changeset 13451:2cbcc2fdc073

Merge
author kvn
date Fri, 04 Aug 2017 12:24:33 -0700
parents fe7fdd0fc266 2e969fa1b29c
children ef53d0cc9271 0edbb08efe57
files
diffstat 19 files changed, 424 insertions(+), 415 deletions(-) [+]
line wrap: on
line diff
--- a/src/os_cpu/linux_zero/vm/os_linux_zero.hpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/os_cpu/linux_zero/vm/os_linux_zero.hpp	Fri Aug 04 12:24:33 2017 -0700
@@ -38,10 +38,10 @@
   static void atomic_copy64(const volatile void *src, volatile void *dst) {
 #if defined(PPC32)
     double tmp;
-    asm volatile ("lfd  %0, 0(%1)\n"
-                  "stfd %0, 0(%2)\n"
-                  : "=f"(tmp)
-                  : "b"(src), "b"(dst));
+    asm volatile ("lfd  %0, %2\n"
+                  "stfd %0, %1\n"
+                  : "=&f"(tmp), "=Q"(*(volatile double*)dst)
+                  : "Q"(*(volatile double*)src));
 #elif defined(S390) && !defined(_LP64)
     double tmp;
     asm volatile ("ld  %0, 0(%1)\n"
--- a/src/share/tools/hsdis/Makefile	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/tools/hsdis/Makefile	Fri Aug 04 12:24:33 2017 -0700
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2008, 2017, 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
@@ -70,14 +70,18 @@
 else   #linux
 CPU             = $(shell uname -m)
 ARCH1=$(CPU:x86_64=amd64)
-ARCH=$(ARCH1:i686=i386)
+ARCH2=$(ARCH1:i686=i386)
+ARCH=$(ARCH2:sparc64=sparcv9)
 ifdef LP64
 CFLAGS/sparcv9	+= -m64
 CFLAGS/amd64	+= -m64
 CFLAGS/ppc64	+= -m64
 CFLAGS/ppc64le  += -m64 -DABI_ELFv2
 else
-ARCH=$(ARCH1:amd64=i386)
+ARCH=$(ARCH2:amd64=i386)
+ifneq ($(findstring arm,$(ARCH)),)
+ARCH=arm
+endif
 CFLAGS/i386	+= -m32
 CFLAGS/sparc	+= -m32
 endif
--- a/src/share/tools/hsdis/hsdis.c	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/tools/hsdis/hsdis.c	Fri Aug 04 12:24:33 2017 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2017, 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
@@ -465,6 +465,9 @@
 #if  defined(LIBARCH_ppc64) || defined(LIBARCH_ppc64le)
   res = "powerpc:common64";
 #endif
+#ifdef LIBARCH_arm
+  res = "arm";
+#endif
 #ifdef LIBARCH_aarch64
   res = "aarch64";
 #endif
--- a/src/share/vm/gc/g1/g1CardLiveData.cpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/gc/g1/g1CardLiveData.cpp	Fri Aug 04 12:24:33 2017 -0700
@@ -221,7 +221,7 @@
     }
     if (hr->is_humongous()) {
       HeapRegion* start_region = hr->humongous_start_region();
-      if (mark_bitmap->isMarked(start_region->bottom())) {
+      if (mark_bitmap->is_marked(start_region->bottom())) {
         mark_card_bitmap_range(start, hr->top());
         return pointer_delta(hr->top(), start, 1);
       } else {
@@ -236,7 +236,7 @@
            p2i(start), p2i(ntams), p2i(hr->end()));
 
     // Find the first marked object at or after "start".
-    start = mark_bitmap->getNextMarkedWordAddress(start, ntams);
+    start = mark_bitmap->get_next_marked_addr(start, ntams);
     while (start < ntams) {
       oop obj = oop(start);
       size_t obj_size = obj->size();
@@ -250,7 +250,7 @@
       marked_bytes += obj_size * HeapWordSize;
 
       // Find the next marked object after this one.
-      start = mark_bitmap->getNextMarkedWordAddress(obj_end, ntams);
+      start = mark_bitmap->get_next_marked_addr(obj_end, ntams);
     }
 
     return marked_bytes;
--- a/src/share/vm/gc/g1/g1CollectedHeap.cpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/gc/g1/g1CollectedHeap.cpp	Fri Aug 04 12:24:33 2017 -0700
@@ -4945,7 +4945,7 @@
                                p2i(r->bottom()),
                                r->rem_set()->occupied(),
                                r->rem_set()->strong_code_roots_list_length(),
-                               next_bitmap->isMarked(r->bottom()),
+                               next_bitmap->is_marked(r->bottom()),
                                g1h->is_humongous_reclaim_candidate(region_idx),
                                obj->is_typeArray()
                               );
@@ -4962,13 +4962,13 @@
                              p2i(r->bottom()),
                              r->rem_set()->occupied(),
                              r->rem_set()->strong_code_roots_list_length(),
-                             next_bitmap->isMarked(r->bottom()),
+                             next_bitmap->is_marked(r->bottom()),
                              g1h->is_humongous_reclaim_candidate(region_idx),
                              obj->is_typeArray()
                             );
 
     // Need to clear mark bit of the humongous object if already set.
-    if (next_bitmap->isMarked(r->bottom())) {
+    if (next_bitmap->is_marked(r->bottom())) {
       next_bitmap->clear(r->bottom());
     }
     _humongous_objects_reclaimed++;
--- a/src/share/vm/gc/g1/g1CollectedHeap.inline.hpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/gc/g1/g1CollectedHeap.inline.hpp	Fri Aug 04 12:24:33 2017 -0700
@@ -135,7 +135,7 @@
 }
 
 inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
-  return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj);
+  return _cm->nextMarkBitMap()->is_marked((HeapWord*)obj);
 }
 
 inline bool G1CollectedHeap::is_in_cset(oop obj) {
--- a/src/share/vm/gc/g1/g1ConcurrentMark.cpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/gc/g1/g1ConcurrentMark.cpp	Fri Aug 04 12:24:33 2017 -0700
@@ -60,76 +60,21 @@
 #include "utilities/align.hpp"
 #include "utilities/growableArray.hpp"
 
