Quelle  g1FullGCCompactionPoint.cpp   Sprache: C

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#include "precompiled.hpp"
#include "gc/g1/g1FullCollector.inline.hpp"
#include "gc/g1/g1FullGCCompactionPoint.hpp"
#include "gc/g1/heapRegion.hpp"
#include "oops/oop.inline.hpp"
#include "utilities/debug.hpp"

G1FullGCCompactionPoint::G1FullGCCompactionPoint(G1FullCollector* collector) :
    _collector(collector),
    _current_region(nullptr),
    _compaction_top(nullptr) {
  _compaction_regions = new (mtGC) GrowableArray<HeapRegion*>(32, mtGC);
  _compaction_region_iterator = _compaction_regions->begin();
}

G1FullGCCompactionPoint::~G1FullGCCompactionPoint() {
  delete _compaction_regions;
}

void G1FullGCCompactionPoint::update() {
  if (is_initialized()) {
    _collector->set_compaction_top(_current_region, _compaction_top);
  }
}

void G1FullGCCompactionPoint::initialize_values() {
  _compaction_top = _collector->compaction_top(_current_region);
}

bool G1FullGCCompactionPoint::has_regions() {
  return !_compaction_regions->is_empty();
}

bool G1FullGCCompactionPoint::is_initialized() {
  return _current_region != NULL;
}

void G1FullGCCompactionPoint::initialize(HeapRegion* hr) {
  _current_region = hr;
  initialize_values();
}

HeapRegion* G1FullGCCompactionPoint::current_region() {
  return *_compaction_region_iterator;
}

HeapRegion* G1FullGCCompactionPoint::next_region() {
  HeapRegion* next = *(++_compaction_region_iterator);
  assert(next != NULL, "Must return valid region");
  return next;
}

GrowableArray<HeapRegion*>* G1FullGCCompactionPoint::regions() {
  return _compaction_regions;
}

bool G1FullGCCompactionPoint::object_will_fit(size_t size) {
  size_t space_left = pointer_delta(_current_region->end(), _compaction_top);
  return size <= space_left;
}

void G1FullGCCompactionPoint::switch_region() {
  // Save compaction top in the region.
  _collector->set_compaction_top(_current_region, _compaction_top);
  // Get the next region and re-initialize the values.
  _current_region = next_region();
  initialize_values();
}

void G1FullGCCompactionPoint::forward(oop object, size_t size) {
  assert(_current_region != NULL, "Must have been initialized");

  // Ensure the object fit in the current region.
  while (!object_will_fit(size)) {
    switch_region();
  }

  // Store a forwarding pointer if the object should be moved.
  if (cast_from_oop<HeapWord*>(object) != _compaction_top) {
    object->forward_to(cast_to_oop(_compaction_top));
    assert(object->is_forwarded(), "must be forwarded");
  } else {
    assert(!object->is_forwarded(), "must not be forwarded");
  }

  // Update compaction values.
  _compaction_top += size;
  _current_region->update_bot_for_block(_compaction_top - size, _compaction_top);
}

void G1FullGCCompactionPoint::add(HeapRegion* hr) {
  _compaction_regions->append(hr);
}

HeapRegion* G1FullGCCompactionPoint::remove_last() {
  return _compaction_regions->pop();
}