--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1RemSet.cpp Thu Jun 05 15:57:56 2008 -0700
@@ -0,0 +1,1003 @@
+/*
+ * Copyright 2001-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_g1RemSet.cpp.incl"
+
+#define CARD_REPEAT_HISTO 0
+
+#if CARD_REPEAT_HISTO
+static size_t ct_freq_sz;
+static jbyte* ct_freq = NULL;
+
+void init_ct_freq_table(size_t heap_sz_bytes) {
+ if (ct_freq == NULL) {
+ ct_freq_sz = heap_sz_bytes/CardTableModRefBS::card_size;
+ ct_freq = new jbyte[ct_freq_sz];
+ for (size_t j = 0; j < ct_freq_sz; j++) ct_freq[j] = 0;
+ }
+}
+
+void ct_freq_note_card(size_t index) {
+ assert(0 <= index && index < ct_freq_sz, "Bounds error.");
+ if (ct_freq[index] < 100) { ct_freq[index]++; }
+}
+
+static IntHistogram card_repeat_count(10, 10);
+
+void ct_freq_update_histo_and_reset() {
+ for (size_t j = 0; j < ct_freq_sz; j++) {
+ card_repeat_count.add_entry(ct_freq[j]);
+ ct_freq[j] = 0;
+ }
+
+}
+#endif
+
+
+class IntoCSOopClosure: public OopsInHeapRegionClosure {
+ OopsInHeapRegionClosure* _blk;
+ G1CollectedHeap* _g1;
+public:
+ IntoCSOopClosure(G1CollectedHeap* g1, OopsInHeapRegionClosure* blk) :
+ _g1(g1), _blk(blk) {}
+ void set_region(HeapRegion* from) {
+ _blk->set_region(from);
+ }
+ virtual void do_oop(narrowOop* p) {
+ guarantee(false, "NYI");
+ }
+ virtual void do_oop(oop* p) {
+ oop obj = *p;
+ if (_g1->obj_in_cs(obj)) _blk->do_oop(p);
+ }
+ bool apply_to_weak_ref_discovered_field() { return true; }
+ bool idempotent() { return true; }
+};
+
+class IntoCSRegionClosure: public HeapRegionClosure {
+ IntoCSOopClosure _blk;
+ G1CollectedHeap* _g1;
+public:
+ IntoCSRegionClosure(G1CollectedHeap* g1, OopsInHeapRegionClosure* blk) :
+ _g1(g1), _blk(g1, blk) {}
+ bool doHeapRegion(HeapRegion* r) {
+ if (!r->in_collection_set()) {
+ _blk.set_region(r);
+ if (r->isHumongous()) {
+ if (r->startsHumongous()) {
+ oop obj = oop(r->bottom());
+ obj->oop_iterate(&_blk);
+ }
+ } else {
+ r->oop_before_save_marks_iterate(&_blk);
+ }
+ }
+ return false;
+ }
+};
+
+void
+StupidG1RemSet::oops_into_collection_set_do(OopsInHeapRegionClosure* oc,
+ int worker_i) {
+ IntoCSRegionClosure rc(_g1, oc);
+ _g1->heap_region_iterate(&rc);
+}
+
+class UpdateRSOopClosure: public OopClosure {
+ HeapRegion* _from;
+ HRInto_G1RemSet* _rs;
+ int _worker_i;
+public:
+ UpdateRSOopClosure(HRInto_G1RemSet* rs, int worker_i = 0) :
+ _from(NULL), _rs(rs), _worker_i(worker_i) {
+ guarantee(_rs != NULL, "Requires an HRIntoG1RemSet");
+ }
+
+ void set_from(HeapRegion* from) {
+ assert(from != NULL, "from region must be non-NULL");
+ _from = from;
+ }
+
+ virtual void do_oop(narrowOop* p) {
+ guarantee(false, "NYI");
+ }
+ virtual void do_oop(oop* p) {
+ assert(_from != NULL, "from region must be non-NULL");
+ _rs->par_write_ref(_from, p, _worker_i);
+ }
+ // Override: this closure is idempotent.
