// Setup current current thread for event collection.

void JvmtiEventCollector::setup_jvmti_thread_state() {

  {- -------------------------------------------
  (1) JvmtiThreadState::state_for() を呼んで, 
      カレントスレッドに対応する JvmtiThreadState を取得する.
      (もし対象のスレッドが JvmtiThreadState を持っていなければ, この中で確保処理が行われる)
      ---------------------------------------- -}

      // set this event collector to be the current one.
      JvmtiThreadState* state = JvmtiThreadState::state_for(JavaThread::current());

  {- -------------------------------------------
  (1) (assert)
      ---------------------------------------- -}

      // state can only be NULL if the current thread is exiting which
      // should not happen since we're trying to configure for event collection
      guarantee(state != NULL, "exiting thread called setup_jvmti_thread_state");

  {- -------------------------------------------
  (1) この JvmtiEventCollector (のサブクラスの) オブジェクトを
      JvmtiThreadState オブジェクト内の適切なリストに追加する.
      (ついでに, 変更前の値を _prev フィールドに保存しておくことで線形リストを構築)

      * JvmtiVMObjectAllocEventCollector オブジェクトの場合:
        JvmtiThreadState::set_vm_object_alloc_event_collector() を呼び出して追加.
      * JvmtiDynamicCodeEventCollector オブジェクトの場合:
        JvmtiThreadState::set_dynamic_code_event_collector() を呼び出して追加.
      ---------------------------------------- -}

      if (is_vm_object_alloc_event()) {
        _prev = state->get_vm_object_alloc_event_collector();
        state->set_vm_object_alloc_event_collector((JvmtiVMObjectAllocEventCollector *)this);
      } else if (is_dynamic_code_event()) {
        _prev = state->get_dynamic_code_event_collector();
        state->set_dynamic_code_event_collector((JvmtiDynamicCodeEventCollector *)this);
      }
    }