacrifice" entry 0 to keep track of surviving bytes for + // non-young regions (where the age is -1) + // We also add a few elements at the beginning and at the end in + // an attempt to eliminate cache contention + uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length(); + uint array_length = PADDING_ELEM_NUM + + real_length + + PADDING_ELEM_NUM; + _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC); + if (_surviving_young_words_base == NULL) + vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR, + "Not enough space for young surv histo."); + _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM; + memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t)); + + _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer; + _alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer; + + _start = os::elapsedTime(); +} + +void +G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st) +{ + st->print_raw_cr("GC Termination Stats"); + st->print_raw_cr(" elapsed --strong roots-- -------termination-------" + " ------waste (KiB)------"); + st->print_raw_cr("thr ms ms % ms % attempts" + " total alloc undo"); + st->print_raw_cr("--- --------- --------- ------ --------- ------ --------" + " ------- ------- -------"); +} + +void +G1ParScanThreadState::print_termination_stats(int i, + outputStream* const st) const +{ + const double elapsed_ms = elapsed_time() * 1000.0; + const double s_roots_ms = strong_roots_time() * 1000.0; + const double term_ms = term_time() * 1000.0; + st->print_cr("%3d %9.2f %9.2f %6.2f " + "%9.2f %6.2f " SIZE_FORMAT_W(8) " " + SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7), + i, elapsed_ms, s_roots_ms, s_roots_ms * 100 / elapsed_ms, + term_ms, term_ms * 100 / elapsed_ms, term_attempts(), + (alloc_buffer_waste() + undo_waste()) * HeapWordSize / K, + alloc_buffer_waste() * HeapWordSize / K, + undo_waste() * HeapWordSize / K); +} + +#ifdef ASSERT +bool G1ParScanThreadState::verify_ref(narrowOop* ref) const { + assert(ref != NULL, "invariant"); + assert(UseCompressedOops, "sanity"); + assert(!has_partial_array_mask(ref), err_msg("ref=" PTR_FORMAT, p2i(ref))); + oop p = oopDesc::load_decode_heap_oop(ref); + assert(_g1h->is_in_g1_reserved(p), + err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p))); + return true; +} + +bool G1ParScanThreadState::verify_ref(oop* ref) const { + assert(ref != NULL, "invariant"); + if (has_partial_array_mask(ref)) { + // Must be in the collection set--it's already been copied. + oop p = clear_partial_array_mask(ref); + assert(_g1h->obj_in_cs(p), + err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p))); + } else { + oop p = oopDesc::load_decode_heap_oop(ref); + assert(_g1h->is_in_g1_reserved(p), + err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p))); + } + return true; +} + +bool G1ParScanThreadState::verify_task(StarTask ref) const { + if (ref.is_narrow()) { + return verify_ref((narrowOop*) ref); + } else { + return verify_ref((oop*) ref); + } +} +#endif // ASSERT + +void G1ParScanThreadState::trim_queue() { + assert(_evac_failure_cl != NULL, "not set"); + + StarTask ref; + do { + // Drain the overflow stack first, so other threads can steal. + while (refs()->pop_overflow(ref)) { + deal_with_reference(ref); + } + + while (refs()->pop_local(ref)) { + deal_with_reference(ref); + } + } while (!refs()->is_empty()); +} + +oop G1ParScanThreadState::copy_to_survivor_space(oop const old) { + size_t word_sz = old->size(); + HeapRegion* from_region = _g1h->heap_region_containing_raw(old); + // +1 to make the -1 indexes valid... + int young_index = from_region->young_index_in_cset()+1; + assert( (from_region->is_young() && young_index > 0) || + (!from_region->is_young() && young_index == 0), "invariant" ); + G1CollectorPolicy* g1p = _g1h->g1_policy(); + markOop m = old->mark(); + int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age() + : m->age(); + GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age, + word_sz); + HeapWord* obj_ptr = allocate(alloc_purpose, word_sz); +#ifndef PRODUCT + // Should this evacuation fail? + if (_g1h->evacuation_should_fail()) { + if (obj_ptr != NULL) { + undo_allocation(alloc_purpose, obj_ptr, word_sz); + obj_ptr = NULL; + } + } +#endif // !PRODUCT + + if (obj_ptr == NULL) { + // This will either forward-to-self, or detect that someone else has + // installed a forwarding pointer. + return _g1h->handle_evacuation_failure_par(this, old); + } + + oop obj = oop(obj_ptr); + + // We're going to allocate linearly, so might as well prefetch ahead. + Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes); + + oop forward_ptr = old->forward_to_atomic(obj); + if (forward_ptr == NULL) { + Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz); + + // alloc_purpose is just a hint to allocate() above, recheck the type of region + // we actually allocated from and update alloc_purpose accordingly + HeapRegion* to_region = _g1h->heap_region_containing_raw(obj_ptr); + alloc_purpose = to_region->is_young() ? GCAllocForSurvived : GCAllocForTenured; + + if (g1p->track_object_age(alloc_purpose)) { + // We could simply do obj->incr_age(). However, this causes a + // performance issue. obj->incr_age() will first check whether + // the object has a displaced mark by checking its mark word; + // getting the mark word from the new location of the object + // stalls. So, given that we already have the mark word and we + // are about to install it anyway, it's better to increase the + // age on the mark word, when the object does not have a + // displaced mark word. We're not expecting many objects to have + // a displaced marked word, so that case is not optimized + // further (it could be...) and we simply call obj->incr_age(). + + if (m->has_displaced_mark_helper()) { + // in this case, we have to install the mark word first, + // otherwise obj looks to be forwarded (the old mark word, + // which contains the forward pointer, was copied) + obj->set_mark(m); + obj->incr_age(); + } else { + m = m->incr_age(); + obj->set_mark(m); + } + age_table()->add(obj, word_sz); + } else { + obj->set_mark(m); + } + + if (G1StringDedup::is_enabled()) { + G1StringDedup::enqueue_from_evacuation(from_region->is_young(), + to_region->is_young(), + queue_num(), + obj); + } + + size_t* surv_young_words = surviving_young_words(); + surv_young_words[young_index] += word_sz; + + if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) { + // We keep track of the next start index in the length field of + // the to-space object. The actual length can be found in the + // length field of the from-space object. + arrayOop(obj)->set_length(0); + oop* old_p = set_partial_array_mask(old); + push_on_queue(old_p); + } else { + // No point in using the slower heap_region_containing() method, + // given that we know obj is in the heap. + _scanner.set_region(_g1h->heap_region_containing_raw(obj)); + obj->oop_iterate_backwards(&_scanner); + } + } else { + undo_allocation(alloc_purpose, obj_ptr, word_sz); + obj = forward_ptr; + } + return obj; +}