diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/hotspot/share/gc/shared/gcTimer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/shared/gcTimer.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,396 @@
+/*
+ * Copyright (c) 2012, 2015, 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/shared/gcTimer.hpp"
+#include "utilities/growableArray.hpp"
+#include "utilities/ticks.inline.hpp"
+
+// the "time" parameter for most functions
+// has a default value set by Ticks::now()
+
+void GCTimer::register_gc_start(const Ticks& time) {
+  _time_partitions.clear();
+  _gc_start = time;
+}
+
+void GCTimer::register_gc_end(const Ticks& time) {
+  assert(!_time_partitions.has_active_phases(),
+      "We should have ended all started phases, before ending the GC");
+
+  _gc_end = time;
+}
+
+void GCTimer::register_gc_pause_start(const char* name, const Ticks& time) {
+  _time_partitions.report_gc_phase_start(name, time);
+}
+
+void GCTimer::register_gc_pause_end(const Ticks& time) {
+  _time_partitions.report_gc_phase_end(time);
+}
+
+void GCTimer::register_gc_phase_start(const char* name, const Ticks& time) {
+  _time_partitions.report_gc_phase_start(name, time);
+}
+
+void GCTimer::register_gc_phase_end(const Ticks& time) {
+  _time_partitions.report_gc_phase_end(time);
+}
+
+void STWGCTimer::register_gc_start(const Ticks& time) {
+  GCTimer::register_gc_start(time);
+  register_gc_pause_start("GC Pause", time);
+}
+
+void STWGCTimer::register_gc_end(const Ticks& time) {
+  register_gc_pause_end(time);
+  GCTimer::register_gc_end(time);
+}
+
+void ConcurrentGCTimer::register_gc_pause_start(const char* name) {
+  assert(!_is_concurrent_phase_active, "A pause phase can't be started while a concurrent phase is active.");
+  GCTimer::register_gc_pause_start(name);
+}
+
+void ConcurrentGCTimer::register_gc_pause_end() {
+  assert(!_is_concurrent_phase_active, "A pause phase can't be ended while a concurrent phase is active.");
+  GCTimer::register_gc_pause_end();
+}
+
+void ConcurrentGCTimer::register_gc_concurrent_start(const char* name, const Ticks& time) {
+  assert(!_is_concurrent_phase_active, "A concurrent phase is already active.");
+  _time_partitions.report_gc_phase_start(name, time, GCPhase::ConcurrentPhaseType);
+  _is_concurrent_phase_active = true;
+}
+
+void ConcurrentGCTimer::register_gc_concurrent_end(const Ticks& time) {
+  assert(_is_concurrent_phase_active, "A concurrent phase is not active.");
+  _time_partitions.report_gc_phase_end(time, GCPhase::ConcurrentPhaseType);
+  _is_concurrent_phase_active = false;
+}
+
+void PhasesStack::clear() {
+  _next_phase_level = 0;
+}
+
+void PhasesStack::push(int phase_index) {
+  assert(_next_phase_level < PHASE_LEVELS, "Overflow");
+
+  _phase_indices[_next_phase_level] = phase_index;
+  _next_phase_level++;
+}
+
+int PhasesStack::pop() {
+  assert(_next_phase_level > 0, "Underflow");
+
+  _next_phase_level--;
+  return _phase_indices[_next_phase_level];
+}
+
+int PhasesStack::count() const {
+  return _next_phase_level;
+}
+
+TimePartitions::TimePartitions() {
+  _phases = new (ResourceObj::C_HEAP, mtGC) GrowableArray<GCPhase>(INITIAL_CAPACITY, true, mtGC);
+  clear();
+}
+
+TimePartitions::~TimePartitions() {
+  delete _phases;
+  _phases = NULL;
+}
+
+void TimePartitions::clear() {
+  _phases->clear();
+  _active_phases.clear();
+  _sum_of_pauses = Tickspan();
+  _longest_pause = Tickspan();
+}
+
+void TimePartitions::report_gc_phase_start(const char* name, const Ticks& time, GCPhase::PhaseType type) {
+  assert(_phases->length() <= 1000, "Too many recored phases?");
+
+  int level = _active_phases.count();
+
+  GCPhase phase;
+  phase.set_type(type);
+  phase.set_level(level);
+  phase.set_name(name);
+  phase.set_start(time);
+
+  int index = _phases->append(phase);
+
+  _active_phases.push(index);
+}
+
+void TimePartitions::update_statistics(GCPhase* phase) {
+  if ((phase->type() == GCPhase::PausePhaseType) && (phase->level() == 0)) {
+    const Tickspan pause = phase->end() - phase->start();
+    _sum_of_pauses += pause;
+    _longest_pause = MAX2(pause, _longest_pause);
+  }
+}
+
+void TimePartitions::report_gc_phase_end(const Ticks& time, GCPhase::PhaseType type) {