-// Concurrent marking bit map wrapper
-
-G1CMBitMapRO::G1CMBitMapRO(int shifter) :
-  _bm(),
-  _shifter(shifter) {
-  _bmStartWord = 0;
-  _bmWordSize = 0;
-}
-
-HeapWord* G1CMBitMapRO::getNextMarkedWordAddress(const HeapWord* addr,
-                                                 const HeapWord* limit) const {
-  // First we must round addr *up* to a possible object boundary.
-  addr = align_up(addr, HeapWordSize << _shifter);
-  size_t addrOffset = heapWordToOffset(addr);
-  assert(limit != NULL, "limit must not be NULL");
-  size_t limitOffset = heapWordToOffset(limit);
-  size_t nextOffset = _bm.get_next_one_offset(addrOffset, limitOffset);
-  HeapWord* nextAddr = offsetToHeapWord(nextOffset);
-  assert(nextAddr >= addr, "get_next_one postcondition");
-  assert(nextAddr == limit || isMarked(nextAddr),
-         "get_next_one postcondition");
-  return nextAddr;
-}
-
-#ifndef PRODUCT
-bool G1CMBitMapRO::covers(MemRegion heap_rs) const {
-  // assert(_bm.map() == _virtual_space.low(), "map inconsistency");
-  assert(((size_t)_bm.size() * ((size_t)1 << _shifter)) == _bmWordSize,
-         "size inconsistency");
-  return _bmStartWord == (HeapWord*)(heap_rs.start()) &&
-         _bmWordSize  == heap_rs.word_size();
-}
-#endif
-
-void G1CMBitMapRO::print_on_error(outputStream* st, const char* prefix) const {
-  _bm.print_on_error(st, prefix);
-}
-
-size_t G1CMBitMap::compute_size(size_t heap_size) {
-  return ReservedSpace::allocation_align_size_up(heap_size / mark_distance());
-}
-
-size_t G1CMBitMap::mark_distance() {
-  return MinObjAlignmentInBytes * BitsPerByte;
-}
-
-void G1CMBitMap::initialize(MemRegion heap, G1RegionToSpaceMapper* storage) {
-  _bmStartWord = heap.start();
-  _bmWordSize = heap.word_size();
-
-  _bm = BitMapView((BitMap::bm_word_t*) storage->reserved().start(), _bmWordSize >> _shifter);
-
-  storage->set_mapping_changed_listener(&_listener);
-}
-
-void G1CMBitMapMappingChangedListener::on_commit(uint start_region, size_t num_regions, bool zero_filled) {
-  if (zero_filled) {
-    return;
-  }
-  // We need to clear the bitmap on commit, removing any existing information.
-  MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_region), num_regions * HeapRegion::GrainWords);
-  _bm->clear_range(mr);
-}
-
-void G1CMBitMap::clear_range(MemRegion mr) {
-  mr.intersection(MemRegion(_bmStartWord, _bmWordSize));
-  assert(!mr.is_empty(), "unexpected empty region");
-  // convert address range into offset range
-  _bm.at_put_range(heapWordToOffset(mr.start()),
-                   heapWordToOffset(mr.end()), false);
+bool G1CMBitMapClosure::do_addr(HeapWord* const addr) {
+  assert(addr < _cm->finger(), "invariant");
+  assert(addr >= _task->finger(), "invariant");
+
+  // We move that task's local finger along.
+  _task->move_finger_to(addr);
+
+  _task->scan_task_entry(G1TaskQueueEntry::from_oop(oop(addr)));
+  // we only partially drain the local queue and global stack
+  _task->drain_local_queue(true);
+  _task->drain_global_stack(true);
+
+  // if the has_aborted flag has been raised, we need to bail out of
+  // the iteration
+  return !_task->has_aborted();
 }
 
 G1CMMarkStack::G1CMMarkStack() :
@@ -438,8 +383,6 @@
   }
 
   assert(CGC_lock != NULL, "Where's the CGC_lock?");
-  assert(_markBitMap1.covers(g1h->reserved_region()), "_markBitMap1 inconsistency");
-  assert(_markBitMap2.covers(g1h->reserved_region()), "_markBitMap2 inconsistency");
 
   SATBMarkQueueSet& satb_qs = JavaThread::satb_mark_queue_set();
   satb_qs.set_buffer_size(G1SATBBufferSize);
@@ -753,7 +696,7 @@
 
 void G1ConcurrentMark::clear_prev_bitmap(WorkGang* workers) {
   assert(SafepointSynchronize::is_at_safepoint(), "Should only clear the entire prev bitmap at a safepoint.");
-  clear_bitmap((G1CMBitMap*)_prevMarkBitMap, workers, false);
+  clear_bitmap(_prevMarkBitMap, workers, false);
 }
 
 class CheckBitmapClearHRClosure : public HeapRegionClosure {
@@ -769,7 +712,7 @@
     // value passed to it as limit to detect any found bits.
     // end never changes in G1.
     HeapWord* end = r->end();
-    return _bitmap->getNextMarkedWordAddress(r->bottom(), end) != end;
+    return _bitmap->get_next_marked_addr(r->bottom(), end) != end;
   }
 };
 
@@ -789,7 +732,6 @@
 
 void G1ConcurrentMark::checkpointRootsInitialPre() {
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
-  G1Policy* g1p = g1h->g1_policy();
 
   _has_aborted = false;
 
@@ -1764,9 +1706,9 @@
 }
 
 void G1ConcurrentMark::swapMarkBitMaps() {
-  G1CMBitMapRO* temp = _prevMarkBitMap;
-  _prevMarkBitMap    = (G1CMBitMapRO*)_nextMarkBitMap;
-  _nextMarkBitMap    = (G1CMBitMap*)  temp;
+  G1CMBitMap* temp = _prevMarkBitMap;
+  _prevMarkBitMap  = _nextMarkBitMap;
+  _nextMarkBitMap  = temp;
 }
 
 // Closure for marking entries in SATB buffers.
@@ -1780,15 +1722,8 @@
   // circumspect about treating the argument as an object.
   void do_entry(void* entry) const {
     _task->increment_refs_reached();
-    HeapRegion* hr = _g1h->heap_region_containing(entry);
-    if (entry < hr->next_top_at_mark_start()) {
-      // Until we get here, we don't know whether entry refers to a valid
-      // object; it could instead have been a stale reference.
-      oop obj = static_cast<oop>(entry);
-      assert(obj->is_oop(true /* ignore mark word */),
-             "Invalid oop in SATB buffer: " PTR_FORMAT, p2i(obj));
-      _task->make_reference_grey(obj);
-    }
+    oop const obj = static_cast<oop>(entry);
+    _task->make_reference_grey(obj);
   }
 
 public:
@@ -1911,9 +1846,7 @@
 }
 
 void G1ConcurrentMark::clearRangePrevBitmap(MemRegion mr) {
-  // Note we are overriding the read-only view of the prev map here, via
-  // the cast.
-  ((G1CMBitMap*)_prevMarkBitMap)->clear_range(mr);
+  _prevMarkBitMap->clear_range(mr);
 }
 
 HeapRegion*
@@ -2160,38 +2093,6 @@
   _nextMarkBitMap->print_on_error(st, " Next Bits: ");
 }
 
