Added the APscheduler 3.9.1 source into the Linspector source tree.

README.md

@@ -46,10 +46,21 @@ alternative is available.
 - The core of Linspector should not use 3rd party libraries. only plugins,
 notifications and types may use other libraries. But coping code into the
 source tree is ok when respecting the license. Not using 3rd party libraries
-should always be preferred though.
+should always be preferred though. If adding 3rd party libraries to the Linspector 
+core all code **must** be included in the Linspector source tree. Not as Git
+submodule but as files imported into the Linspector Git repository!
 - Inline comment should be all lowercase. Descriptions and documentation comments
 must be natural language.
 
+### Included libraries
+
+Currently, the Linspector source tree contains the following 3rd party libraries:
+
+- [APScheduler](https://github.com/agronholm/apscheduler) (3.9.1) - This is the scheduler in Linspector for execution of monitors. I started 
+to use this library in very early versions of Linspector in 2011. Since the main task
+in Linspector is the execution of jobs in regularly intervals I believe it is the right 
+decision to include the code of APScheduler directly into the Linspector project.
+
 ### Version numbering
 
 According to: [https://wiki.unixpeople.org/linux_kernel_version_numbering](https://wiki.unixpeople.org/linux_kernel_version_numbering)

apscheduler/__init__.py

@@ -0,0 +1,10 @@
+from pkg_resources import get_distribution, DistributionNotFound
+
+try:
+    release = get_distribution('APScheduler').version.split('-')[0]
+except DistributionNotFound:
+    release = '3.5.0'
+
+version_info = tuple(int(x) if x.isdigit() else x for x in release.split('.'))
+version = __version__ = '.'.join(str(x) for x in version_info[:3])
+del get_distribution, DistributionNotFound

apscheduler/events.py

@@ -0,0 +1,94 @@
+__all__ = ('EVENT_SCHEDULER_STARTED', 'EVENT_SCHEDULER_SHUTDOWN', 'EVENT_SCHEDULER_PAUSED',
+           'EVENT_SCHEDULER_RESUMED', 'EVENT_EXECUTOR_ADDED', 'EVENT_EXECUTOR_REMOVED',
+           'EVENT_JOBSTORE_ADDED', 'EVENT_JOBSTORE_REMOVED', 'EVENT_ALL_JOBS_REMOVED',
+           'EVENT_JOB_ADDED', 'EVENT_JOB_REMOVED', 'EVENT_JOB_MODIFIED', 'EVENT_JOB_EXECUTED',
+           'EVENT_JOB_ERROR', 'EVENT_JOB_MISSED', 'EVENT_JOB_SUBMITTED', 'EVENT_JOB_MAX_INSTANCES',
+           'SchedulerEvent', 'JobEvent', 'JobExecutionEvent', 'JobSubmissionEvent')
+
+
+EVENT_SCHEDULER_STARTED = EVENT_SCHEDULER_START = 2 ** 0
+EVENT_SCHEDULER_SHUTDOWN = 2 ** 1
+EVENT_SCHEDULER_PAUSED = 2 ** 2
+EVENT_SCHEDULER_RESUMED = 2 ** 3
+EVENT_EXECUTOR_ADDED = 2 ** 4
+EVENT_EXECUTOR_REMOVED = 2 ** 5
+EVENT_JOBSTORE_ADDED = 2 ** 6
+EVENT_JOBSTORE_REMOVED = 2 ** 7
+EVENT_ALL_JOBS_REMOVED = 2 ** 8
+EVENT_JOB_ADDED = 2 ** 9
+EVENT_JOB_REMOVED = 2 ** 10
+EVENT_JOB_MODIFIED = 2 ** 11
+EVENT_JOB_EXECUTED = 2 ** 12
+EVENT_JOB_ERROR = 2 ** 13
+EVENT_JOB_MISSED = 2 ** 14
+EVENT_JOB_SUBMITTED = 2 ** 15
+EVENT_JOB_MAX_INSTANCES = 2 ** 16
+EVENT_ALL = (EVENT_SCHEDULER_STARTED | EVENT_SCHEDULER_SHUTDOWN | EVENT_SCHEDULER_PAUSED |
+             EVENT_SCHEDULER_RESUMED | EVENT_EXECUTOR_ADDED | EVENT_EXECUTOR_REMOVED |
+             EVENT_JOBSTORE_ADDED | EVENT_JOBSTORE_REMOVED | EVENT_ALL_JOBS_REMOVED |
+             EVENT_JOB_ADDED | EVENT_JOB_REMOVED | EVENT_JOB_MODIFIED | EVENT_JOB_EXECUTED |
+             EVENT_JOB_ERROR | EVENT_JOB_MISSED | EVENT_JOB_SUBMITTED | EVENT_JOB_MAX_INSTANCES)
+
+
+class SchedulerEvent(object):
+    """
+    An event that concerns the scheduler itself.
+
+    :ivar code: the type code of this event
+    :ivar alias: alias of the job store or executor that was added or removed (if applicable)
+    """
+
+    def __init__(self, code, alias=None):
+        super(SchedulerEvent, self).__init__()
+        self.code = code
+        self.alias = alias
+
+    def __repr__(self):
+        return '<%s (code=%d)>' % (self.__class__.__name__, self.code)
+
+
+class JobEvent(SchedulerEvent):
+    """
+    An event that concerns a job.
+
+    :ivar code: the type code of this event
+    :ivar job_id: identifier of the job in question
+    :ivar jobstore: alias of the job store containing the job in question
+    """
+
+    def __init__(self, code, job_id, jobstore):
+        super(JobEvent, self).__init__(code)
+        self.code = code
+        self.job_id = job_id
+        self.jobstore = jobstore
+
+
+class JobSubmissionEvent(JobEvent):
+    """
+    An event that concerns the submission of a job to its executor.
+
+    :ivar scheduled_run_times: a list of datetimes when the job was intended to run
+    """
+
+    def __init__(self, code, job_id, jobstore, scheduled_run_times):
+        super(JobSubmissionEvent, self).__init__(code, job_id, jobstore)
+        self.scheduled_run_times = scheduled_run_times
+
+
+class JobExecutionEvent(JobEvent):
+    """
+    An event that concerns the running of a job within its executor.
+
+    :ivar scheduled_run_time: the time when the job was scheduled to be run
+    :ivar retval: the return value of the successfully executed job
+    :ivar exception: the exception raised by the job
+    :ivar traceback: a formatted traceback for the exception
+    """
+
+    def __init__(self, code, job_id, jobstore, scheduled_run_time, retval=None, exception=None,
+                 traceback=None):
+        super(JobExecutionEvent, self).__init__(code, job_id, jobstore)
+        self.scheduled_run_time = scheduled_run_time
+        self.retval = retval
+        self.exception = exception
+        self.traceback = traceback