+ // bool idempotent() { return true; }
+ bool apply_to_weak_ref_discovered_field() { return true; }
+};
+
+class UpdateRSOutOfRegionClosure: public HeapRegionClosure {
+ G1CollectedHeap* _g1h;
+ ModRefBarrierSet* _mr_bs;
+ UpdateRSOopClosure _cl;
+ int _worker_i;
+public:
+ UpdateRSOutOfRegionClosure(G1CollectedHeap* g1, int worker_i = 0) :
+ _cl(g1->g1_rem_set()->as_HRInto_G1RemSet(), worker_i),
+ _mr_bs(g1->mr_bs()),
+ _worker_i(worker_i),
+ _g1h(g1)
+ {}
+ bool doHeapRegion(HeapRegion* r) {
+ if (!r->in_collection_set() && !r->continuesHumongous()) {
+ _cl.set_from(r);
+ r->set_next_filter_kind(HeapRegionDCTOC::OutOfRegionFilterKind);
+ _mr_bs->mod_oop_in_space_iterate(r, &_cl, true, true);
+ }
+ return false;
+ }
+};
+
+class VerifyRSCleanCardOopClosure: public OopClosure {
+ G1CollectedHeap* _g1;
+public:
+ VerifyRSCleanCardOopClosure(G1CollectedHeap* g1) : _g1(g1) {}
+
+ virtual void do_oop(narrowOop* p) {
+ guarantee(false, "NYI");
+ }
+ virtual void do_oop(oop* p) {
+ oop obj = *p;
+ HeapRegion* to = _g1->heap_region_containing(obj);
+ guarantee(to == NULL || !to->in_collection_set(),
+ "Missed a rem set member.");
+ }
+};
+
+HRInto_G1RemSet::HRInto_G1RemSet(G1CollectedHeap* g1, CardTableModRefBS* ct_bs)
+ : G1RemSet(g1), _ct_bs(ct_bs), _g1p(_g1->g1_policy()),
+ _cg1r(g1->concurrent_g1_refine()),
+ _par_traversal_in_progress(false), _new_refs(NULL),
+ _cards_scanned(NULL), _total_cards_scanned(0)
+{
+ _seq_task = new SubTasksDone(NumSeqTasks);
+ _new_refs = NEW_C_HEAP_ARRAY(GrowableArray<oop*>*, ParallelGCThreads);
+}
+
+HRInto_G1RemSet::~HRInto_G1RemSet() {
+ delete _seq_task;
+}
+
+void CountNonCleanMemRegionClosure::do_MemRegion(MemRegion mr) {
+ if (_g1->is_in_g1_reserved(mr.start())) {
+ _n += (int) ((mr.byte_size() / CardTableModRefBS::card_size));
+ if (_start_first == NULL) _start_first = mr.start();
+ }
+}
+
+class ScanRSClosure : public HeapRegionClosure {
+ size_t _cards_done, _cards;
+ G1CollectedHeap* _g1h;
+ OopsInHeapRegionClosure* _oc;
+ G1BlockOffsetSharedArray* _bot_shared;
+ CardTableModRefBS *_ct_bs;
+ int _worker_i;
+ bool _try_claimed;
+public:
+ ScanRSClosure(OopsInHeapRegionClosure* oc, int worker_i) :
+ _oc(oc),
+ _cards(0),
+ _cards_done(0),
+ _worker_i(worker_i),
+ _try_claimed(false)
+ {
+ _g1h = G1CollectedHeap::heap();
+ _bot_shared = _g1h->bot_shared();
+ _ct_bs = (CardTableModRefBS*) (_g1h->barrier_set());
+ }
+
+ void set_try_claimed() { _try_claimed = true; }
+
+ void scanCard(size_t index, HeapRegion *r) {
+ _cards_done++;
+ DirtyCardToOopClosure* cl =
+ r->new_dcto_closure(_oc,
+ CardTableModRefBS::Precise,
+ HeapRegionDCTOC::IntoCSFilterKind);
+
+ // Set the "from" region in the closure.
+ _oc->set_region(r);
+ HeapWord* card_start = _bot_shared->address_for_index(index);
+ HeapWord* card_end = card_start + G1BlockOffsetSharedArray::N_words;
+ Space *sp = SharedHeap::heap()->space_containing(card_start);
+ MemRegion sm_region;
+ if (ParallelGCThreads > 0) {
+ // first find the used area
+ sm_region = sp->used_region_at_save_marks();
+ } else {
+ // The closure is not idempotent. We shouldn't look at objects
+ // allocated during the GC.
+ sm_region = sp->used_region_at_save_marks();
+ }
+ MemRegion mr = sm_region.intersection(MemRegion(card_start,card_end));
+ if (!mr.is_empty()) {
+ cl->do_MemRegion(mr);
+ }
+ }
+
+ void printCard(HeapRegion* card_region, size_t card_index,
+ HeapWord* card_start) {
+ gclog_or_tty->print_cr("T %d Region [" PTR_FORMAT ", " PTR_FORMAT ") "
+ "RS names card %p: "
+ "[" PTR_FORMAT ", " PTR_FORMAT ")",
+ _worker_i,
+ card_region->bottom(), card_region->end(),
+ card_index,
+ card_start, card_start + G1BlockOffsetSharedArray::N_words);
+ }
+
+ bool doHeapRegion(HeapRegion* r) {
+ assert(r->in_collection_set(), "should only be called on elements of CS.");
+ HeapRegionRemSet* hrrs = r->rem_set();
+ if (hrrs->iter_is_complete()) return false; // All done.
+ if (!_try_claimed && !hrrs->claim_iter()) return false;
+ // If we didn't return above, then
+ // _try_claimed || r->claim_iter()
+ // is true: either we're supposed to work on claimed-but-not-complete
+ // regions, or we successfully claimed the region.
+ HeapRegionRemSetIterator* iter = _g1h->rem_set_iterator(_worker_i);
+ hrrs->init_iterator(iter);
+ size_t card_index;
+ while (iter->has_next(card_index)) {
+ HeapWord* card_start = _g1h->bot_shared()->address_for_index(card_index);
+
+#if 0
+ gclog_or_tty->print("Rem set iteration yielded card [" PTR_FORMAT ", " PTR_FORMAT ").\n",
+ card_start, card_start + CardTableModRefBS::card_size_in_words);
+#endif
+
+ HeapRegion* card_region = _g1h->heap_region_containing(card_start);
+ assert(card_region != NULL, "Yielding cards not in the heap?");
+ _cards++;
+
+ if (!card_region->in_collection_set()) {
+ // If the card is dirty, then we will scan it during updateRS.