-// Closure for iteration over bitmaps
-class G1CMBitMapClosure : public BitMapClosure {
-private:
-  // the bitmap that is being iterated over
-  G1CMBitMap*                 _nextMarkBitMap;
-  G1ConcurrentMark*           _cm;
-  G1CMTask*                   _task;
-
-public:
-  G1CMBitMapClosure(G1CMTask *task, G1ConcurrentMark* cm, G1CMBitMap* nextMarkBitMap) :
-    _task(task), _cm(cm), _nextMarkBitMap(nextMarkBitMap) { }
-
-  bool do_bit(size_t offset) {
-    HeapWord* addr = _nextMarkBitMap->offsetToHeapWord(offset);
-    assert(_nextMarkBitMap->isMarked(addr), "invariant");
-    assert( addr < _cm->finger(), "invariant");
-    assert(addr >= _task->finger(), "invariant");
-
-    // We move that task's local finger along.
-    _task->move_finger_to(addr);
-
-    _task->scan_task_entry(G1TaskQueueEntry::from_oop(oop(addr)));
-    // we only partially drain the local queue and global stack
-    _task->drain_local_queue(true);
-    _task->drain_global_stack(true);
-
-    // if the has_aborted flag has been raised, we need to bail out of
-    // the iteration
-    return !_task->has_aborted();
-  }
-};
-
 static ReferenceProcessor* get_cm_oop_closure_ref_processor(G1CollectedHeap* g1h) {
   ReferenceProcessor* result = g1h->ref_processor_cm();
   assert(result != NULL, "CM reference processor should not be NULL");
@@ -2691,7 +2592,7 @@
   // Set up the bitmap and oop closures. Anything that uses them is
   // eventually called from this method, so it is OK to allocate these
   // statically.
-  G1CMBitMapClosure bitmap_closure(this, _cm, _nextMarkBitMap);
+  G1CMBitMapClosure bitmap_closure(this, _cm);
   G1CMOopClosure    cm_oop_closure(_g1h, _cm, this);
   set_cm_oop_closure(&cm_oop_closure);
 
@@ -2747,10 +2648,9 @@
         giveup_current_region();
         regular_clock_call();
       } else if (_curr_region->is_humongous() && mr.start() == _curr_region->bottom()) {
-        if (_nextMarkBitMap->isMarked(mr.start())) {
+        if (_nextMarkBitMap->is_marked(mr.start())) {
           // The object is marked - apply the closure
-          BitMap::idx_t offset = _nextMarkBitMap->heapWordToOffset(mr.start());
-          bitmap_closure.do_bit(offset);
+          bitmap_closure.do_addr(mr.start());
         }
         // Even if this task aborted while scanning the humongous object
         // we can (and should) give up the current region.
@@ -2772,11 +2672,9 @@
         // points to the address of the object we last scanned. If we
         // leave it there, when we restart this task, we will rescan
         // the object. It is easy to avoid this. We move the finger by
-        // enough to point to the next possible object header (the
-        // bitmap knows by how much we need to move it as it knows its
-        // granularity).
+        // enough to point to the next possible object header.
         assert(_finger < _region_limit, "invariant");
-        HeapWord* new_finger = _nextMarkBitMap->nextObject(_finger);
+        HeapWord* const new_finger = _finger + ((oop)_finger)->size();
         // Check if bitmap iteration was aborted while scanning the last object
         if (new_finger >= _region_limit) {
           giveup_current_region();
--- a/src/share/vm/gc/g1/g1ConcurrentMark.hpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/gc/g1/g1ConcurrentMark.hpp	Fri Aug 04 12:24:33 2017 -0700
@@ -26,13 +26,13 @@
 #define SHARE_VM_GC_G1_G1CONCURRENTMARK_HPP
 
 #include "classfile/javaClasses.hpp"
+#include "gc/g1/g1ConcurrentMarkBitMap.hpp"
 #include "gc/g1/g1ConcurrentMarkObjArrayProcessor.hpp"
 #include "gc/g1/g1RegionToSpaceMapper.hpp"
 #include "gc/g1/heapRegionSet.hpp"
 #include "gc/shared/taskqueue.hpp"
 
 class G1CollectedHeap;
-class G1CMBitMap;
 class G1CMTask;
 class G1ConcurrentMark;
 class ConcurrentGCTimer;
@@ -110,97 +110,6 @@
   bool do_object_b(oop obj);
 };
 
-// A generic CM bit map.  This is essentially a wrapper around the BitMap
-// class, with one bit per (1<<_shifter) HeapWords.
-
-class G1CMBitMapRO VALUE_OBJ_CLASS_SPEC {
- protected:
-  HeapWord*  _bmStartWord; // base address of range covered by map
-  size_t     _bmWordSize;  // map size (in #HeapWords covered)
-  const int  _shifter;     // map to char or bit
-  BitMapView _bm;          // the bit map itself
-
- public:
-  // constructor
-  G1CMBitMapRO(int shifter);
-
-  // inquiries
-  HeapWord* startWord()   const { return _bmStartWord; }
-  // the following is one past the last word in space
-  HeapWord* endWord()     const { return _bmStartWord + _bmWordSize; }
-
-  // read marks
-
-  bool isMarked(HeapWord* addr) const {
-    assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize),
-           "outside underlying space?");
-    return _bm.at(heapWordToOffset(addr));
-  }
-
-  // iteration
-  inline bool iterate(BitMapClosure* cl, MemRegion mr);
-
-  // Return the address corresponding to the next marked bit at or after
-  // "addr", and before "limit", if "limit" is non-NULL.  If there is no
-  // such bit, returns "limit" if that is non-NULL, or else "endWord()".
-  HeapWord* getNextMarkedWordAddress(const HeapWord* addr,
-                                     const HeapWord* limit = NULL) const;
-
-  // conversion utilities
-  HeapWord* offsetToHeapWord(size_t offset) const {
-    return _bmStartWord + (offset << _shifter);
-  }
-  size_t heapWordToOffset(const HeapWord* addr) const {
-    return pointer_delta(addr, _bmStartWord) >> _shifter;
-  }
-
-  // The argument addr should be the start address of a valid object
-  inline HeapWord* nextObject(HeapWord* addr);
-
-  void print_on_error(outputStream* st, const char* prefix) const;
-
-  // debugging
-  NOT_PRODUCT(bool covers(MemRegion rs) const;)
-};
-
-class G1CMBitMapMappingChangedListener : public G1MappingChangedListener {
- private:
-  G1CMBitMap* _bm;
- public:
-  G1CMBitMapMappingChangedListener() : _bm(NULL) {}
-
-  void set_bitmap(G1CMBitMap* bm) { _bm = bm; }
-
-  virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled);
-};
-
-class G1CMBitMap : public G1CMBitMapRO {
- private:
-  G1CMBitMapMappingChangedListener _listener;
-
- public:
-  static size_t compute_size(size_t heap_size);
-  // Returns the amount of bytes on the heap between two marks in the bitmap.
-  static size_t mark_distance();
-  // Returns how many bytes (or bits) of the heap a single byte (or bit) of the
-  // mark bitmap corresponds to. This is the same as the mark distance above.
-  static size_t heap_map_factor() {
-    return mark_distance();
-  }
-
-  G1CMBitMap() : G1CMBitMapRO(LogMinObjAlignment), _listener() { _listener.set_bitmap(this); }
-
-  // Initializes the underlying BitMap to cover the given area.
-  void initialize(MemRegion heap, G1RegionToSpaceMapper* storage);
-
-  // Write marks.
-  inline void mark(HeapWord* addr);
-  inline void clear(HeapWord* addr);
-  inline bool parMark(HeapWord* addr);
-
-  void clear_range(MemRegion mr);
-};
-
 // Represents the overflow mark stack used by concurrent marking.
 //
 // Stores oops in a huge buffer in virtual memory that is always fully committed.
@@ -396,7 +305,7 @@
   // Concurrent marking support structures
   G1CMBitMap              _markBitMap1;
   G1CMBitMap              _markBitMap2;
-  G1CMBitMapRO*           _prevMarkBitMap; // Completed mark bitmap
+  G1CMBitMap*             _prevMarkBitMap; // Completed mark bitmap
   G1CMBitMap*             _nextMarkBitMap; // Under-construction mark bitmap
 