apscheduler/executors/asyncio.py

@@ -0,0 +1,59 @@
+from __future__ import absolute_import
+
+import sys
+
+from apscheduler.executors.base import BaseExecutor, run_job
+from apscheduler.util import iscoroutinefunction_partial
+
+try:
+    from apscheduler.executors.base_py3 import run_coroutine_job
+except ImportError:
+    run_coroutine_job = None
+
+
+class AsyncIOExecutor(BaseExecutor):
+    """
+    Runs jobs in the default executor of the event loop.
+
+    If the job function is a native coroutine function, it is scheduled to be run directly in the
+    event loop as soon as possible. All other functions are run in the event loop's default
+    executor which is usually a thread pool.
+
+    Plugin alias: ``asyncio``
+    """
+
+    def start(self, scheduler, alias):
+        super(AsyncIOExecutor, self).start(scheduler, alias)
+        self._eventloop = scheduler._eventloop
+        self._pending_futures = set()
+
+    def shutdown(self, wait=True):
+        # There is no way to honor wait=True without converting this method into a coroutine method
+        for f in self._pending_futures:
+            if not f.done():
+                f.cancel()
+
+        self._pending_futures.clear()
+
+    def _do_submit_job(self, job, run_times):
+        def callback(f):
+            self._pending_futures.discard(f)
+            try:
+                events = f.result()
+            except BaseException:
+                self._run_job_error(job.id, *sys.exc_info()[1:])
+            else:
+                self._run_job_success(job.id, events)
+
+        if iscoroutinefunction_partial(job.func):
+            if run_coroutine_job is not None:
+                coro = run_coroutine_job(job, job._jobstore_alias, run_times, self._logger.name)
+                f = self._eventloop.create_task(coro)
+            else:
+                raise Exception('Executing coroutine based jobs is not supported with Trollius')
+        else:
+            f = self._eventloop.run_in_executor(None, run_job, job, job._jobstore_alias, run_times,
+                                                self._logger.name)
+
+        f.add_done_callback(callback)
+        self._pending_futures.add(f)

