JVM_ENTRY(void, JVM_Sleep(JNIEnv* env, jclass threadClass, jlong millis))

  {- -------------------------------------------
  (1) (トレース出力) (See: JVMWrapper)
      ---------------------------------------- -}

      JVMWrapper("JVM_Sleep");

  {- -------------------------------------------
  (1) スリープ時間として負値が指定されていたら IllegalArgumentException.
      ---------------------------------------- -}

      if (millis < 0) {
        THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "timeout value is negative");
      }

  {- -------------------------------------------
  (1) もし処理対象のスレッドに対して java.lang.Thread.interrupt() が呼ばれていたら, 
      この時点で InterruptedException を出す.
      ---------------------------------------- -}

      if (Thread::is_interrupted (THREAD, true) && !HAS_PENDING_EXCEPTION) {
        THROW_MSG(vmSymbols::java_lang_InterruptedException(), "sleep interrupted");
      }

  {- -------------------------------------------
  (1) JavaThreadSleepState で, JavaThread の状態を一時的に SLEEPING に変更
      (ついでに JMM 用の(プロファイル情報の記録)も行っている.
       See: JavaThreadSleepState)
      ---------------------------------------- -}

      // Save current thread state and restore it at the end of this block.
      // And set new thread state to SLEEPING.
      JavaThreadSleepState jtss(thread);

  {- -------------------------------------------
  (1) (DTrace のフック点)
      ---------------------------------------- -}

      HS_DTRACE_PROBE1(hotspot, thread__sleep__begin, millis);

  {- -------------------------------------------
  (1) 条件に応じて, それぞれ以下の関数を呼び出す.
      * 引数の sleep 時間が 0 で, かつ ConvertSleepToYield オプションが指定されている
        os::yield()
      * 引数の sleep 時間が 0 で, かつ ConvertSleepToYield オプションは指定されていない
        os::sleep()
      * 引数の sleep 時間が 0 ではない
        os::sleep()

      なお, 引数の sleep 時間が 0 ではないケースについては, 
      os::sleep() の返り値が OS_INTRPT でかつ pending exception がなければ 
      InterruptedException を出す.
      (See: java.lang.Thread.interrupt())
      ---------------------------------------- -}

      if (millis == 0) {
        // When ConvertSleepToYield is on, this matches the classic VM implementation of
        // JVM_Sleep. Critical for similar threading behaviour (Win32)
        // It appears that in certain GUI contexts, it may be beneficial to do a short sleep
        // for SOLARIS
        if (ConvertSleepToYield) {
          os::yield();
        } else {
          ThreadState old_state = thread->osthread()->get_state();
          thread->osthread()->set_state(SLEEPING);
          os::sleep(thread, MinSleepInterval, false);
          thread->osthread()->set_state(old_state);
        }
      } else {
        ThreadState old_state = thread->osthread()->get_state();
        thread->osthread()->set_state(SLEEPING);
        if (os::sleep(thread, millis, true) == OS_INTRPT) {
          // An asynchronous exception (e.g., ThreadDeathException) could have been thrown on
          // us while we were sleeping. We do not overwrite those.
          if (!HAS_PENDING_EXCEPTION) {
            HS_DTRACE_PROBE1(hotspot, thread__sleep__end,1);
            // TODO-FIXME: THROW_MSG returns which means we will not call set_state()
            // to properly restore the thread state.  That's likely wrong.
            THROW_MSG(vmSymbols::java_lang_InterruptedException(), "sleep interrupted");
          }
        }
        thread->osthread()->set_state(old_state);
      }

  {- -------------------------------------------
  (1) (DTrace のフック点)
      ---------------------------------------- -}

      HS_DTRACE_PROBE1(hotspot, thread__sleep__end,0);
    JVM_END