   // Heap bounds
@@ -626,8 +535,8 @@
 
   ConcurrentMarkThread* cmThread() { return _cmThread; }
 
-  G1CMBitMapRO* prevMarkBitMap() const { return _prevMarkBitMap; }
-  G1CMBitMap*   nextMarkBitMap() const { return _nextMarkBitMap; }
+  const G1CMBitMap* const prevMarkBitMap() const { return _prevMarkBitMap; }
+  G1CMBitMap* nextMarkBitMap() const { return _nextMarkBitMap; }
 
   // Returns the number of GC threads to be used in a concurrent
   // phase based on the number of GC threads being used in a STW
@@ -637,16 +546,6 @@
   // Calculates the number of GC threads to be used in a concurrent phase.
   uint calc_parallel_marking_threads();
 
-  // The following three are interaction between CM and
-  // G1CollectedHeap
-
-  // This notifies CM that a root during initial-mark needs to be
-  // grayed. It is MT-safe. hr is the region that
-  // contains the object and it's passed optionally from callers who
-  // might already have it (no point in recalculating it).
-  inline void grayRoot(oop obj,
-                       HeapRegion* hr = NULL);
-
   // Prepare internal data structures for the next mark cycle. This includes clearing
   // the next mark bitmap and some internal data structures. This method is intended
   // to be called concurrently to the mutator. It will yield to safepoint requests.
@@ -713,8 +612,9 @@
 
   void print_on_error(outputStream* st) const;
 
-  // Attempts to mark the given object on the next mark bitmap.
-  inline bool par_mark(oop obj);
+  // Mark the given object on the next bitmap if it is below nTAMS.
+  inline bool mark_in_next_bitmap(HeapRegion* const hr, oop const obj);
+  inline bool mark_in_next_bitmap(oop const obj);
 
   // Returns true if initialization was successfully completed.
   bool completed_initialization() const {
--- a/src/share/vm/gc/g1/g1ConcurrentMark.inline.hpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/gc/g1/g1ConcurrentMark.inline.hpp	Fri Aug 04 12:24:33 2017 -0700
@@ -27,70 +27,38 @@
 
 #include "gc/g1/g1CollectedHeap.inline.hpp"
 #include "gc/g1/g1ConcurrentMark.hpp"
+#include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp"
 #include "gc/g1/g1ConcurrentMarkObjArrayProcessor.inline.hpp"
 #include "gc/g1/suspendibleThreadSet.hpp"
 #include "gc/shared/taskqueue.inline.hpp"
 #include "utilities/bitMap.inline.hpp"
 
-inline bool G1ConcurrentMark::par_mark(oop obj) {
-  return _nextMarkBitMap->parMark((HeapWord*)obj);
+inline bool G1ConcurrentMark::mark_in_next_bitmap(oop const obj) {
+  HeapRegion* const hr = _g1h->heap_region_containing(obj);
+  return mark_in_next_bitmap(hr, obj);
 }
 
-inline bool G1CMBitMapRO::iterate(BitMapClosure* cl, MemRegion mr) {
-  HeapWord* start_addr = MAX2(startWord(), mr.start());
-  HeapWord* end_addr = MIN2(endWord(), mr.end());
+inline bool G1ConcurrentMark::mark_in_next_bitmap(HeapRegion* const hr, oop const obj) {
+  assert(hr != NULL, "just checking");
+  assert(hr->is_in_reserved(obj), "Attempting to mark object at " PTR_FORMAT " that is not contained in the given region %u", p2i(obj), hr->hrm_index());
 
-  if (end_addr > start_addr) {
-    // Right-open interval [start-offset, end-offset).
-    BitMap::idx_t start_offset = heapWordToOffset(start_addr);
-    BitMap::idx_t end_offset = heapWordToOffset(end_addr);
+  if (hr->obj_allocated_since_next_marking(obj)) {
+    return false;
+  }
 
-    start_offset = _bm.get_next_one_offset(start_offset, end_offset);
-    while (start_offset < end_offset) {
-      if (!cl->do_bit(start_offset)) {
-        return false;
-      }
-      HeapWord* next_addr = MIN2(nextObject(offsetToHeapWord(start_offset)), end_addr);
-      BitMap::idx_t next_offset = heapWordToOffset(next_addr);
-      start_offset = _bm.get_next_one_offset(next_offset, end_offset);
-    }
+  // Some callers may have stale objects to mark above nTAMS after humongous reclaim.
+  assert(obj->is_oop(true /* ignore mark word */), "Address " PTR_FORMAT " to mark is not an oop", p2i(obj));
+  assert(!hr->is_continues_humongous(), "Should not try to mark object " PTR_FORMAT " in Humongous continues region %u above nTAMS " PTR_FORMAT, p2i(obj), hr->hrm_index(), p2i(hr->next_top_at_mark_start()));
+
+  HeapWord* const obj_addr = (HeapWord*)obj;
+  // Dirty read to avoid CAS.
+  if (_nextMarkBitMap->is_marked(obj_addr)) {
+    return false;
   }
-  return true;
+
+  return _nextMarkBitMap->par_mark(obj_addr);
 }
 
