text: # -*- coding: utf-8 -*-
  from __future__ import (absolute_import, division, print_function,
                          unicode_literals)
  
  import errno
  import logging
  import os
  import random
  import signal
  import socket
  import sys
  import time
  import traceback
  import warnings
  from datetime import timedelta
  from uuid import uuid4
  
  try:
      from signal import SIGKILL
  except ImportError:
      from signal import SIGTERM as SIGKILL
  
  from redis import WatchError
  
  from . import worker_registration
  from .compat import PY2, as_text, string_types, text_type
  from .connections import get_current_connection, push_connection, pop_connection
  
  from .defaults import (DEFAULT_RESULT_TTL,
                         DEFAULT_WORKER_TTL, DEFAULT_JOB_MONITORING_INTERVAL,
                         DEFAULT_LOGGING_FORMAT, DEFAULT_LOGGING_DATE_FORMAT)
  from .exceptions import DequeueTimeout, ShutDownImminentException
  from .job import Job, JobStatus
  from .logutils import setup_loghandlers
  from .queue import Queue
  from .registry import FailedJobRegistry, StartedJobRegistry, clean_registries
  from .scheduler import RQScheduler
  from .suspension import is_suspended
  from .timeouts import JobTimeoutException, HorseMonitorTimeoutException, UnixSignalDeathPenalty
  from .utils import (backend_class, ensure_list, enum,
                      make_colorizer, utcformat, utcnow, utcparse)
  from .version import VERSION
  from .worker_registration import clean_worker_registry, get_keys
  from .serializers import resolve_serializer
  
  try:
      from setproctitle import setproctitle as setprocname
  except ImportError:
      def setprocname(*args, **kwargs):  # noqa
          pass
  
  green = make_colorizer('darkgreen')
  yellow = make_colorizer('darkyellow')
  blue = make_colorizer('darkblue')
  
  
  logger = logging.getLogger(__name__)
  
  
  class StopRequested(Exception):
      pass
  
  
  def compact(l):
      return [x for x in l if x is not None]
  
  
  _signames = dict((getattr(signal, signame), signame)
                   for signame in dir(signal)
                   if signame.startswith('SIG') and '_' not in signame)
  
  
  def signal_name(signum):
      try:
          if sys.version_info[:2] >= (3, 5):
              return signal.Signals(signum).name
          else:
              return _signames[signum]
  
      except KeyError:
          return 'SIG_UNKNOWN'
      except ValueError:
          return 'SIG_UNKNOWN'
  
  
  WorkerStatus = enum(
      'WorkerStatus',
      STARTED='started',
      SUSPENDED='suspended',
      BUSY='busy',
      IDLE='idle'
  )
  
  
  class Worker(object):
      redis_worker_namespace_prefix = 'rq:worker:'
      redis_workers_keys = worker_registration.REDIS_WORKER_KEYS
      death_penalty_class = UnixSignalDeathPenalty
      queue_class = Queue
      job_class = Job
      # `log_result_lifespan` controls whether "Result is kept for XXX seconds"
      # messages are logged after every job, by default they are.
      log_result_lifespan = True
      # `log_job_description` is used to toggle logging an entire jobs description.
      log_job_description = True
  
      @classmethod
      def all(cls, connection=None, job_class=None, queue_class=None, queue=None, serializer=None):
          """Returns an iterable of all Workers.
          """
          if queue:
              connection = queue.connection
          elif connection is None:
              connection = get_current_connection()
  
          worker_keys = get_keys(queue=queue, connection=connection)
          workers = [cls.find_by_key(as_text(key),
                                     connection=connection,
                                     job_class=job_class,
                                     queue_class=queue_class, serializer=serializer)
                     for key in worker_keys]
          return compact(workers)
  
      @classmethod
      def all_keys(cls, connection=None, queue=None):
          return [as_text(key)
                  for key in get_keys(queue=queue, connection=connection)]
  
      @classmethod
      def count(cls, connection=None, queue=None):
          """Returns the number of workers by queue or connection"""
          return len(get_keys(queue=queue, connection=connection))
  