apscheduler/executors/base.py

@@ -0,0 +1,146 @@
+from abc import ABCMeta, abstractmethod
+from collections import defaultdict
+from datetime import datetime, timedelta
+from traceback import format_tb
+import logging
+import sys
+
+from pytz import utc
+import six
+
+from apscheduler.events import (
+    JobExecutionEvent, EVENT_JOB_MISSED, EVENT_JOB_ERROR, EVENT_JOB_EXECUTED)
+
+
+class MaxInstancesReachedError(Exception):
+    def __init__(self, job):
+        super(MaxInstancesReachedError, self).__init__(
+            'Job "%s" has already reached its maximum number of instances (%d)' %
+            (job.id, job.max_instances))
+
+
+class BaseExecutor(six.with_metaclass(ABCMeta, object)):
+    """Abstract base class that defines the interface that every executor must implement."""
+
+    _scheduler = None
+    _lock = None
+    _logger = logging.getLogger('apscheduler.executors')
+
+    def __init__(self):
+        super(BaseExecutor, self).__init__()
+        self._instances = defaultdict(lambda: 0)
+
+    def start(self, scheduler, alias):
+        """
+        Called by the scheduler when the scheduler is being started or when the executor is being
+        added to an already running scheduler.
+
+        :param apscheduler.schedulers.base.BaseScheduler scheduler: the scheduler that is starting
+            this executor
+        :param str|unicode alias: alias of this executor as it was assigned to the scheduler
+
+        """
+        self._scheduler = scheduler
+        self._lock = scheduler._create_lock()
+        self._logger = logging.getLogger('apscheduler.executors.%s' % alias)
+
+    def shutdown(self, wait=True):
+        """
+        Shuts down this executor.
+
+        :param bool wait: ``True`` to wait until all submitted jobs
+            have been executed
+        """
+
+    def submit_job(self, job, run_times):
+        """
+        Submits job for execution.
+
+        :param Job job: job to execute
+        :param list[datetime] run_times: list of datetimes specifying
+            when the job should have been run
+        :raises MaxInstancesReachedError: if the maximum number of
+            allowed instances for this job has been reached
+
+        """
+        assert self._lock is not None, 'This executor has not been started yet'
+        with self._lock:
+            if self._instances[job.id] >= job.max_instances:
+                raise MaxInstancesReachedError(job)
+
+            self._do_submit_job(job, run_times)
+            self._instances[job.id] += 1
+
+    @abstractmethod
+    def _do_submit_job(self, job, run_times):
+        """Performs the actual task of scheduling `run_job` to be called."""
+
+    def _run_job_success(self, job_id, events):
+        """
+        Called by the executor with the list of generated events when :func:`run_job` has been
+        successfully called.
+
+        """
+        with self._lock:
+            self._instances[job_id] -= 1
+            if self._instances[job_id] == 0:
+                del self._instances[job_id]
+
+        for event in events:
+            self._scheduler._dispatch_event(event)
+
+    def _run_job_error(self, job_id, exc, traceback=None):
+        """Called by the executor with the exception if there is an error  calling `run_job`."""
+        with self._lock:
+            self._instances[job_id] -= 1
+            if self._instances[job_id] == 0:
+                del self._instances[job_id]
+
+        exc_info = (exc.__class__, exc, traceback)
+        self._logger.error('Error running job %s', job_id, exc_info=exc_info)
+
+
+def run_job(job, jobstore_alias, run_times, logger_name):
+    """
+    Called by executors to run the job. Returns a list of scheduler events to be dispatched by the
+    scheduler.
+
+    """
+    events = []
+    logger = logging.getLogger(logger_name)
+    for run_time in run_times:
+        # See if the job missed its run time window, and handle
+        # possible misfires accordingly
+        if job.misfire_grace_time is not None:
+            difference = datetime.now(utc) - run_time
+            grace_time = timedelta(seconds=job.misfire_grace_time)
+            if difference > grace_time:
+                events.append(JobExecutionEvent(EVENT_JOB_MISSED, job.id, jobstore_alias,
+                                                run_time))
+                logger.warning('Run time of job "%s" was missed by %s', job, difference)
+                continue
+
+        logger.info('Running job "%s" (scheduled at %s)', job, run_time)
+        try:
+            retval = job.func(*job.args, **job.kwargs)
+        except BaseException:
+            exc, tb = sys.exc_info()[1:]
+            formatted_tb = ''.join(format_tb(tb))
+            events.append(JobExecutionEvent(EVENT_JOB_ERROR, job.id, jobstore_alias, run_time,
+                                            exception=exc, traceback=formatted_tb))
+            logger.exception('Job "%s" raised an exception', job)
+
+            # This is to prevent cyclic references that would lead to memory leaks
+            if six.PY2:
+                sys.exc_clear()
+                del tb
+            else:
+                import traceback
+                traceback.clear_frames(tb)
+                del tb
+        else:
+            events.append(JobExecutionEvent(EVENT_JOB_EXECUTED, job.id, jobstore_alias, run_time,
+                                            retval=retval))
+            logger.info('Job "%s" executed successfully', job)
+
+    return events

