changeset 50162:2fef34f04314

8200626: Restore history for g1ConcurrentMarkThread.* Reviewed-by: shade, sjohanss
author ehelin
date Wed, 04 Apr 2018 10:12:02 +0200
parents 8237a91c1cca
children 8263950638ed
files src/hotspot/share/gc/g1/concurrentMarkThread.cpp src/hotspot/share/gc/g1/concurrentMarkThread.hpp src/hotspot/share/gc/g1/concurrentMarkThread.inline.hpp src/hotspot/share/gc/g1/g1CollectedHeap.cpp src/hotspot/share/gc/g1/g1CollectedHeap.hpp src/hotspot/share/gc/g1/g1ConcurrentMark.cpp src/hotspot/share/gc/g1/g1ConcurrentMark.hpp src/hotspot/share/gc/g1/g1ConcurrentMarkThread.cpp src/hotspot/share/gc/g1/g1ConcurrentMarkThread.hpp src/hotspot/share/gc/g1/g1ConcurrentMarkThread.inline.hpp src/hotspot/share/gc/g1/g1HeapVerifier.cpp src/hotspot/share/gc/g1/g1Policy.cpp src/hotspot/share/gc/g1/vm_operations_g1.cpp src/hotspot/share/prims/whitebox.cpp src/hotspot/share/runtime/thread.cpp
diffstat 15 files changed, 603 insertions(+), 601 deletions(-) [+]
line wrap: on
line diff
--- a/src/hotspot/share/gc/g1/concurrentMarkThread.cpp	Tue Apr 03 13:15:27 2018 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,418 +0,0 @@
-/*
- * Copyright (c) 2001, 2018, 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 "classfile/classLoaderData.hpp"
-#include "gc/g1/concurrentMarkThread.inline.hpp"
-#include "gc/g1/g1Analytics.hpp"
-#include "gc/g1/g1CollectedHeap.inline.hpp"
-#include "gc/g1/g1ConcurrentMark.inline.hpp"
-#include "gc/g1/g1MMUTracker.hpp"
-#include "gc/g1/g1Policy.hpp"
-#include "gc/g1/g1RemSet.hpp"
-#include "gc/g1/vm_operations_g1.hpp"
-#include "gc/shared/concurrentGCPhaseManager.hpp"
-#include "gc/shared/gcId.hpp"
-#include "gc/shared/gcTrace.hpp"
-#include "gc/shared/gcTraceTime.inline.hpp"
-#include "gc/shared/suspendibleThreadSet.hpp"
-#include "logging/log.hpp"
-#include "memory/resourceArea.hpp"
-#include "runtime/handles.inline.hpp"
-#include "runtime/vmThread.hpp"
-#include "utilities/debug.hpp"
-
-// ======= Concurrent Mark Thread ========
-
-// Check order in EXPAND_CURRENT_PHASES
-STATIC_ASSERT(ConcurrentGCPhaseManager::UNCONSTRAINED_PHASE <
-              ConcurrentGCPhaseManager::IDLE_PHASE);
-
-#define EXPAND_CONCURRENT_PHASES(expander)                                 \
-  expander(ANY, = ConcurrentGCPhaseManager::UNCONSTRAINED_PHASE, NULL)     \
-  expander(IDLE, = ConcurrentGCPhaseManager::IDLE_PHASE, NULL)             \
-  expander(CONCURRENT_CYCLE,, "Concurrent Cycle")                          \
-  expander(CLEAR_CLAIMED_MARKS,, "Concurrent Clear Claimed Marks")         \
-  expander(SCAN_ROOT_REGIONS,, "Concurrent Scan Root Regions")             \
-  expander(CONCURRENT_MARK,, "Concurrent Mark")                            \
-  expander(MARK_FROM_ROOTS,, "Concurrent Mark From Roots")                 \
-  expander(BEFORE_REMARK,, NULL)                                           \
-  expander(REMARK,, NULL)                                                  \
-  expander(REBUILD_REMEMBERED_SETS,, "Concurrent Rebuild Remembered Sets") \
-  expander(CLEANUP_FOR_NEXT_MARK,, "Concurrent Cleanup for Next Mark")     \
-  /* */
-
-class G1ConcurrentPhase : public AllStatic {
-public:
-  enum {
-#define CONCURRENT_PHASE_ENUM(tag, value, ignore_title) tag value,
-    EXPAND_CONCURRENT_PHASES(CONCURRENT_PHASE_ENUM)
-#undef CONCURRENT_PHASE_ENUM
-    PHASE_ID_LIMIT
-  };
-};
-
-// The CM thread is created when the G1 garbage collector is used
-
-ConcurrentMarkThread::ConcurrentMarkThread(G1ConcurrentMark* cm) :
-  ConcurrentGCThread(),
-  _cm(cm),
-  _state(Idle),
-  _phase_manager_stack(),
-  _vtime_accum(0.0),
-  _vtime_mark_accum(0.0) {
-
-  set_name("G1 Main Marker");
-  create_and_start();
-}
-
-class CMRemark : public VoidClosure {
-  G1ConcurrentMark* _cm;
-public:
-  CMRemark(G1ConcurrentMark* cm) : _cm(cm) {}
-
-  void do_void(){
-    _cm->remark();
-  }
-};
-
-class CMCleanup : public VoidClosure {
-  G1ConcurrentMark* _cm;
-public:
-  CMCleanup(G1ConcurrentMark* cm) : _cm(cm) {}
-
-  void do_void(){
-    _cm->cleanup();
-  }
-};
-
-double ConcurrentMarkThread::mmu_sleep_time(G1Policy* g1_policy, bool remark) {
-  // There are 3 reasons to use SuspendibleThreadSetJoiner.
-  // 1. To avoid concurrency problem.
-  //    - G1MMUTracker::add_pause(), when_sec() and its variation(when_ms() etc..) can be called
-  //      concurrently from ConcurrentMarkThread and VMThread.
-  // 2. If currently a gc is running, but it has not yet updated the MMU,
-  //    we will not forget to consider that pause in the MMU calculation.
-  // 3. If currently a gc is running, ConcurrentMarkThread will wait it to be finished.
-  //    And then sleep for predicted amount of time by delay_to_keep_mmu().
-  SuspendibleThreadSetJoiner sts_join;
-
-  const G1Analytics* analytics = g1_policy->analytics();
-  double now = os::elapsedTime();
-  double prediction_ms = remark ? analytics->predict_remark_time_ms()
-                                : analytics->predict_cleanup_time_ms();
-  G1MMUTracker *mmu_tracker = g1_policy->mmu_tracker();
-  return mmu_tracker->when_ms(now, prediction_ms);
-}
-
-void ConcurrentMarkThread::delay_to_keep_mmu(G1Policy* g1_policy, bool remark) {
-  if (g1_policy->adaptive_young_list_length()) {
-    jlong sleep_time_ms = mmu_sleep_time(g1_policy, remark);
-    if (!_cm->has_aborted() && sleep_time_ms > 0) {
-      os::sleep(this, sleep_time_ms, false);
-    }
-  }
-}
-
-class G1ConcPhaseTimer : public GCTraceConcTimeImpl<LogLevel::Info, LOG_TAGS(gc, marking)> {
-  G1ConcurrentMark* _cm;
-
- public:
-  G1ConcPhaseTimer(G1ConcurrentMark* cm, const char* title) :
-    GCTraceConcTimeImpl<LogLevel::Info,  LogTag::_gc, LogTag::_marking>(title),
-    _cm(cm)
-  {
-    _cm->gc_timer_cm()->register_gc_concurrent_start(title);
-  }
-
-  ~G1ConcPhaseTimer() {
-    _cm->gc_timer_cm()->register_gc_concurrent_end();
-  }
-};
-
-static const char* const concurrent_phase_names[] = {
-#define CONCURRENT_PHASE_NAME(tag, ignore_value, ignore_title) XSTR(tag),
-  EXPAND_CONCURRENT_PHASES(CONCURRENT_PHASE_NAME)
-#undef CONCURRENT_PHASE_NAME
-  NULL                          // terminator
-};
-// Verify dense enum assumption.  +1 for terminator.
-STATIC_ASSERT(G1ConcurrentPhase::PHASE_ID_LIMIT + 1 ==
-              ARRAY_SIZE(concurrent_phase_names));
-
-// Returns the phase number for name, or a negative value if unknown.
-static int lookup_concurrent_phase(const char* name) {
-  const char* const* names = concurrent_phase_names;
-  for (uint i = 0; names[i] != NULL; ++i) {
-    if (strcmp(name, names[i]) == 0) {
-      return static_cast<int>(i);
-    }
-  }
-  return -1;
-}
-
-// The phase must be valid and must have a title.
-static const char* lookup_concurrent_phase_title(int phase) {
-  static const char* const titles[] = {