-// The argument addr should be the start address of a valid object
-HeapWord* G1CMBitMapRO::nextObject(HeapWord* addr) {
-  oop obj = (oop) addr;
-  HeapWord* res =  addr + obj->size();
-  assert(offsetToHeapWord(heapWordToOffset(res)) == res, "sanity");
-  return res;
-}
-
-#define check_mark(addr)                                                       \
-  assert(_bmStartWord <= (addr) && (addr) < (_bmStartWord + _bmWordSize),      \
-         "outside underlying space?");                                         \
-  assert(G1CollectedHeap::heap()->is_in_exact(addr),                           \
-         "Trying to access not available bitmap " PTR_FORMAT                   \
-         " corresponding to " PTR_FORMAT " (%u)",                              \
-         p2i(this), p2i(addr), G1CollectedHeap::heap()->addr_to_region(addr));
-
-inline void G1CMBitMap::mark(HeapWord* addr) {
-  check_mark(addr);
-  _bm.set_bit(heapWordToOffset(addr));
-}
-
-inline void G1CMBitMap::clear(HeapWord* addr) {
-  check_mark(addr);
-  _bm.clear_bit(heapWordToOffset(addr));
-}
-
-inline bool G1CMBitMap::parMark(HeapWord* addr) {
-  check_mark(addr);
-  return _bm.par_set_bit(heapWordToOffset(addr));
-}
-
-#undef check_mark
-
 #ifndef PRODUCT
 template<typename Fn>
 inline void G1CMMarkStack::iterate(Fn fn) const {
@@ -122,7 +90,7 @@
   assert(task_entry.is_array_slice() || !_g1h->is_on_master_free_list(
               _g1h->heap_region_containing(task_entry.obj())), "invariant");
   assert(task_entry.is_array_slice() || !_g1h->is_obj_ill(task_entry.obj()), "invariant");  // FIXME!!!
-  assert(task_entry.is_array_slice() || _nextMarkBitMap->isMarked((HeapWord*)task_entry.obj()), "invariant");
+  assert(task_entry.is_array_slice() || _nextMarkBitMap->is_marked((HeapWord*)task_entry.obj()), "invariant");
 
   if (!_task_queue->push(task_entry)) {
     // The local task queue looks full. We need to push some entries
@@ -170,7 +138,7 @@
 template<bool scan>
 inline void G1CMTask::process_grey_task_entry(G1TaskQueueEntry task_entry) {
   assert(scan || (task_entry.is_oop() && task_entry.obj()->is_typeArray()), "Skipping scan of grey non-typeArray");
-  assert(task_entry.is_array_slice() || _nextMarkBitMap->isMarked((HeapWord*)task_entry.obj()),
+  assert(task_entry.is_array_slice() || _nextMarkBitMap->is_marked((HeapWord*)task_entry.obj()),
          "Any stolen object should be a slice or marked");
 
   if (scan) {
@@ -194,98 +162,63 @@
 }
 
 inline void G1CMTask::make_reference_grey(oop obj) {
-  if (_cm->par_mark(obj)) {
-    // No OrderAccess:store_load() is needed. It is implicit in the
-    // CAS done in G1CMBitMap::parMark() call in the routine above.
-    HeapWord* global_finger = _cm->finger();
+  if (!_cm->mark_in_next_bitmap(obj)) {
+    return;
+  }
 
-    // We only need to push a newly grey object on the mark
-    // stack if it is in a section of memory the mark bitmap
-    // scan has already examined.  Mark bitmap scanning
-    // maintains progress "fingers" for determining that.
-    //
-    // Notice that the global finger might be moving forward
-    // concurrently. This is not a problem. In the worst case, we
-    // mark the object while it is above the global finger and, by
-    // the time we read the global finger, it has moved forward
-    // past this object. In this case, the object will probably
-    // be visited when a task is scanning the region and will also
-    // be pushed on the stack. So, some duplicate work, but no
-    // correctness problems.
-    if (is_below_finger(obj, global_finger)) {
-      G1TaskQueueEntry entry = G1TaskQueueEntry::from_oop(obj);
-      if (obj->is_typeArray()) {
-        // Immediately process arrays of primitive types, rather
-        // than pushing on the mark stack.  This keeps us from
-        // adding humongous objects to the mark stack that might
-        // be reclaimed before the entry is processed - see
-        // selection of candidates for eager reclaim of humongous
-        // objects.  The cost of the additional type test is
-        // mitigated by avoiding a trip through the mark stack,
-        // by only doing a bookkeeping update and avoiding the
-        // actual scan of the object - a typeArray contains no
-        // references, and the metadata is built-in.
-        process_grey_task_entry<false>(entry);
-      } else {
-        push(entry);
-      }
+  // No OrderAccess:store_load() is needed. It is implicit in the
+  // CAS done in G1CMBitMap::parMark() call in the routine above.
+  HeapWord* global_finger = _cm->finger();
+
+  // We only need to push a newly grey object on the mark
+  // stack if it is in a section of memory the mark bitmap
+  // scan has already examined.  Mark bitmap scanning
+  // maintains progress "fingers" for determining that.
+  //
+  // Notice that the global finger might be moving forward
+  // concurrently. This is not a problem. In the worst case, we
+  // mark the object while it is above the global finger and, by
+  // the time we read the global finger, it has moved forward
+  // past this object. In this case, the object will probably
+  // be visited when a task is scanning the region and will also
+  // be pushed on the stack. So, some duplicate work, but no
+  // correctness problems.
+  if (is_below_finger(obj, global_finger)) {
+    G1TaskQueueEntry entry = G1TaskQueueEntry::from_oop(obj);
+    if (obj->is_typeArray()) {
+      // Immediately process arrays of primitive types, rather
+      // than pushing on the mark stack.  This keeps us from
+      // adding humongous objects to the mark stack that might
+      // be reclaimed before the entry is processed - see
+      // selection of candidates for eager reclaim of humongous
+      // objects.  The cost of the additional type test is
+      // mitigated by avoiding a trip through the mark stack,
+      // by only doing a bookkeeping update and avoiding the
+      // actual scan of the object - a typeArray contains no
+      // references, and the metadata is built-in.
+      process_grey_task_entry<false>(entry);
+    } else {
+      push(entry);
     }
   }
 }
 
 inline void G1CMTask::deal_with_reference(oop obj) {
   increment_refs_reached();
-
-  HeapWord* objAddr = (HeapWord*) obj;
-  assert(obj->is_oop_or_null(true /* ignore mark word */), "Expected an oop or NULL at " PTR_FORMAT, p2i(obj));
-  if (_g1h->is_in_g1_reserved(objAddr)) {
-    assert(obj != NULL, "null check is implicit");
-    if (!_nextMarkBitMap->isMarked(objAddr)) {
-      // Only get the containing region if the object is not marked on the
-      // bitmap (otherwise, it's a waste of time since we won't do
-      // anything with it).
-      HeapRegion* hr = _g1h->heap_region_containing(obj);
-      if (!hr->obj_allocated_since_next_marking(obj)) {
-        make_reference_grey(obj);
-      }
-    }
+  if (obj == NULL) {
+    return;
   }
+  make_reference_grey(obj);
 }
 
 inline void G1ConcurrentMark::markPrev(oop p) {
-  assert(!_prevMarkBitMap->isMarked((HeapWord*) p), "sanity");
-  // Note we are overriding the read-only view of the prev map here, via
-  // the cast.
-  ((G1CMBitMap*)_prevMarkBitMap)->mark((HeapWord*) p);
+  assert(!_prevMarkBitMap->is_marked((HeapWord*) p), "sanity");
+ _prevMarkBitMap->mark((HeapWord*) p);
 }
 
