DefNewGeneration::DefNewGeneration(ReservedSpace rs,
                                   size_t initial_size,
                                   int level,
                                   const char* policy)
  : Generation(rs, initial_size, level),
    _objs_with_preserved_marks(NULL),
    _preserved_marks_of_objs(NULL),
    _promo_failure_scan_stack(NULL),
    _promo_failure_drain_in_progress(false),
    _should_allocate_from_space(false)
{
  MemRegion cmr((HeapWord*)_virtual_space.low(),
                (HeapWord*)_virtual_space.high());
  Universe::heap()->barrier_set()->resize_covered_region(cmr);

  if (GenCollectedHeap::heap()->collector_policy()->has_soft_ended_eden()) {
    _eden_space = new ConcEdenSpace(this);
  } else {
    _eden_space = new EdenSpace(this);
  }
  _from_space = new ContiguousSpace();
  _to_space   = new ContiguousSpace();

  if (_eden_space == NULL || _from_space == NULL || _to_space == NULL)
    vm_exit_during_initialization("Could not allocate a new gen space");

  // Compute the maximum eden and survivor space sizes. These sizes
  // are computed assuming the entire reserved space is committed.
  // These values are exported as performance counters.
  uintx alignment = GenCollectedHeap::heap()->collector_policy()->min_alignment();
  uintx size = _virtual_space.reserved_size();
  _max_survivor_size = compute_survivor_size(size, alignment);
  _max_eden_size = size - (2*_max_survivor_size);

  // allocate the performance counters

  // Generation counters -- generation 0, 3 subspaces
  _gen_counters = new GenerationCounters("new", 0, 3, &_virtual_space);
  _gc_counters = new CollectorCounters(policy, 0);

  _eden_counters = new CSpaceCounters("eden", 0, _max_eden_size, _eden_space,
                                      _gen_counters);
  _from_counters = new CSpaceCounters("s0", 1, _max_survivor_size, _from_space,
                                      _gen_counters);
  _to_counters = new CSpaceCounters("s1", 2, _max_survivor_size, _to_space,
                                    _gen_counters);

  compute_space_boundaries(0, SpaceDecorator::Clear, SpaceDecorator::Mangle);
  update_counters();
  _next_gen = NULL;
  _tenuring_threshold = MaxTenuringThreshold;
  _pretenure_size_threshold_words = PretenureSizeThreshold >> LogHeapWordSize;
}
DefNewGeneration::DefNewGeneration(ReservedSpace rs,
                                   size_t initial_size,
                                   const char* policy)
  : Generation(rs, initial_size),
    _promo_failure_drain_in_progress(false),
    _should_allocate_from_space(false)
{
  MemRegion cmr((HeapWord*)_virtual_space.low(),
                (HeapWord*)_virtual_space.high());
  GenCollectedHeap* gch = GenCollectedHeap::heap();

  gch->barrier_set()->resize_covered_region(cmr);

  _eden_space = new ContiguousSpace();
  _from_space = new ContiguousSpace();
  _to_space   = new ContiguousSpace();

  if (_eden_space == NULL || _from_space == NULL || _to_space == NULL) {
    vm_exit_during_initialization("Could not allocate a new gen space");
  }

  // Compute the maximum eden and survivor space sizes. These sizes
  // are computed assuming the entire reserved space is committed.
  // These values are exported as performance counters.
  uintx alignment = gch->collector_policy()->space_alignment();
  uintx size = _virtual_space.reserved_size();
  _max_survivor_size = compute_survivor_size(size, alignment);
  _max_eden_size = size - (2*_max_survivor_size);

  // allocate the performance counters
  GenCollectorPolicy* gcp = gch->gen_policy();

  // Generation counters -- generation 0, 3 subspaces
  _gen_counters = new GenerationCounters("new", 0, 3,
      gcp->min_young_size(), gcp->max_young_size(), &_virtual_space);
  _gc_counters = new CollectorCounters(policy, 0);

  _eden_counters = new CSpaceCounters("eden", 0, _max_eden_size, _eden_space,
                                      _gen_counters);
  _from_counters = new CSpaceCounters("s0", 1, _max_survivor_size, _from_space,
                                      _gen_counters);
  _to_counters = new CSpaceCounters("s1", 2, _max_survivor_size, _to_space,
                                    _gen_counters);

  compute_space_boundaries(0, SpaceDecorator::Clear, SpaceDecorator::Mangle);
  update_counters();
  _old_gen = NULL;
  _tenuring_threshold = MaxTenuringThreshold;
  _pretenure_size_threshold_words = PretenureSizeThreshold >> LogHeapWordSize;