-#define CONCURRENT_PHASE_TITLE(ignore_tag, ignore_value, title) title,
-    EXPAND_CONCURRENT_PHASES(CONCURRENT_PHASE_TITLE)
-#undef CONCURRENT_PHASE_TITLE
-  };
-  // Verify dense enum assumption.
-  STATIC_ASSERT(G1ConcurrentPhase::PHASE_ID_LIMIT == ARRAY_SIZE(titles));
-
-  assert(0 <= phase, "precondition");
-  assert((uint)phase < ARRAY_SIZE(titles), "precondition");
-  const char* title = titles[phase];
-  assert(title != NULL, "precondition");
-  return title;
-}
-
-class G1ConcPhaseManager : public StackObj {
-  G1ConcurrentMark* _cm;
-  ConcurrentGCPhaseManager _manager;
-
-public:
-  G1ConcPhaseManager(int phase, ConcurrentMarkThread* thread) :
-    _cm(thread->cm()),
-    _manager(phase, thread->phase_manager_stack())
-  { }
-
-  ~G1ConcPhaseManager() {
-    // Deactivate the manager if marking aborted, to avoid blocking on
-    // phase exit when the phase has been requested.
-    if (_cm->has_aborted()) {
-      _manager.deactivate();
-    }
-  }
-
-  void set_phase(int phase, bool force) {
-    _manager.set_phase(phase, force);
-  }
-};
-
-// Combine phase management and timing into one convenient utility.
-class G1ConcPhase : public StackObj {
-  G1ConcPhaseTimer _timer;
-  G1ConcPhaseManager _manager;
-
-public:
-  G1ConcPhase(int phase, ConcurrentMarkThread* thread) :
-    _timer(thread->cm(), lookup_concurrent_phase_title(phase)),
-    _manager(phase, thread)
-  { }
-};
-
-const char* const* ConcurrentMarkThread::concurrent_phases() const {
-  return concurrent_phase_names;
-}
-
-bool ConcurrentMarkThread::request_concurrent_phase(const char* phase_name) {
-  int phase = lookup_concurrent_phase(phase_name);
-  if (phase < 0) return false;
-
-  while (!ConcurrentGCPhaseManager::wait_for_phase(phase,
-                                                   phase_manager_stack())) {
-    assert(phase != G1ConcurrentPhase::ANY, "Wait for ANY phase must succeed");
-    if ((phase != G1ConcurrentPhase::IDLE) && !during_cycle()) {
-      // If idle and the goal is !idle, start a collection.
-      G1CollectedHeap::heap()->collect(GCCause::_wb_conc_mark);
-    }
-  }
-  return true;
-}
-
-void ConcurrentMarkThread::run_service() {
-  _vtime_start = os::elapsedVTime();
-
-  G1CollectedHeap* g1h = G1CollectedHeap::heap();
-  G1Policy* g1_policy = g1h->g1_policy();
-
-  G1ConcPhaseManager cpmanager(G1ConcurrentPhase::IDLE, this);
-
-  while (!should_terminate()) {
-    // wait until started is set.
-    sleep_before_next_cycle();
-    if (should_terminate()) {
-      break;
-    }
-
-    cpmanager.set_phase(G1ConcurrentPhase::CONCURRENT_CYCLE, false /* force */);
-
-    GCIdMark gc_id_mark;
-
-    _cm->concurrent_cycle_start();
-
-    GCTraceConcTime(Info, gc) tt("Concurrent Cycle");
-    {
-      ResourceMark rm;
-      HandleMark   hm;
-      double cycle_start = os::elapsedVTime();
-
-      {
-        G1ConcPhase p(G1ConcurrentPhase::CLEAR_CLAIMED_MARKS, this);
-        ClassLoaderDataGraph::clear_claimed_marks();
-      }
-
-      // We have to ensure that we finish scanning the root regions
-      // before the next GC takes place. To ensure this we have to
-      // make sure that we do not join the STS until the root regions
-      // have been scanned. If we did then it's possible that a
-      // subsequent GC could block us from joining the STS and proceed
-      // without the root regions have been scanned which would be a
-      // correctness issue.
-
-      {
-        G1ConcPhase p(G1ConcurrentPhase::SCAN_ROOT_REGIONS, this);
-        _cm->scan_root_regions();
-      }
-
-      // It would be nice to use the G1ConcPhase class here but
-      // the "end" logging is inside the loop and not at the end of
-      // a scope. Also, the timer doesn't support nesting.
-      // Mimicking the same log output instead.
-      {
-        G1ConcPhaseManager mark_manager(G1ConcurrentPhase::CONCURRENT_MARK, this);
-        jlong mark_start = os::elapsed_counter();
-        const char* cm_title = lookup_concurrent_phase_title(G1ConcurrentPhase::CONCURRENT_MARK);
-        log_info(gc, marking)("%s (%.3fs)",
-                              cm_title,
-                              TimeHelper::counter_to_seconds(mark_start));
-        for (uint iter = 1; !_cm->has_aborted(); ++iter) {
-          // Concurrent marking.
-          {
-            G1ConcPhase p(G1ConcurrentPhase::MARK_FROM_ROOTS, this);
-            _cm->mark_from_roots();
-          }
-          if (_cm->has_aborted()) {
-            break;
-          }
-
-          // Provide a control point after mark_from_roots.
-          {
-            G1ConcPhaseManager p(G1ConcurrentPhase::BEFORE_REMARK, this);
-          }
-          if (_cm->has_aborted()) {
-            break;
-          }
-
-          // Delay remark pause for MMU.
-          double mark_end_time = os::elapsedVTime();
-          jlong mark_end = os::elapsed_counter();
-          _vtime_mark_accum += (mark_end_time - cycle_start);
-          delay_to_keep_mmu(g1_policy, true /* remark */);
-          if (_cm->has_aborted()) {
-            break;
-          }
-
-          // Pause Remark.
-          log_info(gc, marking)("%s (%.3fs, %.3fs) %.3fms",
-                                cm_title,
-                                TimeHelper::counter_to_seconds(mark_start),
-                                TimeHelper::counter_to_seconds(mark_end),
-                                TimeHelper::counter_to_millis(mark_end - mark_start));
-          mark_manager.set_phase(G1ConcurrentPhase::REMARK, false);
-          CMRemark cl(_cm);
-          VM_CGC_Operation op(&cl, "Pause Remark");
-          VMThread::execute(&op);
-          if (_cm->has_aborted()) {
-            break;
-          } else if (!_cm->restart_for_overflow()) {
-            break;              // Exit loop if no restart requested.
-          } else {
-            // Loop to restart for overflow.
-            mark_manager.set_phase(G1ConcurrentPhase::CONCURRENT_MARK, false);
-            log_info(gc, marking)("%s Restart for Mark Stack Overflow (iteration #%u)",
-                                  cm_title, iter);
-          }
-        }
-      }
-
-      if (!_cm->has_aborted()) {
-        G1ConcPhase p(G1ConcurrentPhase::REBUILD_REMEMBERED_SETS, this);
-        _cm->rebuild_rem_set_concurrently();
-      }
-
-      double end_time = os::elapsedVTime();
-      // Update the total virtual time before doing this, since it will try
-      // to measure it to get the vtime for this marking.
-      _vtime_accum = (end_time - _vtime_start);
-
-      if (!_cm->has_aborted()) {
-        delay_to_keep_mmu(g1_policy, false /* cleanup */);
-      }
-
-      if (!_cm->has_aborted()) {
-        CMCleanup cl_cl(_cm);
-        VM_CGC_Operation op(&cl_cl, "Pause Cleanup");
-        VMThread::execute(&op);
-      }
-