+ if (!_ct_bs->is_card_claimed(card_index) &&
+ !_ct_bs->is_card_dirty(card_index)) {
+ assert(_ct_bs->is_card_clean(card_index) ||
+ _ct_bs->is_card_claimed(card_index),
+ "Card is either dirty, clean, or claimed");
+ if (_ct_bs->claim_card(card_index))
+ scanCard(card_index, card_region);
+ }
+ }
+ }
+ hrrs->set_iter_complete();
+ return false;
+ }
+ // Set all cards back to clean.
+ void cleanup() {_g1h->cleanUpCardTable();}
+ size_t cards_done() { return _cards_done;}
+ size_t cards_looked_up() { return _cards;}
+};
+
+// We want the parallel threads to start their scanning at
+// different collection set regions to avoid contention.
+// If we have:
+// n collection set regions
+// p threads
+// Then thread t will start at region t * floor (n/p)
+
+HeapRegion* HRInto_G1RemSet::calculateStartRegion(int worker_i) {
+ HeapRegion* result = _g1p->collection_set();
+ if (ParallelGCThreads > 0) {
+ size_t cs_size = _g1p->collection_set_size();
+ int n_workers = _g1->workers()->total_workers();
+ size_t cs_spans = cs_size / n_workers;
+ size_t ind = cs_spans * worker_i;
+ for (size_t i = 0; i < ind; i++)
+ result = result->next_in_collection_set();
+ }
+ return result;
+}
+
+void HRInto_G1RemSet::scanRS(OopsInHeapRegionClosure* oc, int worker_i) {
+ double rs_time_start = os::elapsedTime();
+ HeapRegion *startRegion = calculateStartRegion(worker_i);
+
+ BufferingOopsInHeapRegionClosure boc(oc);
+ ScanRSClosure scanRScl(&boc, worker_i);
+ _g1->collection_set_iterate_from(startRegion, &scanRScl);
+ scanRScl.set_try_claimed();
+ _g1->collection_set_iterate_from(startRegion, &scanRScl);
+
+ boc.done();
+ double closure_app_time_sec = boc.closure_app_seconds();
+ double scan_rs_time_sec = (os::elapsedTime() - rs_time_start) -
+ closure_app_time_sec;
+ double closure_app_time_ms = closure_app_time_sec * 1000.0;
+
+ assert( _cards_scanned != NULL, "invariant" );
+ _cards_scanned[worker_i] = scanRScl.cards_done();
+
+ _g1p->record_scan_rs_start_time(worker_i, rs_time_start * 1000.0);
+ _g1p->record_scan_rs_time(worker_i, scan_rs_time_sec * 1000.0);
+ if (ParallelGCThreads > 0) {
+ // In this case, we called scanNewRefsRS and recorded the corresponding
+ // time.
+ double scan_new_refs_time_ms = _g1p->get_scan_new_refs_time(worker_i);
+ if (scan_new_refs_time_ms > 0.0) {
+ closure_app_time_ms += scan_new_refs_time_ms;
+ }
+ }
+ _g1p->record_obj_copy_time(worker_i, closure_app_time_ms);
+}
+
+void HRInto_G1RemSet::updateRS(int worker_i) {
+ ConcurrentG1Refine* cg1r = _g1->concurrent_g1_refine();
+
+ double start = os::elapsedTime();
+ _g1p->record_update_rs_start_time(worker_i, start * 1000.0);
+
+ if (G1RSBarrierUseQueue && !cg1r->do_traversal()) {
+ // Apply the appropriate closure to all remaining log entries.
+ _g1->iterate_dirty_card_closure(false, worker_i);
+ // Now there should be no dirty cards.
+ if (G1RSLogCheckCardTable) {
+ CountNonCleanMemRegionClosure cl(_g1);
+ _ct_bs->mod_card_iterate(&cl);
+ // XXX This isn't true any more: keeping cards of young regions
+ // marked dirty broke it. Need some reasonable fix.
+ guarantee(cl.n() == 0, "Card table should be clean.");
+ }
+ } else {
+ UpdateRSOutOfRegionClosure update_rs(_g1, worker_i);
+ _g1->heap_region_iterate(&update_rs);
+ // We did a traversal; no further one is necessary.
