WSACancelBlockingCall exception

Question

Ok, I have a strange exception thrown from my code that\'s been bothering me for ages.

System.Net.Sockets.SocketException: A blocking operation was interrupt         


        

Answer 1

More recently I saw this exception when using HttpWebRequest to PUT a large file and the Timeout period was passed.

Using the following code as long as your upload time > 3 seconds it will cause this error as far as I could see.

string path = "Reasonably large file.dat";
int bufferSize = 1024;
byte[] buffer = new byte[bufferSize];
System.Net.HttpWebRequest req = (HttpWebRequest)System.Net.HttpWebRequest.Create("Some URL");
req.Method = "PUT";
req.Timeout = 3000; //3 seconds, small timeout to demonstrate
long length = new System.IO.FileInfo(path).Length;
using (FileStream input = File.OpenRead(path))
{
    using (Stream output = req.GetRequestStream())
    {
        long remaining = length;
        int bytesRead = 0;
        while ((bytesRead = input.Read(buffer, 0, (int)Math.Min(remaining, (decimal)bufferSize))) > 0)
        {
            output.Write(buffer, 0, bytesRead);
            remaining -= bytesRead;
        }
        output.Close();
    }
input.Close();
}