-      // We now want to allow clearing of the marking bitmap to be
-      // suspended by a collection pause.
-      // We may have aborted just before the remark. Do not bother clearing the
-      // bitmap then, as it has been done during mark abort.
-      if (!_cm->has_aborted()) {
-        G1ConcPhase p(G1ConcurrentPhase::CLEANUP_FOR_NEXT_MARK, this);
-        _cm->cleanup_for_next_mark();
-      } else {
-        assert(!G1VerifyBitmaps || _cm->next_mark_bitmap_is_clear(), "Next mark bitmap must be clear");
-      }
-    }
-
-    // Update the number of full collections that have been
-    // completed. This will also notify the FullGCCount_lock in case a
-    // Java thread is waiting for a full GC to happen (e.g., it
-    // called System.gc() with +ExplicitGCInvokesConcurrent).
-    {
-      SuspendibleThreadSetJoiner sts_join;
-      g1h->increment_old_marking_cycles_completed(true /* concurrent */);
-
-      _cm->concurrent_cycle_end();
-    }
-
-    cpmanager.set_phase(G1ConcurrentPhase::IDLE, _cm->has_aborted() /* force */);
-  }
-  _cm->root_regions()->cancel_scan();
-}
-
-void ConcurrentMarkThread::stop_service() {
-  MutexLockerEx ml(CGC_lock, Mutex::_no_safepoint_check_flag);
-  CGC_lock->notify_all();
-}
-
-void ConcurrentMarkThread::sleep_before_next_cycle() {
-  // We join here because we don't want to do the "shouldConcurrentMark()"
-  // below while the world is otherwise stopped.
-  assert(!in_progress(), "should have been cleared");
-
-  MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag);
-  while (!started() && !should_terminate()) {
-    CGC_lock->wait(Mutex::_no_safepoint_check_flag);
-  }
-
-  if (started()) {
-    set_in_progress();
-  }
-}
--- a/src/hotspot/share/gc/g1/concurrentMarkThread.hpp	Tue Apr 03 13:15:27 2018 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,101 +0,0 @@
-/*
- * Copyright (c) 2001, 2018, 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.
- *
- */
-
-#ifndef SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_HPP
-#define SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_HPP
-
-#include "gc/shared/concurrentGCPhaseManager.hpp"
-#include "gc/shared/concurrentGCThread.hpp"
-
-class G1ConcurrentMark;
-class G1Policy;
-
-// The concurrent mark thread triggers the various steps of the concurrent marking
-// cycle, including various marking cleanup.
-class ConcurrentMarkThread: public ConcurrentGCThread {
-  friend class VMStructs;
-
-  double _vtime_start;  // Initial virtual time.
-  double _vtime_accum;  // Accumulated virtual time.
-  double _vtime_mark_accum;
-
-  G1ConcurrentMark* _cm;
-
-  enum State {
-    Idle,
-    Started,
-    InProgress
-  };
-
-  volatile State _state;
-
-  // WhiteBox testing support.
-  ConcurrentGCPhaseManager::Stack _phase_manager_stack;
-
-  void sleep_before_next_cycle();
-  // Delay marking to meet MMU.
-  void delay_to_keep_mmu(G1Policy* g1_policy, bool remark);
-  double mmu_sleep_time(G1Policy* g1_policy, bool remark);
-
-  void run_service();
-  void stop_service();
-
- public:
-  // Constructor
-  ConcurrentMarkThread(G1ConcurrentMark* cm);
-
-  // Total virtual time so far for this thread and concurrent marking tasks.
-  double vtime_accum();
-  // Marking virtual time so far this thread and concurrent marking tasks.
-  double vtime_mark_accum();
-
-  G1ConcurrentMark* cm()   { return _cm; }
-
-  void set_idle()          { assert(_state != Started, "must not be starting a new cycle"); _state = Idle; }
-  bool idle()              { return _state == Idle; }
-  void set_started()       { assert(_state == Idle, "cycle in progress"); _state = Started; }
-  bool started()           { return _state == Started; }
-  void set_in_progress()   { assert(_state == Started, "must be starting a cycle"); _state = InProgress; }
-  bool in_progress()       { return _state == InProgress; }
-
-  // Returns true from the moment a marking cycle is
-  // initiated (during the initial-mark pause when started() is set)
-  // to the moment when the cycle completes (just after the next
-  // marking bitmap has been cleared and in_progress() is
-  // cleared). While during_cycle() is true we will not start another cycle
-  // so that cycles do not overlap. We cannot use just in_progress()
-  // as the CM thread might take some time to wake up before noticing
-  // that started() is set and set in_progress().
-  bool during_cycle()      { return !idle(); }
-
-  // WhiteBox testing support.
-  const char* const* concurrent_phases() const;
-  bool request_concurrent_phase(const char* phase);
-
-  ConcurrentGCPhaseManager::Stack* phase_manager_stack() {
-    return &_phase_manager_stack;
-  }
-};
-
-#endif // SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_HPP
--- a/src/hotspot/share/gc/g1/concurrentMarkThread.inline.hpp	Tue Apr 03 13:15:27 2018 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,41 +0,0 @@
-/*
- * Copyright (c) 2001, 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.
- *
- */
-
-#ifndef SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_INLINE_HPP
-#define SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_INLINE_HPP
-
-#include "gc/g1/concurrentMarkThread.hpp"
-#include "gc/g1/g1ConcurrentMark.hpp"
-
-  // Total virtual time so far.
-inline double ConcurrentMarkThread::vtime_accum() {
-  return _vtime_accum + _cm->all_task_accum_vtime();
-}
-
-// Marking virtual time so far
-inline double ConcurrentMarkThread::vtime_mark_accum() {
-  return _vtime_mark_accum + _cm->all_task_accum_vtime();
-}
-
-#endif // SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_INLINE_HPP
--- a/src/hotspot/share/gc/g1/g1CollectedHeap.cpp	Tue Apr 03 13:15:27 2018 +0200
+++ b/src/hotspot/share/gc/g1/g1CollectedHeap.cpp	Wed Apr 04 10:12:02 2018 +0200
@@ -29,7 +29,6 @@
 #include "code/codeCache.hpp"
 #include "code/icBuffer.hpp"
 #include "gc/g1/bufferingOopClosure.hpp"
-#include "gc/g1/concurrentMarkThread.inline.hpp"
 #include "gc/g1/g1Allocator.inline.hpp"
 #include "gc/g1/g1CollectedHeap.inline.hpp"
 #include "gc/g1/g1CollectionSet.hpp"
@@ -37,6 +36,7 @@
 #include "gc/g1/g1CollectorState.hpp"
 #include "gc/g1/g1ConcurrentRefine.hpp"
 #include "gc/g1/g1ConcurrentRefineThread.hpp"
+#include "gc/g1/g1ConcurrentMarkThread.inline.hpp"
 #include "gc/g1/g1EvacStats.inline.hpp"
 #include "gc/g1/g1FullCollector.hpp"
 #include "gc/g1/g1GCPhaseTimes.hpp"
--- a/src/hotspot/share/gc/g1/g1CollectedHeap.hpp	Tue Apr 03 13:15:27 2018 +0200
+++ b/src/hotspot/share/gc/g1/g1CollectedHeap.hpp	Wed Apr 04 10:12:02 2018 +0200
@@ -79,7 +79,7 @@
 class G1YoungRemSetSamplingThread;
 class HeapRegionRemSetIterator;
 class G1ConcurrentMark;
-class ConcurrentMarkThread;
+class G1ConcurrentMarkThread;
 class G1ConcurrentRefine;
 class GenerationCounters;
 class STWGCTimer;
@@ -766,7 +766,7 @@
 
