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6746 :: Trouble using parallel

• ElAfalw (orginal) [2020-08-29T11:25:38+02:00] view original

  I'm experimenting a bit with parallel (my main goal is to implement a simple parallel loop - that's all).

  I've imported threadpool with --threads:on and {.experimental: "parallel".}.

  Here's the code in question:

  parallel:
           for item in collection:
                  discard spawn doSomethingWith(item)
  Run

  However, I keep getting an error:

  
  ../code/test.nim(124, 31) template/generic instantiation of `nimCreateFlowVar` from here
  ../.choosenim/toolchains/nim-1.2.6/lib/pure/concurrency/threadpool.nim(214, 6) Error: cannot bind another '=destroy' to: FlowVarObj; previous declaration was constructed here implicitly: ../.choosenim/toolchains/nim-1.2.6/lib/pure/concurrency/threadpool.nim(211, 48)
  Run

  Any idea what is going on? (or any other idea how to implement a proper parallel loop?)

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• ElAfalw (orginal) [2020-08-31T10:06:37+02:00] view original

  So, any idea?

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• mratsim (orginal) [2020-08-31T10:36:43+02:00] view original

  There is a bug in either threadpool or in parallel introduced by the new destructor changes.

  I tried to use parallel myself and never managed to besides the example in the experimental manual (and I wrote an entire multithreading library Weave).

  Just use the plain threadpool:

  for item in collection:
      discard spawn doSomethingWith(item)
  Run

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