  _gc_timer = new (ResourceObj::C_HEAP, mtGC) STWGCTimer();
}
void DefNewGeneration::compute_space_boundaries(uintx minimum_eden_size) {
  // All space sizes must be multiples of car size in order for the CarTable to work.
  // Note that the CarTable is used with and without train gc (for fast lookup).
  uintx alignment = CarSpace::car_size();

  // Compute sizes
  uintx size = _virtual_space.committed_size();
  uintx survivor_size = compute_survivor_size(size, alignment);
  uintx eden_size = size - (2*survivor_size);
  assert(eden_size > 0 && survivor_size <= eden_size, "just checking");

  if (eden_size < minimum_eden_size) {
    // May happen due to 64Kb rounding, if so adjust eden size back up
    minimum_eden_size = align_size_up(minimum_eden_size, alignment);
    uintx maximum_survivor_size = (size - minimum_eden_size) / 2;
    uintx unaligned_survivor_size = 
      align_size_down(maximum_survivor_size, alignment);
    survivor_size = MAX2(unaligned_survivor_size, alignment);
    eden_size = size - (2*survivor_size);
    assert(eden_size > 0 && survivor_size <= eden_size, "just checking");
    assert(eden_size >= minimum_eden_size, "just checking");
  }

  char *eden_start = _virtual_space.low();
  char *from_start = eden_start + eden_size;
  char *to_start   = from_start + survivor_size;
  char *to_end     = to_start   + survivor_size;

  assert(to_end == _virtual_space.high(), "just checking");
  assert(Space::is_aligned((HeapWord*)eden_start), "checking alignment");
  assert(Space::is_aligned((HeapWord*)from_start), "checking alignment");
  assert(Space::is_aligned((HeapWord*)to_start),   "checking alignment");

  MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)from_start);
  MemRegion fromMR((HeapWord*)from_start, (HeapWord*)to_start);
  MemRegion toMR  ((HeapWord*)to_start, (HeapWord*)to_end);

  eden()->initialize(edenMR, (minimum_eden_size == 0));
  from()->initialize(fromMR, true);
    to()->initialize(toMR  , true);

  if (jvmpi::is_event_enabled(JVMPI_EVENT_ARENA_NEW)) {
    CollectedHeap* ch = Universe::heap();
    jvmpi::post_arena_new_event(ch->addr_to_arena_id(eden_start), "Eden");
    jvmpi::post_arena_new_event(ch->addr_to_arena_id(from_start), "Semi");
    jvmpi::post_arena_new_event(ch->addr_to_arena_id(to_start), "Semi");
  }
}
DefNewGeneration::DefNewGeneration(ReservedSpace rs,
				   size_t initial_size,
				   int level,
				   const char* policy)
  : Generation(rs, initial_size, level) {
  MemRegion cmr((HeapWord*)_virtual_space.low(),
		(HeapWord*)_virtual_space.high());
  Universe::heap()->barrier_set()->resize_covered_region(cmr);

  _eden_space = new EdenSpace(this);
  _from_space = new ContiguousSpace();
  _to_space   = new ContiguousSpace();

  if (_eden_space == NULL || _from_space == NULL || _to_space == NULL)
    vm_exit_during_initialization("Could not allocate a new gen space");

  // Compute the maximum eden and survivor space sizes. These sizes
  // are computed assuming the entire reserved space is committed.
  // These values are exported as performance counters.
  uintx alignment = CarSpace::car_size();
  uintx size = _virtual_space.reserved_size();
  uintx max_survivor_size = compute_survivor_size(size, alignment);
  uintx max_eden_size = size - (2*max_survivor_size);

  // allocate the performance counters

  // Generation counters -- generation 0, 3 subspaces
  _gen_counters = new GenerationCounters(PERF_GC, "new", 0, 3, &_virtual_space);
  _gc_counters = new CollectorCounters(PERF_GC, policy, 0);

  const char* ns = _gen_counters->name_space();
  _eden_counters = new CSpaceCounters(ns, "eden", 0, max_eden_size, _eden_space);
  _from_counters = new CSpaceCounters(ns, "s0", 1, max_survivor_size, _from_space);
  _to_counters = new CSpaceCounters(ns, "s1", 2, max_survivor_size, _to_space);

