// Fills names with VM internal thread names and times with the corresponding
// CPU times.  If names or times is NULL, a NullPointerException is thrown.
// If the element type of names is not String, an IllegalArgumentException is
// thrown.
// If an array is not large enough to hold all the entries, only the entries
// that fit will be returned.  Return value is the number of VM internal
// threads entries.

JVM_ENTRY(jint, jmm_GetInternalThreadTimes(JNIEnv *env,
                                           jobjectArray names,
                                           jlongArray times))

  {- -------------------------------------------
  (1) もし, 配列であるべき引数が実は NULL だった場合, NullPointerException.
      ---------------------------------------- -}

      if (names == NULL || times == NULL) {
         THROW_(vmSymbols::java_lang_NullPointerException(), 0);
      }

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

      objArrayOop na = objArrayOop(JNIHandles::resolve_non_null(names));
      objArrayHandle names_ah(THREAD, na);

  {- -------------------------------------------
  (1) 引数(names)の型をチェックしておく.
      もし String 配列でなければ IllegalArgumentException.
      ---------------------------------------- -}

      // Make sure we have a String array
      klassOop element_klass = objArrayKlass::cast(names_ah->klass())->element_klass();
      if (element_klass != SystemDictionary::String_klass()) {
        THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
                   "Array element type is not String class", 0);
      }

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

      typeArrayOop ta = typeArrayOop(JNIHandles::resolve_non_null(times));
      typeArrayHandle times_ah(THREAD, ta);

  {- -------------------------------------------
  (1) ThreadTimesClosure によって, 
      引数で渡されていた配列(names, times)の中に
      各スレッドのスレッド名と CPU 使用時間を格納し, 
      その結果をリターン.
      ---------------------------------------- -}

      ThreadTimesClosure ttc(names_ah(), times_ah());
      {
        MutexLockerEx ml(Threads_lock);
        Threads::threads_do(&ttc);
      }

      return ttc.count();
    JVM_END