      @classmethod
      def find_by_key(cls, worker_key, connection=None, job_class=None,
                      queue_class=None, serializer=None):
          """Returns a Worker instance, based on the naming conventions for
          naming the internal Redis keys.  Can be used to reverse-lookup Workers
          by their Redis keys.
          """
          prefix = cls.redis_worker_namespace_prefix
          if not worker_key.startswith(prefix):
              raise ValueError('Not a valid RQ worker key: %s' % worker_key)
  
          if connection is None:
              connection = get_current_connection()
          if not connection.exists(worker_key):
              connection.srem(cls.redis_workers_keys, worker_key)
              return None
  
          name = worker_key[len(prefix):]
          worker = cls([], name, connection=connection, job_class=job_class,
                       queue_class=queue_class, prepare_for_work=False, serializer=serializer)
  
          worker.refresh()
  
          return worker
  
      def __init__(self, queues, name=None, default_result_ttl=DEFAULT_RESULT_TTL,
                   connection=None, exc_handler=None, exception_handlers=None,
                   default_worker_ttl=DEFAULT_WORKER_TTL, job_class=None,
                   queue_class=None, log_job_description=True,
                   job_monitoring_interval=DEFAULT_JOB_MONITORING_INTERVAL,
                   disable_default_exception_handler=False,
                   prepare_for_work=True, serializer=None):  # noqa
          if connection is None:
              connection = get_current_connection()
          self.connection = connection
  
          if prepare_for_work:
              self.hostname = socket.gethostname()
              self.pid = os.getpid()
          else:
              self.hostname = None
              self.pid = None
  
          self.job_class = backend_class(self, 'job_class', override=job_class)
          self.queue_class = backend_class(self, 'queue_class', override=queue_class)
          self.version = VERSION
          self.python_version = sys.version
          self.serializer = resolve_serializer(serializer)
  
          queues = [self.queue_class(name=q,
                                     connection=connection,
                                     job_class=self.job_class, serializer=self.serializer)
                    if isinstance(q, string_types) else q
                    for q in ensure_list(queues)]
  
          self.name = name or uuid4().hex
          self.queues = queues
          self.validate_queues()
          self._exc_handlers = []
  
          self.default_result_ttl = default_result_ttl
          self.default_worker_ttl = default_worker_ttl
          self.job_monitoring_interval = job_monitoring_interval
  
          self._state = 'starting'
          self._is_horse = False
          self._horse_pid = 0
          self._stop_requested = False
          self.log = logger
          self.log_job_description = log_job_description
          self.last_cleaned_at = None
          self.successful_job_count = 0
          self.failed_job_count = 0
          self.total_working_time = 0
          self.birth_date = None
          self.scheduler = None
  
          self.disable_default_exception_handler = disable_default_exception_handler
  
          if isinstance(exception_handlers, (list, tuple)):
              for handler in exception_handlers:
                  self.push_exc_handler(handler)
          elif exception_handlers is not None:
              self.push_exc_handler(exception_handlers)
  
      def validate_queues(self):
          """Sanity check for the given queues."""
          for queue in self.queues:
              if not isinstance(queue, self.queue_class):
                  raise TypeError('{0} is not of type {1} or string types'.format(queue, self.queue_class))
  
      def queue_names(self):
          """Returns the queue names of this worker's queues."""
          return [queue.name for queue in self.queues]
  
      def queue_keys(self):
          """Returns the Redis keys representing this worker's queues."""
          return [queue.key for queue in self.queues]
  
      @property
      def key(self):
          """Returns the worker's Redis hash key."""
          return self.redis_worker_namespace_prefix + self.name
  
      @property
      def horse_pid(self):
          """The horse's process ID.  Only available in the worker.  Will return
          0 in the horse part of the fork.
          """
          return self._horse_pid
  
      @property
      def is_horse(self):
          """Returns whether or not this is the worker or the work horse."""
          return self._is_horse
  
      def procline(self, message):
          """Changes the current procname for the process.
  
          This can be used to make `ps -ef` output more readable.
          """
          setprocname('rq: {0}'.format(message))
  
      def register_birth(self):
          """Registers its own birth."""
          self.log.debug('Registering birth of worker %s', self.name)
          if self.connection.exists(self.key) and \
                  not self.connection.hexists(self.key, 'death'):
              msg = 'There exists an active worker named {0!r} already'
              raise ValueError(msg.format(self.name))
          key = self.key
          queues = ','.join(self.queue_names())
          with self.connection.pipeline() as p:
              p.delete(key)
              now = utcnow()
              now_in_string = utcformat(now)
              self.birth_date = now
              p.hmset(key, {
                  'birth': now_in_string,
                  'last_heartbeat': now_in_string,
                  'queues': queues,
                  'pid': self.pid,
                  'hostname': self.hostname,
                  'version': self.version,
                  'python_version': self.python_version,
              })
              worker_registration.register(self, p)
              p.expire(key, self.default_worker_ttl)
              p.execute()
  
      def register_death(self):
          """Registers its own death."""
          self.log.debug('Registering death')
          with self.connection.pipeline() as p:
              # We cannot use self.state = 'dead' here, because that would
              # rollback the pipeline
              worker_registration.unregister(self, p)
              p.hset(self.key, 'death', utcformat(utcnow()))
              p.expire(self.key, 60)
              p.execute()
  
      def set_shutdown_requested_date(self):
          """Sets the date on which the worker received a (warm) shutdown request"""
          self.connection.hset(self.key, 'shutdown_requested_date', utcformat(utcnow()))
  
