我需要实现算法,以便利用多核处理器。
到目前为止,我有这个:

def handle_primes(n, segments):
    """ Returns the count of primes below n, using segments """
    if __name__ == '__main__' :
        # Initialize
        count = 0
        pool = Pool(processes=segments)
        segment_size = n/segments

        # Count primes in each segment
        for start in xrange(2, n+1, segment_size+1):
            end = start+segment_size
            if end>n:
                end = n
            count += pool.apply_async(countprimes, [start, end]).get()

        return count


countprimes()从开始到限制计数段中的素数。

此代码比仅使用countprimes()的常规实现运行慢。
我是否错误地使用了多处理模块?

最佳答案

get将阻止。您需要编写两个循环。尝试这个:

 # Count primes in each segment
 processes = []
 for start in xrange(2, n+1, segment_size+1):
     end = start+segment_size
     if end>n:
         end = n
     processes.append(pool.apply_async(countprimes, [start, end]))
 for process in processes:
     count += process.get()

10-05 20:36
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