/// <summary>
/// Calls the specified asynchronous method of a <see cref="Socket" /> and returns an
/// awaitable object that provides the operation result when awaited.
/// </summary>
/// <param name="socket">
/// <see cref="Socket" /> to run an asynchronous operation.
/// </param>
/// <param name="awaitable">
/// The <see cref="SocketAwaitable" /> object to use for this asynchronous socket
/// operation.
/// </param>
/// <param name="operation">
/// Socket operation to perform.
/// </param>
/// <returns>
/// A <see cref="SocketAwaitable" /> which, when awaited, returns a
/// <see cref="SocketError" /> object that corresponds to the result of
/// <paramref name="operation" />.
/// </returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="socket" /> or <paramref name="awaitable" /> is null.
/// </exception>
/// <exception cref="InvalidOperationException">
/// A socket operation was already in progress using <paramref name="awaitable"/>.
/// -or-
/// For accept operations:
/// <paramref name="socket" /> is not bound, is not listening for connections, or is
/// already connected.
/// -or-
/// For connect operations:
/// <paramref name="socket" /> is listening.
/// </exception>
/// <exception cref="NotSupportedException">
/// Windows XP or later is required for this method.
/// -or-
/// For connect operations:
/// Address family of <see cref="Socket.LocalEndPoint" /> is different than the address
/// family of <see cref="SocketAsyncEventArgs.RemoteEndPoint" />.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// <paramref name="socket" /> has been disposed.
/// </exception>
/// <exception cref="SecurityException">
/// For connection operations:
/// A caller higher in the call stack does not have permission for the requested
/// operation.
/// </exception>
private static SocketAwaitable OperateAsync(
Socket socket,
SocketAwaitable awaitable,
Func <Socket, SocketAwaitable, bool> operation)
{
if (socket == null)
{
throw new ArgumentNullException("socket", "Socket must not be null.");
}
if (awaitable == null)
{
throw new ArgumentNullException("awaitable", "Awaitable must not be null.");
}
var a = awaitable.GetAwaiter();
lock (a.SyncRoot)
{
if (!a.IsCompleted)
{
throw new InvalidOperationException(
"A socket operation is already in progress"
+ " using the same awaitable arguments.");
}
a.Reset();
if (awaitable.ShouldCaptureContext)
{
a.SyncContext = SynchronizationContext.Current;
}
}
try
{
if (!operation.Invoke(socket, awaitable))
{
a.Complete();
}
}
catch (SocketException x)
{
a.Complete();
awaitable.Arguments.SocketError = x.SocketErrorCode != SocketError.Success
? x.SocketErrorCode
: SocketError.SocketError;
}
catch (Exception)
{
a.Complete();
awaitable.Arguments.SocketError = SocketError.Success;
throw;
}
return(awaitable);
}
/// <summary>
/// Initializes a new instance of the <see cref="SocketAwaiter" /> class.
/// </summary>
/// <param name="awaitable">
/// The asynchronous socket arguments to await.
/// </param>
internal SocketAwaiter(SocketAwaitable awaitable)
{
this.awaitable = awaitable;
this.awaitable.Arguments.Completed += delegate
{
var c = this.continuation ?? Interlocked.CompareExchange(ref this.continuation, sentinel, null);
if (c != null)
{
var syncContext = this.awaitable.ShouldCaptureContext ? this.SyncContext : null;
this.Complete();
if (syncContext != null)
{
syncContext.Post(s => c.Invoke(), null);
}
else
{
c.Invoke();
}
}
};
}
/// <summary>
/// Begins an awaitable operation to accept an incoming connection attempt.
/// </summary>
/// <param name="socket">
/// Socket that will accept the connection.
/// </param>
/// <param name="awaitable">
/// The <see cref="SocketAwaitable" /> object to use for this asynchronous socket operation.
/// </param>
/// <returns>
/// <paramref name="awaitable" />, when awaited, will have the accepted socket
/// in its <see cref="SocketAwaitable.AcceptSocket" /> property. Awaiter of the result returns a
/// <see cref="SocketError" /> that corresponds to the result of this asynchronous operation.
/// </returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="socket" /> or <paramref name="awaitable" /> is null.
/// </exception>
/// <exception cref="ArgumentException">
/// <see cref="SocketAwaitable.Buffer" /> of the <paramref name="awaitable" /> is not large enough.
