80 }
  81 
  82 void ShenandoahHeapRegionSet::clear() {
  83   assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Must be at a safepoint");
  84   Copy::zero_to_bytes(_set_map, _map_size);
  85 
  86   _region_count = 0;
  87 }
  88 
  89 ShenandoahHeapRegion* ShenandoahHeapRegionSetIterator::claim_next() {
  90   size_t num_regions = _heap->num_regions();
  91   if (_current_index >= (jint)num_regions) {
  92     return NULL;
  93   }
  94 
  95   jint saved_current = _current_index;
  96   size_t index = (size_t)saved_current;
  97 
  98   while(index < num_regions) {
  99     if (_set->is_in(index)) {
 100       jint cur = Atomic::cmpxchg((jint)(index + 1), &_current_index, saved_current);
 101       assert(cur >= (jint)saved_current, "Must move forward");
 102       if (cur == saved_current) {
 103         assert(_set->is_in(index), "Invariant");
 104         return _heap->get_region(index);
 105       } else {
 106         index = (size_t)cur;
 107         saved_current = cur;
 108       }
 109     } else {
 110       index ++;
 111     }
 112   }
 113   return NULL;
 114 }
 115 
 116 ShenandoahHeapRegion* ShenandoahHeapRegionSetIterator::next() {
 117   size_t num_regions = _heap->num_regions();
 118   for (size_t index = (size_t)_current_index; index < num_regions; index ++) {
 119     if (_set->is_in(index)) {
 120       _current_index = (jint)(index + 1);

  80 }
  81 
  82 void ShenandoahHeapRegionSet::clear() {
  83   assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Must be at a safepoint");
  84   Copy::zero_to_bytes(_set_map, _map_size);
  85 
  86   _region_count = 0;
  87 }
  88 
  89 ShenandoahHeapRegion* ShenandoahHeapRegionSetIterator::claim_next() {
  90   size_t num_regions = _heap->num_regions();
  91   if (_current_index >= (jint)num_regions) {
  92     return NULL;
  93   }
  94 
  95   jint saved_current = _current_index;
  96   size_t index = (size_t)saved_current;
  97 
  98   while(index < num_regions) {
  99     if (_set->is_in(index)) {
 100       jint cur = Atomic::cmpxchg(&_current_index, saved_current, (jint)(index + 1));
 101       assert(cur >= (jint)saved_current, "Must move forward");
 102       if (cur == saved_current) {
 103         assert(_set->is_in(index), "Invariant");
 104         return _heap->get_region(index);
 105       } else {
 106         index = (size_t)cur;
 107         saved_current = cur;
 108       }
 109     } else {
 110       index ++;
 111     }
 112   }
 113   return NULL;
 114 }
 115 
 116 ShenandoahHeapRegion* ShenandoahHeapRegionSetIterator::next() {
 117   size_t num_regions = _heap->num_regions();
 118   for (size_t index = (size_t)_current_index; index < num_regions; index ++) {
 119     if (_set->is_in(index)) {
 120       _current_index = (jint)(index + 1);