Fix for CancellationTokenSource not disposed #1234

#1234

LanguageExt.Core/Effects/Aff/Aff.cs

@@ -100,27 +100,35 @@ public Eff<RT, Eff<Unit>> Fork()
  var reg = env.CancellationToken.Register(() => lenv.CancellationTokenSource.Cancel());
  
  // Run
- ignore(t(lenv).Iter(_ => Dispose()));
+ ignore(Go(t, lenv, reg));
  
  // Return an effect that cancels the fire-and-forget expression
- return Eff<Unit>(() =>
- {
- lenv.CancellationTokenSource.Cancel();
- Dispose();
- return unit;
- });
-
- void Dispose()
- {
- try
- {
- reg.Dispose();
- }
- catch
- {
- }
- }
+ return Eff(() =>
+ {
+ try
+ {
+ lenv.CancellationTokenSource.Cancel();
+ }
+ catch
+ {
+ // The token-source might have already been disposed, so let's ignore that error
+ }
+ return unit;
+ });
  });
+
+ async Task Go(Func<RT, ValueTask<Fin<A>>> thunk, RT lenv, CancellationTokenRegistration reg)
+ {
+ try
+ {
+ await thunk(lenv).ConfigureAwait(false);
+ }
+ finally
+ {
+ lenv.CancellationTokenSource.Dispose();
+ reg.Dispose();
+ }
+ }
  }
 
  /// <summary>
@@ -177,20 +185,39 @@ public Aff<RT, A> Timeout(TimeSpan timeoutDelay)
  using var delayTokSrc = new CancellationTokenSource();
  var lenv = env.LocalCancel;
  var delay = Task.Delay(timeoutDelay, delayTokSrc.Token);
- var task = t(lenv).AsTask();
- var completed = await Task.WhenAny(new Task[] {delay, task}).ConfigureAwait(false);
+ var task = Go(t, lenv);
+ var completed = await Task.WhenAny(delay, task).ConfigureAwait(false);
 
  if (completed == delay)
  {
- lenv.CancellationTokenSource.Cancel();
- return FinFail<A>(Errors.TimedOut);
+ try
+ {
+ lenv.CancellationTokenSource.Cancel();
+ }
+ catch
+ {
+ // The token-source might have already been disposed, so let's ignore that error
+ }
+ return FinFail<A>(Errors.TimedOut);
  }
  else
  {
  delayTokSrc.Cancel();
  return await task.ConfigureAwait(false);
  }
  });
+
+ async Task<Fin<A>> Go(Func<RT, ValueTask<Fin<A>>> thunk, RT lenv)
+ {
+ try
+ {
+ return await thunk(lenv).ConfigureAwait(false);
+ }
+ finally
+ {
+ lenv.CancellationTokenSource.Dispose();
+ }
+ }
  }
 
  [Pure, MethodImpl(Opt.Default)]

LanguageExt.Core/Effects/Eff/Eff.cs

@@ -3,7 +3,6 @@
 using static LanguageExt.Prelude;
 using System.Diagnostics.Contracts;
 using System.Runtime.CompilerServices;
-using LanguageExt.Thunks;
 
 namespace LanguageExt
 {