   // The concurrent marker (and the thread it runs in.)
   G1ConcurrentMark* _cm;
-  ConcurrentMarkThread* _cmThread;
+  G1ConcurrentMarkThread* _cmThread;
 
   // The concurrent refiner.
   G1ConcurrentRefine* _cr;
--- a/src/hotspot/share/gc/g1/g1ConcurrentMark.cpp	Tue Apr 03 13:15:27 2018 +0200
+++ b/src/hotspot/share/gc/g1/g1ConcurrentMark.cpp	Wed Apr 04 10:12:02 2018 +0200
@@ -26,10 +26,10 @@
 #include "classfile/metadataOnStackMark.hpp"
 #include "classfile/symbolTable.hpp"
 #include "code/codeCache.hpp"
-#include "gc/g1/concurrentMarkThread.inline.hpp"
 #include "gc/g1/g1CollectedHeap.inline.hpp"
 #include "gc/g1/g1CollectorState.hpp"
 #include "gc/g1/g1ConcurrentMark.inline.hpp"
+#include "gc/g1/g1ConcurrentMarkThread.inline.hpp"
 #include "gc/g1/g1HeapVerifier.hpp"
 #include "gc/g1/g1OopClosures.inline.hpp"
 #include "gc/g1/g1Policy.hpp"
@@ -398,7 +398,7 @@
   _mark_bitmap_2.initialize(g1h->reserved_region(), next_bitmap_storage);
 
   // Create & start ConcurrentMark thread.
-  _cm_thread = new ConcurrentMarkThread(this);
+  _cm_thread = new G1ConcurrentMarkThread(this);
   if (_cm_thread->osthread() == NULL) {
     vm_shutdown_during_initialization("Could not create ConcurrentMarkThread");
   }
@@ -824,6 +824,7 @@
 
 class G1CMConcurrentMarkingTask : public AbstractGangTask {
   G1ConcurrentMark*     _cm;
+
 public:
   void work(uint worker_id) {
     assert(Thread::current()->is_ConcurrentGC_thread(), "Not a concurrent GC thread");
--- a/src/hotspot/share/gc/g1/g1ConcurrentMark.hpp	Tue Apr 03 13:15:27 2018 +0200
+++ b/src/hotspot/share/gc/g1/g1ConcurrentMark.hpp	Wed Apr 04 10:12:02 2018 +0200
@@ -33,7 +33,7 @@
 #include "memory/allocation.hpp"
 
 class ConcurrentGCTimer;
-class ConcurrentMarkThread;
+class G1ConcurrentMarkThread;
 class G1CollectedHeap;
 class G1CMTask;
 class G1ConcurrentMark;
@@ -277,7 +277,7 @@
 // This class manages data structures and methods for doing liveness analysis in
 // G1's concurrent cycle.
 class G1ConcurrentMark : public CHeapObj<mtGC> {
-  friend class ConcurrentMarkThread;
+  friend class G1ConcurrentMarkThread;
   friend class G1CMRefProcTaskProxy;
   friend class G1CMRefProcTaskExecutor;
   friend class G1CMKeepAliveAndDrainClosure;
@@ -287,35 +287,35 @@
   friend class G1CMRemarkTask;
   friend class G1CMTask;
 
-  ConcurrentMarkThread*  _cm_thread;     // The thread doing the work
-  G1CollectedHeap*       _g1h;           // The heap
-  bool                   _completed_initialization; // Set to true when initialization is complete
+  G1ConcurrentMarkThread* _cm_thread;     // The thread doing the work
+  G1CollectedHeap*        _g1h;           // The heap
+  bool                    _completed_initialization; // Set to true when initialization is complete
 
   // Concurrent marking support structures
-  G1CMBitMap             _mark_bitmap_1;
-  G1CMBitMap             _mark_bitmap_2;
-  G1CMBitMap*            _prev_mark_bitmap; // Completed mark bitmap
-  G1CMBitMap*            _next_mark_bitmap; // Under-construction mark bitmap
+  G1CMBitMap              _mark_bitmap_1;
+  G1CMBitMap              _mark_bitmap_2;
+  G1CMBitMap*             _prev_mark_bitmap; // Completed mark bitmap
+  G1CMBitMap*             _next_mark_bitmap; // Under-construction mark bitmap
 
   // Heap bounds
-  MemRegion const        _heap;
+  MemRegion const         _heap;
 
   // Root region tracking and claiming
-  G1CMRootRegions        _root_regions;
+  G1CMRootRegions         _root_regions;
 