+ if (G1RSBarrierUseQueue) {
+ assert(cg1r->do_traversal(), "Or we shouldn't have gotten here.");
+ cg1r->set_pya_cancel();
+ }
+ if (_cg1r->use_cache()) {
+ _cg1r->clear_and_record_card_counts();
+ _cg1r->clear_hot_cache();
+ }
+ }
+ _g1p->record_update_rs_time(worker_i, (os::elapsedTime() - start) * 1000.0);
+}
+
+#ifndef PRODUCT
+class PrintRSClosure : public HeapRegionClosure {
+ int _count;
+public:
+ PrintRSClosure() : _count(0) {}
+ bool doHeapRegion(HeapRegion* r) {
+ HeapRegionRemSet* hrrs = r->rem_set();
+ _count += (int) hrrs->occupied();
+ if (hrrs->occupied() == 0) {
+ gclog_or_tty->print("Heap Region [" PTR_FORMAT ", " PTR_FORMAT ") "
+ "has no remset entries\n",
+ r->bottom(), r->end());
+ } else {
+ gclog_or_tty->print("Printing rem set for heap region [" PTR_FORMAT ", " PTR_FORMAT ")\n",
+ r->bottom(), r->end());
+ r->print();
+ hrrs->print();
+ gclog_or_tty->print("\nDone printing rem set\n");
+ }
+ return false;
+ }
+ int occupied() {return _count;}
+};
+#endif
+
+class CountRSSizeClosure: public HeapRegionClosure {
+ size_t _n;
+ size_t _tot;
+ size_t _max;
+ HeapRegion* _max_r;
+ enum {
+ N = 20,
+ MIN = 6
+ };
+ int _histo[N];
+public:
+ CountRSSizeClosure() : _n(0), _tot(0), _max(0), _max_r(NULL) {
+ for (int i = 0; i < N; i++) _histo[i] = 0;
+ }
+ bool doHeapRegion(HeapRegion* r) {
+ if (!r->continuesHumongous()) {
+ size_t occ = r->rem_set()->occupied();
+ _n++;
+ _tot += occ;
+ if (occ > _max) {
+ _max = occ;
+ _max_r = r;
+ }
+ // Fit it into a histo bin.
+ int s = 1 << MIN;
+ int i = 0;
+ while (occ > (size_t) s && i < (N-1)) {
+ s = s << 1;
+ i++;
+ }
+ _histo[i]++;
+ }
+ return false;
+ }
+ size_t n() { return _n; }
+ size_t tot() { return _tot; }
+ size_t mx() { return _max; }
+ HeapRegion* mxr() { return _max_r; }
+ void print_histo() {
+ int mx = N;
+ while (mx >= 0) {
+ if (_histo[mx-1] > 0) break;
+ mx--;
+ }
+ gclog_or_tty->print_cr("Number of regions with given RS sizes:");
+ gclog_or_tty->print_cr(" <= %8d %8d", 1 << MIN, _histo[0]);
+ for (int i = 1; i < mx-1; i++) {
+ gclog_or_tty->print_cr(" %8d - %8d %8d",
+ (1 << (MIN + i - 1)) + 1,
+ 1 << (MIN + i),
+ _histo[i]);
+ }
+ gclog_or_tty->print_cr(" > %8d %8d", (1 << (MIN+mx-2))+1, _histo[mx-1]);
+ }
+};
+
+void
+HRInto_G1RemSet::scanNewRefsRS(OopsInHeapRegionClosure* oc,
+ int worker_i) {
+ double scan_new_refs_start_sec = os::elapsedTime();
+ G1CollectedHeap* g1h = G1CollectedHeap::heap();
+ CardTableModRefBS* ct_bs = (CardTableModRefBS*) (g1h->barrier_set());
+ while (_new_refs[worker_i]->is_nonempty()) {
+ oop* p = _new_refs[worker_i]->pop();
+ oop obj = *p;
+ // *p was in the collection set when p was pushed on "_new_refs", but
+ // another thread may have processed this location from an RS, so it
+ // might not point into the CS any longer. If so, it's obviously been
+ // processed, and we don't need to do anything further.
+ if (g1h->obj_in_cs(obj)) {
+ HeapRegion* r = g1h->heap_region_containing(p);
+
+ DEBUG_ONLY(HeapRegion* to = g1h->heap_region_containing(obj));
+ assert(ParallelGCThreads > 1
+ || to->rem_set()->contains_reference(p),
+ "Invariant: pushed after being added."
+ "(Not reliable in parallel code.)");
+ oc->set_region(r);
+ // If "p" has already been processed concurrently, this is
+ // idempotent.
+ oc->do_oop(p);
+ }
+ }
+ _g1p->record_scan_new_refs_time(worker_i,
+ (os::elapsedTime() - scan_new_refs_start_sec)
+ * 1000.0);
+}
+
+void HRInto_G1RemSet::set_par_traversal(bool b) {
+ _par_traversal_in_progress = b;
+ HeapRegionRemSet::set_par_traversal(b);
+}
+
+void HRInto_G1RemSet::cleanupHRRS() {
+ HeapRegionRemSet::cleanup();
+}
+
+void
+HRInto_G1RemSet::oops_into_collection_set_do(OopsInHeapRegionClosure* oc,
+ int worker_i) {
+#if CARD_REPEAT_HISTO
+ ct_freq_update_histo_and_reset();
+#endif
+ if (worker_i == 0) {
+ _cg1r->clear_and_record_card_counts();
+ }
+
+ // Make this into a command-line flag...
+ if (G1RSCountHisto && (ParallelGCThreads == 0 || worker_i == 0)) {
+ CountRSSizeClosure count_cl;
+ _g1->heap_region_iterate(&count_cl);
+ gclog_or_tty->print_cr("Avg of %d RS counts is %f, max is %d, "
+ "max region is " PTR_FORMAT,
+ count_cl.n(), (float)count_cl.tot()/(float)count_cl.n(),
+ count_cl.mx(), count_cl.mxr());
+ count_cl.print_histo();
+ }
+
+ if (ParallelGCThreads > 0) {
+ // This is a temporary change to serialize the update and scanning
+ // of remembered sets. There are some race conditions when this is
+ // done in parallel and they are causing failures. When we resolve
+ // said race conditions, we'll revert back to parallel remembered
+ // set updating and scanning. See CRs 6677707 and 6677708.
