/usr/lib/python2.7/dist-packages/apscheduler/threadpool.py is in python-apscheduler 2.1.2-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 | """
Generic thread pool class. Modeled after Java's ThreadPoolExecutor.
Please note that this ThreadPool does *not* fully implement the PEP 3148
ThreadPool!
"""
from threading import Thread, Lock, currentThread
from weakref import ref
import logging
import atexit
try:
from queue import Queue, Empty
except ImportError:
from Queue import Queue, Empty
logger = logging.getLogger(__name__)
_threadpools = set()
# Worker threads are daemonic in order to let the interpreter exit without
# an explicit shutdown of the thread pool. The following trick is necessary
# to allow worker threads to finish cleanly.
def _shutdown_all():
for pool_ref in tuple(_threadpools):
pool = pool_ref()
if pool:
pool.shutdown()
atexit.register(_shutdown_all)
class ThreadPool(object):
def __init__(self, core_threads=0, max_threads=20, keepalive=1):
"""
:param core_threads: maximum number of persistent threads in the pool
:param max_threads: maximum number of total threads in the pool
:param thread_class: callable that creates a Thread object
:param keepalive: seconds to keep non-core worker threads waiting
for new tasks
"""
self.core_threads = core_threads
self.max_threads = max(max_threads, core_threads, 1)
self.keepalive = keepalive
self._queue = Queue()
self._threads_lock = Lock()
self._threads = set()
self._shutdown = False
_threadpools.add(ref(self))
logger.info('Started thread pool with %d core threads and %s maximum '
'threads', core_threads, max_threads or 'unlimited')
def _adjust_threadcount(self):
self._threads_lock.acquire()
try:
if self.num_threads < self.max_threads:
self._add_thread(self.num_threads < self.core_threads)
finally:
self._threads_lock.release()
def _add_thread(self, core):
t = Thread(target=self._run_jobs, args=(core,))
t.setDaemon(True)
t.start()
self._threads.add(t)
def _run_jobs(self, core):
logger.debug('Started worker thread')
block = True
timeout = None
if not core:
block = self.keepalive > 0
timeout = self.keepalive
while True:
try:
func, args, kwargs = self._queue.get(block, timeout)
except Empty:
break
if self._shutdown:
break
try:
func(*args, **kwargs)
except:
logger.exception('Error in worker thread')
self._threads_lock.acquire()
self._threads.remove(currentThread())
self._threads_lock.release()
logger.debug('Exiting worker thread')
@property
def num_threads(self):
return len(self._threads)
def submit(self, func, *args, **kwargs):
if self._shutdown:
raise RuntimeError('Cannot schedule new tasks after shutdown')
self._queue.put((func, args, kwargs))
self._adjust_threadcount()
def shutdown(self, wait=True):
if self._shutdown:
return
logging.info('Shutting down thread pool')
self._shutdown = True
_threadpools.remove(ref(self))
self._threads_lock.acquire()
for _ in range(self.num_threads):
self._queue.put((None, None, None))
self._threads_lock.release()
if wait:
self._threads_lock.acquire()
threads = tuple(self._threads)
self._threads_lock.release()
for thread in threads:
thread.join()
def __repr__(self):
if self.max_threads:
threadcount = '%d/%d' % (self.num_threads, self.max_threads)
else:
threadcount = '%d' % self.num_threads
return '<ThreadPool at %x; threads=%s>' % (id(self), threadcount)
|