C++ oop::blueprint方法代码示例

  void do_object(oop obj) {
    // instanceKlass objects need some adjustment.
    if (obj->blueprint()->oop_is_instanceKlass()) {
      instanceKlass* ik = instanceKlass::cast((klassOop)obj);

      sort_methods(ik, _thread);
    }
  }

void CollectedHeap::post_allocation_install_obj_klass(KlassHandle klass,
                                                   oop obj) {
  // These asserts are kind of complicated because of klassKlass
  // and the beginning of the world.
  assert(klass() != NULL || !Universe::is_fully_initialized(), "NULL klass");
  assert(klass() == NULL || klass()->is_klass(), "not a klass");
  assert(klass() == NULL || klass()->klass_part() != NULL, "not a klass");
  assert(obj != NULL, "NULL object pointer");
  obj->set_klass(klass());
  assert(!Universe::is_fully_initialized() || obj->blueprint() != NULL,
         "missing blueprint");
}

object_type ClassifyObjectClosure::classify_object(oop obj, bool count) {
  object_type type = unknown_type;

  Klass* k = obj->blueprint();

  if (k->as_klassOop() == SystemDictionary::Object_klass()) {
    tty->print_cr("Found the class!");
  }

  if (count) {
    k->set_alloc_count(k->alloc_count() + 1);
  }

  if (obj->is_instance()) {
    if (k->oop_is_instanceRef()) {
      type = instanceRef_type;
    } else {
      type = instance_type;
    }
  } else if (obj->is_typeArray()) {
    type = typeArray_type;
  } else if (obj->is_objArray()) {
    type = objArray_type;
  } else if (obj->is_symbol()) {
    type = symbol_type;
  } else if (obj->is_klass()) {
    Klass* k = ((klassOop)obj)->klass_part();
    if (k->oop_is_instance()) {
      type = instanceKlass_type;
    } else {
      type = klass_type;
    }
  } else if (obj->is_method()) {
    type = method_type;
  } else if (obj->is_constMethod()) {
    type = constMethod_type;
  } else if (obj->is_methodData()) {
    ShouldNotReachHere();
  } else if (obj->is_constantPool()) {
    type = constantPool_type;
  } else if (obj->is_constantPoolCache()) {
    type = constantPoolCache_type;
  } else if (obj->is_compiledICHolder()) {
    type = compiledICHolder_type;
  } else {
    ShouldNotReachHere();
  }

  assert(type != unknown_type, "found object of unknown type.");
  return type;
}

static HeuristicsResult update_heuristics(oop o, bool allow_rebias) {
  markOop mark = o->mark();
  if (!mark->has_bias_pattern()) {
    return HR_NOT_BIASED;
  }

  // Heuristics to attempt to throttle the number of revocations.
  // Stages:
  // 1. Revoke the biases of all objects in the heap of this type,
  //    but allow rebiasing of those objects if unlocked.
  // 2. Revoke the biases of all objects in the heap of this type
  //    and don't allow rebiasing of these objects. Disable
  //    allocation of objects of that type with the bias bit set.
  Klass* k = o->blueprint();
  jlong cur_time = os::javaTimeMillis();
  jlong last_bulk_revocation_time = k->last_biased_lock_bulk_revocation_time();
  int revocation_count = k->biased_lock_revocation_count();
  if ((revocation_count >= BiasedLockingBulkRebiasThreshold) &&
      (revocation_count <  BiasedLockingBulkRevokeThreshold) &&
      (last_bulk_revocation_time != 0) &&
      (cur_time - last_bulk_revocation_time >= BiasedLockingDecayTime)) {
    // This is the first revocation we've seen in a while of an
    // object of this type since the last time we performed a bulk
    // rebiasing operation. The application is allocating objects in
    // bulk which are biased toward a thread and then handing them
    // off to another thread. We can cope with this allocation
    // pattern via the bulk rebiasing mechanism so we reset the
    // klass's revocation count rather than allow it to increase
    // monotonically. If we see the need to perform another bulk
    // rebias operation later, we will, and if subsequently we see
    // many more revocation operations in a short period of time we
    // will completely disable biasing for this type.
    k->set_biased_lock_revocation_count(0);
    revocation_count = 0;
  }