   // For grey objects
-  G1CMMarkStack          _global_mark_stack; // Grey objects behind global finger
-  HeapWord* volatile     _finger;            // The global finger, region aligned,
-                                             // always pointing to the end of the
-                                             // last claimed region
+  G1CMMarkStack           _global_mark_stack; // Grey objects behind global finger
+  HeapWord* volatile      _finger;            // The global finger, region aligned,
+                                              // always pointing to the end of the
+                                              // last claimed region
 
-  uint                   _worker_id_offset;
-  uint                   _max_num_tasks;    // Maximum number of marking tasks
-  uint                   _num_active_tasks; // Number of tasks currently active
-  G1CMTask**             _tasks;            // Task queue array (max_worker_id length)
+  uint                    _worker_id_offset;
+  uint                    _max_num_tasks;    // Maximum number of marking tasks
+  uint                    _num_active_tasks; // Number of tasks currently active
+  G1CMTask**              _tasks;            // Task queue array (max_worker_id length)
 
-  G1CMTaskQueueSet*      _task_queues;      // Task queue set
-  ParallelTaskTerminator _terminator;       // For termination
+  G1CMTaskQueueSet*       _task_queues;      // Task queue set
+  ParallelTaskTerminator  _terminator;       // For termination
 
   // Two sync barriers that are used to synchronize tasks when an
   // overflow occurs. The algorithm is the following. All tasks enter
@@ -326,30 +326,30 @@
   // ensure, that no task starts doing work before all data
   // structures (local and global) have been re-initialized. When they
   // exit it, they are free to start working again.
-  WorkGangBarrierSync    _first_overflow_barrier_sync;
-  WorkGangBarrierSync    _second_overflow_barrier_sync;
+  WorkGangBarrierSync     _first_overflow_barrier_sync;
+  WorkGangBarrierSync     _second_overflow_barrier_sync;
 
   // This is set by any task, when an overflow on the global data
   // structures is detected
-  volatile bool          _has_overflown;
+  volatile bool           _has_overflown;
   // True: marking is concurrent, false: we're in remark
-  volatile bool          _concurrent;
+  volatile bool           _concurrent;
   // Set at the end of a Full GC so that marking aborts
-  volatile bool          _has_aborted;
+  volatile bool           _has_aborted;
 
   // Used when remark aborts due to an overflow to indicate that
   // another concurrent marking phase should start
-  volatile bool          _restart_for_overflow;
+  volatile bool           _restart_for_overflow;
 
   // This is true from the very start of concurrent marking until the
   // point when all the tasks complete their work. It is really used
   // to determine the points between the end of concurrent marking and
   // time of remark.
-  volatile bool          _concurrent_marking_in_progress;
+  volatile bool           _concurrent_marking_in_progress;
 
-  ConcurrentGCTimer*     _gc_timer_cm;
+  ConcurrentGCTimer*      _gc_timer_cm;
 
-  G1OldTracer*           _gc_tracer_cm;
+  G1OldTracer*            _gc_tracer_cm;
 
   // Timing statistics. All of them are in ms
   NumberSeq _init_times;
@@ -523,7 +523,7 @@
                    G1RegionToSpaceMapper* next_bitmap_storage);
   ~G1ConcurrentMark();
 
-  ConcurrentMarkThread* cm_thread() { return _cm_thread; }
+  G1ConcurrentMarkThread* cm_thread() { return _cm_thread; }
 
