我有一个在这里定义的超级简单的python脚本
import multiprocessing
from multiprocessing import Pool
print "CPUs: " + str(multiprocessing.cpu_count())
convertPool = Pool(multiprocessing.cpu_count())
在 Linux 上,这似乎与我预期的一样,程序刚刚启动,然后打印出内核数,然后退出。但是,在 Windows 上,该程序将继续调用新的 python 命令并打印出“CPUs: 4”(我有 4 个内核)并且永远不会停止运行并最终会杀死该框。有人可以解释一下这里发生了什么吗?
谢谢
编辑:我现在有以下程序,但仍然无法按预期运行
import sys
import os
import subprocess
from subprocess import Popen, PIPE
from threading import Thread
import multiprocessing
from multiprocessing import Pool, freeze_support
try:
from Queue import Queue, Empty
except ImportError:
from queue import Queue, Empty # python 3.x
ON_POSIX = "posix" in sys.builtin_module_names
def myPrint(line, logWriter):
if logWriter is None:
# This will print without a newline, cause the process
# has its own newlines
sys.stdout.write(line)
else:
logWriter.write(line.strip())
logWriter.write("\n")
logWriter.flush()
# This is gotten from http://stackoverflow.com/questions/375427/non-blocking-read-on-a-subprocess-pipe-in-python
def executeCommand(cmd, logWriter):
myPrint(cmd + "\n", logWriter)
p = Popen(cmd, stdout=PIPE, bufsize=4096, close_fds=ON_POSIX, shell=True)
q = Queue()
t = Thread(target=enqueue_output, args=(p.stdout, q))
t.daemon = True # thread dies with the program
t.start()
# read line without blocking
while t.isAlive() or not q.empty():
try:
line = q.get_nowait() # or q.get(timeout=.1)
except Empty:
pass # Do nothing
else: # If there is a line, then print it
if logWriter is not None:
myPrint(line, logWriter)
# Sleep to prevent python from using too much cpu
time.sleep(0.05)
if __name__ == "__main__":
freeze_support()
convertPool = Pool(multiprocessing.cpu_count())
# Now let's smooth and threshold all the masks
for foo in bar:
threshSmoothCmd = "ConvertImage.exe -i " + foo + " -o " + foo
myPrint(threshSmoothCmd + "\n", None)
convertPool.apply_async(executeCommand,(threshSmoothCmd, None,))
convertPool.close()
convertPool.join()
print "Finished processing"
ConvertImage.exe 是我自己编写的可执行文件 foo 和 bar 只是占位符。在 Linux 上,这将启动 multiprocessing.cpu_count() 数量的 ConvertImage.exe 进程,然后在所有 ConvertImage.exe 进程完成后打印 Finished processing。在 Windows 上,这会立即启动 len(bar) ConvertImage.exe 进程,然后立即打印 Finished processing 并退出。如何让 Windows 版本表现得像 Linux 版本?