private static async Task <TResult> PerformTaskAsync <TArg, TResult>(
Func <TArg, TResult> func, TArg arg,
TaskScheduler scheduler, CancellationToken cancellationToken) where TArg : struct
{
// Get a pooled delegate that can be used to prevent having to alloc a new lambda that calls 'func' while
// capturing 'arg'. This is needed as Task.Factory.StartNew has no way to pass extra data around with it
// except by boxing it as an object.
using var _ = PooledDelegates.GetPooledFunction(func, arg, out var boundFunction);
var task = Task.Factory.StartNew(boundFunction, cancellationToken, TaskCreationOptions.None, scheduler);
return(await task.ConfigureAwait(false));
}
public static TValue GetOrAdd <TKey, TArg, TValue>(this ConcurrentDictionary <TKey, TValue> dictionary, TKey key, Func <TKey, TArg, TValue> valueFactory, TArg factoryArgument)
where TKey : notnull
{
#if NETCOREAPP
return(dictionary.GetOrAdd(key, valueFactory, factoryArgument));
#else
if (dictionary.TryGetValue(key, out var value))
{
return(value);
}
using var _ = PooledDelegates.GetPooledFunction(valueFactory, factoryArgument, out var boundFunction);
return(dictionary.GetOrAdd(key, boundFunction));
#endif
}