+ if (worker_i == 0) {
+ updateRS(worker_i);
+ scanNewRefsRS(oc, worker_i);
+ scanRS(oc, worker_i);
+ }
+ } else {
+ assert(worker_i == 0, "invariant");
+
+ updateRS(0);
+ scanRS(oc, 0);
+ }
+}
+
+void HRInto_G1RemSet::
+prepare_for_oops_into_collection_set_do() {
+#if G1_REM_SET_LOGGING
+ PrintRSClosure cl;
+ _g1->collection_set_iterate(&cl);
+#endif
+ cleanupHRRS();
+ ConcurrentG1Refine* cg1r = _g1->concurrent_g1_refine();
+ _g1->set_refine_cte_cl_concurrency(false);
+ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+ dcqs.concatenate_logs();
+
+ assert(!_par_traversal_in_progress, "Invariant between iterations.");
+ if (ParallelGCThreads > 0) {
+ set_par_traversal(true);
+ int n_workers = _g1->workers()->total_workers();
+ _seq_task->set_par_threads(n_workers);
+ for (uint i = 0; i < ParallelGCThreads; i++)
+ _new_refs[i] = new (ResourceObj::C_HEAP) GrowableArray<oop*>(8192,true);
+
+ if (cg1r->do_traversal()) {
+ updateRS(0);
+ // Have to do this again after updaters
+ cleanupHRRS();
+ }
+ }
+ guarantee( _cards_scanned == NULL, "invariant" );
+ _cards_scanned = NEW_C_HEAP_ARRAY(size_t, n_workers());
+ _total_cards_scanned = 0;
+}
+
+
+class cleanUpIteratorsClosure : public HeapRegionClosure {
+ bool doHeapRegion(HeapRegion *r) {
+ HeapRegionRemSet* hrrs = r->rem_set();
+ hrrs->init_for_par_iteration();
+ return false;
+ }
+};
+
+void HRInto_G1RemSet::cleanup_after_oops_into_collection_set_do() {
+ guarantee( _cards_scanned != NULL, "invariant" );
+ _total_cards_scanned = 0;
+ for (uint i = 0; i < n_workers(); ++i)
+ _total_cards_scanned += _cards_scanned[i];
+ FREE_C_HEAP_ARRAY(size_t, _cards_scanned);
+ _cards_scanned = NULL;
+ // Cleanup after copy
+#if G1_REM_SET_LOGGING
+ PrintRSClosure cl;
+ _g1->heap_region_iterate(&cl);
+#endif
+ _g1->set_refine_cte_cl_concurrency(true);
+ cleanUpIteratorsClosure iterClosure;
+ _g1->collection_set_iterate(&iterClosure);
+ // Set all cards back to clean.
+ _g1->cleanUpCardTable();
+ if (ParallelGCThreads > 0) {
+ ConcurrentG1Refine* cg1r = _g1->concurrent_g1_refine();
+ if (cg1r->do_traversal()) {
+ cg1r->cg1rThread()->set_do_traversal(false);
+ }
+ for (uint i = 0; i < ParallelGCThreads; i++) {
+ delete _new_refs[i];
+ }
+ set_par_traversal(false);
+ }
+ assert(!_par_traversal_in_progress, "Invariant between iterations.");
+}
+
+class UpdateRSObjectClosure: public ObjectClosure {
+ UpdateRSOopClosure* _update_rs_oop_cl;
+public:
+ UpdateRSObjectClosure(UpdateRSOopClosure* update_rs_oop_cl) :
+ _update_rs_oop_cl(update_rs_oop_cl) {}
+ void do_object(oop obj) {
+ obj->oop_iterate(_update_rs_oop_cl);
+ }
+
+};
+
+class ScrubRSClosure: public HeapRegionClosure {
+ G1CollectedHeap* _g1h;
+ BitMap* _region_bm;
+ BitMap* _card_bm;
+ CardTableModRefBS* _ctbs;
+public:
+ ScrubRSClosure(BitMap* region_bm, BitMap* card_bm) :
+ _g1h(G1CollectedHeap::heap()),
+ _region_bm(region_bm), _card_bm(card_bm),
+ _ctbs(NULL)
+ {
+ ModRefBarrierSet* bs = _g1h->mr_bs();
+ guarantee(bs->is_a(BarrierSet::CardTableModRef), "Precondition");
+ _ctbs = (CardTableModRefBS*)bs;
+ }
+
+ bool doHeapRegion(HeapRegion* r) {
+ if (!r->continuesHumongous()) {
+ r->rem_set()->scrub(_ctbs, _region_bm, _card_bm);
+ }
+ return false;
+ }
+};
+
+void HRInto_G1RemSet::scrub(BitMap* region_bm, BitMap* card_bm) {
+ ScrubRSClosure scrub_cl(region_bm, card_bm);
+ _g1->heap_region_iterate(&scrub_cl);
+}
+
+void HRInto_G1RemSet::scrub_par(BitMap* region_bm, BitMap* card_bm,
+ int worker_num, int claim_val) {
+ ScrubRSClosure scrub_cl(region_bm, card_bm);
+ _g1->heap_region_par_iterate_chunked(&scrub_cl, worker_num, claim_val);
+}
+
+
+class ConcRefineRegionClosure: public HeapRegionClosure {
+ G1CollectedHeap* _g1h;
+ CardTableModRefBS* _ctbs;
+ ConcurrentGCThread* _cgc_thrd;
