@Override
  public void run2() {
    try {
      if (executor != null) {
        executor.execute(this::runInThreadPool);
      } else {
        // inline
        runInThreadPool();
      }
    } catch (RejectedExecutionException ex) {
      try {
        if (logger.isDebugEnabled()) {
          logger.debug("Rejected execution in expiration task", ex);
        }
      } catch (VirtualMachineError err) {
        SystemFailure.initiateFailure(err);
        // If this ever returns, rethrow the error. We're poisoned
        // now, so don't let this thread continue.
        throw err;
      } catch (Throwable t) {
        // Whenever you catch Error or Throwable, you must also
        // catch VirtualMachineError (see above). However, there is
        // _still_ a possibility that you are dealing with a cascading
        // error condition, so you also need to check to see if the JVM
        // is still usable:
        SystemFailure.checkFailure();
        // for surviving and debugging exceptions getting the logger
        t.printStackTrace();
      }
    } catch (CancelException e) {
      return; // just bail
    } catch (VirtualMachineError err) {
      SystemFailure.initiateFailure(err);
      // If this ever returns, rethrow the error. We're poisoned
      // now, so don't let this thread continue.
      throw err;
    } catch (Throwable ex) {
      // Whenever you catch Error or Throwable, you must also
      // catch VirtualMachineError (see above). However, there is
      // _still_ a possibility that you are dealing with a cascading
      // error condition, so you also need to check to see if the JVM
      // is still usable:
      SystemFailure.checkFailure();
      logger.fatal("Exception in expiration task", ex);
    }
  }
An ExpiryTask is sent run() to perform its task. Note that this run() method should never throw
an exception - otherwise, it takes out the java.util.Timer thread, causing an exception
whenever we try to schedule more expiration tasks.
geode-core/src/main/java/org/apache/geode/internal/cache/ExpiryTask.java