Client disconnects periodically when in channels with a moderate amount of traffic

Bug #862420 reported by Andy Jump on 2011-09-29
12
This bug affects 2 people
Affects Status Importance Assigned to Milestone
IRC.NET
Medium
Alexander Regueiro

Bug Description

We're using IRC.Net in the SpikeLite IRC bot.

When running in ##csharp it periodically disconnects and reconnects.

This happens on both Linux with MONO and on Windows with .Net.

From the logs I can see that the bot appears to simply stop receiving data from the server and then disconnects a few minutes later.

At a guess this is because it's no longer receiving 'pings' and so send no 'pongs'.

Changed in ircdotnet:
importance: Undecided → Medium
assignee: nobody → Alex Regueiro (alexreg)
status: New → Confirmed
milestone: none → 0.4.2
Mat D (always-funny) wrote :

Because the activity on this project is very low I gathered the soruces and figured some bugs out, especially this one (which was not easy at all to fix...)

I was not really able to track this one down but I know what I changed to resove the issue:
I did change the CircularBufferStream in the following ways:
 public override long Length
        {
            get
            {
                var length = this.writePosition - this.readPosition;
                return length < 0 ? this.buffer.Length + length : length;
            }
        }

 public override long Seek(long offset, SeekOrigin origin)
        {
            throw new NotSupportedException();
        }

public override void Write(byte[] buffer, int offset, int count)
        {
            // Write block of bytes from given buffer into circular buffer, wrapping around when necessary.
            int writeCount;
            while ((writeCount = Math.Min(count, (int)(this.buffer.Length - this.writePosition))) > 0)
            {
                var oldWritePosition = this.writePosition;
                var newWritePosition = (this.writePosition + writeCount) % this.buffer.Length;
                if (newWritePosition > readPosition && oldWritePosition < readPosition)
                {
                    throw new InternalBufferOverflowException("Der CircularBuffer wurde überlaufen!");
                }
                System.Buffer.BlockCopy(buffer, offset, this.buffer, (int)this.writePosition, writeCount);
                this.writePosition = newWritePosition;

                offset += writeCount;
                count -= writeCount; //writeCount <= count => now is count >=0
            }
        }

 public override int Read(byte[] buffer, int offset, int count)
        {
            // Read block of bytes from circular buffer, wrapping around when necessary.
            int totalReadCount = 0;
            int readCount;
            count = Math.Min(buffer.Length - offset, count);
            while ((readCount = Math.Min(count, (int)(Length))) > 0)
            {
                if (readCount > this.buffer.Length - readPosition)
                {
                    readCount = (int)(this.buffer.Length - readPosition);
                }
                System.Buffer.BlockCopy(this.buffer, (int)this.readPosition, buffer, offset, readCount);
                this.readPosition = (this.readPosition + readCount) % this.buffer.Length;
                offset += readCount;
                count = Math.Min(buffer.Length - offset, count);
                totalReadCount += readCount;
            }
            return totalReadCount;
        }

I think the problem occured on some special cases at the end of the CircularBuffer which were not handled correctly.
( but I'm not 100% sure )
Added the patched file as Attachment (not sure if it will compile in the current version on this site)

It's not possible for me to reupload my complete implementation as i changed lots of Logging to be able to track this down...

Hope this helps!
reddragon

Alexander Regueiro (alexreg) wrote :
Changed in ircdotnet:
status: Confirmed → Fix Committed
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