+  int phase_index = _active_phases.pop();
+  GCPhase* phase = _phases->adr_at(phase_index);
+  phase->set_end(time);
+  update_statistics(phase);
+}
+
+int TimePartitions::num_phases() const {
+  return _phases->length();
+}
+
+GCPhase* TimePartitions::phase_at(int index) const {
+  assert(index >= 0, "Out of bounds");
+  assert(index < _phases->length(), "Out of bounds");
+
+  return _phases->adr_at(index);
+}
+
+bool TimePartitions::has_active_phases() {
+  return _active_phases.count() > 0;
+}
+
+bool TimePartitionPhasesIterator::has_next() {
+  return _next < _time_partitions->num_phases();
+}
+
+GCPhase* TimePartitionPhasesIterator::next() {
+  assert(has_next(), "Must have phases left");
+  return _time_partitions->phase_at(_next++);
+}
+
+
+/////////////// Unit tests ///////////////
+
+#ifndef PRODUCT
+
+class TimePartitionPhasesIteratorTest {
+ public:
+  static void all() {
+    one_pause();
+    two_pauses();
+    one_sub_pause_phase();
+    many_sub_pause_phases();
+    many_sub_pause_phases2();
+    max_nested_pause_phases();
+    one_concurrent();
+  }
+
+  static void validate_gc_phase(GCPhase* phase, int level, const char* name, const Ticks& start, const Ticks& end) {
+    assert(phase->level() == level, "Incorrect level");
+    assert(strcmp(phase->name(), name) == 0, "Incorrect name");
+    assert(phase->start() == start, "Incorrect start");
+    assert(phase->end() == end, "Incorrect end");
+  }
+
+  static void one_pause() {
+    TimePartitions time_partitions;
+    time_partitions.report_gc_phase_start("PausePhase", 2);
+    time_partitions.report_gc_phase_end(8);
+
+    TimePartitionPhasesIterator iter(&time_partitions);
+
+    validate_gc_phase(iter.next(), 0, "PausePhase", 2, 8);
+    assert(time_partitions.sum_of_pauses() == Ticks(8) - Ticks(2), "Incorrect");
+    assert(time_partitions.longest_pause() == Ticks(8) - Ticks(2), "Incorrect");
+
+    assert(!iter.has_next(), "Too many elements");
+  }
+
+  static void two_pauses() {
+    TimePartitions time_partitions;
+    time_partitions.report_gc_phase_start("PausePhase1", 2);
+    time_partitions.report_gc_phase_end(3);
+    time_partitions.report_gc_phase_start("PausePhase2", 4);
+    time_partitions.report_gc_phase_end(6);
+
+    TimePartitionPhasesIterator iter(&time_partitions);
+
+    validate_gc_phase(iter.next(), 0, "PausePhase1", 2, 3);
+    validate_gc_phase(iter.next(), 0, "PausePhase2", 4, 6);
+
+    assert(time_partitions.sum_of_pauses() == Ticks(3) - Ticks(0), "Incorrect");
+    assert(time_partitions.longest_pause() == Ticks(2) - Ticks(0), "Incorrect");
+
+    assert(!iter.has_next(), "Too many elements");
+  }
+
+  static void one_sub_pause_phase() {
+    TimePartitions time_partitions;
+    time_partitions.report_gc_phase_start("PausePhase", 2);
+    time_partitions.report_gc_phase_start("SubPhase", 3);
+    time_partitions.report_gc_phase_end(4);
+    time_partitions.report_gc_phase_end(5);
+
+    TimePartitionPhasesIterator iter(&time_partitions);
+
+    validate_gc_phase(iter.next(), 0, "PausePhase", 2, 5);
+    validate_gc_phase(iter.next(), 1, "SubPhase", 3, 4);
+
+    assert(time_partitions.sum_of_pauses() == Ticks(3) - Ticks(0), "Incorrect");
+    assert(time_partitions.longest_pause() == Ticks(3) - Ticks(0), "Incorrect");
+
+    assert(!iter.has_next(), "Too many elements");
+  }
+
+  static void max_nested_pause_phases() {
+    TimePartitions time_partitions;
+    time_partitions.report_gc_phase_start("PausePhase", 2);
+    time_partitions.report_gc_phase_start("SubPhase1", 3);
+    time_partitions.report_gc_phase_start("SubPhase2", 4);
+    time_partitions.report_gc_phase_start("SubPhase3", 5);
+    time_partitions.report_gc_phase_end(6);
+    time_partitions.report_gc_phase_end(7);
+    time_partitions.report_gc_phase_end(8);
+    time_partitions.report_gc_phase_end(9);
+
+    TimePartitionPhasesIterator iter(&time_partitions);
+
+    validate_gc_phase(iter.next(), 0, "PausePhase", 2, 9);
+    validate_gc_phase(iter.next(), 1, "SubPhase1", 3, 8);
+    validate_gc_phase(iter.next(), 2, "SubPhase2", 4, 7);
+    validate_gc_phase(iter.next(), 3, "SubPhase3", 5, 6);
+
+    assert(time_partitions.sum_of_pauses() == Ticks(7) - Ticks(0), "Incorrect");