apscheduler/executors/base_py3.py

@@ -0,0 +1,43 @@
+import logging
+import sys
+import traceback
+from datetime import datetime, timedelta
+from traceback import format_tb
+
+from pytz import utc
+
+from apscheduler.events import (
+    JobExecutionEvent, EVENT_JOB_MISSED, EVENT_JOB_ERROR, EVENT_JOB_EXECUTED)
+
+
+async def run_coroutine_job(job, jobstore_alias, run_times, logger_name):
+    """Coroutine version of run_job()."""
+    events = []
+    logger = logging.getLogger(logger_name)
+    for run_time in run_times:
+        # See if the job missed its run time window, and handle possible misfires accordingly
+        if job.misfire_grace_time is not None:
+            difference = datetime.now(utc) - run_time
+            grace_time = timedelta(seconds=job.misfire_grace_time)
+            if difference > grace_time:
+                events.append(JobExecutionEvent(EVENT_JOB_MISSED, job.id, jobstore_alias,
+                                                run_time))
+                logger.warning('Run time of job "%s" was missed by %s', job, difference)
+                continue
+
+        logger.info('Running job "%s" (scheduled at %s)', job, run_time)
+        try:
+            retval = await job.func(*job.args, **job.kwargs)
+        except BaseException:
+            exc, tb = sys.exc_info()[1:]
+            formatted_tb = ''.join(format_tb(tb))
+            events.append(JobExecutionEvent(EVENT_JOB_ERROR, job.id, jobstore_alias, run_time,
+                                            exception=exc, traceback=formatted_tb))
+            logger.exception('Job "%s" raised an exception', job)
+            traceback.clear_frames(tb)
+        else:
+            events.append(JobExecutionEvent(EVENT_JOB_EXECUTED, job.id, jobstore_alias, run_time,
+                                            retval=retval))
+            logger.info('Job "%s" executed successfully', job)
+
+    return events

apscheduler/executors/debug.py

@@ -0,0 +1,20 @@
+import sys
+
+from apscheduler.executors.base import BaseExecutor, run_job
+
+
+class DebugExecutor(BaseExecutor):
+    """
+    A special executor that executes the target callable directly instead of deferring it to a
+    thread or process.
+
+    Plugin alias: ``debug``
+    """
+
+    def _do_submit_job(self, job, run_times):
+        try:
+            events = run_job(job, job._jobstore_alias, run_times, self._logger.name)
+        except BaseException:
+            self._run_job_error(job.id, *sys.exc_info()[1:])
+        else:
+            self._run_job_success(job.id, events)

apscheduler/executors/gevent.py

@@ -0,0 +1,30 @@
+from __future__ import absolute_import
+import sys
+
+from apscheduler.executors.base import BaseExecutor, run_job
+
+
+try:
+    import gevent
+except ImportError:  # pragma: nocover
+    raise ImportError('GeventExecutor requires gevent installed')
+
+
+class GeventExecutor(BaseExecutor):
+    """
+    Runs jobs as greenlets.
+
+    Plugin alias: ``gevent``
+    """
+
+    def _do_submit_job(self, job, run_times):
+        def callback(greenlet):
+            try:
+                events = greenlet.get()
+            except BaseException:
+                self._run_job_error(job.id, *sys.exc_info()[1:])
+            else:
+                self._run_job_success(job.id, events)
+
+        gevent.spawn(run_job, job, job._jobstore_alias, run_times, self._logger.name).\
+            link(callback)

apscheduler/executors/pool.py

@@ -0,0 +1,71 @@
+from abc import abstractmethod
+import concurrent.futures
+
+from apscheduler.executors.base import BaseExecutor, run_job
+
+try:
+    from concurrent.futures.process import BrokenProcessPool
+except ImportError:
+    BrokenProcessPool = None
+
+
+class BasePoolExecutor(BaseExecutor):
+    @abstractmethod
+    def __init__(self, pool):
+        super(BasePoolExecutor, self).__init__()
+        self._pool = pool
+
+    def _do_submit_job(self, job, run_times):
+        def callback(f):
+            exc, tb = (f.exception_info() if hasattr(f, 'exception_info') else
+                       (f.exception(), getattr(f.exception(), '__traceback__', None)))
+            if exc:
+                self._run_job_error(job.id, exc, tb)
+            else:
+                self._run_job_success(job.id, f.result())
+
+        try:
+            f = self._pool.submit(run_job, job, job._jobstore_alias, run_times, self._logger.name)
+        except BrokenProcessPool:
+            self._logger.warning('Process pool is broken; replacing pool with a fresh instance')
+            self._pool = self._pool.__class__(self._pool._max_workers)
+            f = self._pool.submit(run_job, job, job._jobstore_alias, run_times, self._logger.name)
+
+        f.add_done_callback(callback)
+
+    def shutdown(self, wait=True):
+        self._pool.shutdown(wait)
+
+
+class ThreadPoolExecutor(BasePoolExecutor):
+    """
+    An executor that runs jobs in a concurrent.futures thread pool.
+
+    Plugin alias: ``threadpool``
+
+    :param max_workers: the maximum number of spawned threads.
+    :param pool_kwargs: dict of keyword arguments to pass to the underlying
+        ThreadPoolExecutor constructor
+    """
+
+    def __init__(self, max_workers=10, pool_kwargs=None):
+        pool_kwargs = pool_kwargs or {}
+        pool = concurrent.futures.ThreadPoolExecutor(int(max_workers), **pool_kwargs)
+        super(ThreadPoolExecutor, self).__init__(pool)
+
+
+class ProcessPoolExecutor(BasePoolExecutor):
+    """
+    An executor that runs jobs in a concurrent.futures process pool.
+
+    Plugin alias: ``processpool``
+
+    :param max_workers: the maximum number of spawned processes.
+    :param pool_kwargs: dict of keyword arguments to pass to the underlying
+        ProcessPoolExecutor constructor
+    """
+
+    def __init__(self, max_workers=10, pool_kwargs=None):
+        pool_kwargs = pool_kwargs or {}
+        pool = concurrent.futures.ProcessPoolExecutor(int(max_workers), **pool_kwargs)
+        super(ProcessPoolExecutor, self).__init__(pool)