      # @property
      # def birth_date(self):
      #     """Fetches birth date from Redis."""
      #     birth_timestamp = self.connection.hget(self.key, 'birth')
      #     if birth_timestamp is not None:
      #         return utcparse(as_text(birth_timestamp))
  
      @property
      def shutdown_requested_date(self):
          """Fetches shutdown_requested_date from Redis."""
          shutdown_requested_timestamp = self.connection.hget(self.key, 'shutdown_requested_date')
          if shutdown_requested_timestamp is not None:
              return utcparse(as_text(shutdown_requested_timestamp))
  
      @property
      def death_date(self):
          """Fetches death date from Redis."""
          death_timestamp = self.connection.hget(self.key, 'death')
          if death_timestamp is not None:
              return utcparse(as_text(death_timestamp))
  
      def set_state(self, state, pipeline=None):
          self._state = state
          connection = pipeline if pipeline is not None else self.connection
          connection.hset(self.key, 'state', state)
  
      def _set_state(self, state):
          """Raise a DeprecationWarning if ``worker.state = X`` is used"""
          warnings.warn(
              "worker.state is deprecated, use worker.set_state() instead.",
              DeprecationWarning
          )
          self.set_state(state)
  
      def get_state(self):
          return self._state
  
      def _get_state(self):
          """Raise a DeprecationWarning if ``worker.state == X`` is used"""
          warnings.warn(
              "worker.state is deprecated, use worker.get_state() instead.",
              DeprecationWarning
          )
          return self.get_state()
  
      state = property(_get_state, _set_state)
  
      def set_current_job_id(self, job_id, pipeline=None):
          connection = pipeline if pipeline is not None else self.connection
  
          if job_id is None:
              connection.hdel(self.key, 'current_job')
          else:
              connection.hset(self.key, 'current_job', job_id)
  
      def get_current_job_id(self, pipeline=None):
          connection = pipeline if pipeline is not None else self.connection
          return as_text(connection.hget(self.key, 'current_job'))
  
      def get_current_job(self):
          """Returns the job id of the currently executing job."""
          job_id = self.get_current_job_id()
  
          if job_id is None:
              return None
  
          return self.job_class.fetch(job_id, self.connection)
  
      def _install_signal_handlers(self):
          """Installs signal handlers for handling SIGINT and SIGTERM
          gracefully.
          """
  
          signal.signal(signal.SIGINT, self.request_stop)
          signal.signal(signal.SIGTERM, self.request_stop)
  
      def kill_horse(self, sig=SIGKILL):
          """
          Kill the horse but catch "No such process" error has the horse could already be dead.
          """
          try:
              os.kill(self.horse_pid, sig)
              os.waitpid(self.horse_pid, 0)
              self.log.info('Killed horse pid %s', self.horse_pid)
          except OSError as e:
              if e.errno == errno.ESRCH:
                  # "No such process" is fine with us
                  self.log.debug('Horse already dead')
              else:
                  raise
  
      def request_force_stop(self, signum, frame):
          """Terminates the application (cold shutdown).
          """
          self.log.warning('Cold shut down')
  
          # Take down the horse with the worker
          if self.horse_pid:
              self.log.debug('Taking down horse %s with me', self.horse_pid)
              self.kill_horse()
          raise SystemExit()
  
      def request_stop(self, signum, frame):
          """Stops the current worker loop but waits for child processes to
          end gracefully (warm shutdown).
          """
          self.log.debug('Got signal %s', signal_name(signum))
  
          signal.signal(signal.SIGINT, self.request_force_stop)
          signal.signal(signal.SIGTERM, self.request_force_stop)
  
          self.handle_warm_shutdown_request()
  
