private Task Start()
{
IoAsyncMachine self = this;
_atm.Start(ref self);
return(_atm.Task);
}
void IAsyncStateMachine.MoveNext()
{
try
{
switch (_state)
{
case 0:
{
_state = 1;
_fs = new FileStream(
_filePath, //string path,
FileMode.Create, //FileMode mode,
FileAccess.Write, //FileAccess access,
FileShare.None, //FileShare share,
4096, //int bufferSize,
FileOptions.Asynchronous //,//FileOptions options
);
_buffer = new byte[4097];
Task twrite = _fs.WriteAsync(_buffer, 0, _buffer.Length);
_awaiter = twrite.GetAwaiter();
if (_awaiter.IsCompleted)
{
goto case 1;
}
else
{
IoAsyncMachine self = this;
_atm.AwaitUnsafeOnCompleted(ref _awaiter, ref self);
}
}
break;
case 1:
{
_state = 2;
Task tflush = _fs.FlushAsync();
_awaiter = tflush.GetAwaiter();
if (_awaiter.IsCompleted)
{
goto case 2;
}
else
{
IoAsyncMachine self = this;
_atm.AwaitUnsafeOnCompleted(ref _awaiter, ref self);
}
}
break;
case 2:
{
_state = 3;
_fs.Dispose();
_atm.SetResult();
}
break;
case 3:
{
_state = 4;
throw new Exception("should not go here!");
}
break;
}
}
catch (Exception ex)
{
_atm.SetException(ex);
}
}
public static Task IoAsync(string filePath)
{
var stateMachine = new IoAsyncMachine(filePath);
return(stateMachine.Start());
}
