/// <summary>
/// The connection establishment is attempted multiple times and is given up
/// only on the last failure.
/// </summary>
/// <remarks>
/// The connection establishment is attempted multiple times and is given up
/// only on the last failure. Instead of connecting with a timeout of
/// X, we try connecting with a timeout of x < X but multiple times.
/// </remarks>
/// <exception cref="System.IO.IOException"/>
private void Connect(URLConnection connection, int connectionTimeout)
{
int unit = 0;
if (connectionTimeout < 0)
{
throw new IOException("Invalid timeout " + "[timeout = " + connectionTimeout + " ms]"
);
}
else
{
if (connectionTimeout > 0)
{
unit = Math.Min(UnitConnectTimeout, connectionTimeout);
}
}
long startTime = Time.MonotonicNow();
long lastTime = startTime;
int attempts = 0;
// set the connect timeout to the unit-connect-timeout
connection.SetConnectTimeout(unit);
while (true)
{
try
{
attempts++;
connection.Connect();
break;
}
catch (IOException ioe)
{
long currentTime = Time.MonotonicNow();
long retryTime = currentTime - startTime;
long leftTime = connectionTimeout - retryTime;
long timeSinceLastIteration = currentTime - lastTime;
// throw an exception if we have waited for timeout amount of time
// note that the updated value if timeout is used here
if (leftTime <= 0)
{
int retryTimeInSeconds = (int)retryTime / 1000;
Log.Error("Connection retry failed with " + attempts + " attempts in " + retryTimeInSeconds
+ " seconds");
throw;
}
// reset the connect timeout for the last try
if (leftTime < unit)
{
unit = (int)leftTime;
// reset the connect time out for the final connect
connection.SetConnectTimeout(unit);
}
if (timeSinceLastIteration < unit)
{
try
{
// sleep the left time of unit
Sleep(unit - timeSinceLastIteration);
}
catch (Exception)
{
Log.Warn("Sleep in connection retry get interrupted.");
if (stopped)
{
return;
}
}
}
// update the total remaining connect-timeout
lastTime = Time.MonotonicNow();
}
}
}
private static void SetTimeouts(URLConnection connection, int socketTimeout)
{
connection.SetConnectTimeout(socketTimeout);
connection.SetReadTimeout(socketTimeout);
}