+ ConcurrentG1Refine* _cg1r;
+ unsigned _cards_processed;
+ UpdateRSOopClosure _update_rs_oop_cl;
+public:
+ ConcRefineRegionClosure(CardTableModRefBS* ctbs,
+ ConcurrentG1Refine* cg1r,
+ HRInto_G1RemSet* g1rs) :
+ _ctbs(ctbs), _cg1r(cg1r), _cgc_thrd(cg1r->cg1rThread()),
+ _update_rs_oop_cl(g1rs), _cards_processed(0),
+ _g1h(G1CollectedHeap::heap())
+ {}
+
+ bool doHeapRegion(HeapRegion* r) {
+ if (!r->in_collection_set() &&
+ !r->continuesHumongous() &&
+ !r->is_young()) {
+ _update_rs_oop_cl.set_from(r);
+ UpdateRSObjectClosure update_rs_obj_cl(&_update_rs_oop_cl);
+
+ // For each run of dirty card in the region:
+ // 1) Clear the cards.
+ // 2) Process the range corresponding to the run, adding any
+ // necessary RS entries.
+ // 1 must precede 2, so that a concurrent modification redirties the
+ // card. If a processing attempt does not succeed, because it runs
+ // into an unparseable region, we will do binary search to find the
+ // beginning of the next parseable region.
+ HeapWord* startAddr = r->bottom();
+ HeapWord* endAddr = r->used_region().end();
+ HeapWord* lastAddr;
+ HeapWord* nextAddr;
+
+ for (nextAddr = lastAddr = startAddr;
+ nextAddr < endAddr;
+ nextAddr = lastAddr) {
+ MemRegion dirtyRegion;
+
+ // Get and clear dirty region from card table
+ MemRegion next_mr(nextAddr, endAddr);
+ dirtyRegion =
+ _ctbs->dirty_card_range_after_reset(
+ next_mr,
+ true, CardTableModRefBS::clean_card_val());
+ assert(dirtyRegion.start() >= nextAddr,
+ "returned region inconsistent?");
+
+ if (!dirtyRegion.is_empty()) {
+ HeapWord* stop_point =
+ r->object_iterate_mem_careful(dirtyRegion,
+ &update_rs_obj_cl);
+ if (stop_point == NULL) {
+ lastAddr = dirtyRegion.end();
+ _cards_processed +=
+ (int) (dirtyRegion.word_size() / CardTableModRefBS::card_size_in_words);
+ } else {
+ // We're going to skip one or more cards that we can't parse.
+ HeapWord* next_parseable_card =
+ r->next_block_start_careful(stop_point);
+ // Round this up to a card boundary.
+ next_parseable_card =
+ _ctbs->addr_for(_ctbs->byte_after_const(next_parseable_card));
+ // Now we invalidate the intervening cards so we'll see them
+ // again.
+ MemRegion remaining_dirty =
+ MemRegion(stop_point, dirtyRegion.end());
+ MemRegion skipped =
+ MemRegion(stop_point, next_parseable_card);
+ _ctbs->invalidate(skipped.intersection(remaining_dirty));
+
+ // Now start up again where we can parse.
+ lastAddr = next_parseable_card;
+
+ // Count how many we did completely.
+ _cards_processed +=
+ (stop_point - dirtyRegion.start()) /
+ CardTableModRefBS::card_size_in_words;
+ }
+ // Allow interruption at regular intervals.
+ // (Might need to make them more regular, if we get big
+ // dirty regions.)
+ if (_cgc_thrd != NULL) {
+ if (_cgc_thrd->should_yield()) {
+ _cgc_thrd->yield();
+ switch (_cg1r->get_pya()) {
+ case PYA_continue:
+ // This may have changed: re-read.
+ endAddr = r->used_region().end();
+ continue;
+ case PYA_restart: case PYA_cancel:
+ return true;
+ }
+ }
+ }
+ } else {
+ break;
+ }
+ }
+ }
+ // A good yield opportunity.
+ if (_cgc_thrd != NULL) {
+ if (_cgc_thrd->should_yield()) {
+ _cgc_thrd->yield();
+ switch (_cg1r->get_pya()) {
+ case PYA_restart: case PYA_cancel:
+ return true;
+ default:
+ break;
+ }
+
+ }
+ }
+ return false;
+ }
+
+ unsigned cards_processed() { return _cards_processed; }
+};
+
+
+void HRInto_G1RemSet::concurrentRefinementPass(ConcurrentG1Refine* cg1r) {
+ ConcRefineRegionClosure cr_cl(ct_bs(), cg1r, this);
+ _g1->heap_region_iterate(&cr_cl);
+ _conc_refine_traversals++;
+ _conc_refine_cards += cr_cl.cards_processed();
+}
+
+static IntHistogram out_of_histo(50, 50);
+
+
+
+void HRInto_G1RemSet::concurrentRefineOneCard(jbyte* card_ptr, int worker_i) {
+ // If the card is no longer dirty, nothing to do.
