Message Buffer Issue.

[hassanfarrukh]

Hellio Jjenkov,
I was using your server, I like the way you have coded it but there is an issue I found out when I bombarded the server with multiple clients. It can receive the total of 512 messages.

Furthermore, I found out that if I change the size of:
public static int KB = Constant.maxLimit; public static int MB = Constant.maxLimit * KB; byte[] smallMessageBuffer = new byte[Constant.maxLimit * 4 * KB]; QueueIntFlip smallMessageBufferFreeBlocks = new QueueIntFlip(Constant.maxLimit);

The maxLimit is:

public class Constant { public static int maxLimit = 2048; }

In Server Class

Queue socketQueue = new ArrayBlockingQueue(Constant.maxLimit);

In SocketProcessor

private ByteBuffer readByteBuffer = ByteBuffer.allocate(Constant.maxLimit * Constant.maxLimit); private ByteBuffer writeByteBuffer = ByteBuffer.allocate(Constant.maxLimit * Constant.maxLimit); private double nextSocketId = 16 * Constant.maxLimit;

The client code I am using is:

client = SocketChannel.open(); isa = new InetSocketAddress("127.0.0.1", 9998); client.connect(isa); client.configureBlocking(false); sendMessage(); //here i send PING. client.close(); try { Thread.sleep(500); } catch (InterruptedException ex) { Logger.getLogger(test.class.getName()).log(Level.SEVERE, null, ex); }

Please reply to the issue and help me accordingly.

[hassanfarrukh]

This was the error:
Exception in thread "Thread-1" java.lang.NullPointerException at SmartCity.HttpMessageReader.read(HttpMessageReader.java:51) at SmartCity.SocketProcessor.readFromSocket(SocketProcessor.java:134) at SmartCity.SocketProcessor.readFromSockets(SocketProcessor.java:121) at SmartCity.SocketProcessor.executeCycle(SocketProcessor.java:81) at SmartCity.SocketProcessor.run(SocketProcessor.java:65) at java.lang.Thread.run(Thread.java:745)

[jjenkov]

I'll have a look at it - but I have used this design to send millions of messages to a server without a single hickup. To be fair though, I was using IAP as network protocol instead of HTTP. Seeing that your error occurs in the HttpMessageReader hints that this might be where the issue is hidden.

[jjenkov]

Oh, it will take me at least 1-2 weeks before I have time to look into it... please see if you can find out what the error is yourself too, and if you do, please let me know!

[hassanfarrukh]

First of I am using this Server as a TCP server. I have worked, it might be a solution but I am not sure, as it gave birth to a new issue, which I couldn't resolve yet!

In MessageBuffer class I commented return null and it resolved more socket generation issue;

public Message getMessage() {
int nextFreeSmallBlock = this.smallMessageBufferFreeBlocks.take(); if(nextFreeSmallBlock == -1)
{
// return null;
}
Message message = new Message(this); //todo get from Message pool - caps memory usage. message.sharedArray = this.smallMessageBuffer; message.capacity = CAPACITY_SMALL; message.offset = nextFreeSmallBlock; message.length = 0; return message;
}

As mentioned earlier this gave birth to a new issue; when we send simultaneous messages at the same time otherwise it works okay. And the issue is in Message Class here;
public int writeToMessage(byte[] byteArray, int offset, int length)

System.arraycopy(byteArray, offset, this.sharedArray, this.offset + this.length, bytesToCopy);

And this gives an error of out of array index. I will post the error as soon as I regenerate this issue.