apscheduler/executors/tornado.py

@@ -0,0 +1,54 @@
+from __future__ import absolute_import
+
+import sys
+from concurrent.futures import ThreadPoolExecutor
+
+from tornado.gen import convert_yielded
+
+from apscheduler.executors.base import BaseExecutor, run_job
+
+try:
+    from apscheduler.executors.base_py3 import run_coroutine_job
+    from apscheduler.util import iscoroutinefunction_partial
+except ImportError:
+    def iscoroutinefunction_partial(func):
+        return False
+
+
+class TornadoExecutor(BaseExecutor):
+    """
+    Runs jobs either in a thread pool or directly on the I/O loop.
+
+    If the job function is a native coroutine function, it is scheduled to be run directly in the
+    I/O loop as soon as possible. All other functions are run in a thread pool.
+
+    Plugin alias: ``tornado``
+
+    :param int max_workers: maximum number of worker threads in the thread pool
+    """
+
+    def __init__(self, max_workers=10):
+        super(TornadoExecutor, self).__init__()
+        self.executor = ThreadPoolExecutor(max_workers)
+
+    def start(self, scheduler, alias):
+        super(TornadoExecutor, self).start(scheduler, alias)
+        self._ioloop = scheduler._ioloop
+
+    def _do_submit_job(self, job, run_times):
+        def callback(f):
+            try:
+                events = f.result()
+            except BaseException:
+                self._run_job_error(job.id, *sys.exc_info()[1:])
+            else:
+                self._run_job_success(job.id, events)
+
+        if iscoroutinefunction_partial(job.func):
+            f = run_coroutine_job(job, job._jobstore_alias, run_times, self._logger.name)
+        else:
+            f = self.executor.submit(run_job, job, job._jobstore_alias, run_times,
+                                     self._logger.name)
+
+        f = convert_yielded(f)
+        f.add_done_callback(callback)

apscheduler/executors/twisted.py

@@ -0,0 +1,25 @@
+from __future__ import absolute_import
+
+from apscheduler.executors.base import BaseExecutor, run_job
+
+
+class TwistedExecutor(BaseExecutor):
+    """
+    Runs jobs in the reactor's thread pool.
+
+    Plugin alias: ``twisted``
+    """
+
+    def start(self, scheduler, alias):
+        super(TwistedExecutor, self).start(scheduler, alias)
+        self._reactor = scheduler._reactor
+
+    def _do_submit_job(self, job, run_times):
+        def callback(success, result):
+            if success:
+                self._run_job_success(job.id, result)
+            else:
+                self._run_job_error(job.id, result.value, result.tb)
+
+        self._reactor.getThreadPool().callInThreadWithCallback(
+            callback, run_job, job, job._jobstore_alias, run_times, self._logger.name)

