What is good C# coding style for catching SQLException and retrying

Question

I have a method that calls a SQLServer function to perform a free text search against a table. That function will occasionally on the first call result in a SQLException: \"

Answer 1

It's not good style, but sometimes you have to do it, because you simply can't change existing code and have to deal with it.

I am using the following generic method for this scenario. Note the PreserveStackTrace() method, which can sometimes be very helpful in a re-throw scenario.

public static void RetryBeforeThrow(Action action, int retries, int timeout) where T : Exception
{
    if (action == null)
        throw new ArgumentNullException("action", string.Format("Argument '{0}' cannot be null.", "action"));

    int tries = 1;

    do
    {
        try
        {
            action();
            return;
        }
        catch (T ex)
        {
            if (retries <= 0)
            {
                PreserveStackTrace(ex);
                throw;
            }

            Thread.Sleep(timeout);
        }
    }
    while (tries++ < retries);
}

/// 

/// Sets a flag on an  so that all the stack trace information is preserved 
/// when the exception is re-thrown.
/// 
/// This is useful because "throw" removes information, such as the original stack frame.
/// 
public static void PreserveStackTrace(Exception ex)
{
    MethodInfo preserveStackTrace = typeof(Exception).GetMethod("InternalPreserveStackTrace", BindingFlags.Instance | BindingFlags.NonPublic);
    preserveStackTrace.Invoke(ex, null);
}

You would call it like that:

RetryBeforeThrow(() => MethodWhichFails(), 3, 100);