PlexKodiConnect/resources/lib/backgroundthread.py

328 lines
8.6 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import absolute_import, division, unicode_literals
from logging import getLogger
import threading
import Queue
import heapq
import xbmc
from . import utils
from Queue import Empty
LOG = getLogger('PLEX.' + __name__)
class KillableThread(threading.Thread):
pass
'''A thread class that supports raising exception in the thread from
another thread.
'''
# def _get_my_tid(self):
# """determines this (self's) thread id
# CAREFUL : this function is executed in the context of the caller
# thread, to get the identity of the thread represented by this
# instance.
# """
# if not self.isAlive():
# raise threading.ThreadError("the thread is not active")
# return self.ident
# def _raiseExc(self, exctype):
# """Raises the given exception type in the context of this thread.
# If the thread is busy in a system call (time.sleep(),
# socket.accept(), ...), the exception is simply ignored.
# If you are sure that your exception should terminate the thread,
# one way to ensure that it works is:
# t = ThreadWithExc( ... )
# ...
# t.raiseExc( SomeException )
# while t.isAlive():
# time.sleep( 0.1 )
# t.raiseExc( SomeException )
# If the exception is to be caught by the thread, you need a way to
# check that your thread has caught it.
# CAREFUL : this function is executed in the context of the
# caller thread, to raise an excpetion in the context of the
# thread represented by this instance.
# """
# _async_raise(self._get_my_tid(), exctype)
def kill(self, force_and_wait=False):
pass
# try:
# self._raiseExc(KillThreadException)
# if force_and_wait:
# time.sleep(0.1)
# while self.isAlive():
# self._raiseExc(KillThreadException)
# time.sleep(0.1)
# except threading.ThreadError:
# pass
# def onKilled(self):
# pass
# def run(self):
# try:
# self._Thread__target(*self._Thread__args, **self._Thread__kwargs)
# except KillThreadException:
# self.onKilled()
class Tasks(list):
def add(self, task):
for t in self:
if not t.isValid():
self.remove(t)
if isinstance(task, list):
self += task
else:
self.append(task)
def cancel(self):
while self:
self.pop().cancel()
class Task(object):
def __init__(self, priority=None):
self._priority = priority
self._canceled = False
self.finished = False
def __cmp__(self, other):
return self._priority - other._priority
def start(self):
BGThreader.addTask(self)
def _run(self):
self.run()
self.finished = True
def run(self):
pass
def cancel(self):
self._canceled = True
def isCanceled(self):
return self._canceled or xbmc.abortRequested
def isValid(self):
return not self.finished and not self._canceled
class MutablePriorityQueue(Queue.PriorityQueue):
def _get(self, heappop=heapq.heappop):
self.queue.sort()
return heappop(self.queue)
def lowest(self):
"""Return the lowest priority item in the queue (not reliable!)."""
self.mutex.acquire()
try:
lowest = self.queue and min(self.queue) or None
except:
lowest = None
utils.ERROR()
finally:
self.mutex.release()
return lowest
class BackgroundWorker(object):
def __init__(self, queue, name=None):
self._queue = queue
self.name = name
self._thread = None
self._abort = False
self._task = None
def _runTask(self, task):
if task._canceled:
return
try:
task._run()
except:
utils.ERROR()
def abort(self):
self._abort = True
return self
def aborted(self):
return self._abort or xbmc.abortRequested
def start(self):
if self._thread and self._thread.isAlive():
return
self._thread = KillableThread(target=self._queueLoop, name='BACKGROUND-WORKER({0})'.format(self.name))
self._thread.start()
def _queueLoop(self):
if self._queue.empty():
return
LOG.debug('(%s): Active', self.name)
try:
while not self.aborted():
self._task = self._queue.get_nowait()
self._runTask(self._task)
self._queue.task_done()
self._task = None
except Queue.Empty:
LOG.debug('(%s): Idle', self.name)
def shutdown(self):
self.abort()
if self._task:
self._task.cancel()
if self._thread and self._thread.isAlive():
LOG.debug('thread (%s): Waiting...', self.name)
self._thread.join()
LOG.debug('thread (%s): Done', self.name)
def working(self):
return self._thread and self._thread.isAlive()
class NonstoppingBackgroundWorker(BackgroundWorker):
def __init__(self, queue, name=None):
self._working = False
super(NonstoppingBackgroundWorker, self).__init__(queue, name)
def _queueLoop(self):
LOG.debug('(%s): Active', self.name)
while not self.aborted():
try:
self._task = self._queue.get_nowait()
self._working = True
self._runTask(self._task)
self._working = False
self._queue.task_done()
self._task = None
except Queue.Empty:
xbmc.sleep(50)
def working(self):
return self._working
class BackgroundThreader:
def __init__(self, name=None, worker=BackgroundWorker,
worker_count=int(utils.settings('syncThreadNumber'))):
self.name = name
self._queue = MutablePriorityQueue()
self._abort = False
self._priority = -1
self.workers = [worker(self._queue, 'queue.{0}:worker.{1}'.format(self.name, x)) for x in range(worker_count)]
def _nextPriority(self):
self._priority += 1
return self._priority
def abort(self):
self._abort = True
for w in self.workers:
w.abort()
return self
def aborted(self):
return self._abort or xbmc.abortRequested
def shutdown(self):
self.abort()
for w in self.workers:
w.shutdown()
def addTask(self, task):
task._priority = self._nextPriority()
self._queue.put(task)
self.startWorkers()
def addTasks(self, tasks):
for t in tasks:
t._priority = self._nextPriority()
self._queue.put(t)
self.startWorkers()
def addTasksToFront(self, tasks):
lowest = self.getLowestPrority()
if lowest is None:
return self.addTasks(tasks)
p = lowest - len(tasks)
for t in tasks:
t._priority = p
self._queue.put(t)
p += 1
self.startWorkers()
def startWorkers(self):
for w in self.workers:
w.start()
def working(self):
return not self._queue.empty() or self.hasTask()
def hasTask(self):
return any([w.working() for w in self.workers])
def getLowestPrority(self):
lowest = self._queue.lowest()
if not lowest:
return None
return lowest._priority
def moveToFront(self, qitem):
lowest = self.getLowestPrority()
if lowest is None:
return
qitem._priority = lowest - 1
class ThreaderManager:
def __init__(self, worker=BackgroundWorker):
self.index = 0
self.abandoned = []
self._workerhandler = worker
self.threader = BackgroundThreader(name=str(self.index), worker=worker)
def __getattr__(self, name):
return getattr(self.threader, name)
def reset(self):
if self.threader._queue.empty() and not self.threader.hasTask():
return
self.index += 1
self.abandoned.append(self.threader.abort())
self.threader = BackgroundThreader(name=str(self.index),
worker=self._workerhandler)
def shutdown(self):
self.threader.shutdown()
for a in self.abandoned:
a.shutdown()
BGThreader = ThreaderManager()