+    assert(time_partitions.longest_pause() == Ticks(7) - Ticks(0), "Incorrect");
+
+    assert(!iter.has_next(), "Too many elements");
+  }
+
+  static void many_sub_pause_phases() {
+    TimePartitions time_partitions;
+    time_partitions.report_gc_phase_start("PausePhase", 2);
+
+    time_partitions.report_gc_phase_start("SubPhase1", 3);
+    time_partitions.report_gc_phase_end(4);
+    time_partitions.report_gc_phase_start("SubPhase2", 5);
+    time_partitions.report_gc_phase_end(6);
+    time_partitions.report_gc_phase_start("SubPhase3", 7);
+    time_partitions.report_gc_phase_end(8);
+    time_partitions.report_gc_phase_start("SubPhase4", 9);
+    time_partitions.report_gc_phase_end(10);
+
+    time_partitions.report_gc_phase_end(11);
+
+    TimePartitionPhasesIterator iter(&time_partitions);
+
+    validate_gc_phase(iter.next(), 0, "PausePhase", 2, 11);
+    validate_gc_phase(iter.next(), 1, "SubPhase1", 3, 4);
+    validate_gc_phase(iter.next(), 1, "SubPhase2", 5, 6);
+    validate_gc_phase(iter.next(), 1, "SubPhase3", 7, 8);
+    validate_gc_phase(iter.next(), 1, "SubPhase4", 9, 10);
+
+    assert(time_partitions.sum_of_pauses() == Ticks(9) - Ticks(0), "Incorrect");
+    assert(time_partitions.longest_pause() == Ticks(9) - Ticks(0), "Incorrect");
+
+    assert(!iter.has_next(), "Too many elements");
+  }
+
+  static void many_sub_pause_phases2() {
+    TimePartitions time_partitions;
+    time_partitions.report_gc_phase_start("PausePhase", 2);
+
+    time_partitions.report_gc_phase_start("SubPhase1", 3);
+    time_partitions.report_gc_phase_start("SubPhase11", 4);
+    time_partitions.report_gc_phase_end(5);
+    time_partitions.report_gc_phase_start("SubPhase12", 6);
+    time_partitions.report_gc_phase_end(7);
+    time_partitions.report_gc_phase_end(8);
+    time_partitions.report_gc_phase_start("SubPhase2", 9);
+    time_partitions.report_gc_phase_start("SubPhase21", 10);
+    time_partitions.report_gc_phase_end(11);
+    time_partitions.report_gc_phase_start("SubPhase22", 12);
+    time_partitions.report_gc_phase_end(13);
+    time_partitions.report_gc_phase_end(14);
+    time_partitions.report_gc_phase_start("SubPhase3", 15);
+    time_partitions.report_gc_phase_end(16);
+
+    time_partitions.report_gc_phase_end(17);
+
+    TimePartitionPhasesIterator iter(&time_partitions);
+
+    validate_gc_phase(iter.next(), 0, "PausePhase", 2, 17);
+    validate_gc_phase(iter.next(), 1, "SubPhase1", 3, 8);
+    validate_gc_phase(iter.next(), 2, "SubPhase11", 4, 5);
+    validate_gc_phase(iter.next(), 2, "SubPhase12", 6, 7);
+    validate_gc_phase(iter.next(), 1, "SubPhase2", 9, 14);
+    validate_gc_phase(iter.next(), 2, "SubPhase21", 10, 11);
+    validate_gc_phase(iter.next(), 2, "SubPhase22", 12, 13);
+    validate_gc_phase(iter.next(), 1, "SubPhase3", 15, 16);
+
+    assert(time_partitions.sum_of_pauses() == Ticks(15) - Ticks(0), "Incorrect");
+    assert(time_partitions.longest_pause() == Ticks(15) - Ticks(0), "Incorrect");
+
+    assert(!iter.has_next(), "Too many elements");
+  }
+
+  static void one_concurrent() {
+    TimePartitions time_partitions;
+    time_partitions.report_gc_phase_start("ConcurrentPhase", 2, GCPhase::ConcurrentPhaseType);
+    time_partitions.report_gc_phase_end(8, GCPhase::ConcurrentPhaseType);
+
+    TimePartitionPhasesIterator iter(&time_partitions);
+
+    validate_gc_phase(iter.next(), 0, "ConcurrentPhase", 2, 8);
+    // ConcurrentPhaseType should not affect to both 'sum_of_pauses()' and 'longest_pause()'.
+    assert(time_partitions.sum_of_pauses() == Tickspan(), "Incorrect");
+    assert(time_partitions.longest_pause() == Tickspan(), "Incorrect");
+
+    assert(!iter.has_next(), "Too many elements");
+  }
+};
+
+class GCTimerTest {
+public:
+  static void all() {
+    gc_start();
+    gc_end();
+  }
+
+  static void gc_start() {
+    GCTimer gc_timer;
+    gc_timer.register_gc_start(1);
+
+    assert(gc_timer.gc_start() == 1, "Incorrect");
+  }
+
+  static void gc_end() {
+    GCTimer gc_timer;
+    gc_timer.register_gc_start(1);
+    gc_timer.register_gc_end(2);
+
+    assert(gc_timer.gc_end() == 2, "Incorrect");
+  }
+};
+
+void GCTimer_test() {
+  GCTimerTest::all();
+  TimePartitionPhasesIteratorTest::all();
+}
+
+#endif