 bool G1ConcurrentMark::isPrevMarked(oop p) const {
   assert(p != NULL && p->is_oop(), "expected an oop");
-  HeapWord* addr = (HeapWord*)p;
-  assert(addr >= _prevMarkBitMap->startWord() ||
-         addr < _prevMarkBitMap->endWord(), "in a region");
-
-  return _prevMarkBitMap->isMarked(addr);
-}
-
-inline void G1ConcurrentMark::grayRoot(oop obj, HeapRegion* hr) {
-  assert(obj != NULL, "pre-condition");
-  HeapWord* addr = (HeapWord*) obj;
-  if (hr == NULL) {
-    hr = _g1h->heap_region_containing(addr);
-  } else {
-    assert(hr->is_in(addr), "pre-condition");
-  }
-  assert(hr != NULL, "sanity");
-  // Given that we're looking for a region that contains an object
-  // header it's impossible to get back a HC region.
-  assert(!hr->is_continues_humongous(), "sanity");
-
-  if (addr < hr->next_top_at_mark_start()) {
-    if (!_nextMarkBitMap->isMarked(addr)) {
-      par_mark(obj);
-    }
-  }
+  return _prevMarkBitMap->is_marked((HeapWord*)p);
 }
 
 inline bool G1ConcurrentMark::do_yield_check() {
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc/g1/g1ConcurrentMarkBitMap.cpp	Fri Aug 04 12:24:33 2017 -0700
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2017, 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/g1/g1CollectedHeap.inline.hpp"
+#include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp"
+#include "memory/virtualspace.hpp"
+
+void G1CMBitMap::print_on_error(outputStream* st, const char* prefix) const {
+  _bm.print_on_error(st, prefix);
+}
+
+size_t G1CMBitMap::compute_size(size_t heap_size) {
+  return ReservedSpace::allocation_align_size_up(heap_size / mark_distance());
+}
+
+size_t G1CMBitMap::mark_distance() {
+  return MinObjAlignmentInBytes * BitsPerByte;
+}
+
+void G1CMBitMap::initialize(MemRegion heap, G1RegionToSpaceMapper* storage) {
+  _covered = heap;
+
+  _bm = BitMapView((BitMap::bm_word_t*) storage->reserved().start(), _covered.word_size() >> _shifter);
+
+  storage->set_mapping_changed_listener(&_listener);
+}
+
+void G1CMBitMapMappingChangedListener::on_commit(uint start_region, size_t num_regions, bool zero_filled) {
+  if (zero_filled) {
+    return;
+  }
+  // We need to clear the bitmap on commit, removing any existing information.
+  MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_region), num_regions * HeapRegion::GrainWords);
+  _bm->clear_range(mr);
+}
+
+void G1CMBitMap::clear_range(MemRegion mr) {
+  MemRegion intersection = mr.intersection(_covered);
+  assert(!intersection.is_empty(),
+         "Given range from " PTR_FORMAT " to " PTR_FORMAT " is completely outside the heap",
+         p2i(mr.start()), p2i(mr.end()));
+  // convert address range into offset range
+  _bm.at_put_range(addr_to_offset(intersection.start()),
+                   addr_to_offset(intersection.end()), false);
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc/g1/g1ConcurrentMarkBitMap.hpp	Fri Aug 04 12:24:33 2017 -0700
@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2017, 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_G1CONCURRENTMARKBITMAP_HPP
+#define SHARE_VM_GC_G1_G1CONCURRENTMARKBITMAP_HPP
+
+#include "gc/g1/g1RegionToSpaceMapper.hpp"
+#include "memory/allocation.hpp"
+#include "memory/memRegion.hpp"
+#include "utilities/bitMap.hpp"
+#include "utilities/globalDefinitions.hpp"
+#include "utilities/macros.hpp"
+
+class G1CMBitMap;
+class G1CMTask;
+class G1ConcurrentMark;
+
+// Closure for iteration over bitmaps
+class G1CMBitMapClosure VALUE_OBJ_CLASS_SPEC {
+private:
+  G1ConcurrentMark* const _cm;
+  G1CMTask* const _task;
+public:
+  G1CMBitMapClosure(G1CMTask *task, G1ConcurrentMark* cm) : _task(task), _cm(cm) { }
+
+  bool do_addr(HeapWord* const addr);
+};
+
+class G1CMBitMapMappingChangedListener : public G1MappingChangedListener {
+ private:
+  G1CMBitMap* _bm;
+ public:
+  G1CMBitMapMappingChangedListener() : _bm(NULL) {}
+
+  void set_bitmap(G1CMBitMap* bm) { _bm = bm; }
+
+  virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled);
+};
+
+// A generic mark bitmap for concurrent marking.  This is essentially a wrapper
+// around the BitMap class that is based on HeapWords, with one bit per (1 << _shifter) HeapWords.
+class G1CMBitMap VALUE_OBJ_CLASS_SPEC {
+private:
+  MemRegion _covered;    // The heap area covered by this bitmap.
+
+  const int _shifter;    // Shift amount from heap index to bit index in the bitmap.
+
+  BitMapView _bm;        // The actual bitmap.
+
+  G1CMBitMapMappingChangedListener _listener;
+
+  inline void check_mark(HeapWord* addr) NOT_DEBUG_RETURN;
+
+  // Convert from bit offset to address.
+  HeapWord* offset_to_addr(size_t offset) const {
+    return _covered.start() + (offset << _shifter);
+  }
+  // Convert from address to bit offset.
+  size_t addr_to_offset(const HeapWord* addr) const {
+    return pointer_delta(addr, _covered.start()) >> _shifter;
+  }
+public:
+  static size_t compute_size(size_t heap_size);
+  // Returns the amount of bytes on the heap between two marks in the bitmap.
+  static size_t mark_distance();
+  // Returns how many bytes (or bits) of the heap a single byte (or bit) of the
+  // mark bitmap corresponds to. This is the same as the mark distance above.
+  static size_t heap_map_factor() {
+    return mark_distance();
+  }
+
+  G1CMBitMap() : _covered(), _bm(), _shifter(LogMinObjAlignment), _listener() { _listener.set_bitmap(this); }
+
+  // Initializes the underlying BitMap to cover the given area.
+  void initialize(MemRegion heap, G1RegionToSpaceMapper* storage);
+
+  // Read marks
+  bool is_marked(HeapWord* addr) const {
+    assert(_covered.contains(addr),
+           "Address " PTR_FORMAT " is outside underlying space from " PTR_FORMAT " to " PTR_FORMAT,
+           p2i(addr), p2i(_covered.start()), p2i(_covered.end()));
+    return _bm.at(addr_to_offset(addr));
+  }
+
+  // Apply the closure to the addresses that correspond to marked bits in the bitmap.
+  inline bool iterate(G1CMBitMapClosure* cl, MemRegion mr);
+
+  // Return the address corresponding to the next marked bit at or after
+  // "addr", and before "limit", if "limit" is non-NULL.  If there is no
+  // such bit, returns "limit" if that is non-NULL, or else "endWord()".
+  inline HeapWord* get_next_marked_addr(const HeapWord* addr,
+                                        const HeapWord* limit) const;
+
+  // The argument addr should be the start address of a valid object
+  inline HeapWord* addr_after_obj(HeapWord* addr);
+
+  void print_on_error(outputStream* st, const char* prefix) const;
+
+  // Write marks.
+  inline void mark(HeapWord* addr);
+  inline void clear(HeapWord* addr);
+  inline bool par_mark(HeapWord* addr);
+
+  void clear_range(MemRegion mr);
+};
+
+#endif // SHARE_VM_GC_G1_G1CONCURRENTMARKBITMAP_HPP
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc/g1/g1ConcurrentMarkBitMap.inline.hpp	Fri Aug 04 12:24:33 2017 -0700
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2017, 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_G1CONCURRENTMARKBITMAP_INLINE_HPP
+#define SHARE_VM_GC_G1_G1CONCURRENTMARKBITMAP_INLINE_HPP
+
+#include "gc/g1/g1ConcurrentMarkBitMap.hpp"
+#include "memory/memRegion.hpp"
+#include "utilities/align.hpp"
+#include "utilities/bitMap.inline.hpp"
+
+inline bool G1CMBitMap::iterate(G1CMBitMapClosure* cl, MemRegion mr) {
+  assert(!mr.is_empty(), "Does not support empty memregion to iterate over");
+  assert(_covered.contains(mr),
+         "Given MemRegion from " PTR_FORMAT " to " PTR_FORMAT " not contained in heap area",
+         p2i(mr.start()), p2i(mr.end()));
+
+  BitMap::idx_t const end_offset = addr_to_offset(mr.end());
+  BitMap::idx_t offset = _bm.get_next_one_offset(addr_to_offset(mr.start()), end_offset);
+
+  while (offset < end_offset) {
+    HeapWord* const addr = offset_to_addr(offset);
+    if (!cl->do_addr(addr)) {
+      return false;
+    }
+    size_t const obj_size = (size_t)((oop)addr)->size();
+    offset = _bm.get_next_one_offset(offset + (obj_size >> _shifter), end_offset);
+  }
+  return true;
+}
+
+inline HeapWord* G1CMBitMap::get_next_marked_addr(const HeapWord* addr,
+                                                  const HeapWord* limit) const {
+  assert(limit != NULL, "limit must not be NULL");
+  // Round addr up to a possible object boundary to be safe.
+  size_t const addr_offset = addr_to_offset(align_up(addr, HeapWordSize << _shifter));
+  size_t const limit_offset = addr_to_offset(limit);
+  size_t const nextOffset = _bm.get_next_one_offset(addr_offset, limit_offset);
+  return offset_to_addr(nextOffset);
+}
+
+#ifdef ASSERT
+inline void G1CMBitMap::check_mark(HeapWord* addr) {
+  assert(G1CollectedHeap::heap()->is_in_exact(addr),
+         "Trying to access bitmap " PTR_FORMAT " for address " PTR_FORMAT " not in the heap.",
+         p2i(this), p2i(addr));
+}
+#endif
+
+inline void G1CMBitMap::mark(HeapWord* addr) {
+  check_mark(addr);
+  _bm.set_bit(addr_to_offset(addr));
+}
+
+inline void G1CMBitMap::clear(HeapWord* addr) {
+  check_mark(addr);
+  _bm.clear_bit(addr_to_offset(addr));
+}
+
+inline bool G1CMBitMap::par_mark(HeapWord* addr) {
+  check_mark(addr);
+  return _bm.par_set_bit(addr_to_offset(addr));
+}
+
+#endif // SHARE_VM_GC_G1_G1CONCURRENTMARKBITMAP_INLINE_HPP
--- a/src/share/vm/gc/g1/g1EvacFailure.cpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/gc/g1/g1EvacFailure.cpp	Fri Aug 04 12:24:33 2017 -0700
@@ -124,7 +124,7 @@
         // explicitly and all objects in the CSet are considered
         // (implicitly) live. So, we won't mark them explicitly and
         // we'll leave them over NTAMS.
-        _cm->grayRoot(obj, _hr);
+        _cm->mark_in_next_bitmap(_hr, obj);
       }
       size_t obj_size = obj->size();
 