          # If shutdown is requested in the middle of a job, wait until
          # finish before shutting down and save the request in redis
          if self.get_state() == WorkerStatus.BUSY:
              self._stop_requested = True
              self.set_shutdown_requested_date()
              self.log.debug('Stopping after current horse is finished. '
                             'Press Ctrl+C again for a cold shutdown.')
              if self.scheduler:
                  self.stop_scheduler()
          else:
              if self.scheduler:
                  self.stop_scheduler()
              raise StopRequested()
  
      def handle_warm_shutdown_request(self):
          self.log.info('Warm shut down requested')
  
      def check_for_suspension(self, burst):
          """Check to see if workers have been suspended by `rq suspend`"""
  
          before_state = None
          notified = False
  
          while not self._stop_requested and is_suspended(self.connection, self):
  
              if burst:
                  self.log.info('Suspended in burst mode, exiting')
                  self.log.info('Note: There could still be unfinished jobs on the queue')
                  raise StopRequested
  
              if not notified:
                  self.log.info('Worker suspended, run `rq resume` to resume')
                  before_state = self.get_state()
                  self.set_state(WorkerStatus.SUSPENDED)
                  notified = True
              time.sleep(1)
  
          if before_state:
              self.set_state(before_state)
  
      def run_maintenance_tasks(self):
          """
          Runs periodic maintenance tasks, these include:
          1. Check if scheduler should be started. This check should not be run
             on first run since worker.work() already calls
             `scheduler.enqueue_scheduled_jobs()` on startup.
          2. Cleaning registries
          """
          # No need to try to start scheduler on first run
          if self.last_cleaned_at:
              if self.scheduler and not self.scheduler._process:
                  self.scheduler.acquire_locks(auto_start=True)
          self.clean_registries()
  
      def work(self, burst=False, logging_level="INFO", date_format=DEFAULT_LOGGING_DATE_FORMAT,
               log_format=DEFAULT_LOGGING_FORMAT, max_jobs=None, with_scheduler=False):
          """Starts the work loop.
  
          Pops and performs all jobs on the current list of queues.  When all
          queues are empty, block and wait for new jobs to arrive on any of the
          queues, unless `burst` mode is enabled.
  
          The return value indicates whether any jobs were processed.
          """
          setup_loghandlers(logging_level, date_format, log_format)
          completed_jobs = 0
          self.register_birth()
          self.log.info("Worker %s: started, version %s", self.key, VERSION)
          self.set_state(WorkerStatus.STARTED)
          qnames = self.queue_names()
          self.log.info('*** Listening on %s...', green(', '.join(qnames)))
  
          if with_scheduler:
              self.scheduler = RQScheduler(self.queues, connection=self.connection)
              self.scheduler.acquire_locks()
              # If lock is acquired, start scheduler
              if self.scheduler.acquired_locks:
                  # If worker is run on burst mode, enqueue_scheduled_jobs()
                  # before working. Otherwise, start scheduler in a separate process
                  if burst:
                      self.scheduler.enqueue_scheduled_jobs()
                  else:
                      self.scheduler.start()
  
          self._install_signal_handlers()
  
          try:
              while True:
                  try:
                      self.check_for_suspension(burst)
  
                      if self.should_run_maintenance_tasks:
                          self.run_maintenance_tasks()
  
                      if self._stop_requested:
                          self.log.info('Worker %s: stopping on request', self.key)
                          break
  
                      timeout = None if burst else max(1, self.default_worker_ttl - 15)
  
                      result = self.dequeue_job_and_maintain_ttl(timeout)
                      if result is None:
                          if burst:
                              self.log.info("Worker %s: done, quitting", self.key)
                          break
  
                      job, queue = result
                      self.execute_job(job, queue)
                      self.heartbeat()
  
                      completed_jobs += 1
                      if max_jobs is not None:
                          if completed_jobs >= max_jobs:
                              self.log.info(
                                  "Worker %s: finished executing %d jobs, quitting",
                                  self.key, completed_jobs
                              )
                              break
  
                  except StopRequested:
                      break
  
                  except SystemExit:
                      # Cold shutdown detected
                      raise
  
                  except:  # noqa
                      self.log.error(
                          'Worker %s: found an unhandled exception, quitting...',
                          self.key, exc_info=True
                      )
                      break
          finally:
              if not self.is_horse:
  
                  if self.scheduler:
                      self.stop_scheduler()
  
                  self.register_death()
          return bool(completed_jobs)
  
      def stop_scheduler(self):
          """Ensure scheduler process is stopped"""
          if self.scheduler._process and self.scheduler._process.pid:
              # Send the kill signal to scheduler process
              try:
                  os.kill(self.scheduler._process.pid, signal.SIGTERM)
              except OSError:
                  pass
              self.scheduler._process.join()
  
      def dequeue_job_and_maintain_ttl(self, timeout):
          result = None
          qnames = ','.join(self.queue_names())
  
          self.set_state(WorkerStatus.IDLE)
          self.procline('Listening on ' + qnames)
          self.log.debug('*** Listening on %s...', green(qnames))
  
