How to get response data by socket connections in native C code?

ESP32 module, WIFI connected.

In C native code , I send datas to a server by a socket connection.

JsVar *req = jswrap_net_connect(options, callback, ST_NORMAL);
JsVar *data = jsvNewFromString("Hello world" ); ///< Create a new string
jswrap_net_socket_write(req, data);

The server receives the data correctly, then it sends a response string "hello client" to ESP32.

bool waitForInput(JsVar *req) {
  JsVarFloat now = jshGetMillisecondsFromTime(jshGetSystemTime());
	//unsigned long now = millis();
	while (!jswrap_stream_available(req) && ((jshGetMillisecondsFromTime(jshGetSystemTime()) - now) < 30000UL)) { jshDelayMicroseconds(200); }
  if(jswrap_stream_available(req)){
    return true;
  }
	return false;
}

I use waitForInput to detect response data, but it always return FASLE.

And, should I use the following function to receive data?

JsVar *jswrap_stream_read(JsVar *parent, JsVarInt chars);