+ if (*card_ptr != CardTableModRefBS::dirty_card_val()) return;
+
+ // Construct the region representing the card.
+ HeapWord* start = _ct_bs->addr_for(card_ptr);
+ // And find the region containing it.
+ HeapRegion* r = _g1->heap_region_containing(start);
+ if (r == NULL) {
+ guarantee(_g1->is_in_permanent(start), "Or else where?");
+ return; // Not in the G1 heap (might be in perm, for example.)
+ }
+ // Why do we have to check here whether a card is on a young region,
+ // given that we dirty young regions and, as a result, the
+ // post-barrier is supposed to filter them out and never to enqueue
+ // them? When we allocate a new region as the "allocation region" we
+ // actually dirty its cards after we release the lock, since card
+ // dirtying while holding the lock was a performance bottleneck. So,
+ // as a result, it is possible for other threads to actually
+ // allocate objects in the region (after the acquire the lock)
+ // before all the cards on the region are dirtied. This is unlikely,
+ // and it doesn't happen often, but it can happen. So, the extra
+ // check below filters out those cards.
+ if (r->is_young()) {
+ return;
+ }
+ // While we are processing RSet buffers during the collection, we
+ // actually don't want to scan any cards on the collection set,
+ // since we don't want to update remebered sets with entries that
+ // point into the collection set, given that live objects from the
+ // collection set are about to move and such entries will be stale
+ // very soon. This change also deals with a reliability issue which
+ // involves scanning a card in the collection set and coming across
+ // an array that was being chunked and looking malformed. Note,
+ // however, that if evacuation fails, we have to scan any objects
+ // that were not moved and create any missing entries.
+ if (r->in_collection_set()) {
+ return;
+ }
+
+ // Should we defer it?
+ if (_cg1r->use_cache()) {
+ card_ptr = _cg1r->cache_insert(card_ptr);
+ // If it was not an eviction, nothing to do.
+ if (card_ptr == NULL) return;
+
+ // OK, we have to reset the card start, region, etc.
+ start = _ct_bs->addr_for(card_ptr);
+ r = _g1->heap_region_containing(start);
+ if (r == NULL) {
+ guarantee(_g1->is_in_permanent(start), "Or else where?");
+ return; // Not in the G1 heap (might be in perm, for example.)
+ }
+ guarantee(!r->is_young(), "It was evicted in the current minor cycle.");
+ }
+
+ HeapWord* end = _ct_bs->addr_for(card_ptr + 1);
+ MemRegion dirtyRegion(start, end);
+
+#if CARD_REPEAT_HISTO
+ init_ct_freq_table(_g1->g1_reserved_obj_bytes());
+ ct_freq_note_card(_ct_bs->index_for(start));
+#endif
+
+ UpdateRSOopClosure update_rs_oop_cl(this, worker_i);
+ update_rs_oop_cl.set_from(r);
+ FilterOutOfRegionClosure filter_then_update_rs_oop_cl(r, &update_rs_oop_cl);
+
+ // Undirty the card.
+ *card_ptr = CardTableModRefBS::clean_card_val();
+ // We must complete this write before we do any of the reads below.
+ OrderAccess::storeload();
+ // And process it, being careful of unallocated portions of TLAB's.
+ HeapWord* stop_point =
+ r->oops_on_card_seq_iterate_careful(dirtyRegion,
+ &filter_then_update_rs_oop_cl);
+ // If stop_point is non-null, then we encountered an unallocated region
+ // (perhaps the unfilled portion of a TLAB.) For now, we'll dirty the
+ // card and re-enqueue: if we put off the card until a GC pause, then the
+ // unallocated portion will be filled in. Alternatively, we might try
+ // the full complexity of the technique used in "regular" precleaning.
+ if (stop_point != NULL) {
+ // The card might have gotten re-dirtied and re-enqueued while we
+ // worked. (In fact, it's pretty likely.)
