// info_ptr - pre-checked for NULL

jvmtiError
JvmtiEnv::GetObjectMonitorUsage(jobject object, jvmtiMonitorUsage* info_ptr) {

  {- -------------------------------------------
  (1) (変数宣言など)
      ---------------------------------------- -}

      JavaThread* calling_thread = JavaThread::current();

  {- -------------------------------------------
  (1) まず JvmtiEnvBase::get_object_monitor_usage() での取得を試みる.
      ---------------------------------------- -}

      jvmtiError err = get_object_monitor_usage(calling_thread, object, info_ptr);

  {- -------------------------------------------
  (1) 対象のスレッドがサスペンドしていなかった場合(JVMTI_ERROR_THREAD_NOT_SUSPENDED エラーが返された場合)は
      VM_GetObjectMonitorUsage による取得を行う.
      ---------------------------------------- -}

      if (err == JVMTI_ERROR_THREAD_NOT_SUSPENDED) {
        // Some of the critical threads were not suspended. go to a safepoint and try again
        VM_GetObjectMonitorUsage op(this, calling_thread, object, info_ptr);
        VMThread::execute(&op);
        err = op.result();
      }

  {- -------------------------------------------
  (1) リターン
      ---------------------------------------- -}

      return err;
    } /* end GetObjectMonitorUsage */