我在线程内部运行了以下代码。“expand”C可执行文件为每个输入“url”生成唯一的字符串输出：
p = Popen(["expand", url], bufsize=65536, stdout=PIPE, stderr=PIPE, close_fds=True)
output,error = p.communicate()
print output
我已经实现了一个基于队列的多线程解决方案，该解决方案每批100个处理5000个网址。
当我运行脚本时;它挂起.. ps -aef显示2个进程仍在运行：
1. 10177 5721 6662 6 09:25 pts/15 00:04:36 python expandPlaylist.py -s -t
2. 10177 11004 5721 0 09:26 pts/15 00:00:00 expand http://www.sample.com
主python脚本的堆栈跟踪：
# ThreadID: 140332211570432
File: "expandPlaylist.py", line 902, in <module>
Main()
File: "expandPlaylist.py", line 894, in Main
startmain(db, c, conf)
File: "expandPlaylist.py", line 834, in startmain
stream_queue.join()
File: "/usr/lib64/python2.7/Queue.py", line 82, in join
self.all_tasks_done.wait()
File: "/usr/lib64/python2.7/threading.py", line 238, in wait
waiter.acquire()
陷入僵局的线程的堆栈跟踪
# ThreadID: 140332016596736
File: "/usr/lib64/python2.7/threading.py", line 503, in __bootstrap
self.__bootstrap_inner()
File: "/usr/lib64/python2.7/threading.py", line 530, in __bootstrap_inner
self.run()
File: "expandPlaylist.py", line 120, in run
self.process.wait()
File: "/usr/lib64/python2.7/subprocess.py", line 1242, in wait
pid, sts = _eintr_retry_call(os.waitpid, self.pid, 0)
File: "/usr/lib64/python2.7/subprocess.py", line 471, in _eintr_retry_call
return func(*args)
process_id的详细信息：11004
(gdb) bt
#0 __lll_lock_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:136
#1 0x00007fc36bd33294 in _L_lock_999 () from /lib64/libpthread.so.0
#2 0x00007fc36bd330aa in __pthread_mutex_lock (mutex=0x6a8c20) at pthread_mutex_lock.c:61
#3 0x00007fc36c204dcd in g_mutex_lock (mutex=0x6a8c50) at gthread-posix.c:213
#4 0x00007fc36c1b11df in g_source_unref_internal (source=0x844f90, context=0x6a8c50, have_lock=0) at gmain.c:1975
#5 0x00007fc36c1b13e3 in g_source_unref (source=0x844f90) at gmain.c:2044
#6 0x00007fc36cb475a9 in soup_session_dispose (object=0x61e100) at soup-session.c:305
#7 0x00007fc36c4d270e in g_object_unref (_object=0x61e100) at gobject.c:3160
#8 0x000000000040584b in dispose_session (parser=0x618020) at al_playlist_parser.c:859
#9 0x0000000000403b0b in al_playlist_parser_dispose (obj=0x618020) at al_playlist_parser.c:129
#10 0x00007fc36c4d270e in g_object_unref (_object=0x618020) at gobject.c:3160
#11 0x0000000000403315 in main (argc=1, argv=0x7fff462cdca8) at al_expand.c:143
self.process.wait()绑定，如果子进程处理时间过长，则终止该线程？答案 0 :(得分：0)
如果你只需要在一个参数列表上调用一个子进程，我倾向于这样做：
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# Author: R.F. Smith <rsmith@xs4all.nl>
# $Date: 2013-11-24 11:06:39 +0100 $
#
# To the extent possible under law, Roland Smith has waived all copyright and
# related or neighboring rights to vid2mp4.py. This work is published from the
# Netherlands. See http://creativecommons.org/publicdomain/zero/1.0/
"""Convert all video files given on the command line to H.264/AAC streams in
an MP4 container."""
from __future__ import print_function, division # for compatibility with Python 2.
__version__ = '$Revision: cac4808 $'[11:-2]
import os
import sys
import subprocess
from multiprocessing import cpu_count
from time import sleep
def warn(s):
"""Print a warning message.
:param s: Message string
"""
s = ' '.join(['Warning:', s])
print(s, file=sys.stderr)
def checkfor(args, rv=0):
"""Make sure that a program necessary for using this script is
available.
:param args: String or list of strings of commands. A single string may
not contain spaces.
:param rv: Expected return value from evoking the command.
"""
if isinstance(args, str):
if ' ' in args:
raise ValueError('no spaces in single command allowed')
args = [args]
try:
with open(os.devnull, 'w') as bb:
rc = subprocess.call(args, stdout=bb, stderr=bb)
if rc != rv:
raise OSError
except OSError as oops:
outs = "Required program '{}' not found: {}."
print(outs.format(args[0], oops.strerror))
sys.exit(1)
def startencoder(fname):
"""Use ffmpeg to convert a video file to H.264/AAC
streams in an MP4 container.
:param fname: Name of the file to convert.
:returns: a 3-tuple of a Process, input path and output path
"""
basename, ext = os.path.splitext(fname)
known = ['.mp4', '.avi', '.wmv', '.flv', '.mpg', '.mpeg', '.mov', '.ogv']
if ext.lower() not in known:
warn("File {} has unknown extension, ignoring it.".format(fname))
return (None, fname, None)
ofn = basename + '.mp4'
args = ['ffmpeg', '-i', fname, '-c:v', 'libx264', '-crf', '29', '-flags',
'+aic+mv4', '-c:a', 'libfaac', '-sn', ofn]
with open(os.devnull, 'w') as bitbucket:
try:
p = subprocess.Popen(args, stdout=bitbucket, stderr=bitbucket)
print("Conversion of {} to {} started.".format(fname, ofn))
except:
warn("Starting conversion of {} failed.".format(fname))
return (p, fname, ofn)
def manageprocs(proclist):
"""Check a list of subprocesses tuples for processes that have ended and
remove them from the list.
:param proclist: a list of (process, input filename, output filename)
tuples.
"""
print('# of conversions running: {}\r'.format(len(proclist)), end='')
sys.stdout.flush()
for p in proclist:
pr, ifn, ofn = p
if pr is None:
proclist.remove(p)
elif pr.poll() is not None:
print('Conversion of {} to {} finished.'.format(ifn, ofn))
proclist.remove(p)
sleep(0.5)
def main(argv):
"""Main program.
:param argv: command line arguments
"""
if len(argv) == 1:
binary = os.path.basename(argv[0])
print("{} version {}".format(binary, __version__), file=sys.stderr)
print("Usage: {} [file ...]".format(binary), file=sys.stderr)
sys.exit(0)
checkfor(['ffmpeg', '-version'])
avis = argv[1:]
procs = []
maxprocs = cpu_count()
for ifile in avis:
while len(procs) == maxprocs:
manageprocs(procs)
procs.append(startencoder(ifile))
while len(procs) > 0:
manageprocs(procs)
if __name__ == '__main__':
main(sys.argv)
如果挂起进程存在问题，您可以在一段时间后适应manageprocs以终止子进程。