numpy并行运算

concurrent_numpy.py

from time import time
from handythread import foreach
from multiprocessing.pool import Pool
import numpy as np
import math

def f(x):
    # print(x)
    y = [1]*10000000
    [math.exp(i) for i in y]
def g(x):
    # print(x)
    y = np.ones(10000000)
    np.exp(y)


def fornorm(f, l):
    for i in l:
        f(i)


result = {}
start_time = time()
fornorm(g,range(100))
end_time = time()
result['norm g 100'] = end_time - start_time

start_time = time()
fornorm(f,range(10))
end_time = time()
result['norm f 10'] = end_time - start_time

start_time = time()
foreach(g,range(100),threads=2)
end_time = time()
result['2 threads g 100'] = end_time - start_time

start_time = time()
foreach(f,range(10),threads=2)
end_time = time()
result['2 threads f 10'] = end_time - start_time


p = Pool(2)
start_time = time()
p.map(g,range(100))
end_time = time()
result['2 processes g 100'] = end_time - start_time

start_time = time()
p.map(f,range(10))
end_time = time()
result['2 processes f 10'] = end_time - start_time

print(result)

handythread.py

import sys
import time
import threading
from itertools import count

def foreach(f,l,threads=3,return_=False):
    """
    Apply f to each element of l, in parallel
    """

    if threads>1:
        iteratorlock = threading.Lock()
        exceptions = []
        if return_:
            n = 0
            d = {}
            i = zip(count(),l.__iter__())
        else:
            i = l.__iter__()


        def runall():
            while True:
                iteratorlock.acquire()
                try:
                    try:
                        if exceptions:
                            return
                        v = next(i)
                    finally:
                        iteratorlock.release()
                except StopIteration:
                    return
                try:
                    if return_:
                        n,x = v
                        d[n] = f(x)
                    else:
                        f(v)
                except:
                    e = sys.exc_info()
                    iteratorlock.acquire()
                    try:
                        exceptions.append(e)
                    finally:
                        iteratorlock.release()
        
        threadlist = [threading.Thread(target=runall) for j in range(threads)]
        for t in threadlist:
            t.start()
        for t in threadlist:
            t.join()
        if exceptions:
            a, b, c = exceptions[0]
            raise a | b | c
        if return_:
            r = d.items()
            r.sort()
            return [v for (n,v) in r]
    else:
        if return_:
            return [f(v) for v in l]
        else:
            for v in l:
                f(v)
            return

def parallel_map(f,l,threads=3):
    return foreach(f,l,threads=threads,return_=True)

if __name__=='__main__':
    def f(x):
        print(x)
        time.sleep(0.5)
    foreach(f,range(10))
    def g(x):
        time.sleep(0.5)
        print(x)
        raise ValueError
        time.sleep(0.5)
    foreach(g,range(10))