   const G1CMBitMap* const prev_mark_bitmap() const { return _prev_mark_bitmap; }
   G1CMBitMap* next_mark_bitmap() const { return _next_mark_bitmap; }
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1ConcurrentMarkThread.cpp	Wed Apr 04 10:12:02 2018 +0200
@@ -0,0 +1,419 @@
+/*
+ * Copyright (c) 2001, 2018, 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 "classfile/classLoaderData.hpp"
+#include "gc/g1/g1Analytics.hpp"
+#include "gc/g1/g1CollectedHeap.inline.hpp"
+#include "gc/g1/g1ConcurrentMark.inline.hpp"
+#include "gc/g1/g1ConcurrentMarkThread.inline.hpp"
+#include "gc/g1/g1MMUTracker.hpp"
+#include "gc/g1/g1Policy.hpp"
+#include "gc/g1/g1RemSet.hpp"
+#include "gc/g1/vm_operations_g1.hpp"
+#include "gc/shared/concurrentGCPhaseManager.hpp"
+#include "gc/shared/gcId.hpp"
+#include "gc/shared/gcTrace.hpp"
+#include "gc/shared/gcTraceTime.inline.hpp"
+#include "gc/shared/suspendibleThreadSet.hpp"
+#include "logging/log.hpp"
+#include "memory/resourceArea.hpp"
+#include "runtime/handles.inline.hpp"
+#include "runtime/vmThread.hpp"
+#include "utilities/debug.hpp"
+
+// ======= Concurrent Mark Thread ========
+
+// Check order in EXPAND_CURRENT_PHASES
+STATIC_ASSERT(ConcurrentGCPhaseManager::UNCONSTRAINED_PHASE <
+              ConcurrentGCPhaseManager::IDLE_PHASE);
+
+#define EXPAND_CONCURRENT_PHASES(expander)                                 \
+  expander(ANY, = ConcurrentGCPhaseManager::UNCONSTRAINED_PHASE, NULL)     \
+  expander(IDLE, = ConcurrentGCPhaseManager::IDLE_PHASE, NULL)             \
+  expander(CONCURRENT_CYCLE,, "Concurrent Cycle")                          \
+  expander(CLEAR_CLAIMED_MARKS,, "Concurrent Clear Claimed Marks")         \
+  expander(SCAN_ROOT_REGIONS,, "Concurrent Scan Root Regions")             \
+  expander(CONCURRENT_MARK,, "Concurrent Mark")                            \
+  expander(MARK_FROM_ROOTS,, "Concurrent Mark From Roots")                 \
+  expander(BEFORE_REMARK,, NULL)                                           \
+  expander(REMARK,, NULL)                                                  \
+  expander(REBUILD_REMEMBERED_SETS,, "Concurrent Rebuild Remembered Sets") \
+  expander(CLEANUP_FOR_NEXT_MARK,, "Concurrent Cleanup for Next Mark")     \
+  /* */
+
+class G1ConcurrentPhase : public AllStatic {
+public:
+  enum {
+#define CONCURRENT_PHASE_ENUM(tag, value, ignore_title) tag value,
+    EXPAND_CONCURRENT_PHASES(CONCURRENT_PHASE_ENUM)
+#undef CONCURRENT_PHASE_ENUM
+    PHASE_ID_LIMIT
+  };
+};
+
+// The CM thread is created when the G1 garbage collector is used
+
+G1ConcurrentMarkThread::G1ConcurrentMarkThread(G1ConcurrentMark* cm) :
+  ConcurrentGCThread(),
+  _cm(cm),
+  _state(Idle),
+  _phase_manager_stack(),
+  _vtime_accum(0.0),
+  _vtime_mark_accum(0.0) {
+
+  set_name("G1 Main Marker");
+  create_and_start();
+}
+
+class CMRemark : public VoidClosure {
+  G1ConcurrentMark* _cm;
+public:
+  CMRemark(G1ConcurrentMark* cm) : _cm(cm) {}
+
+  void do_void(){
+    _cm->remark();
+  }
+};
+
+class CMCleanup : public VoidClosure {
+  G1ConcurrentMark* _cm;
+public:
+  CMCleanup(G1ConcurrentMark* cm) : _cm(cm) {}
+
+  void do_void(){
+    _cm->cleanup();
+  }
+};
+
+double G1ConcurrentMarkThread::mmu_sleep_time(G1Policy* g1_policy, bool remark) {
+  // There are 3 reasons to use SuspendibleThreadSetJoiner.
+  // 1. To avoid concurrency problem.
+  //    - G1MMUTracker::add_pause(), when_sec() and its variation(when_ms() etc..) can be called
+  //      concurrently from ConcurrentMarkThread and VMThread.
+  // 2. If currently a gc is running, but it has not yet updated the MMU,
+  //    we will not forget to consider that pause in the MMU calculation.
+  // 3. If currently a gc is running, ConcurrentMarkThread will wait it to be finished.
+  //    And then sleep for predicted amount of time by delay_to_keep_mmu().
+  SuspendibleThreadSetJoiner sts_join;
+
+  const G1Analytics* analytics = g1_policy->analytics();
+  double now = os::elapsedTime();
+  double prediction_ms = remark ? analytics->predict_remark_time_ms()
+                                : analytics->predict_cleanup_time_ms();
+  G1MMUTracker *mmu_tracker = g1_policy->mmu_tracker();
+  return mmu_tracker->when_ms(now, prediction_ms);
+}
+
+void G1ConcurrentMarkThread::delay_to_keep_mmu(G1Policy* g1_policy, bool remark) {
+  if (g1_policy->adaptive_young_list_length()) {
+    jlong sleep_time_ms = mmu_sleep_time(g1_policy, remark);
+    if (!_cm->has_aborted() && sleep_time_ms > 0) {
+      os::sleep(this, sleep_time_ms, false);
+    }
+  }
+}
+
+class G1ConcPhaseTimer : public GCTraceConcTimeImpl<LogLevel::Info, LOG_TAGS(gc, marking)> {
+  G1ConcurrentMark* _cm;
+
+ public:
+  G1ConcPhaseTimer(G1ConcurrentMark* cm, const char* title) :
+    GCTraceConcTimeImpl<LogLevel::Info,  LogTag::_gc, LogTag::_marking>(title),
+    _cm(cm)
+  {
+    _cm->gc_timer_cm()->register_gc_concurrent_start(title);
+  }
+
+  ~G1ConcPhaseTimer() {
+    _cm->gc_timer_cm()->register_gc_concurrent_end();
+  }
+};
+
+static const char* const concurrent_phase_names[] = {
+#define CONCURRENT_PHASE_NAME(tag, ignore_value, ignore_title) XSTR(tag),
+  EXPAND_CONCURRENT_PHASES(CONCURRENT_PHASE_NAME)
+#undef CONCURRENT_PHASE_NAME
+  NULL                          // terminator
+};
+// Verify dense enum assumption.  +1 for terminator.
+STATIC_ASSERT(G1ConcurrentPhase::PHASE_ID_LIMIT + 1 ==
+              ARRAY_SIZE(concurrent_phase_names));
+
+// Returns the phase number for name, or a negative value if unknown.
+static int lookup_concurrent_phase(const char* name) {
+  const char* const* names = concurrent_phase_names;
+  for (uint i = 0; names[i] != NULL; ++i) {
+    if (strcmp(name, names[i]) == 0) {
+      return static_cast<int>(i);
+    }
+  }
+  return -1;
+}
+
+// The phase must be valid and must have a title.
+static const char* lookup_concurrent_phase_title(int phase) {
+  static const char* const titles[] = {
+#define CONCURRENT_PHASE_TITLE(ignore_tag, ignore_value, title) title,
+    EXPAND_CONCURRENT_PHASES(CONCURRENT_PHASE_TITLE)
+#undef CONCURRENT_PHASE_TITLE
+  };
+  // Verify dense enum assumption.
+  STATIC_ASSERT(G1ConcurrentPhase::PHASE_ID_LIMIT == ARRAY_SIZE(titles));
+
+  assert(0 <= phase, "precondition");
+  assert((uint)phase < ARRAY_SIZE(titles), "precondition");
+  const char* title = titles[phase];
+  assert(title != NULL, "precondition");
+  return title;
+}
+
+class G1ConcPhaseManager : public StackObj {
+  G1ConcurrentMark* _cm;
+  ConcurrentGCPhaseManager _manager;
+
+public:
+  G1ConcPhaseManager(int phase, G1ConcurrentMarkThread* thread) :
+    _cm(thread->cm()),
+    _manager(phase, thread->phase_manager_stack())
+  { }
+
+  ~G1ConcPhaseManager() {
+    // Deactivate the manager if marking aborted, to avoid blocking on
+    // phase exit when the phase has been requested.
+    if (_cm->has_aborted()) {
+      _manager.deactivate();
+    }
+  }
+
+  void set_phase(int phase, bool force) {
+    _manager.set_phase(phase, force);
+  }
+};
+
+// Combine phase management and timing into one convenient utility.
+class G1ConcPhase : public StackObj {
+  G1ConcPhaseTimer _timer;
+  G1ConcPhaseManager _manager;
+
+public:
+  G1ConcPhase(int phase, G1ConcurrentMarkThread* thread) :
+    _timer(thread->cm(), lookup_concurrent_phase_title(phase)),
+    _manager(phase, thread)
+  { }
+};
+
+const char* const* G1ConcurrentMarkThread::concurrent_phases() const {
+  return concurrent_phase_names;
+}
+
+bool G1ConcurrentMarkThread::request_concurrent_phase(const char* phase_name) {
+  int phase = lookup_concurrent_phase(phase_name);
+  if (phase < 0) return false;
+
+  while (!ConcurrentGCPhaseManager::wait_for_phase(phase,
+                                                   phase_manager_stack())) {
+    assert(phase != G1ConcurrentPhase::ANY, "Wait for ANY phase must succeed");
+    if ((phase != G1ConcurrentPhase::IDLE) && !during_cycle()) {
+      // If idle and the goal is !idle, start a collection.
+      G1CollectedHeap::heap()->collect(GCCause::_wb_conc_mark);
+    }
+  }
+  return true;
+}
+
+void G1ConcurrentMarkThread::run_service() {
+  _vtime_start = os::elapsedVTime();
+
+  G1CollectedHeap* g1h = G1CollectedHeap::heap();
+  G1Policy* g1_policy = g1h->g1_policy();
+
+  G1ConcPhaseManager cpmanager(G1ConcurrentPhase::IDLE, this);
+
+  while (!should_terminate()) {
+    // wait until started is set.
+    sleep_before_next_cycle();
+    if (should_terminate()) {
+      break;
+    }
+
+    cpmanager.set_phase(G1ConcurrentPhase::CONCURRENT_CYCLE, false /* force */);
+
+    GCIdMark gc_id_mark;
+
+    _cm->concurrent_cycle_start();
+
+    GCTraceConcTime(Info, gc) tt("Concurrent Cycle");
+    {
+      ResourceMark rm;
+      HandleMark   hm;
+      double cycle_start = os::elapsedVTime();
+
+      {
+        G1ConcPhase p(G1ConcurrentPhase::CLEAR_CLAIMED_MARKS, this);
+        ClassLoaderDataGraph::clear_claimed_marks();
+      }
+
+      // We have to ensure that we finish scanning the root regions
+      // before the next GC takes place. To ensure this we have to
+      // make sure that we do not join the STS until the root regions
+      // have been scanned. If we did then it's possible that a
