Just a really dummy sample of parallel C# code (and also using continuations)

ParallelSender.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace TaskParallelization
{
    public class ParallelSender
    {
        private readonly IList<string> _contents;
        private readonly ErrorLogger _errorLogger;

        public ParallelSender(IList<string> contents)
        {
            _contents = contents;
            _errorLogger = new ErrorLogger();
        }

        public void Send()
        {
            Console.WriteLine("Sending {0} contents...", _contents.Count);

            var sendingTasks = _contents.Select(
                    content =>
                        {
                            var senderTask = new SenderTask(content, _errorLogger);

                            return Task.Factory.StartNew(() => senderTask.Do());
                        }
                );

            var dumpingLogTask = Task.Factory.ContinueWhenAll(
                                        sendingTasks.ToArray(),
                                        completedSendingTasks => _errorLogger.Dump()
                                    );

            dumpingLogTask.Wait();

            Console.WriteLine("All contents were sent with sucess");
        }
    }
}

SenderTask.cs

using System;

namespace TaskParallelization
{
    class SenderTask
    {
        private readonly string _input;
        private readonly ErrorLogger _errorLogger;
        
        public SenderTask(string input, ErrorLogger errorLogger)
        {
            _input = input;
            _errorLogger = errorLogger;
        }
        
        public bool Do()
        {
            try
            {
                Console.WriteLine("- Sending {0}", _input);
                
                return true;
            }
            catch (Exception e)
            {
                _errorLogger.Log(String.Format("- An error sending {0}: {1}", _input, e.Message));
                
                return false;
            }
        }
    }
}