linkchecker/linkcheck/threader.py
2005-01-19 15:08:02 +00:00

96 lines
2.6 KiB
Python

# -*- coding: iso-8859-1 -*-
# Copyright (C) 2000-2005 Bastian Kleineidam
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
"""
Threading support.
"""
import time
try:
import threading
except ImportError:
import dummy_threading as threading
class Threader (object):
"""
A thread generating class.
"""
def __init__ (self, num=5):
"""
Store maximum number of threads to generate, and initialize
an empty thread list.
"""
# this allows negative numbers
self.threads_max = max(num, 1)
# list of active threads to watch
self.threads = []
def _acquire (self):
"""
Wait until we are allowed to start a new thread.
"""
while self.active_threads() >= self.threads_max:
self._reduce_threads()
time.sleep(0.1)
def _reduce_threads (self):
"""
Remove inactive threads.
"""
self.threads = [ t for t in self.threads if t.isAlive() ]
def active_threads (self):
"""
Return number of active threads.
"""
return len(self.threads)
def finished (self):
"""
Return True if no active threads are left.
"""
if self.threads_max > 0:
self._reduce_threads()
return self.active_threads() == 0
def finish (self):
"""
Remove inactive threads.
"""
self._reduce_threads()
# XXX don't know how to stop a thread
def start_thread (self, func, args):
"""
Generate a new thread.
"""
if self.threads_max < 1:
# threading is disabled
func(*args)
else:
self._acquire()
t = threading.Thread(None, func, None, args)
t.start()
self.threads.append(t)
def __str__ (self):
"""
String representation of threader state.
"""
return "Threader with %d threads (max %d)" % \
(self.active_threads(), self.threads_max)