apscheduler/job.py

@@ -0,0 +1,302 @@
+from inspect import ismethod, isclass
+from uuid import uuid4
+
+import six
+
+from apscheduler.triggers.base import BaseTrigger
+from apscheduler.util import (
+    ref_to_obj, obj_to_ref, datetime_repr, repr_escape, get_callable_name, check_callable_args,
+    convert_to_datetime)
+
+try:
+    from collections.abc import Iterable, Mapping
+except ImportError:
+    from collections import Iterable, Mapping
+
+
+class Job(object):
+    """
+    Contains the options given when scheduling callables and its current schedule and other state.
+    This class should never be instantiated by the user.
+
+    :var str id: the unique identifier of this job
+    :var str name: the description of this job
+    :var func: the callable to execute
+    :var tuple|list args: positional arguments to the callable
+    :var dict kwargs: keyword arguments to the callable
+    :var bool coalesce: whether to only run the job once when several run times are due
+    :var trigger: the trigger object that controls the schedule of this job
+    :var str executor: the name of the executor that will run this job
+    :var int misfire_grace_time: the time (in seconds) how much this job's execution is allowed to
+        be late (``None`` means "allow the job to run no matter how late it is")
+    :var int max_instances: the maximum number of concurrently executing instances allowed for this
+        job
+    :var datetime.datetime next_run_time: the next scheduled run time of this job
+
+    .. note::
+        The ``misfire_grace_time`` has some non-obvious effects on job execution. See the
+        :ref:`missed-job-executions` section in the documentation for an in-depth explanation.
+    """
+
+    __slots__ = ('_scheduler', '_jobstore_alias', 'id', 'trigger', 'executor', 'func', 'func_ref',
+                 'args', 'kwargs', 'name', 'misfire_grace_time', 'coalesce', 'max_instances',
+                 'next_run_time', '__weakref__')
+
+    def __init__(self, scheduler, id=None, **kwargs):
+        super(Job, self).__init__()
+        self._scheduler = scheduler
+        self._jobstore_alias = None
+        self._modify(id=id or uuid4().hex, **kwargs)
+
+    def modify(self, **changes):
+        """
+        Makes the given changes to this job and saves it in the associated job store.
+
+        Accepted keyword arguments are the same as the variables on this class.
+
+        .. seealso:: :meth:`~apscheduler.schedulers.base.BaseScheduler.modify_job`
+
+        :return Job: this job instance
+
+        """
+        self._scheduler.modify_job(self.id, self._jobstore_alias, **changes)
+        return self
+
+    def reschedule(self, trigger, **trigger_args):
+        """
+        Shortcut for switching the trigger on this job.
+
+        .. seealso:: :meth:`~apscheduler.schedulers.base.BaseScheduler.reschedule_job`
+
+        :return Job: this job instance
+
+        """
+        self._scheduler.reschedule_job(self.id, self._jobstore_alias, trigger, **trigger_args)
+        return self
+
+    def pause(self):
+        """
+        Temporarily suspend the execution of this job.
+
+        .. seealso:: :meth:`~apscheduler.schedulers.base.BaseScheduler.pause_job`
+
+        :return Job: this job instance
+
+        """
+        self._scheduler.pause_job(self.id, self._jobstore_alias)
+        return self
+
+    def resume(self):
+        """
+        Resume the schedule of this job if previously paused.
+
+        .. seealso:: :meth:`~apscheduler.schedulers.base.BaseScheduler.resume_job`
+
+        :return Job: this job instance
+
+        """
+        self._scheduler.resume_job(self.id, self._jobstore_alias)
+        return self
+
+    def remove(self):
+        """
+        Unschedules this job and removes it from its associated job store.
+
+        .. seealso:: :meth:`~apscheduler.schedulers.base.BaseScheduler.remove_job`
+
+        """
+        self._scheduler.remove_job(self.id, self._jobstore_alias)
+
+    @property
+    def pending(self):
+        """
+        Returns ``True`` if the referenced job is still waiting to be added to its designated job
+        store.
+
+        """
+        return self._jobstore_alias is None
+
+    #
+    # Private API
+    #
+
+    def _get_run_times(self, now):
+        """
+        Computes the scheduled run times between ``next_run_time`` and ``now`` (inclusive).
+
+        :type now: datetime.datetime
+        :rtype: list[datetime.datetime]
+
+        """
+        run_times = []
+        next_run_time = self.next_run_time
+        while next_run_time and next_run_time <= now:
+            run_times.append(next_run_time)
+            next_run_time = self.trigger.get_next_fire_time(next_run_time, now)
+
+        return run_times
+
+    def _modify(self, **changes):
+        """
+        Validates the changes to the Job and makes the modifications if and only if all of them
+        validate.
+
+        """
+        approved = {}
+
+        if 'id' in changes:
+            value = changes.pop('id')
+            if not isinstance(value, six.string_types):
+                raise TypeError("id must be a nonempty string")
+            if hasattr(self, 'id'):
+                raise ValueError('The job ID may not be changed')
+            approved['id'] = value
+
+        if 'func' in changes or 'args' in changes or 'kwargs' in changes:
+            func = changes.pop('func') if 'func' in changes else self.func
+            args = changes.pop('args') if 'args' in changes else self.args
+            kwargs = changes.pop('kwargs') if 'kwargs' in changes else self.kwargs
+
+            if isinstance(func, six.string_types):
+                func_ref = func
+                func = ref_to_obj(func)
+            elif callable(func):
