src/hotspot/share/gc/z/zLiveMap.cpp

*** 1,7 ****
  /*
!  * Copyright (c) 2015, 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.
--- 1,7 ----
  /*
!  * Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 32,50 ****
  #include "utilities/debug.hpp"
  
  static const ZStatCounter ZCounterMarkSeqNumResetContention("Contention", "Mark SeqNum Reset Contention", ZStatUnitOpsPerSecond);
  static const ZStatCounter ZCounterMarkSegmentResetContention("Contention", "Mark Segment Reset Contention", ZStatUnitOpsPerSecond);
  
  ZLiveMap::ZLiveMap(uint32_t size) :
      _seqnum(0),
      _live_objects(0),
      _live_bytes(0),
      _segment_live_bits(0),
      _segment_claim_bits(0),
!     // We need at least one bit per segment.
!     _bitmap(MAX2<size_t>(size, nsegments) * 2),
!     _shift(exact_log2(segment_size())) {}
  
  void ZLiveMap::reset(size_t index) {
    const uint32_t seqnum_initializing = (uint32_t)-1;
    bool contention = false;
  
--- 32,54 ----
  #include "utilities/debug.hpp"
  
  static const ZStatCounter ZCounterMarkSeqNumResetContention("Contention", "Mark SeqNum Reset Contention", ZStatUnitOpsPerSecond);
  static const ZStatCounter ZCounterMarkSegmentResetContention("Contention", "Mark Segment Reset Contention", ZStatUnitOpsPerSecond);
  
+ static size_t bitmap_size(uint32_t size, size_t nsegments) {
+   // We need at least one bit per segment
+   return MAX2<size_t>(size, nsegments) * 2;
+ }
+ 
  ZLiveMap::ZLiveMap(uint32_t size) :
      _seqnum(0),
      _live_objects(0),
      _live_bytes(0),
      _segment_live_bits(0),
      _segment_claim_bits(0),
!     _bitmap(bitmap_size(size, nsegments)),
!     _segment_shift(exact_log2(segment_size())) {}
  
  void ZLiveMap::reset(size_t index) {
    const uint32_t seqnum_initializing = (uint32_t)-1;
    bool contention = false;
  
*** 119,123 ****
--- 123,135 ----
  
    // Set live bit
    const bool success = set_segment_live_atomic(segment);
    assert(success, "Should never fail");
  }
+ 
+ void ZLiveMap::resize(uint32_t size) {
+   const size_t new_bitmap_size = bitmap_size(size, nsegments);
+   if (_bitmap.size() != new_bitmap_size) {
+     _bitmap.reinitialize(new_bitmap_size, false /* clear */);
+     _segment_shift = exact_log2(segment_size());
+   }
+ }