// -----------------------------------------------------------------------------
// Interpreter/Compiler Slow Case
// This routine is used to handle interpreter/compiler slow case
// We don't need to use fast path here, because it must have been
// failed in the interpreter/compiler code.

void ObjectSynchronizer::slow_enter(Handle obj, BasicLock* lock, TRAPS) {

  {- -------------------------------------------
  (1) neutral なら, CAS でロックを試みる. 成功すればここでロック処理は終了.
      (この場合 BasicLock には mark を入れておく)
      ---------------------------------------- -}

      markOop mark = obj->mark();
      assert(!mark->has_bias_pattern(), "should not see bias pattern here");

      if (mark->is_neutral()) {
        // Anticipate successful CAS -- the ST of the displaced mark must
        // be visible <= the ST performed by the CAS.
        lock->set_displaced_header(mark);
        if (mark == (markOop) Atomic::cmpxchg_ptr(lock, obj()->mark_addr(), mark)) {
          TEVENT (slow_enter: release stacklock) ;
          return ;
        }
        // Fall through to inflate() ...

  {- -------------------------------------------
  (1) 自分がロック済み (かつ stack-locked) かどうかを確認する.
      そうだった場合にはここでロック処理は終了.           
      (この場合 BasicLock には NULL を入れておく)
      ---------------------------------------- -}

      } else
      if (mark->has_locker() && THREAD->is_lock_owned((address)mark->locker())) {
        assert(lock != mark->locker(), "must not re-lock the same lock");
        assert(lock != (BasicLock*)obj->mark(), "don't relock with same BasicLock");
        lock->set_displaced_header(NULL);
        return;
      }

  {- -------------------------------------------
  (1) ?? (採用されなかった最適化が書かれているようだが..)
      ---------------------------------------- -}

    #if 0
      // The following optimization isn't particularly useful.
      if (mark->has_monitor() && mark->monitor()->is_entered(THREAD)) {
        lock->set_displaced_header (NULL) ;
        return ;
      }
    #endif

  {- -------------------------------------------
  (1) 上記のどれでもなければ (あるいは CAS が失敗した場合は), 
      ObjectSynchronizer::inflate() で ObjectMonitor オブジェクトを取得した後, 
      ObjectMonitor::enter() でロックを行う.
      (この場合, BasicLock には unused_mark を入れておく)
      ---------------------------------------- -}

      // The object header will never be displaced to this lock,
      // so it does not matter what the value is, except that it
      // must be non-zero to avoid looking like a re-entrant lock,
      // and must not look locked either.
      lock->set_displaced_header(markOopDesc::unused_mark());
      ObjectSynchronizer::inflate(THREAD, obj())->enter(THREAD);
    }