  // Make revocation count saturate just beyond BiasedLockingBulkRevokeThreshold
  if (revocation_count <= BiasedLockingBulkRevokeThreshold) {
    revocation_count = k->atomic_incr_biased_lock_revocation_count();
  }

  if (revocation_count == BiasedLockingBulkRevokeThreshold) {
    return HR_BULK_REVOKE;
  }

  if (revocation_count == BiasedLockingBulkRebiasThreshold) {
    return HR_BULK_REBIAS;
  }

  return HR_SINGLE_REVOKE;
}

 void do_object(oop obj) {
   Klass* k = obj->blueprint();
   k->set_alloc_count(k->alloc_count() + 1);
   k->set_alloc_size(k->alloc_size() + obj->size());
 }

static BiasedLocking::Condition bulk_revoke_or_rebias_at_safepoint(oop o,
                                                                   bool bulk_rebias,
                                                                   bool attempt_rebias_of_object,
                                                                   JavaThread* requesting_thread) {
  assert(SafepointSynchronize::is_at_safepoint(), "must be done at safepoint");

  if (TraceBiasedLocking) {
    tty->print_cr("* Beginning bulk revocation (kind == %s) because of object "
                  INTPTR_FORMAT " , mark " INTPTR_FORMAT " , type %s",
                  (bulk_rebias ? "rebias" : "revoke"),
                  (intptr_t) o, (intptr_t) o->mark(), Klass::cast(o->klass())->external_name());
  }

  jlong cur_time = os::javaTimeMillis();
  o->blueprint()->set_last_biased_lock_bulk_revocation_time(cur_time);


  klassOop k_o = o->klass();
  Klass* klass = Klass::cast(k_o);

  if (bulk_rebias) {
    // Use the epoch in the klass of the object to implicitly revoke
    // all biases of objects of this data type and force them to be
    // reacquired. However, we also need to walk the stacks of all
    // threads and update the headers of lightweight locked objects
    // with biases to have the current epoch.

    // If the prototype header doesn't have the bias pattern, don't
    // try to update the epoch -- assume another VM operation came in
    // and reset the header to the unbiased state, which will
    // implicitly cause all existing biases to be revoked
    if (klass->prototype_header()->has_bias_pattern()) {
      int prev_epoch = klass->prototype_header()->bias_epoch();
      klass->set_prototype_header(klass->prototype_header()->incr_bias_epoch());
      int cur_epoch = klass->prototype_header()->bias_epoch();

      // Now walk all threads' stacks and adjust epochs of any biased
      // and locked objects of this data type we encounter
      for (JavaThread* thr = Threads::first(); thr != NULL; thr = thr->next()) {
        GrowableArray<MonitorInfo*>* cached_monitor_info = get_or_compute_monitor_info(thr);
        for (int i = 0; i < cached_monitor_info->length(); i++) {
          MonitorInfo* mon_info = cached_monitor_info->at(i);
          oop owner = mon_info->owner();
          markOop mark = owner->mark();
          if ((owner->klass() == k_o) && mark->has_bias_pattern()) {
            // We might have encountered this object already in the case of recursive locking
            assert(mark->bias_epoch() == prev_epoch || mark->bias_epoch() == cur_epoch, "error in bias epoch adjustment");
            owner->set_mark(mark->set_bias_epoch(cur_epoch));
          }
        }
      }
    }

    // At this point we're done. All we have to do is potentially
    // adjust the header of the given object to revoke its bias.
    revoke_bias(o, attempt_rebias_of_object && klass->prototype_header()->has_bias_pattern(), true, requesting_thread);
  } else {
    if (TraceBiasedLocking) {
      ResourceMark rm;
      tty->print_cr("* Disabling biased locking for type %s", klass->external_name());
    }

    // Disable biased locking for this data type. Not only will this
    // cause future instances to not be biased, but existing biased
    // instances will notice that this implicitly caused their biases
    // to be revoked.
    klass->set_prototype_header(markOopDesc::prototype());

    // Now walk all threads' stacks and forcibly revoke the biases of
    // any locked and biased objects of this data type we encounter.
    for (JavaThread* thr = Threads::first(); thr != NULL; thr = thr->next()) {
      GrowableArray<MonitorInfo*>* cached_monitor_info = get_or_compute_monitor_info(thr);
      for (int i = 0; i < cached_monitor_info->length(); i++) {
        MonitorInfo* mon_info = cached_monitor_info->at(i);
        oop owner = mon_info->owner();
        markOop mark = owner->mark();
        if ((owner->klass() == k_o) && mark->has_bias_pattern()) {
          revoke_bias(owner, false, true, requesting_thread);
        }
      }
    }

    // Must force the bias of the passed object to be forcibly revoked
    // as well to ensure guarantees to callers
    revoke_bias(o, false, true, requesting_thread);
  }

  if (TraceBiasedLocking) {
    tty->print_cr("* Ending bulk revocation");
  }

  BiasedLocking::Condition status_code = BiasedLocking::BIAS_REVOKED;

  if (attempt_rebias_of_object &&
      o->mark()->has_bias_pattern() &&
      klass->prototype_header()->has_bias_pattern()) {
    markOop new_mark = markOopDesc::encode(requesting_thread, o->mark()->age(),
                                           klass->prototype_header()->bias_epoch());
    o->set_mark(new_mark);
    status_code = BiasedLocking::BIAS_REVOKED_AND_REBIASED;
//.........这里部分代码省略.........