mirror of
https://github.com/logos-storage/apatheia.git
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64 lines
2.1 KiB
Nim
64 lines
2.1 KiB
Nim
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import std/[strutils, math, cpuinfo]
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import taskpools
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# From https://github.com/nim-lang/Nim/blob/v1.6.2/tests/parallel/tpi.nim
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# Leibniz Formula https://en.wikipedia.org/wiki/Leibniz_formula_for_%CF%80
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proc term(k: int): float =
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if k mod 2 == 1:
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-4'f / float(2*k + 1)
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else:
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4'f / float(2*k + 1)
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proc piApprox(tp: Taskpool, n: int): float =
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var pendingFuts = newSeq[FlowVar[float]](n)
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for k in 0 ..< pendingFuts.len:
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pendingFuts[k] = tp.spawn term(k) # Schedule a task on the threadpool a return a handle to retrieve the result.
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for k in 0 ..< pendingFuts.len:
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result += sync pendingFuts[k] # Block until the result is available.
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proc main() =
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var n = 1_000
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var nthreads = countProcessors()
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var tp = Taskpool.new(num_threads = nthreads) # Default to the number of hardware threads.
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echo formatFloat(tp.piApprox(n))
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tp.syncAll() # Block until all pending tasks are processed (implied in tp.shutdown())
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tp.shutdown()
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# Compile with nim c -r -d:release --threads:on --outdir:build example.nim
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main()
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when false:
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type
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ScratchObj_486539477 = object
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k: int
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fut: Flowvar[float]
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let scratch_486539455 = cast[ptr ScratchObj_486539477](c_calloc(csize_t 1,
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csize_t sizeof(ScratchObj_486539477)))
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if scratch_486539455.isNil:
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raise newException(OutOfMemDefect, "Could not allocate memory")
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block:
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var isoTemp_486539473 = isolate(k)
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scratch_486539455.k = extract(isoTemp_486539473)
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var isoTemp_486539475 = isolate(fut)
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scratch_486539455.fut = extract(isoTemp_486539475)
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proc taskpool_term_486539478(args: pointer) {.gcsafe, nimcall,
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raises: [].} =
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let objTemp_486539472 = cast[ptr ScratchObj_486539477](args)
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let k_486539474 = objTemp_486539472.k
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let fut_486539476 = objTemp_486539472.fut
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taskpool_term(k = k_486539474, fut = fut_486539476)
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proc destroyScratch_486539479(args: pointer) {.gcsafe, nimcall,
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raises: [].} =
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let obj_486539480 = cast[ptr ScratchObj_486539477](args)
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`=destroy`(obj_486539480[])
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Task(callback: taskpool_term_486539478, args: scratch_486539455,
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destroy: destroyScratch_486539479)
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