          while True:
              self.heartbeat()
  
              if self.should_run_maintenance_tasks:
                  self.run_maintenance_tasks()
  
              try:
                  result = self.queue_class.dequeue_any(self.queues, timeout,
                                                        connection=self.connection,
                                                        job_class=self.job_class)
                  if result is not None:
  
                      job, queue = result
                      if self.log_job_description:
                          self.log.info(
                              '%s: %s (%s)', green(queue.name),
                              blue(job.description), job.id)
                      else:
                          self.log.info('%s: %s', green(queue.name), job.id)
  
                  break
              except DequeueTimeout:
                  pass
  
          self.heartbeat()
          return result
  
      def heartbeat(self, timeout=None, pipeline=None):
          """Specifies a new worker timeout, typically by extending the
          expiration time of the worker, effectively making this a "heartbeat"
          to not expire the worker until the timeout passes.
  
          The next heartbeat should come before this time, or the worker will
          die (at least from the monitoring dashboards).
  
          If no timeout is given, the default_worker_ttl will be used to update
          the expiration time of the worker.
          """
          timeout = timeout or self.default_worker_ttl
          connection = pipeline if pipeline is not None else self.connection
          connection.expire(self.key, timeout)
          connection.hset(self.key, 'last_heartbeat', utcformat(utcnow()))
          self.log.debug('Sent heartbeat to prevent worker timeout. '
                         'Next one should arrive within %s seconds.', timeout)
  
      def refresh(self):
          data = self.connection.hmget(
              self.key, 'queues', 'state', 'current_job', 'last_heartbeat',
              'birth', 'failed_job_count', 'successful_job_count',
              'total_working_time', 'hostname', 'pid', 'version', 'python_version',
          )
          (queues, state, job_id, last_heartbeat, birth, failed_job_count,
           successful_job_count, total_working_time, hostname, pid, version, python_version) = data
          queues = as_text(queues)
          self.hostname = as_text(hostname)
          self.pid = int(pid) if pid else None
          self.version = as_text(version)
          self.python_version = as_text(python_version)
          self._state = as_text(state or '?')
          self._job_id = job_id or None
          if last_heartbeat:
              self.last_heartbeat = utcparse(as_text(last_heartbeat))
          else:
              self.last_heartbeat = None
          if birth:
              self.birth_date = utcparse(as_text(birth))
          else:
              self.birth_date = None
          if failed_job_count:
              self.failed_job_count = int(as_text(failed_job_count))
          if successful_job_count:
              self.successful_job_count = int(as_text(successful_job_count))
          if total_working_time:
              self.total_working_time = float(as_text(total_working_time))
  
          if queues:
              self.queues = [self.queue_class(queue,
                                              connection=self.connection,
                                              job_class=self.job_class, serializer=self.serializer)
                             for queue in queues.split(',')]
  
      def increment_failed_job_count(self, pipeline=None):
          connection = pipeline if pipeline is not None else self.connection
          connection.hincrby(self.key, 'failed_job_count', 1)
  
      def increment_successful_job_count(self, pipeline=None):
          connection = pipeline if pipeline is not None else self.connection
          connection.hincrby(self.key, 'successful_job_count', 1)
  
      def increment_total_working_time(self, job_execution_time, pipeline):
          pipeline.hincrbyfloat(self.key, 'total_working_time',
                                job_execution_time.total_seconds())
  
      def fork_work_horse(self, job, queue):
          """Spawns a work horse to perform the actual work and passes it a job.
          """
          child_pid = os.fork()
          os.environ['RQ_WORKER_ID'] = self.name
          os.environ['RQ_JOB_ID'] = job.id
          if child_pid == 0:
              self.main_work_horse(job, queue)
          else:
              self._horse_pid = child_pid
              self.procline('Forked {0} at {1}'.format(child_pid, time.time()))
  
      def monitor_work_horse(self, job):
          """The worker will monitor the work horse and make sure that it
          either executes successfully or the status of the job is set to
          failed
          """
  
          ret_val = None
          job.started_at = utcnow()
          while True:
              try:
                  with UnixSignalDeathPenalty(self.job_monitoring_interval, HorseMonitorTimeoutException):
                      retpid, ret_val = os.waitpid(self._horse_pid, 0)
                  break
              except HorseMonitorTimeoutException:
                  # Horse has not exited yet and is still running.
                  # Send a heartbeat to keep the worker alive.
                  self.heartbeat(self.job_monitoring_interval + 30)
  
