// If this throw happens frequently, an uncommon trap might cause
  // a performance pothole.  If there is a local exception handler,
  // and if this particular bytecode appears to be deoptimizing often,
  // let us handle the throw inline, with a preconstructed instance.
  // Note:   If the deopt count has blown up, the uncommon trap
  // runtime is going to flush this nmethod, not matter what.
  // 这里要满足两个条件：1.检测到频繁抛出异常，2. OmitStackTraceInFastThrow为true，或StackTraceInThrowable为false
  if (treat_throw_as_hot
      && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
    // If the throw is local, we use a pre-existing instance and
    // punt on the backtrace.  This would lead to a missing backtrace
    // (a repeat of 4292742) if the backtrace object is ever asked
    // for its backtrace.
    // Fixing this remaining case of 4292742 requires some flavor of
    // escape analysis.  Leave that for the future.
    ciInstance* ex_obj = NULL;
    switch (reason) {
    case Deoptimization::Reason_null_check:
      ex_obj = env()->NullPointerException_instance();
      break;
    case Deoptimization::Reason_div0_check:
      ex_obj = env()->ArithmeticException_instance();
      break;
    case Deoptimization::Reason_range_check:
      ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
      break;
    case Deoptimization::Reason_class_check:
      if (java_bc() == Bytecodes::_aastore) {
        ex_obj = env()->ArrayStoreException_instance();
      } else {
        ex_obj = env()->ClassCastException_instance();
      }
      break;
    }
    ... ...
}

 public static void main(String[] args)
    {
        String test = null;
        int i = 0;
        while (true)
        {
            try
            {
                test.length();
            }
            catch (Exception e)
            {
                System.out.println("次数为:" + i++ + "，堆栈长度为:" + e.getStackTrace().length);
                //log.error("StackTrace is ",e);
                if (e.getStackTrace().length == 0)
                {
                    log.error("no StackTrace is ", e);
                    break;
                }
            }
        }
    }

local OMIT_STACKTRACE_OPTS="-XX:-OmitStackTraceInFastThrow"
nohup $JAVA_HOME/bin/java $OMIT_STACKTRACE_OPTS -jar $JAR_NAME >/dev/null 2>&1 &