--- a/src/share/vm/gc/g1/g1HeapVerifier.cpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/gc/g1/g1HeapVerifier.cpp	Fri Aug 04 12:24:33 2017 -0700
@@ -598,11 +598,11 @@
   _g1h->collection_set()->iterate(&cl);
 }
 
-bool G1HeapVerifier::verify_no_bits_over_tams(const char* bitmap_name, G1CMBitMapRO* bitmap,
+bool G1HeapVerifier::verify_no_bits_over_tams(const char* bitmap_name, const G1CMBitMap* const bitmap,
                                                HeapWord* tams, HeapWord* end) {
   guarantee(tams <= end,
             "tams: " PTR_FORMAT " end: " PTR_FORMAT, p2i(tams), p2i(end));
-  HeapWord* result = bitmap->getNextMarkedWordAddress(tams, end);
+  HeapWord* result = bitmap->get_next_marked_addr(tams, end);
   if (result < end) {
     log_error(gc, verify)("## wrong marked address on %s bitmap: " PTR_FORMAT, bitmap_name, p2i(result));
     log_error(gc, verify)("## %s tams: " PTR_FORMAT " end: " PTR_FORMAT, bitmap_name, p2i(tams), p2i(end));
@@ -612,10 +612,9 @@
 }
 
 bool G1HeapVerifier::verify_bitmaps(const char* caller, HeapRegion* hr) {
-  G1CMBitMapRO* prev_bitmap = _g1h->concurrent_mark()->prevMarkBitMap();
-  G1CMBitMapRO* next_bitmap = (G1CMBitMapRO*) _g1h->concurrent_mark()->nextMarkBitMap();
+  const G1CMBitMap* const prev_bitmap = _g1h->concurrent_mark()->prevMarkBitMap();
+  const G1CMBitMap* const next_bitmap = _g1h->concurrent_mark()->nextMarkBitMap();
 
-  HeapWord* bottom = hr->bottom();
   HeapWord* ptams  = hr->prev_top_at_mark_start();
   HeapWord* ntams  = hr->next_top_at_mark_start();
   HeapWord* end    = hr->end();
--- a/src/share/vm/gc/g1/g1HeapVerifier.hpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/gc/g1/g1HeapVerifier.hpp	Fri Aug 04 12:24:33 2017 -0700
@@ -82,7 +82,7 @@
   // range [from,limit). If it does, print an error message and return
   // false. Otherwise, just return true. bitmap_name should be "prev"
   // or "next".
-  bool verify_no_bits_over_tams(const char* bitmap_name, G1CMBitMapRO* bitmap,
+  bool verify_no_bits_over_tams(const char* bitmap_name, const G1CMBitMap* const bitmap,
                                 HeapWord* from, HeapWord* limit);
 
