System.Linq.Parallel OrderedPipeliningMergeEnumerator.MoveNext is using API unsupported on browser

[buyaa-n]

System.Linq.Parallel OrderedPipeliningMergeEnumerator.MoveNext is using API unsupported on browser (Monitor.Wait();). It needs to be fixed so it works without Monitor.Wait() on browser

OrderedPipeliningMergeEnumerator.TryWaitForElement It is calling Monitor.Wait() which is unsupported on browser. Which is further called from OrderedPipeliningMergeEnumerator.MoveNext which is overriding IEnumerator.MoveNext(...)

Originally posted by @buyaa-n in #43363 (comment)

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[buyaa-n]

AsynchronousChannelMergeEnumerator.MoveNextSlowPath() also accessing non suppurted ManualResetEventSlim.Wait(), i think it doesn't need separate issue as AsynchronousChannelMergeEnumerator.MoveNextSlowPath() also affecting IEnumerator.MoveNext(...)

[buyaa-n]

More similar references found:

1. OrderedHashRepartitionEnumerator.MoveNext(ref Pair<TInputOutput, THashKey> currentElement, ref TOrderKey currentKey)
2. HashRepartitionEnumerator.MoveNext(ref Pair<TInputOutput, THashKey> currentElement, ref int currentKey)
3. DefaultIfEmptyQueryOperator.MoveNext(ref TSource currentElement, ref TKey currentKey)
4. FirstQueryOperator.MoveNext(ref TSource currentElement, ref int currentKey)
5. LastQueryOperator.MoveNext(ref TSource currentElement, ref int currentKey)
6. TakeOrSkipQueryOperator.MoveNext(ref TResult currentElement, ref TKey currentKey)
7. TakeOrSkipWhileQueryOperator. MoveNext(ref TResult currentElement, ref TKey currentKey)

[stephentoub]

These are all the guts of PLINQ. Really it's just that PLINQ isn't supported on browser, all up. Either the whole assembly should be annotated as unsupported, or if there's a goal of having it be supported, browser should have its own effectively nop implementation that just delegates everything to Enumerable.

[buyaa-n]

As per the suggestion and discussion, marked the entire assembly unsupported

[akoeplinger]

I think we should do what @stephentoub suggested and replace it with an implementation that delegates to Enumerable.