// rmonitor - pre-checked for validity

jvmtiError
JvmtiEnv::DestroyRawMonitor(JvmtiRawMonitor * rmonitor) {

  {- -------------------------------------------
  (1) (以下の処理は, HotSpot の起動中(= Threads::number_of_threads() が 0)かどうかで ２通りに分かれる)
      ---------------------------------------- -}

  {- -------------------------------------------
  (1) (以下は HotSpot の起動中(= Threads::number_of_threads() が 0)の場合)
      ---------------------------------------- -}

      if (Threads::number_of_threads() == 0) {

    {- -------------------------------------------
  (1.1) JvmtiPendingMonitors::destroy() を呼んで, JvmtiPendingMonitors 内の pending list から外しておく.
        ---------------------------------------- -}

        // Remove this  monitor from pending raw monitors list
        // if it has entered in onload or start phase.
        JvmtiPendingMonitors::destroy(rmonitor);

  {- -------------------------------------------
  (1) (以下は HotSpot の起動完了後の場合)
      ---------------------------------------- -}

      } else {

    {- -------------------------------------------
  (1.1) まず破棄対象の JvmtiRawMonitor のロックをカレントスレッドが取っているかどうかを確認し, 
        ロックを取っている場合は開放しておく.
        (しないと delete 時に assert に引っかかるため)
        (再帰的にロックを取っている可能性もあるので
         recursions() の回数だけ JvmtiRawMonitor::raw_exit() を呼び出す.
         JvmtiRawMonitor::raw_exit() が一度でも失敗したら, ここでリターン(JVMTI_ERROR_INTERNAL))
        ---------------------------------------- -}

        Thread* thread  = Thread::current();
        if (rmonitor->is_entered(thread)) {
          // The caller owns this monitor which we are about to destroy.
          // We exit the underlying synchronization object so that the
          // "delete monitor" call below can work without an assertion
          // failure on systems that don't like destroying synchronization
          // objects that are locked.
          int r;
          intptr_t recursion = rmonitor->recursions();
          for (intptr_t i=0; i <= recursion; i++) {
            r = rmonitor->raw_exit(thread);
            assert(r == ObjectMonitor::OM_OK, "raw_exit should have worked");
            if (r != ObjectMonitor::OM_OK) {  // robustness
              return JVMTI_ERROR_INTERNAL;
            }
          }
        }

    {- -------------------------------------------
  (1.1) もし破棄対象の JvmtiRawMonitor が誰かにロックを取られていたら, 
        ここでリターン (JVMTI_ERROR_NOT_MONITOR_OWNER).

        (これは JVMTI 仕様では禁止されていないが, HotSpot 内の assert には引っかかるケース)
        ---------------------------------------- -}

        if (rmonitor->owner() != NULL) {
          // The caller is trying to destroy a monitor that is locked by
          // someone else. While this is not forbidden by the JVMTI
          // spec, it will cause an assertion failure on systems that don't
          // like destroying synchronization objects that are locked.
          // We indicate a problem with the error return (and leak the
          // monitor's memory).
          return JVMTI_ERROR_NOT_MONITOR_OWNER;
        }
      }

  {- -------------------------------------------
  (1) 破棄対象の JvmtiRawMonitor オブジェクトを delete する
      ---------------------------------------- -}

      delete rmonitor;

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

      return JVMTI_ERROR_NONE;
    } /* end DestroyRawMonitor */