/// <summary>
/// Waits for the value to change
/// </summary>
/// <param name="timeout">The amount of time to wait for the event to be set</param>
/// <param name="token">A cancellation token to abort waiting</param>
/// <returns>A task that returns True when the value has changed, or False if the timeout elapsed</returns>
/// <exception cref="OperationCanceledException">The given cancellation token was cancelled</exception>
/// <exception cref="TimeoutException">The timeout elapsed</exception>
public ValueTask <bool> Wait(TimeSpan timeout, CancellationToken token = default)
{
if (_State == null)
{
throw new ObjectDisposedException(nameof(AsyncValue <T>), "Value has been disposed of");
}
var Instance = AsyncValueInstance.GetOrCreate(this);
var ValueTask = new ValueTask <bool>(Instance, Instance.Version);
Instance.ApplyCancellation(token, timeout);
// Not set, add ourselves to the queue waiting
_Waiters.Enqueue(Instance);
return(ValueTask);
}
/// <summary>
/// Waits for the event to become set, or if set return immediately
/// </summary>
/// <param name="value">The value to check for</param>
/// <param name="timeout">The amount of time to wait for the event to be set</param>
/// <param name="token">A cancellation token to abort waiting</param>
/// <returns>A task that completes when the event has been set</returns>
/// <exception cref="OperationCanceledException">The given cancellation token was cancelled</exception>
public ValueTask <bool> WaitUnless(T value, TimeSpan timeout, CancellationToken token = default)
{
if (_Comparer.Equals(value, Value))
{
return(new ValueTask <bool>(true));
}
var Instance = AsyncValueInstance.GetOrCreate(this);
var ValueTask = new ValueTask <bool>(Instance, Instance.Version);
if (!ValueTask.IsCompleted)
{
Instance.ApplyCancellation(token, timeout);
// Not set, add ourselves to the queue waiting
_Waiters.Enqueue(Instance);
// Did the event become set while we were busy?
var State = _State;
if (State == null)
{
_Waiters.Erase(Instance);
Instance.SetDisposed();
}
else if (_Comparer.Equals(value, State.Value))
{
_Waiters.Erase(Instance);
Instance.SetCompleted();
}
}
return(ValueTask);
}