kwcoco.util.util_parallel module

kwcoco.util.util_parallel.coerce_num_workers(num_workers='auto', minimum=0)

Return some number of CPUs based on a chosen hueristic

Parameters:

• num_workers (int | str) – A special string code, or an exact number of cpus

• minimum (int) – minimum workers we are allowed to return

Returns:

number of available cpus based on request parameters

Return type:

int

CommandLine

xdoctest -m kwcoco.util.util_parallel coerce_num_workers

Example

>>> from kwcoco.util.util_parallel import *  # NOQA
>>> print(coerce_num_workers('all'))
>>> print(coerce_num_workers('avail'))
>>> print(coerce_num_workers('auto'))
>>> print(coerce_num_workers('all-2'))
>>> print(coerce_num_workers('avail-2'))
>>> print(coerce_num_workers('all/2'))
>>> print(coerce_num_workers('min(all,2)'))
>>> print(coerce_num_workers('[max(all,2)][0]'))
>>> import pytest
>>> with pytest.raises(Exception):
>>>     print(coerce_num_workers('all + 1' + (' + 1' * 100)))
>>> total_cpus = coerce_num_workers('all')
>>> assert coerce_num_workers('all-2') == max(total_cpus - 2, 0)
>>> assert coerce_num_workers('all-100') == max(total_cpus - 100, 0)
>>> assert coerce_num_workers('avail') <= coerce_num_workers('all')
>>> assert coerce_num_workers(3) == max(3, 0)