+      // subsequent GC could block us from joining the STS and proceed
+      // without the root regions have been scanned which would be a
+      // correctness issue.
+
+      {
+        G1ConcPhase p(G1ConcurrentPhase::SCAN_ROOT_REGIONS, this);
+        _cm->scan_root_regions();
+      }
+
+      // It would be nice to use the G1ConcPhase class here but
+      // the "end" logging is inside the loop and not at the end of
+      // a scope. Also, the timer doesn't support nesting.
+      // Mimicking the same log output instead.
+      {
+        G1ConcPhaseManager mark_manager(G1ConcurrentPhase::CONCURRENT_MARK, this);
+        jlong mark_start = os::elapsed_counter();
+        const char* cm_title = lookup_concurrent_phase_title(G1ConcurrentPhase::CONCURRENT_MARK);
+        log_info(gc, marking)("%s (%.3fs)",
+                              cm_title,
+                              TimeHelper::counter_to_seconds(mark_start));
+        for (uint iter = 1; !_cm->has_aborted(); ++iter) {
+          // Concurrent marking.
+          {
+            G1ConcPhase p(G1ConcurrentPhase::MARK_FROM_ROOTS, this);
+            _cm->mark_from_roots();
+          }
+          if (_cm->has_aborted()) {
+            break;
+          }
+
+          // Provide a control point after mark_from_roots.
+          {
+            G1ConcPhaseManager p(G1ConcurrentPhase::BEFORE_REMARK, this);
+          }
+          if (_cm->has_aborted()) {
+            break;
+          }
+
+          // Delay remark pause for MMU.
+          double mark_end_time = os::elapsedVTime();
+          jlong mark_end = os::elapsed_counter();
+          _vtime_mark_accum += (mark_end_time - cycle_start);
+          delay_to_keep_mmu(g1_policy, true /* remark */);
+          if (_cm->has_aborted()) {
+            break;
+          }
+
+          // Pause Remark.
+          log_info(gc, marking)("%s (%.3fs, %.3fs) %.3fms",
+                                cm_title,
+                                TimeHelper::counter_to_seconds(mark_start),
+                                TimeHelper::counter_to_seconds(mark_end),
+                                TimeHelper::counter_to_millis(mark_end - mark_start));
+          mark_manager.set_phase(G1ConcurrentPhase::REMARK, false);
+          CMRemark cl(_cm);
+          VM_CGC_Operation op(&cl, "Pause Remark");
+          VMThread::execute(&op);
+          if (_cm->has_aborted()) {
+            break;
+          } else if (!_cm->restart_for_overflow()) {
+            break;              // Exit loop if no restart requested.
+          } else {
+            // Loop to restart for overflow.
+            mark_manager.set_phase(G1ConcurrentPhase::CONCURRENT_MARK, false);
+            log_info(gc, marking)("%s Restart for Mark Stack Overflow (iteration #%u)",
+                                  cm_title, iter);
+          }
+        }
+      }
+
+      if (!_cm->has_aborted()) {
+        G1ConcPhase p(G1ConcurrentPhase::REBUILD_REMEMBERED_SETS, this);
+        _cm->rebuild_rem_set_concurrently();
+      }
+
+      double end_time = os::elapsedVTime();
+      // Update the total virtual time before doing this, since it will try
+      // to measure it to get the vtime for this marking.
+      _vtime_accum = (end_time - _vtime_start);
+
+      if (!_cm->has_aborted()) {
+        delay_to_keep_mmu(g1_policy, false /* cleanup */);
+      }
+
+      if (!_cm->has_aborted()) {
+        CMCleanup cl_cl(_cm);
+        VM_CGC_Operation op(&cl_cl, "Pause Cleanup");
+        VMThread::execute(&op);
+      }
+
+      // We now want to allow clearing of the marking bitmap to be
+      // suspended by a collection pause.
+      // We may have aborted just before the remark. Do not bother clearing the
+      // bitmap then, as it has been done during mark abort.
+      if (!_cm->has_aborted()) {
+        G1ConcPhase p(G1ConcurrentPhase::CLEANUP_FOR_NEXT_MARK, this);
+        _cm->cleanup_for_next_mark();
+      } else {
+        assert(!G1VerifyBitmaps || _cm->next_mark_bitmap_is_clear(), "Next mark bitmap must be clear");
+      }
+    }
+
+    // Update the number of full collections that have been
+    // completed. This will also notify the FullGCCount_lock in case a
+    // Java thread is waiting for a full GC to happen (e.g., it
+    // called System.gc() with +ExplicitGCInvokesConcurrent).
+    {
+      SuspendibleThreadSetJoiner sts_join;
+      g1h->increment_old_marking_cycles_completed(true /* concurrent */);
+
+      _cm->concurrent_cycle_end();
+    }
+
+    cpmanager.set_phase(G1ConcurrentPhase::IDLE, _cm->has_aborted() /* force */);
+  }
+  _cm->root_regions()->cancel_scan();
+}
+
+void G1ConcurrentMarkThread::stop_service() {
+  MutexLockerEx ml(CGC_lock, Mutex::_no_safepoint_check_flag);
+  CGC_lock->notify_all();
+}
+
+
+void G1ConcurrentMarkThread::sleep_before_next_cycle() {
+  // We join here because we don't want to do the "shouldConcurrentMark()"
+  // below while the world is otherwise stopped.
+  assert(!in_progress(), "should have been cleared");
+
+  MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag);
+  while (!started() && !should_terminate()) {
+    CGC_lock->wait(Mutex::_no_safepoint_check_flag);
+  }
+
+  if (started()) {
+    set_in_progress();
+  }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1ConcurrentMarkThread.hpp	Wed Apr 04 10:12:02 2018 +0200
@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2001, 2018, 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.
+ *
+ */
+
+#ifndef SHARE_VM_GC_G1_G1CONCURRENTMARKTHREAD_HPP
+#define SHARE_VM_GC_G1_G1CONCURRENTMARKTHREAD_HPP
+
+#include "gc/shared/concurrentGCPhaseManager.hpp"
+#include "gc/shared/concurrentGCThread.hpp"
+
+class G1ConcurrentMark;
+class G1Policy;
+
+// The concurrent mark thread triggers the various steps of the concurrent marking
+// cycle, including various marking cleanup.
+class G1ConcurrentMarkThread: public ConcurrentGCThread {
+  friend class VMStructs;
+
+  double _vtime_start;  // Initial virtual time.
+  double _vtime_accum;  // Accumulated virtual time.
+  double _vtime_mark_accum;
+
+  G1ConcurrentMark* _cm;
+
+  enum State {
+    Idle,
+    Started,
+    InProgress
+  };
+
+  volatile State _state;
+
+  // WhiteBox testing support.
+  ConcurrentGCPhaseManager::Stack _phase_manager_stack;
+
+  void sleep_before_next_cycle();
+  // Delay marking to meet MMU.
+  void delay_to_keep_mmu(G1Policy* g1_policy, bool remark);
+  double mmu_sleep_time(G1Policy* g1_policy, bool remark);
+
+  void run_service();
+  void stop_service();
+
+ public:
+  // Constructor
+  G1ConcurrentMarkThread(G1ConcurrentMark* cm);
+
+  // Total virtual time so far for this thread and concurrent marking tasks.
+  double vtime_accum();
+  // Marking virtual time so far this thread and concurrent marking tasks.
+  double vtime_mark_accum();
+
+  G1ConcurrentMark* cm()   { return _cm; }
+
+  void set_idle()          { assert(_state != Started, "must not be starting a new cycle"); _state = Idle; }
+  bool idle()              { return _state == Idle; }
+  void set_started()       { assert(_state == Idle, "cycle in progress"); _state = Started; }
+  bool started()           { return _state == Started; }
+  void set_in_progress()   { assert(_state == Started, "must be starting a cycle"); _state = InProgress; }
+  bool in_progress()       { return _state == InProgress; }
+
+  // Returns true from the moment a marking cycle is
+  // initiated (during the initial-mark pause when started() is set)
+  // to the moment when the cycle completes (just after the next
+  // marking bitmap has been cleared and in_progress() is
+  // cleared). While during_cycle() is true we will not start another cycle
+  // so that cycles do not overlap. We cannot use just in_progress()
+  // as the CM thread might take some time to wake up before noticing
+  // that started() is set and set in_progress().
+  bool during_cycle()      { return !idle(); }
+
+  // WhiteBox testing support.
+  const char* const* concurrent_phases() const;
+  bool request_concurrent_phase(const char* phase);
+
+  ConcurrentGCPhaseManager::Stack* phase_manager_stack() {
+    return &_phase_manager_stack;
+  }
+};
+
+#endif // SHARE_VM_GC_G1_G1CONCURRENTMARKTHREAD_HPP
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1ConcurrentMarkThread.inline.hpp	Wed Apr 04 10:12:02 2018 +0200
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2001, 2018, 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.
+ *
+ */
+
+#ifndef SHARE_VM_GC_G1_G1CONCURRENTMARKTHREAD_INLINE_HPP
+#define SHARE_VM_GC_G1_G1CONCURRENTMARKTHREAD_INLINE_HPP
+
+#include "gc/g1/g1ConcurrentMark.hpp"
+#include "gc/g1/g1ConcurrentMarkThread.hpp"
+
+  // Total virtual time so far.
+inline double G1ConcurrentMarkThread::vtime_accum() {
+  return _vtime_accum + _cm->all_task_accum_vtime();
+}
+
+// Marking virtual time so far
+inline double G1ConcurrentMarkThread::vtime_mark_accum() {
+  return _vtime_mark_accum + _cm->all_task_accum_vtime();
+}
+
+#endif // SHARE_VM_GC_G1_G1CONCURRENTMARKTHREAD_INLINE_HPP
--- a/src/hotspot/share/gc/g1/g1HeapVerifier.cpp	Tue Apr 03 13:15:27 2018 +0200
+++ b/src/hotspot/share/gc/g1/g1HeapVerifier.cpp	Wed Apr 04 10:12:02 2018 +0200
@@ -23,10 +23,10 @@
  */
 
