这是我使用多处理的示例程序。计算是通过multiprocessing.Process
并使用收集结果multiprocessing.Queue
.
#THIS PROGRAM RUNS WITH ~40Gb RAM. (you can reduce a,b,c for less RAM
#but then it works for smaller values)
#PROBLEM OCCURS ONLY FOR HUGE DATA.
from numpy import *
import multiprocessing as mp
a = arange(0, 3500, 5)
b = arange(0, 3500, 5)
c = arange(0, 3500, 5)
a0 = 540. #random values
b0 = 26.
c0 = 826.
def rand_function(a, b, c, a0, b0, c0):
Nloop = 100.
def loop(Nloop, out):
res_total = zeros((700, 700, 700), dtype = 'float')
n = 1
while n <= Nloop:
rad = sqrt((a-a0)**2 + (b-b0)**2 + (c-c0)**2)
res_total += rad
n +=1
out.put(res_total)
out = mp.Queue()
jobs = []
Nprocs = mp.cpu_count()
print "No. of processors : ", Nprocs
for i in range(Nprocs):
p = mp.Process(target = loop, args=(Nloop/Nprocs, out))
jobs.append(p)
p.start()
final_result = zeros((700, 700, 700), dtype = 'float')
for i in range(Nprocs):
final_result = final_result + out.get()
p.join()
test = rand_function(a,b,c,a0, b0, c0)
这是错误消息:
Traceback (most recent call last):
File "/usr/lib/python2.7/multiprocessing/queues.py", line 266, in _feed
send(obj)
SystemError: NULL result without error in PyObject_Call
I read here http://bugs.python.org/issue17560这是一个错误。但我无法理解。
谁能告诉我使用多重处理计算大量数据的方法吗?
非常感谢