+                try:
+                    func_ref = obj_to_ref(func)
+                except ValueError:
+                    # If this happens, this Job won't be serializable
+                    func_ref = None
+            else:
+                raise TypeError('func must be a callable or a textual reference to one')
+
+            if not hasattr(self, 'name') and changes.get('name', None) is None:
+                changes['name'] = get_callable_name(func)
+
+            if isinstance(args, six.string_types) or not isinstance(args, Iterable):
+                raise TypeError('args must be a non-string iterable')
+            if isinstance(kwargs, six.string_types) or not isinstance(kwargs, Mapping):
+                raise TypeError('kwargs must be a dict-like object')
+
+            check_callable_args(func, args, kwargs)
+
+            approved['func'] = func
+            approved['func_ref'] = func_ref
+            approved['args'] = args
+            approved['kwargs'] = kwargs
+
+        if 'name' in changes:
+            value = changes.pop('name')
+            if not value or not isinstance(value, six.string_types):
+                raise TypeError("name must be a nonempty string")
+            approved['name'] = value
+
+        if 'misfire_grace_time' in changes:
+            value = changes.pop('misfire_grace_time')
+            if value is not None and (not isinstance(value, six.integer_types) or value <= 0):
+                raise TypeError('misfire_grace_time must be either None or a positive integer')
+            approved['misfire_grace_time'] = value
+
+        if 'coalesce' in changes:
+            value = bool(changes.pop('coalesce'))
+            approved['coalesce'] = value
+
+        if 'max_instances' in changes:
+            value = changes.pop('max_instances')
+            if not isinstance(value, six.integer_types) or value <= 0:
+                raise TypeError('max_instances must be a positive integer')
+            approved['max_instances'] = value
+
+        if 'trigger' in changes:
+            trigger = changes.pop('trigger')
+            if not isinstance(trigger, BaseTrigger):
+                raise TypeError('Expected a trigger instance, got %s instead' %
+                                trigger.__class__.__name__)
+
+            approved['trigger'] = trigger
+
+        if 'executor' in changes:
+            value = changes.pop('executor')
+            if not isinstance(value, six.string_types):
+                raise TypeError('executor must be a string')
+            approved['executor'] = value
+
+        if 'next_run_time' in changes:
+            value = changes.pop('next_run_time')
+            approved['next_run_time'] = convert_to_datetime(value, self._scheduler.timezone,
+                                                            'next_run_time')
+
+        if changes:
+            raise AttributeError('The following are not modifiable attributes of Job: %s' %
+                                 ', '.join(changes))
+
+        for key, value in six.iteritems(approved):
+            setattr(self, key, value)
+
+    def __getstate__(self):
+        # Don't allow this Job to be serialized if the function reference could not be determined
+        if not self.func_ref:
+            raise ValueError(
+                'This Job cannot be serialized since the reference to its callable (%r) could not '
+                'be determined. Consider giving a textual reference (module:function name) '
+                'instead.' % (self.func,))
+
+        # Instance methods cannot survive serialization as-is, so store the "self" argument
+        # explicitly
+        func = self.func
+        if ismethod(func) and not isclass(func.__self__) and obj_to_ref(func) == self.func_ref:
+            args = (func.__self__,) + tuple(self.args)
+        else:
+            args = self.args
+
+        return {
+            'version': 1,
+            'id': self.id,
+            'func': self.func_ref,
+            'trigger': self.trigger,
+            'executor': self.executor,
+            'args': args,
+            'kwargs': self.kwargs,
+            'name': self.name,
+            'misfire_grace_time': self.misfire_grace_time,
+            'coalesce': self.coalesce,
+            'max_instances': self.max_instances,
+            'next_run_time': self.next_run_time
+        }
+
+    def __setstate__(self, state):
+        if state.get('version', 1) > 1:
+            raise ValueError('Job has version %s, but only version 1 can be handled' %
+                             state['version'])
+
+        self.id = state['id']
+        self.func_ref = state['func']
+        self.func = ref_to_obj(self.func_ref)
+        self.trigger = state['trigger']
+        self.executor = state['executor']
+        self.args = state['args']
+        self.kwargs = state['kwargs']
+        self.name = state['name']
+        self.misfire_grace_time = state['misfire_grace_time']
+        self.coalesce = state['coalesce']
+        self.max_instances = state['max_instances']
+        self.next_run_time = state['next_run_time']
+
+    def __eq__(self, other):
+        if isinstance(other, Job):
+            return self.id == other.id
+        return NotImplemented
+
+    def __repr__(self):
+        return '<Job (id=%s name=%s)>' % (repr_escape(self.id), repr_escape(self.name))
+
+    def __str__(self):
+        return repr_escape(self.__unicode__())
+
+    def __unicode__(self):
+        if hasattr(self, 'next_run_time'):
+            status = ('next run at: ' + datetime_repr(self.next_run_time) if
+                      self.next_run_time else 'paused')
+        else:
+            status = 'pending'
+
+        return u'%s (trigger: %s, %s)' % (self.name, self.trigger, status)