   // Verify that the prev / next bitmap range [tams,end) for the given
--- a/src/share/vm/gc/g1/g1OopClosures.inline.hpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/gc/g1/g1OopClosures.inline.hpp	Fri Aug 04 12:24:33 2017 -0700
@@ -95,11 +95,11 @@
 template <class T>
 inline void G1RootRegionScanClosure::do_oop_nv(T* p) {
   T heap_oop = oopDesc::load_heap_oop(p);
-  if (!oopDesc::is_null(heap_oop)) {
-    oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
-    HeapRegion* hr = _g1h->heap_region_containing((HeapWord*) obj);
-    _cm->grayRoot(obj, hr);
+  if (oopDesc::is_null(heap_oop)) {
+    return;
   }
+  oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
+  _cm->mark_in_next_bitmap(obj);
 }
 
 template <class T>
@@ -205,8 +205,7 @@
 void G1ParCopyHelper::mark_object(oop obj) {
   assert(!_g1->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
 
-  // We know that the object is not moving so it's safe to read its size.
-  _cm->grayRoot(obj);
+  _cm->mark_in_next_bitmap(obj);
 }
 
 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
@@ -217,11 +216,7 @@
   assert(_g1->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet");
   assert(!_g1->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet");
 
-  // The object might be in the process of being copied by another
-  // worker so we cannot trust that its to-space image is
-  // well-formed. So we have to read its size from its from-space
-  // image which we know should not be changing.
-  _cm->grayRoot(to_obj);
+  _cm->mark_in_next_bitmap(to_obj);
 }
 
 template <G1Barrier barrier, G1Mark do_mark_object, bool use_ext>
--- a/src/share/vm/gc/g1/heapRegion.hpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/gc/g1/heapRegion.hpp	Fri Aug 04 12:24:33 2017 -0700
@@ -56,7 +56,7 @@
 // room for filler objects to pad out to the end of the region.
 
 class G1CollectedHeap;
-class G1CMBitMapRO;
+class G1CMBitMap;
 class HeapRegionRemSet;
 class HeapRegionRemSetIterator;
 class HeapRegion;
@@ -225,7 +225,7 @@
   // May
   // - only called with obj < top()
   // - not called on humongous objects or archive regions
-  inline bool is_obj_dead_with_size(const oop obj, G1CMBitMapRO* prev_bitmap, size_t* size) const;
+  inline bool is_obj_dead_with_size(const oop obj, const G1CMBitMap* const prev_bitmap, size_t* size) const;
 
  protected:
   // The index of this region in the heap region sequence.
@@ -301,7 +301,7 @@
 
   // Returns the block size of the given (dead, potentially having its class unloaded) object
   // starting at p extending to at most the prev TAMS using the given mark bitmap.
-  inline size_t block_size_using_bitmap(const HeapWord* p, const G1CMBitMapRO* prev_bitmap) const;
+  inline size_t block_size_using_bitmap(const HeapWord* p, const G1CMBitMap* const prev_bitmap) const;
  public:
   HeapRegion(uint hrm_index,
              G1BlockOffsetTable* bot,
@@ -349,7 +349,7 @@
   bool block_is_obj(const HeapWord* p) const;
 
   // Returns whether the given object is dead based on TAMS and bitmap.
-  bool is_obj_dead(const oop obj, const G1CMBitMapRO* prev_bitmap) const;
+  bool is_obj_dead(const oop obj, const G1CMBitMap* const prev_bitmap) const;
 
   // Returns the object size for all valid block starts
   // and the amount of unallocated words if called on top()
--- a/src/share/vm/gc/g1/heapRegion.inline.hpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/gc/g1/heapRegion.inline.hpp	Fri Aug 04 12:24:33 2017 -0700
@@ -113,7 +113,7 @@
   return _bot_part.block_start_const(p);
 }
 
-inline bool HeapRegion::is_obj_dead_with_size(const oop obj, G1CMBitMapRO* prev_bitmap, size_t* size) const {
+inline bool HeapRegion::is_obj_dead_with_size(const oop obj, const G1CMBitMap* const prev_bitmap, size_t* size) const {
   HeapWord* addr = (HeapWord*) obj;
 
   assert(addr < top(), "must be");
@@ -145,7 +145,7 @@
   return p < top();
 }
 
-inline size_t HeapRegion::block_size_using_bitmap(const HeapWord* addr, const G1CMBitMapRO* prev_bitmap) const {
+inline size_t HeapRegion::block_size_using_bitmap(const HeapWord* addr, const G1CMBitMap* const prev_bitmap) const {
   assert(ClassUnloadingWithConcurrentMark,
          "All blocks should be objects if class unloading isn't used, so this method should not be called. "
          "HR: [" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT ") "
@@ -154,15 +154,15 @@
 
   // Old regions' dead objects may have dead classes
   // We need to find the next live object using the bitmap
-  HeapWord* next = prev_bitmap->getNextMarkedWordAddress(addr, prev_top_at_mark_start());
+  HeapWord* next = prev_bitmap->get_next_marked_addr(addr, prev_top_at_mark_start());
 
   assert(next > addr, "must get the next live object");
   return pointer_delta(next, addr);
 }
 
-inline bool HeapRegion::is_obj_dead(const oop obj, const G1CMBitMapRO* prev_bitmap) const {
+inline bool HeapRegion::is_obj_dead(const oop obj, const G1CMBitMap* const prev_bitmap) const {
   assert(is_in_reserved(obj), "Object " PTR_FORMAT " must be in region", p2i(obj));
-  return !obj_allocated_since_prev_marking(obj) && !prev_bitmap->isMarked((HeapWord*)obj);
+  return !obj_allocated_since_prev_marking(obj) && !prev_bitmap->is_marked((HeapWord*)obj);
 }
 
 inline size_t HeapRegion::block_size(const HeapWord *addr) const {
@@ -331,7 +331,7 @@
   }
 #endif
 
-  G1CMBitMapRO* bitmap = g1h->concurrent_mark()->prevMarkBitMap();
+  const G1CMBitMap* const bitmap = g1h->concurrent_mark()->prevMarkBitMap();
   do {
     oop obj = oop(cur);
     assert(obj->is_oop(true), "Not an oop at " PTR_FORMAT, p2i(cur));
--- a/src/share/vm/oops/array.hpp	Mon Jul 03 14:33:00 2017 +0200
+++ b/src/share/vm/oops/array.hpp	Fri Aug 04 12:24:33 2017 -0700
@@ -134,10 +134,6 @@
 
     return (int)words;
   }
-  static int size(int length, int elm_byte_size) {
-    return align_size_up(byte_sizeof(length, elm_byte_size), BytesPerWord) / BytesPerWord; // FIXME
-  }
-
   int size() {
     return size(_length);
   }