--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1ParScanThreadState.cpp Thu Jun 26 15:45:07 2014 +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;
+}