/// <summary>
/// Runs code within a new loader context before firing any pending
/// <see cref="DataLoader{TKey,TReturn}">DataLoader</see> instances.
/// </summary>
public static Task <T> Run <T>(Func <DataLoaderContext, Task <T> > func)
{
if (func == null)
{
throw new ArgumentNullException(nameof(func));
}
// TODO: Investigate this.
//
// For some reason, using `Task.Run` causes <see cref="TaskCompletionSource{T}"/> to run continuations
// synchronously, which prevents the main loop from continuing on to the next loader before they're done.
//
// I presume this is because once we're inside the ThreadPool, continuations will be scheduled using the
// local queues (in LIFO order) instead of the global queue (which executes in FIFO order). This is really
// a hack I think - the same thing should be accomplished using a custom TaskScheduler or custom awaiter.
return(Task.Run <T>(() =>
{
using (var scope = new DataLoaderScope())
{
var task = func(scope.Context);
if (task == null)
{
throw new InvalidOperationException("No task provided.");
}
return task;
}
}));
}
/// <summary>
/// Runs code within a new loader context before firing any pending
/// <see cref="DataLoader{TKey,TReturn}">DataLoader</see> instances.
/// </summary>
public static Task Run(Func <DataLoaderContext, Task> func)
{
if (func == null)
{
throw new ArgumentNullException(nameof(func));
}
// TODO: see above
return(Task.Run(() =>
{
using (var scope = new DataLoaderScope())
{
var task = func(scope.Context);
if (task == null)
{
throw new InvalidOperationException("No task provided.");
}
return task;
}
}));
}