C++ oop::age方法代码示例

bool G1StringDedup::is_candidate_from_evacuation(bool from_young, bool to_young, oop obj) {
  if (from_young && java_lang_String::is_instance(obj)) {
    if (to_young && obj->age() == StringDeduplicationAgeThreshold) {
      // Candidate found. String is being evacuated from young to young and just
      // reached the deduplication age threshold.
      return true;
    }
    if (!to_young && obj->age() < StringDeduplicationAgeThreshold) {
      // Candidate found. String is being evacuated from young to old but has not
      // reached the deduplication age threshold, i.e. has not previously been a
      // candidate during its life in the young generation.
      return true;
    }
  }

  // Not a candidate
  return false;
}

oop DefNewGeneration::copy_to_survivor_space(oop old, oop* from) {
  assert(is_in_reserved(old) && !old->is_forwarded(),
	 "shouldn't be scavenging this oop"); 
  size_t s = old->size();
  oop obj = NULL;
  
  // Try allocating obj in to-space (unless too old or won't fit or JVMPI
  // enabled)
  if (old->age() < tenuring_threshold() &&
      !Universe::jvmpi_slow_allocation()) {
    obj = (oop) to()->allocate(s);
  }

  // Otherwise try allocating obj tenured
  if (obj == NULL) {
    obj = _next_gen->promote(old, s, from);
    if (obj == NULL) {
      // A failed promotion likely means the MaxLiveObjectEvacuationRatio flag
      // is incorrectly set. In any case, its seriously wrong to be here!
      vm_exit_out_of_memory(s*wordSize, "promotion");
    }
  } else {
    // Prefetch beyond obj
    const intx interval = PrefetchCopyIntervalInBytes;
    atomic::prefetch_write(obj, interval);

    // Copy obj
    Memory::copy_words_aligned((HeapWord*)old, (HeapWord*)obj, s);

    // Increment age if obj still in new generation
    obj->incr_age(); 
    age_table()->add(obj, s);
  }

  if (Universe::jvmpi_move_event_enabled()) {
    Universe::jvmpi_object_move(old, obj);
  }

  // Done, insert forward pointer to obj in this header
  old->forward_to(obj);

  return obj;
}

oop DefNewGeneration::copy_to_survivor_space(oop old) {
  assert(is_in_reserved(old) && !old->is_forwarded(),
         "shouldn't be scavenging this oop");
  size_t s = old->size();
  oop obj = NULL;

  // Try allocating obj in to-space (unless too old)
  if (old->age() < tenuring_threshold()) {
    obj = (oop) to()->allocate(s);
  }

  // Otherwise try allocating obj tenured
  if (obj == NULL) {
    obj = _next_gen->promote(old, s);
    if (obj == NULL) {
      if (!HandlePromotionFailure) {
        // A failed promotion likely means the MaxLiveObjectEvacuationRatio flag
        // is incorrectly set. In any case, its seriously wrong to be here!
        vm_exit_out_of_memory(s*wordSize, "promotion");
      }

      handle_promotion_failure(old);
      return old;
    }
  } else {
    // Prefetch beyond obj
    const intx interval = PrefetchCopyIntervalInBytes;
    Prefetch::write(obj, interval);

    // Copy obj
    Copy::aligned_disjoint_words((HeapWord*)old, (HeapWord*)obj, s);

    // Increment age if obj still in new generation
    obj->incr_age();
    age_table()->add(obj, s);
  }

  // Done, insert forward pointer to obj in this header
  old->forward_to(obj);

  return obj;
}

oop DefNewGeneration::copy_to_survivor_space(oop old) {
  assert(is_in_reserved(old) && !old->is_forwarded(),
         "shouldn't be scavenging this oop");
  size_t s = old->size();
  oop obj = NULL;

  // Try allocating obj in to-space (unless too old)
  if (old->age() < tenuring_threshold()) {
    obj = (oop) to()->allocate(s);
  }

  // Otherwise try allocating obj tenured
  if (obj == NULL) {
    obj = _next_gen->promote(old, s);
    if (obj == NULL) {
      handle_promotion_failure(old);
      return old;
    }
  } else {
    // Prefetch beyond obj
    const intx interval = PrefetchCopyIntervalInBytes;
    Prefetch::write(obj, interval);

    // Copy obj
    Copy::aligned_disjoint_words((HeapWord*)old, (HeapWord*)obj, s);

    // Increment age if obj still in new generation
    obj->incr_age();
    age_table()->add(obj, s);
  }

  // Done, insert forward pointer to obj in this header
  old->forward_to(obj);

  return obj;
}

 // add entry
 void add(oop p, size_t oop_size) {
   int age = p->age();
   assert(age > 0 && age < table_size, "invalid age of object");
   sizes[age] += oop_size; 
 }

// add entry
void AgeTable::add(oop p, size_t oop_size) {
  add(p->age(), oop_size);
}

 // add entry
 void add(oop p, size_t oop_size) {
     add(p->age(), oop_size);
 }