/// The buffer must be at least 2 * (sizeof(SOCKADDR_STORAGE + 16) bytes.
/// </exception>
/// <exception cref="InvalidOperationException">
/// <paramref name="socket" /> is not bound, is not listening for connections, or is already connected.
/// -or-
/// A socket operation was already in progress using <paramref name="awaitable" />
/// </exception>
/// <exception cref="NotSupportedException">
/// Windows XP or later is required for this method.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// <paramref name="socket" /> has been disposed.
/// </exception>
public static SocketAwaitable AcceptAsync(this Socket socket, SocketAwaitable awaitable)
{
return(OperateAsync(socket, awaitable, acceptOp));
}
/// <summary>
/// Sends data asynchronously to a connected <see cref="Socket" /> object and returns a
/// <see cref="SocketAwaitable" /> to await.
/// </summary>
/// <param name="socket">
/// Socket to send the data to.
/// </param>
/// <param name="awaitable">
/// The <see cref="SocketAwaitable" /> object to use for this asynchronous socket operation.
/// </param>
/// <returns>
/// The specified <see cref="SocketAwaitable" /> which, when awaited, will return a
/// <see cref="SocketError" /> object that corresponds to the result of the send operation.
/// </returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="socket" /> or <paramref name="awaitable" /> is null.
/// </exception>
/// <exception cref="InvalidOperationException">
/// A socket operation was already in progress using <paramref name="awaitable"/>.
/// </exception>
/// <exception cref="NotSupportedException">
/// Windows XP or later is required for this method.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// <paramref name="socket" /> has been disposed.
/// </exception>
public static SocketAwaitable SendAsync(this Socket socket, SocketAwaitable awaitable)
{
return(OperateAsync(socket, awaitable, sendOp));
}
/// <summary>
/// Begins an awaitable request to receive data from a connected <see cref="Socket" /> object.
/// </summary>
/// <param name="socket">
/// Socket that will receive data.
/// </param>
/// <param name="awaitable">
/// The <see cref="SocketAwaitable" /> object to use for this asynchronous socket operation.
/// </param>
/// <returns>
/// The specified <see cref="SocketAwaitable" /> which, when awaited, will hold the received
/// data in its <see cref="SocketAsyncEventArgs.Buffer" /> property. Awaiter of <see cref="SocketAwaitable" />
/// returns a <see cref="SocketError" /> object that corresponds to the result of the asynchronous operation.
/// </returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="socket" /> or <paramref name="awaitable" /> is null.
/// </exception>
/// <exception cref="InvalidOperationException">
/// A socket operation was already in progress using <paramref name="awaitable"/>.
/// </exception>
/// <exception cref="NotSupportedException">
/// Windows XP or later is required for this method.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// <paramref name="socket" /> has been disposed.
/// </exception>
public static SocketAwaitable ReceiveAsync(this Socket socket, SocketAwaitable awaitable)
{
return(OperateAsync(socket, awaitable, receiveOp));
}
/// <summary>
/// Begins an awaitable request to disconnect from a remote endpoint.
/// </summary>
/// <param name="socket">
/// Socket that will connect to a remote host.
/// </param>
/// <param name="awaitable">
/// The <see cref="SocketAwaitable" /> object to use for this asynchronous socket operation.
/// </param>
/// <returns>
/// The specified <see cref="SocketAwaitable" /> which, when awaited, returns a
/// <see cref="SocketError" /> object that corresponds to the result of the connection attempt.
/// </returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="socket" /> or <paramref name="awaitable" /> is null.
/// </exception>
/// <exception cref="InvalidOperationException">
/// A socket operation was already in progress using <paramref name="awaitable" />.
/// </exception>
/// <exception cref="NotSupportedException">
/// Windows XP or later is required for this method. This exception also occurs if the local endpoint
/// and the <see cref="SocketAwaitable.RemoteEndPoint" /> are not the same address family.
/// -or-
/// Address family of <see cref="Socket.LocalEndPoint" /> is different than the address family of
/// <see cref="SocketAsyncEventArgs.RemoteEndPoint" />.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// <paramref name="socket" /> has been disposed.
/// </exception>
public static SocketAwaitable DisonnectAsync(this Socket socket, SocketAwaitable awaitable)
{
return(OperateAsync(socket, awaitable, disconnectOp));
}