public static IDisposable ChangeColor(ConsoleColor color)
{
var current = Console.ForegroundColor;
Console.ForegroundColor = color;
return(Disposables.Call(() => Console.ForegroundColor = current));
}
public IDisposable Use()
{
Interlocked.Increment(ref _counter);
return(Disposables.Call(() =>
{
var shouldCallAction = false;
lock (_mutex)
{
_counter--;
shouldCallAction = (_counter == 0);
}
if (shouldCallAction)
{
_action?.Invoke();
}
}));
}
private void Release()
{
lock (_mutex)
{
if (_queue.Any())
{
// somebody is awaiting for a token
var tcs = _queue.Dequeue();
var token = Disposables.Call(Release);
_currentToken = token;
tcs.SetResult(token);
}
else
{
// nobody is waiting for a token
_currentToken = null;
}
}
}
public Task <IDisposable> Lock()
{
lock (_mutex)
{
if (_currentToken == null)
{
// 1. There is no current token, and the lock is free
var token = Disposables.Call(Release);
_currentToken = token;
return(Task.FromResult <IDisposable>(token));
}
else
{
// 2. The lock is busy
var tcs = new TaskCompletionSource <IDisposable>();
_queue.Enqueue(tcs);
return(tcs.Task);
}
}
}