  compute_space_boundaries(0);
  update_counters();
  _next_gen = NULL;
  _tenuring_threshold = MaxTenuringThreshold;
  _pretenure_size_threshold_words = PretenureSizeThreshold >> LogHeapWordSize;
}
Ejemplo n.º 5
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size_t DefNewGeneration::max_capacity() const {
  const size_t alignment = GenCollectedHeap::heap()->collector_policy()->space_alignment();
  const size_t reserved_bytes = reserved().byte_size();
  return reserved_bytes - compute_survivor_size(reserved_bytes, alignment);
}
Ejemplo n.º 6
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void DefNewGeneration::compute_space_boundaries(uintx minimum_eden_size,
                                                bool clear_space,
                                                bool mangle_space) {
  uintx alignment =
    GenCollectedHeap::heap()->collector_policy()->space_alignment();

  // If the spaces are being cleared (only done at heap initialization
  // currently), the survivor spaces need not be empty.
  // Otherwise, no care is taken for used areas in the survivor spaces
  // so check.
  assert(clear_space || (to()->is_empty() && from()->is_empty()),
    "Initialization of the survivor spaces assumes these are empty");

  // Compute sizes
  uintx size = _virtual_space.committed_size();
  uintx survivor_size = compute_survivor_size(size, alignment);
  uintx eden_size = size - (2*survivor_size);
  assert(eden_size > 0 && survivor_size <= eden_size, "just checking");

  if (eden_size < minimum_eden_size) {
    // May happen due to 64Kb rounding, if so adjust eden size back up
    minimum_eden_size = align_size_up(minimum_eden_size, alignment);
    uintx maximum_survivor_size = (size - minimum_eden_size) / 2;
    uintx unaligned_survivor_size =
      align_size_down(maximum_survivor_size, alignment);
    survivor_size = MAX2(unaligned_survivor_size, alignment);
    eden_size = size - (2*survivor_size);
    assert(eden_size > 0 && survivor_size <= eden_size, "just checking");
    assert(eden_size >= minimum_eden_size, "just checking");
  }

  char *eden_start = _virtual_space.low();
  char *from_start = eden_start + eden_size;
  char *to_start   = from_start + survivor_size;
  char *to_end     = to_start   + survivor_size;

  assert(to_end == _virtual_space.high(), "just checking");
  assert(Space::is_aligned((HeapWord*)eden_start), "checking alignment");
  assert(Space::is_aligned((HeapWord*)from_start), "checking alignment");
  assert(Space::is_aligned((HeapWord*)to_start),   "checking alignment");

  MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)from_start);
  MemRegion fromMR((HeapWord*)from_start, (HeapWord*)to_start);
  MemRegion toMR  ((HeapWord*)to_start, (HeapWord*)to_end);

  // A minimum eden size implies that there is a part of eden that
  // is being used and that affects the initialization of any
  // newly formed eden.
  bool live_in_eden = minimum_eden_size > 0;

  // If not clearing the spaces, do some checking to verify that
  // the space are already mangled.
  if (!clear_space) {
    // Must check mangling before the spaces are reshaped.  Otherwise,
    // the bottom or end of one space may have moved into another
    // a failure of the check may not correctly indicate which space
    // is not properly mangled.
    if (ZapUnusedHeapArea) {
      HeapWord* limit = (HeapWord*) _virtual_space.high();
      eden()->check_mangled_unused_area(limit);
      from()->check_mangled_unused_area(limit);
        to()->check_mangled_unused_area(limit);
    }
  }

  // Reset the spaces for their new regions.
  eden()->initialize(edenMR,
                     clear_space && !live_in_eden,
                     SpaceDecorator::Mangle);
  // If clear_space and live_in_eden, we will not have cleared any
  // portion of eden above its top. This can cause newly
  // expanded space not to be mangled if using ZapUnusedHeapArea.
  // We explicitly do such mangling here.
  if (ZapUnusedHeapArea && clear_space && live_in_eden && mangle_space) {
    eden()->mangle_unused_area();
  }
  from()->initialize(fromMR, clear_space, mangle_space);
  to()->initialize(toMR, clear_space, mangle_space);

  // Set next compaction spaces.
  eden()->set_next_compaction_space(from());
  // The to-space is normally empty before a compaction so need
  // not be considered.  The exception is during promotion
  // failure handling when to-space can contain live objects.
  from()->set_next_compaction_space(NULL);
}
size_t DefNewGeneration::max_capacity() const {
  const size_t alignment = CarSpace::car_size();
  const size_t reserved_bytes = reserved().byte_size();
  return reserved_bytes - compute_survivor_size(reserved_bytes, alignment);
}