                  # Kill the job from this side if something is really wrong (interpreter lock/etc).
                  if job.timeout != -1 and (utcnow() - job.started_at).total_seconds() > (job.timeout + 1):
                      self.kill_horse()
                      break
  
              except OSError as e:
                  # In case we encountered an OSError due to EINTR (which is
                  # caused by a SIGINT or SIGTERM signal during
                  # os.waitpid()), we simply ignore it and enter the next
                  # iteration of the loop, waiting for the child to end.  In
                  # any other case, this is some other unexpected OS error,
                  # which we don't want to catch, so we re-raise those ones.
                  if e.errno != errno.EINTR:
                      raise
                  # Send a heartbeat to keep the worker alive.
                  self.heartbeat()
  
          if ret_val == os.EX_OK:  # The process exited normally.
              return
          job_status = job.get_status()
          if job_status is None:  # Job completed and its ttl has expired
              return
          if job_status not in [JobStatus.FINISHED, JobStatus.FAILED]:
  
              if not job.ended_at:
                  job.ended_at = utcnow()
  
              # Unhandled failure: move the job to the failed queue
              self.log.warning((
                  'Moving job to FailedJobRegistry '
                  '(work-horse terminated unexpectedly; waitpid returned {})'
              ).format(ret_val))
  
              self.handle_job_failure(
                  job,
                  exc_string="Work-horse was terminated unexpectedly "
                             "(waitpid returned %s)" % ret_val
              )
  
      def execute_job(self, job, queue):
          """Spawns a work horse to perform the actual work and passes it a job.
          The worker will wait for the work horse and make sure it executes
          within the given timeout bounds, or will end the work horse with
          SIGALRM.
          """
          self.set_state(WorkerStatus.BUSY)
          self.fork_work_horse(job, queue)
          self.monitor_work_horse(job)
          self.set_state(WorkerStatus.IDLE)
  
      def main_work_horse(self, job, queue):
          """This is the entry point of the newly spawned work horse."""
          # After fork()'ing, always assure we are generating random sequences
          # that are different from the worker.
          random.seed()
  
          self.setup_work_horse_signals()
          self._is_horse = True
          self.log = logger
          self.perform_job(job, queue)
  
          # os._exit() is the way to exit from childs after a fork(), in
          # contrast to the regular sys.exit()
          os._exit(0)
  
      def setup_work_horse_signals(self):
          """Setup signal handing for the newly spawned work horse."""
          # Always ignore Ctrl+C in the work horse, as it might abort the
          # currently running job.
          # The main worker catches the Ctrl+C and requests graceful shutdown
          # after the current work is done.  When cold shutdown is requested, it
          # kills the current job anyway.
          signal.signal(signal.SIGINT, signal.SIG_IGN)
          signal.signal(signal.SIGTERM, signal.SIG_DFL)
  
      def prepare_job_execution(self, job, heartbeat_ttl=None):
          """Performs misc bookkeeping like updating states prior to
          job execution.
          """
          if job.timeout == -1:
              timeout = -1
          else:
              timeout = job.timeout or 180
  
          if heartbeat_ttl is None:
              heartbeat_ttl = self.job_monitoring_interval + 5
  
          with self.connection.pipeline() as pipeline:
              self.set_state(WorkerStatus.BUSY, pipeline=pipeline)
              self.set_current_job_id(job.id, pipeline=pipeline)
              self.heartbeat(heartbeat_ttl, pipeline=pipeline)
              registry = StartedJobRegistry(job.origin, self.connection,
                                            job_class=self.job_class)
              registry.add(job, timeout, pipeline=pipeline)
              job.set_status(JobStatus.STARTED, pipeline=pipeline)
              pipeline.hset(job.key, 'started_at', utcformat(utcnow()))
              pipeline.execute()
  
          msg = 'Processing {0} from {1} since {2}'
          self.procline(msg.format(job.func_name, job.origin, time.time()))
  
      def handle_job_failure(self, job, started_job_registry=None,
                             exc_string=''):
          """Handles the failure or an executing job by:
              1. Setting the job status to failed
              2. Removing the job from StartedJobRegistry
              3. Setting the workers current job to None
              4. Add the job to FailedJobRegistry
          """
          self.log.debug('Handling failed execution of job %s', job.id)
          with self.connection.pipeline() as pipeline:
              if started_job_registry is None:
                  started_job_registry = StartedJobRegistry(
                      job.origin,
                      self.connection,
                      job_class=self.job_class
                  )
              job.set_status(JobStatus.FAILED, pipeline=pipeline)
              started_job_registry.remove(job, pipeline=pipeline)
  
