Python: Verwendung von Value und Array im Multiprocessing-Pool
Zummultiprocessing
mitProcess
, Ich kann nutzenValue, Array
indem man es einstelltargs
param.
Mitmultiprocessing
mitPool
, wie kann ich @ verwendValue, Array.
In den Dokumenten steht nichts darüber, wie das geht.
from multiprocessing import Process, Value, Array
def f(n, a):
n.value = 3.1415927
for i in range(len(a)):
, a[i] = -a[i]
if __name__ == '__main__':
num = Value('d', 0.0)
arr = Array('i', range(10))
p = Process(target=f, args=(num, arr))
p.start()
p.join()
print(num.value)
print(arr[:])
Ich versuche, @ zu verwendValue, Array
im Code-Snippet unten.
import multiprocessing
def do_calc(data):
# access num or
# work to update arr
newdata =data * 2
return newdata
def start_process():
print 'Starting', multiprocessing.current_process().name
if __name__ == '__main__':
num = Value('d', 0.0)
arr = Array('i', range(10))
inputs = list(range(10))
print 'Input :', inputs
pool_size = multiprocessing.cpu_count() * 2
pool = multiprocessing.Pool(processes=pool_size,initializer=start_process, )
pool_outputs = pool.map(do_calc, inputs)
pool.close() # no more tasks
pool.join() # wrap up current tasks
print 'Pool :', pool_outputs