+ if (*card_ptr != CardTableModRefBS::dirty_card_val()) {
+ *card_ptr = CardTableModRefBS::dirty_card_val();
+ MutexLockerEx x(Shared_DirtyCardQ_lock,
+ Mutex::_no_safepoint_check_flag);
+ DirtyCardQueue* sdcq =
+ JavaThread::dirty_card_queue_set().shared_dirty_card_queue();
+ sdcq->enqueue(card_ptr);
+ }
+ } else {
+ out_of_histo.add_entry(filter_then_update_rs_oop_cl.out_of_region());
+ _conc_refine_cards++;
+ }
+}
+
+class HRRSStatsIter: public HeapRegionClosure {
+ size_t _occupied;
+ size_t _total_mem_sz;
+ size_t _max_mem_sz;
+ HeapRegion* _max_mem_sz_region;
+public:
+ HRRSStatsIter() :
+ _occupied(0),
+ _total_mem_sz(0),
+ _max_mem_sz(0),
+ _max_mem_sz_region(NULL)
+ {}
+
+ bool doHeapRegion(HeapRegion* r) {
+ if (r->continuesHumongous()) return false;
+ size_t mem_sz = r->rem_set()->mem_size();
+ if (mem_sz > _max_mem_sz) {
+ _max_mem_sz = mem_sz;
+ _max_mem_sz_region = r;
+ }
+ _total_mem_sz += mem_sz;
+ size_t occ = r->rem_set()->occupied();
+ _occupied += occ;
+ return false;
+ }
+ size_t total_mem_sz() { return _total_mem_sz; }
+ size_t max_mem_sz() { return _max_mem_sz; }
+ size_t occupied() { return _occupied; }
+ HeapRegion* max_mem_sz_region() { return _max_mem_sz_region; }
+};
+
+void HRInto_G1RemSet::print_summary_info() {
+ G1CollectedHeap* g1 = G1CollectedHeap::heap();
+ ConcurrentG1RefineThread* cg1r_thrd =
+ g1->concurrent_g1_refine()->cg1rThread();
+
+#if CARD_REPEAT_HISTO
+ gclog_or_tty->print_cr("\nG1 card_repeat count histogram: ");
+ gclog_or_tty->print_cr(" # of repeats --> # of cards with that number.");
+ card_repeat_count.print_on(gclog_or_tty);
+#endif
+
+ if (FILTEROUTOFREGIONCLOSURE_DOHISTOGRAMCOUNT) {
+ gclog_or_tty->print_cr("\nG1 rem-set out-of-region histogram: ");
+ gclog_or_tty->print_cr(" # of CS ptrs --> # of cards with that number.");
+ out_of_histo.print_on(gclog_or_tty);
+ }
+ gclog_or_tty->print_cr("\n Concurrent RS processed %d cards in "
+ "%5.2fs.",
+ _conc_refine_cards, cg1r_thrd->vtime_accum());
+
+ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+ jint tot_processed_buffers =
+ dcqs.processed_buffers_mut() + dcqs.processed_buffers_rs_thread();
+ gclog_or_tty->print_cr(" Of %d completed buffers:", tot_processed_buffers);
+ gclog_or_tty->print_cr(" %8d (%5.1f%%) by conc RS thread.",
+ dcqs.processed_buffers_rs_thread(),
+ 100.0*(float)dcqs.processed_buffers_rs_thread()/
+ (float)tot_processed_buffers);
+ gclog_or_tty->print_cr(" %8d (%5.1f%%) by mutator threads.",
+ dcqs.processed_buffers_mut(),
+ 100.0*(float)dcqs.processed_buffers_mut()/
+ (float)tot_processed_buffers);
+ gclog_or_tty->print_cr(" Did %d concurrent refinement traversals.",
+ _conc_refine_traversals);
+ if (!G1RSBarrierUseQueue) {
+ gclog_or_tty->print_cr(" Scanned %8.2f cards/traversal.",
+ _conc_refine_traversals > 0 ?
+ (float)_conc_refine_cards/(float)_conc_refine_traversals :
+ 0);
+ }
+ gclog_or_tty->print_cr("");
+ if (G1UseHRIntoRS) {
+ HRRSStatsIter blk;
+ g1->heap_region_iterate(&blk);
+ gclog_or_tty->print_cr(" Total heap region rem set sizes = " SIZE_FORMAT "K."
+ " Max = " SIZE_FORMAT "K.",
+ blk.total_mem_sz()/K, blk.max_mem_sz()/K);
+ gclog_or_tty->print_cr(" Static structures = " SIZE_FORMAT "K,"
+ " free_lists = " SIZE_FORMAT "K.",
+ HeapRegionRemSet::static_mem_size()/K,
+ HeapRegionRemSet::fl_mem_size()/K);
+ gclog_or_tty->print_cr(" %d occupied cards represented.",
+ blk.occupied());
+ gclog_or_tty->print_cr(" Max sz region = [" PTR_FORMAT ", " PTR_FORMAT " )"
+ " %s, cap = " SIZE_FORMAT "K, occ = " SIZE_FORMAT "K.",
+ blk.max_mem_sz_region()->bottom(), blk.max_mem_sz_region()->end(),
+ (blk.max_mem_sz_region()->popular() ? "POP" : ""),
+ (blk.max_mem_sz_region()->rem_set()->mem_size() + K - 1)/K,
+ (blk.max_mem_sz_region()->rem_set()->occupied() + K - 1)/K);
+ gclog_or_tty->print_cr(" Did %d coarsenings.",
+ HeapRegionRemSet::n_coarsenings());
+
+ }
+}
+void HRInto_G1RemSet::prepare_for_verify() {
+ if (G1HRRSFlushLogBuffersOnVerify && VerifyBeforeGC && !_g1->full_collection()) {
+ cleanupHRRS();
+ _g1->set_refine_cte_cl_concurrency(false);
+ if (SafepointSynchronize::is_at_safepoint()) {
+ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+ dcqs.concatenate_logs();
+ }
+ bool cg1r_use_cache = _cg1r->use_cache();
+ _cg1r->set_use_cache(false);
+ updateRS(0);
+ _cg1r->set_use_cache(cg1r_use_cache);
+ }
+}