              if not self.disable_default_exception_handler:
                  failed_job_registry = FailedJobRegistry(job.origin, job.connection,
                                                          job_class=self.job_class)
                  failed_job_registry.add(job, ttl=job.failure_ttl,
                                          exc_string=exc_string, pipeline=pipeline)
  
              self.set_current_job_id(None, pipeline=pipeline)
              self.increment_failed_job_count(pipeline)
              if job.started_at and job.ended_at:
                  self.increment_total_working_time(
                      job.ended_at - job.started_at,
                      pipeline
                  )
  
              try:
                  pipeline.execute()
              except Exception:
                  # Ensure that custom exception handlers are called
                  # even if Redis is down
                  pass
  
      def handle_job_success(self, job, queue, started_job_registry):
          self.log.debug('Handling successful execution of job %s', job.id)
          with self.connection.pipeline() as pipeline:
              while True:
                  try:
                      # if dependencies are inserted after enqueue_dependents
                      # a WatchError is thrown by execute()
                      pipeline.watch(job.dependents_key)
                      # enqueue_dependents calls multi() on the pipeline!
                      queue.enqueue_dependents(job, pipeline=pipeline)
  
                      self.set_current_job_id(None, pipeline=pipeline)
                      self.increment_successful_job_count(pipeline=pipeline)
                      self.increment_total_working_time(
                          job.ended_at - job.started_at, pipeline
                      )
  
                      result_ttl = job.get_result_ttl(self.default_result_ttl)
                      if result_ttl != 0:
                          job.set_status(JobStatus.FINISHED, pipeline=pipeline)
                          # Don't clobber the user's meta dictionary!
                          job.save(pipeline=pipeline, include_meta=False)
  
                          finished_job_registry = queue.finished_job_registry
                          finished_job_registry.add(job, result_ttl, pipeline)
  
                      job.cleanup(result_ttl, pipeline=pipeline,
                                  remove_from_queue=False)
                      started_job_registry.remove(job, pipeline=pipeline)
  
                      pipeline.execute()
                      break
                  except WatchError:
                      continue
  
      def perform_job(self, job, queue, heartbeat_ttl=None):
          """Performs the actual work of a job.  Will/should only be called
          inside the work horse's process.
          """
          self.prepare_job_execution(job, heartbeat_ttl)
          push_connection(self.connection)
  
          started_job_registry = queue.started_job_registry
  
          try:
              job.started_at = utcnow()
              timeout = job.timeout or self.queue_class.DEFAULT_TIMEOUT
              with self.death_penalty_class(timeout, JobTimeoutException, job_id=job.id):
                  rv = job.perform()
  
              job.ended_at = utcnow()
  
              # Pickle the result in the same try-except block since we need
              # to use the same exc handling when pickling fails
              job._result = rv
              self.handle_job_success(job=job,
                                      queue=queue,
                                      started_job_registry=started_job_registry)
          except:  # NOQA
              job.ended_at = utcnow()
              exc_info = sys.exc_info()
              exc_string = self._get_safe_exception_string(
                  traceback.format_exception(*exc_info)
              )
              self.handle_job_failure(job=job, exc_string=exc_string,
                                      started_job_registry=started_job_registry)
              self.handle_exception(job, *exc_info)
              return False
  
          finally:
              pop_connection()
  
          self.log.info('%s: %s (%s)', green(job.origin), blue('Job OK'), job.id)
          if rv is not None:
              log_result = "{0!r}".format(as_text(text_type(rv)))
              self.log.debug('Result: %s', yellow(log_result))
  
          if self.log_result_lifespan:
              result_ttl = job.get_result_ttl(self.default_result_ttl)
              if result_ttl == 0:
                  self.log.info('Result discarded immediately')
              elif result_ttl > 0:
                  self.log.info('Result is kept for %s seconds', result_ttl)
              else:
                  self.log.info('Result will never expire, clean up result key manually')
  
          return True
  
      def handle_exception(self, job, *exc_info):
          """Walks the exception handler stack to delegate exception handling."""
          exc_string = Worker._get_safe_exception_string(
              traceback.format_exception_only(*exc_info[:2]) + traceback.format_exception(*exc_info)
          )
          self.log.error(exc_string, exc_info=True, extra={
              'func': job.func_name,
              'arguments': job.args,
              'kwargs': job.kwargs,
              'queue': job.origin,
              'job_id': job.id,
          })
  
          for handler in self._exc_handlers:
              self.log.debug('Invoking exception handler %s', handler)
              fallthrough = handler(job, *exc_info)
  
