151120 TPL/async/await 정리
151120 TPL/async/await 정리
황현동 노트북 c# .net uwp 
public partial class MainWindow : Window
{
// . . .
private async void startButton_Click(object sender, RoutedEventArgs e)
{
// ONE
Task<int> getLengthTask = AccessTheWebAsync();
// FOUR
int contentLength = await getLengthTask;
// SIX
resultsTextBox.Text +=
String.Format("\r\nLength of the downloaded string: {0}.\r\n", contentLength);
}
async Task<int> AccessTheWebAsync()
{
// TWO
HttpClient client = new HttpClient();
Task<string> getStringTask =
client.GetStringAsync("http://msdn.microsoft.com");
// THREE
string urlContents = await getStringTask;
// FIVE
return urlContents.Length;
}
}비동기 작업의 취소
https://msdn.microsoft.com/ko-kr/library/jj155759.aspx
CancellationTokenSource cts.Token cts.Cancel();cts = new CancellationTokenSource();
HttpResponseMessage response = await client.GetAsync("http://msdn.microsoft.com/en-us/library/dd470362.aspx", cts.Token);
cts.Cancel();다수의 비동기 작업 모두 완료되면 다수의 값을 배열로 리턴
// Create a query.
IEnumerable<Task<int>> downloadTasksQuery = from url in urlList select ProcessURL(url, client);
Task<int>[] downloadTasks = downloadTasksQuery.ToArray();
// You can do other work here before awaiting.
// Await the completion of all the running tasks.
int[] lengths = await Task.WhenAll(downloadTasks);다수의 비동기 작업중 한개가 완료되면 모두 취소하는 기능
Task<int>[] downloadTasks = downloadTasksQuery.ToArray();
Task<int> firstFinishedTask = await Task.WhenAny(downloadTasks);다수의 비동기 작업중 한개가 완료될때마다 처리
// ***Create a query that, when executed, returns a collection of tasks.
IEnumerable<Task<int>> downloadTasksQuery =
from url in urlList select ProcessURL(url, client, ct);
// ***Use ToList to execute the query and start the tasks.
List<Task<int>> downloadTasks = downloadTasksQuery.ToList();
// ***Add a loop to process the tasks one at a time until none remain.
while (downloadTasks.Count > 0)
{
// Identify the first task that completes.
Task<int> firstFinishedTask = await Task.WhenAny(downloadTasks);
// ***Remove the selected task from the list so that you don't
// process it more than once.
downloadTasks.Remove(firstFinishedTask);
}C# http web server with TPL/async/await
서버메인클래스
클라이언트 접속처리
class Listener
{
public readonly int Port;
private readonly TcpListener _tcpListener;
private readonly Task _listenTask;
public Listener(int port)
{
Port = port;
// Start listening
_tcpListener = new TcpListener(IPAddress.Any, Port);
_tcpListener.Start();
// Start a background thread to listen for incoming
_listenTask = Task.Factory.StartNew(() => ListenLoop());
}
private async void ListenLoop()
{
for (; ; )
{
// Wait for connection
var socket = await _tcpListener.AcceptSocketAsync();
if (socket == null)
break;
// Got new connection, create a client handler for it
var client = new Client(socket);
// Create a task to handle new connection
Task.Factory.StartNew(client.Do);
}
}
}서버에 접속한 클라이언트 처리
class Client
{
private readonly Socket _socket;
private readonly NetworkStream _networkStream;
private readonly MemoryStream _memoryStream = new MemoryStream();
private readonly StreamReader _streamReader;
private readonly string _serverName = "Tedd.Demo.HttpServer";
public Client(Socket socket)
{
_socket = socket;
_networkStream = new NetworkStream(socket, true);
_streamReader = new StreamReader(_memoryStream);
}
public async void Do()
{
// We are executed on a separate thread from listener, but will release this back to the threadpool as often as we can.
byte[] buffer = new byte[4096];
for (; ; )
{
// Read a chunk of data
int bytesRead = await _networkStream.ReadAsync(buffer, 0, buffer.Length);
// If Read returns with no data then the connection is closed.
if (bytesRead == 0)
return;
// Write to buffer and process
_memoryStream.Seek(0, SeekOrigin.End);
_memoryStream.Write(buffer, 0, bytesRead);
bool done = ProcessHeader();
if (done)
break;
}
}
private bool ProcessHeader()
{
// Our task is to find when full HTTP header has been received, then send reply.
for (; ; )
{
_memoryStream.Seek(0, SeekOrigin.Begin);
var line = _streamReader.ReadLine();
if (line == null)
break;
if (line.ToUpperInvariant().StartsWith("GET "))
{
// We got a request: GET /file HTTP/1.1
var file = line.Split(' ')[1].TrimStart('/');
// Default document is index.html
if (string.IsNullOrWhiteSpace(file))
file = "index.html";
// Send header+file
SendFile(file);
return true;
}
}
return false;
}
private async void SendFile(string file)
{
// Get info and assemble header
byte[] data;
string responseCode = "";
string contentType = "";
try
{
if (File.Exists(file))
{
// Read file
data = File.ReadAllBytes(file);
contentType = GetContentType(Path.GetExtension(file).TrimStart(".".ToCharArray()));
responseCode = "200 OK";
}
else
{
data = System.Text.Encoding.ASCII.GetBytes("<html><body><h1>404 File Not Found</h1></body></html>");
contentType = GetContentType("html");
responseCode = "404 Not found";
}
}
catch (Exception exception)
{
// In case of error dump exception to client.
data = System.Text.Encoding.ASCII.GetBytes("<html><body><h1>500 Internal server error</h1><pre>" + exception.ToString() + "</pre></body></html>");
responseCode = "500 Internal server error";
}
string header = string.Format("HTTP/1.1 {0}\r\n"
+ "Server: {1}\r\n"
+ "Content-Length: {2}\r\n"
+ "Content-Type: {3}\r\n"
+ "Keep-Alive: Close\r\n"
+ "\r\n",
responseCode, _serverName, data.Length, contentType);
// Send header & data
var headerBytes = System.Text.Encoding.ASCII.GetBytes(header)
await _networkStream.WriteAsync(headerBytes, 0, headerBytes.Length);
await _networkStream.WriteAsync(data, 0, data.Length);
await _networkStream.FlushAsync();
// Close connection (we don't support keep-alive)
_networkStream.Dispose();
}
/// <summary>
/// Get mime type from a file extension
/// </summary>
/// <param name="extension">File extension without starting dot (html, not .html)</param>
/// <returns>Mime type or default mime type "application/octet-stream" if not found.</returns>
private string GetContentType(string extension)
{
// We are accessing the registry with data received from third party, so we need to have a strict security test. We only allow letters and numbers.
if (Regex.IsMatch(extension, "^[a-z0-9]+$", RegexOptions.IgnoreCase | RegexOptions.Compiled))
return (Registry.GetValue(@"HKEY_CLASSES_ROOT\." + extension, "Content Type", null) as string) ?? "application/octet-stream";
return "application/octet-stream";
}
}서버실행
class Program
{
private static Listener listener;
static void Main(string[] args)
{
listener = new Listener(8080);
Console.WriteLine("Listening on port 8080 (http://localhost:8080/).");
Console.WriteLine("Remember to put the files you want to serve in the output folder of the project.");
Console.WriteLine("Press any key to exit.");
Console.ReadKey();
}
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