Web server on WiFi Shield R3 with firmware 1.1.0 unresponsive after some hours

Using Arduino Networking, Protocols, and Devices
#1

I've read tens of posts in different forums about this subject.
In many times the solution was to upgrade the shield to the latest firmware.
What can I do with this issue, using the latest firmware? I have the typical issue of instability. After a couple of hours, depending of how many requests are made, the shield becomes unresponsive.

The project is a simple REST web server.
The purpose is to respond with JSON if the request is correct REST otherwise a HTTP 400 error.
I post a simplified version of it, so you can see the way I've written the program (apart from the setup(), here is the loop()):

void loop() {  
  WiFiClient client = server.available();
  if (client)
  {    
    if (client.connected())
    {
      Serial.println("New client:");
      
      String response = client.readString();
      Serial.println(response);
      
      // request finished, send response
      String command = "";
      int index = response.indexOf('\n');
      if (index > 0)
      {
        command = response.substring(0, index - 1);
      }
      
      if (command.length() > 0) 
      {
        // Operations: do something

        client.println("HTTP/1.1 200 OK\nContent-Type: application/json");
        client.println("Content-Length:19\nConnection: close\n");
        client.println("{ \"result\":\"OK\" }\n");

        // close the connection:
        delay(20);
        client.stop();
  
        Serial.println("Client disconnected");        
        return;
      }

      client.println("HTTP/1.1 400 OK\nContent-Type: text/html");
      client.println("Connection: close\n");
      client.println("HTTP 400");

      // close the connection:
      delay(20);
      client.stop();
  
      Serial.println("Client disconnected");
    }
  }
}

Any suggestions are really appreciated!
Greetings

#2

Please guys...
I can add that I've made many different versions of the program, for example using client.available(), using a while loop as many examples/tutorials suggest and so on.
Unfortunately none of the different versions have given an improvement what so ever.

#3

It seems the solution is to detect the connection and make a soft reset accordingly to the server status.
It means that the first thing to do in loop() is this:

  // do a soft-reset in case of lost connection
  uint8_t serverStatus = server.status();
  if (serverStatus == WL_IDLE_STATUS || serverStatus == WL_CONNECT_FAILED)
  {
    asm volatile ("  jmp 0");
    return;
  }

The soft reset is necessary. In case of unresponsiveness, the server won't react if you try to recover it.

#4

But no, it's not the right solution.
Even trying with another soft reset alternative, such as:

void(* resetFunc) (void) = 0; //declare reset function @ address 0

the soft reset doesn't really make a clean restart of the Wifi server.
it works once, maybe twice, then the Wifi becomes unresponsive anyway.

I hope there's a better solution - not a work-around like mine.

#5