/*
* Copyright (c) 2019, 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
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*/
#include "precompiled.hpp"
#include "gc/shared/collectedHeap.hpp"
#include "jfr/leakprofiler/leakProfiler.hpp"
#include "jfr/leakprofiler/chains/bfsClosure.hpp"
#include "jfr/leakprofiler/chains/bitset.inline.hpp"
#include "jfr/leakprofiler/chains/dfsClosure.hpp"
#include "jfr/leakprofiler/chains/edge.hpp"
#include "jfr/leakprofiler/chains/edgeQueue.hpp"
#include "jfr/leakprofiler/chains/edgeStore.hpp"
#include "jfr/leakprofiler/chains/objectSampleMarker.hpp"
#include "jfr/leakprofiler/chains/rootSetClosure.hpp"
#include "jfr/leakprofiler/chains/edgeStore.hpp"
#include "jfr/leakprofiler/chains/objectSampleMarker.hpp"
#include "jfr/leakprofiler/chains/pathToGcRootsOperation.hpp"
#include "jfr/leakprofiler/checkpoint/eventEmitter.hpp"
#include "jfr/leakprofiler/checkpoint/objectSampleCheckpoint.hpp"
#include "jfr/leakprofiler/sampling/objectSample.hpp"
#include "jfr/leakprofiler/sampling/objectSampler.hpp"
#include "jfr/leakprofiler/utilities/granularTimer.hpp"
#include "logging/log.hpp"
#include "memory/universe.hpp"
#include "oops/oop.inline.hpp"
#include "runtime/safepoint.hpp"
#include "utilities/globalDefinitions.hpp"
PathToGcRootsOperation::PathToGcRootsOperation(ObjectSampler* sampler, EdgeStore* edge_store, int64_t cutoff, bool emit_all) :
_sampler(sampler),_edge_store(edge_store), _cutoff_ticks(cutoff), _emit_all(emit_all) {}
/* The EdgeQueue is backed by directly managed virtual memory.
* We will attempt to dimension an initial reservation
* in proportion to the size of the heap (represented by heap_region).
* Initial memory reservation: 5% of the heap OR at least 32 Mb
* Commit ratio: 1 : 10 (subject to allocation granularties)
*/
static size_t edge_queue_memory_reservation() {
const size_t memory_reservation_bytes = MAX2(MaxHeapSize / 20, 32*M);
assert(memory_reservation_bytes >= (size_t)32*M, "invariant");
return memory_reservation_bytes;
}
static size_t edge_queue_memory_commit_size(size_t memory_reservation_bytes) {
const size_t memory_commit_block_size_bytes = memory_reservation_bytes / 10;
assert(memory_commit_block_size_bytes >= (size_t)3*M, "invariant");
return memory_commit_block_size_bytes;
}
static void log_edge_queue_summary(const EdgeQueue& edge_queue) {
log_trace(jfr, system)("EdgeQueue reserved size total: " SIZE_FORMAT " [KB]", edge_queue.reserved_size() / K);
log_trace(jfr, system)("EdgeQueue edges total: " SIZE_FORMAT, edge_queue.top());
log_trace(jfr, system)("EdgeQueue liveset total: " SIZE_FORMAT " [KB]", edge_queue.live_set() / K);
if (edge_queue.reserved_size() > 0) {
log_trace(jfr, system)("EdgeQueue commit reserve ratio: %f\n",
((double)edge_queue.live_set() / (double)edge_queue.reserved_size()));
}
}
void PathToGcRootsOperation::doit() {
assert(SafepointSynchronize::is_at_safepoint(), "invariant");
assert(_cutoff_ticks > 0, "invariant");
// The bitset used for marking is dimensioned as a function of the heap size
BitSet mark_bits;
// The edge queue is dimensioned as a fraction of the heap size
const size_t edge_queue_reservation_size = edge_queue_memory_reservation();
EdgeQueue edge_queue(edge_queue_reservation_size, edge_queue_memory_commit_size(edge_queue_reservation_size));
// The initialize() routines will attempt to reserve and allocate backing storage memory.
// Failure to accommodate will render root chain processing impossible.
// As a fallback on failure, just write out the existing samples, flat, without chains.
if (!edge_queue.initialize()) {
log_warning(jfr)("Unable to allocate memory for root chain processing");
return;
}
// Save the original markWord for the potential leak objects,
// to be restored on function exit
ObjectSampleMarker marker;
if (ObjectSampleCheckpoint::save_mark_words(_sampler, marker, _emit_all) == 0) {
// no valid samples to process
return;
}
// Necessary condition for attempting a root set iteration
Universe::heap()->ensure_parsability(false);
BFSClosure bfs(&edge_queue, _edge_store, &mark_bits);
RootSetClosure<BFSClosure> roots(&bfs);
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