 #include "precompiled.hpp"
-#include "gc/g1/concurrentMarkThread.hpp"
 #include "gc/g1/g1Allocator.inline.hpp"
 #include "gc/g1/g1CollectedHeap.hpp"
 #include "gc/g1/g1CollectedHeap.inline.hpp"
+#include "gc/g1/g1ConcurrentMarkThread.hpp"
 #include "gc/g1/g1HeapVerifier.hpp"
 #include "gc/g1/g1Policy.hpp"
 #include "gc/g1/g1RemSet.hpp"
--- a/src/hotspot/share/gc/g1/g1Policy.cpp	Tue Apr 03 13:15:27 2018 +0200
+++ b/src/hotspot/share/gc/g1/g1Policy.cpp	Wed Apr 04 10:12:02 2018 +0200
@@ -23,11 +23,11 @@
  */
 
 #include "precompiled.hpp"
-#include "gc/g1/concurrentMarkThread.inline.hpp"
 #include "gc/g1/g1Analytics.hpp"
 #include "gc/g1/g1CollectedHeap.inline.hpp"
 #include "gc/g1/g1CollectionSet.hpp"
 #include "gc/g1/g1ConcurrentMark.hpp"
+#include "gc/g1/g1ConcurrentMarkThread.inline.hpp"
 #include "gc/g1/g1ConcurrentRefine.hpp"
 #include "gc/g1/g1HotCardCache.hpp"
 #include "gc/g1/g1IHOPControl.hpp"
--- a/src/hotspot/share/gc/g1/vm_operations_g1.cpp	Tue Apr 03 13:15:27 2018 +0200
+++ b/src/hotspot/share/gc/g1/vm_operations_g1.cpp	Wed Apr 04 10:12:02 2018 +0200
@@ -23,8 +23,8 @@
  */
 
 #include "precompiled.hpp"
-#include "gc/g1/concurrentMarkThread.inline.hpp"
 #include "gc/g1/g1CollectedHeap.inline.hpp"
+#include "gc/g1/g1ConcurrentMarkThread.inline.hpp"
 #include "gc/g1/g1Policy.hpp"
 #include "gc/shared/gcId.hpp"
 #include "gc/g1/vm_operations_g1.hpp"
--- a/src/hotspot/share/prims/whitebox.cpp	Tue Apr 03 13:15:27 2018 +0200
+++ b/src/hotspot/share/prims/whitebox.cpp	Wed Apr 04 10:12:02 2018 +0200
@@ -73,9 +73,9 @@
 #include "prims/cdsoffsets.hpp"
 #endif // INCLUDE_CDS
 #if INCLUDE_ALL_GCS
-#include "gc/g1/concurrentMarkThread.hpp"
 #include "gc/g1/g1CollectedHeap.inline.hpp"
 #include "gc/g1/g1ConcurrentMark.hpp"
+#include "gc/g1/g1ConcurrentMarkThread.hpp"
 #include "gc/g1/heapRegionRemSet.hpp"
 #include "gc/parallel/parallelScavengeHeap.inline.hpp"
 #include "gc/parallel/adjoiningGenerations.hpp"
--- a/src/hotspot/share/runtime/thread.cpp	Tue Apr 03 13:15:27 2018 +0200
+++ b/src/hotspot/share/runtime/thread.cpp	Wed Apr 04 10:12:02 2018 +0200
@@ -114,7 +114,7 @@
 #include "utilities/vmError.hpp"
 #if INCLUDE_ALL_GCS
 #include "gc/cms/concurrentMarkSweepThread.hpp"
-#include "gc/g1/concurrentMarkThread.inline.hpp"
+#include "gc/g1/g1ConcurrentMarkThread.inline.hpp"
 #include "gc/parallel/pcTasks.hpp"
 #endif // INCLUDE_ALL_GCS
 #if INCLUDE_JVMCI