              # Only handlers with explicit return values should disable further
              # exc handling, so interpret a None return value as True.
              if fallthrough is None:
                  fallthrough = True
  
              if not fallthrough:
                  break
  
      @staticmethod
      def _get_safe_exception_string(exc_strings):
          """Ensure list of exception strings is decoded on Python 2 and joined as one string safely."""
          if sys.version_info[0] < 3:
              try:
                  exc_strings = [exc.decode("utf-8") for exc in exc_strings]
              except ValueError:
                  exc_strings = [exc.decode("latin-1") for exc in exc_strings]
          return ''.join(exc_strings)
  
      def push_exc_handler(self, handler_func):
          """Pushes an exception handler onto the exc handler stack."""
          self._exc_handlers.append(handler_func)
  
      def pop_exc_handler(self):
          """Pops the latest exception handler off of the exc handler stack."""
          return self._exc_handlers.pop()
  
      def __eq__(self, other):
          """Equality does not take the database/connection into account"""
          if not isinstance(other, self.__class__):
              raise TypeError('Cannot compare workers to other types (of workers)')
          return self.name == other.name
  
      def __hash__(self):
          """The hash does not take the database/connection into account"""
          return hash(self.name)
  
      def clean_registries(self):
          """Runs maintenance jobs on each Queue's registries."""
          for queue in self.queues:
              # If there are multiple workers running, we only want 1 worker
              # to run clean_registries().
              if queue.acquire_cleaning_lock():
                  self.log.info('Cleaning registries for queue: %s', queue.name)
                  clean_registries(queue)
                  clean_worker_registry(queue)
          self.last_cleaned_at = utcnow()
  
      @property
      def should_run_maintenance_tasks(self):
          """Maintenance tasks should run on first startup or 15 minutes."""
          if self.last_cleaned_at is None:
              return True
          if (utcnow() - self.last_cleaned_at) > timedelta(minutes=15):
              return True
          return False
  
  
  class SimpleWorker(Worker):
      def main_work_horse(self, *args, **kwargs):
          raise NotImplementedError("Test worker does not implement this method")
  
      def execute_job(self, job, queue):
          """Execute job in same thread/process, do not fork()"""
          timeout = (job.timeout or DEFAULT_WORKER_TTL) + 5
          return self.perform_job(job, queue, heartbeat_ttl=timeout)
  
  
  class HerokuWorker(Worker):
      """
      Modified version of rq worker which:
      * stops work horses getting killed with SIGTERM
      * sends SIGRTMIN to work horses on SIGTERM to the main process which in turn
      causes the horse to crash `imminent_shutdown_delay` seconds later
      """
      imminent_shutdown_delay = 6
  
      frame_properties = ['f_code', 'f_lasti', 'f_lineno', 'f_locals', 'f_trace']
      if PY2:
          frame_properties.extend(
              ['f_exc_traceback', 'f_exc_type', 'f_exc_value', 'f_restricted']
          )
  
      def setup_work_horse_signals(self):
          """Modified to ignore SIGINT and SIGTERM and only handle SIGRTMIN"""
          signal.signal(signal.SIGRTMIN, self.request_stop_sigrtmin)
          signal.signal(signal.SIGINT, signal.SIG_IGN)
          signal.signal(signal.SIGTERM, signal.SIG_IGN)
  
      def handle_warm_shutdown_request(self):
          """If horse is alive send it SIGRTMIN"""
          if self.horse_pid != 0:
              self.log.info(
                  'Worker %s: warm shut down requested, sending horse SIGRTMIN signal',
                  self.key
              )
              self.kill_horse(sig=signal.SIGRTMIN)
          else:
              self.log.warning('Warm shut down requested, no horse found')
  
      def request_stop_sigrtmin(self, signum, frame):
          if self.imminent_shutdown_delay == 0:
              self.log.warning('Imminent shutdown, raising ShutDownImminentException immediately')
              self.request_force_stop_sigrtmin(signum, frame)
          else:
              self.log.warning('Imminent shutdown, raising ShutDownImminentException in %d seconds',
                               self.imminent_shutdown_delay)
              signal.signal(signal.SIGRTMIN, self.request_force_stop_sigrtmin)
              signal.signal(signal.SIGALRM, self.request_force_stop_sigrtmin)
              signal.alarm(self.imminent_shutdown_delay)
  
      def request_force_stop_sigrtmin(self, signum, frame):
          info = dict((attr, getattr(frame, attr)) for attr in self.frame_properties)
          self.log.warning('raising ShutDownImminentException to cancel job...')
          raise ShutDownImminentException('shut down imminent (signal: %s)' % signal_name(signum), info)
  