/// <summary>
/// Calls <see cref="EnterBusy"/> then returns an instance of <see cref="DisposableValueToken"/> that will call <see cref="ExitBusy"/> when disposed.
/// </summary>
/// <remarks>
/// <para>The returned token can be used in a using block to ensure correct enter/exit behaviour.</para>
/// </remarks>
/// <returns>A <see cref="DisposableValueToken"/> instance.</returns>
/// <exception cref="System.ObjectDisposedException">Thrown if the object is disposed or being disposed.</exception>
protected DisposableValueToken ObtainBusyToken()
{
#pragma warning disable 420
return(DisposeAssistant.ObtainBusyToken(this, _DisposedState, ref _BusyCount, this.ExitBusy));
#pragma warning restore 420
}
/// <summary>
/// Disposes this object and all internal resources.
/// </summary>
public virtual void Dispose()
{
#pragma warning disable 420
DisposeAssistant.Dispose(this, ref _DisposedState, ref _BusyCount, (disposing) => this.Dispose(disposing));
#pragma warning restore 420
//int priorState = _DisposedState;
//if (priorState == DisposedState) return; //If we are already disposed, do nothing.
////Wait until there is no work in progress on the object (via EnterBusy/ExitBusy)
//System.Threading.SpinWait.SpinUntil
//(
// () => (System.Threading.Interlocked.CompareExchange(ref _BusyCount, int.MinValue, 0)) <= 0
//);
//// Atomically set our state to 'disposing' but only if it's not already in that state.
//// If it is already in a 'disposing' state, wait for the dispose to complete before
//// returning to the caller.
//System.Threading.SpinWait.SpinUntil
//(
// () => (priorState = System.Threading.Interlocked.CompareExchange(ref _DisposedState, DisposingState, UndisposedState)) != DisposingState
//);
//if (_DisposedState == DisposedState) return; //If someone else completed disposing the object, do nothing.
//try
//{
// Dispose(true);
//}
//finally
//{
// //Call SuppressFinalize in case a derived class adds a finaliser.
// //Ensure it is done in the finally block. We're unlikely to be disposed again,
// //but if we are and we encountered an error last time, we're likely to get the
// //same error again. Worse, we may also get the error when disposed from the
// //finalizer thread, and throwing exceptions there is a bad idea (https://ericlippert.com/2015/05/18/when-everything-you-know-is-wrong-part-one/).
// //Additionally, code in a finally block will also execute if a thread abort
// //occurs on the executing thread.
// GC.SuppressFinalize(this);
// //Now mark the object as disposed rather than disposing,
// System.Threading.Interlocked.Exchange(ref _DisposedState, DisposedState);
//}
}
/// <summary>
/// Throws an <see cref="System.ObjectDisposedException"/> if the object is currently disposed, otherwise does nothing.
/// </summary>
/// <exception cref="ObjectDisposedException">Deliberately thrown if this object has been or is being disposed.</exception>
protected void ThrowIfDisposed()
{
DisposeAssistant.ThrowIfDisposed(this, _DisposedState, _BusyCount);
}
/// <summary>
/// Reduces the count of current operations on the object, returning it to a non-busy state if no other work is in progress thereby allowing calls to <see cref="Dispose()"/> to complete.
/// </summary>
/// <seealso cref="EnterBusy"/>
/// <seealso cref="ObtainBusyToken"/>
/// <exception cref="System.ObjectDisposedException">Thrown if this object is already disposed or being disposed.</exception>
protected void ExitBusy()
{
#pragma warning disable 420
DisposeAssistant.ExitBusy(this, _DisposedState, ref _BusyCount);
#pragma warning restore 420
}
