Source code for gluonts.nursery.glide.parallel

# Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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# Licensed under the Apache License, Version 2.0 (the "License").
# You may not use this file except in compliance with the License.
# A copy of the License is located at
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#     http://www.apache.org/licenses/LICENSE-2.0
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# or in the "license" file accompanying this file. This file is distributed
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import multiprocessing as mp
from functools import partial

from toolz.itertoolz import partition_all as into_batches
from toolz.functoolz import identity


[docs]class sentinel: pass
[docs]def map_to_queue(fn, emitter, queue, encode, batch_size): for batch in into_batches(batch_size, map(encode, fn(emitter))): queue.put(batch) queue.put(sentinel)
[docs]class ParApplyIterator: def __init__(self, procs, queue, decode): self.procs = procs self.queue = queue self.decode = decode self._current = [] self._sentinel_count = 0
[docs] def join(self): for proc in self.procs: proc.join()
[docs] def start(self): for proc in self.procs: proc.start()
[docs] def kill(self): for proc in self.procs: proc.kill()
[docs] def terminate(self): for proc in self.procs: proc.terminate()
def __next__(self): while not self._current: val = self.queue.get() if val is sentinel: self._sentinel_count += 1 if self._sentinel_count >= len(self.procs): raise StopIteration else: self._current = list(reversed(val)) return self.decode(self._current.pop())
[docs]class ParApply: def __init__( self, fn, emitter, batch_size=1, queue_size=50, encode=identity, decode=identity, ): self.fn = fn self.emitter = emitter self.batch_size = batch_size self.queue_size = queue_size self.encode = encode self.decode = decode def __iter__(self): queue = mp.Queue(self.queue_size) Process = partial(mp.Process, target=map_to_queue, daemon=True) it = ParApplyIterator( procs=[ Process( args=( self.fn, emitter, queue, self.encode, self.batch_size, ) ) for emitter in self.emitter ], queue=queue, decode=self.decode, ) it.start() return it