apscheduler/jobstores/base.py

@@ -0,0 +1,143 @@
+from abc import ABCMeta, abstractmethod
+import logging
+
+import six
+
+
+class JobLookupError(KeyError):
+    """Raised when the job store cannot find a job for update or removal."""
+
+    def __init__(self, job_id):
+        super(JobLookupError, self).__init__(u'No job by the id of %s was found' % job_id)
+
+
+class ConflictingIdError(KeyError):
+    """Raised when the uniqueness of job IDs is being violated."""
+
+    def __init__(self, job_id):
+        super(ConflictingIdError, self).__init__(
+            u'Job identifier (%s) conflicts with an existing job' % job_id)
+
+
+class TransientJobError(ValueError):
+    """
+    Raised when an attempt to add transient (with no func_ref) job to a persistent job store is
+    detected.
+    """
+
+    def __init__(self, job_id):
+        super(TransientJobError, self).__init__(
+            u'Job (%s) cannot be added to this job store because a reference to the callable '
+            u'could not be determined.' % job_id)
+
+
+class BaseJobStore(six.with_metaclass(ABCMeta)):
+    """Abstract base class that defines the interface that every job store must implement."""
+
+    _scheduler = None
+    _alias = None
+    _logger = logging.getLogger('apscheduler.jobstores')
+
+    def start(self, scheduler, alias):
+        """
+        Called by the scheduler when the scheduler is being started or when the job store is being
+        added to an already running scheduler.
+
+        :param apscheduler.schedulers.base.BaseScheduler scheduler: the scheduler that is starting
+            this job store
+        :param str|unicode alias: alias of this job store as it was assigned to the scheduler
+        """
+
+        self._scheduler = scheduler
+        self._alias = alias
+        self._logger = logging.getLogger('apscheduler.jobstores.%s' % alias)
+
+    def shutdown(self):
+        """Frees any resources still bound to this job store."""
+
+    def _fix_paused_jobs_sorting(self, jobs):
+        for i, job in enumerate(jobs):
+            if job.next_run_time is not None:
+                if i > 0:
+                    paused_jobs = jobs[:i]
+                    del jobs[:i]
+                    jobs.extend(paused_jobs)
+                break
+
+    @abstractmethod
+    def lookup_job(self, job_id):
+        """
+        Returns a specific job, or ``None`` if it isn't found..
+
+        The job store is responsible for setting the ``scheduler`` and ``jobstore`` attributes of
+        the returned job to point to the scheduler and itself, respectively.
+
+        :param str|unicode job_id: identifier of the job
+        :rtype: Job
+        """
+
+    @abstractmethod
+    def get_due_jobs(self, now):
+        """
+        Returns the list of jobs that have ``next_run_time`` earlier or equal to ``now``.
+        The returned jobs must be sorted by next run time (ascending).
+
+        :param datetime.datetime now: the current (timezone aware) datetime
+        :rtype: list[Job]
+        """
+
+    @abstractmethod
+    def get_next_run_time(self):
+        """
+        Returns the earliest run time of all the jobs stored in this job store, or ``None`` if
+        there are no active jobs.
+
+        :rtype: datetime.datetime
+        """
+
+    @abstractmethod
+    def get_all_jobs(self):
+        """
+        Returns a list of all jobs in this job store.
+        The returned jobs should be sorted by next run time (ascending).
+        Paused jobs (next_run_time == None) should be sorted last.
+
+        The job store is responsible for setting the ``scheduler`` and ``jobstore`` attributes of
+        the returned jobs to point to the scheduler and itself, respectively.
+
+        :rtype: list[Job]
+        """
+
+    @abstractmethod
+    def add_job(self, job):
+        """
+        Adds the given job to this store.
+
+        :param Job job: the job to add
+        :raises ConflictingIdError: if there is another job in this store with the same ID
+        """
+
+    @abstractmethod
+    def update_job(self, job):
+        """
+        Replaces the job in the store with the given newer version.
+
+        :param Job job: the job to update
+        :raises JobLookupError: if the job does not exist
+        """
+
+    @abstractmethod
+    def remove_job(self, job_id):
+        """
+        Removes the given job from this store.
+
+        :param str|unicode job_id: identifier of the job
+        :raises JobLookupError: if the job does not exist
+        """
+
+    @abstractmethod
+    def remove_all_jobs(self):
+        """Removes all jobs from this store."""
+
+    def __repr__(self):
+        return '<%s>' % self.__class__.__name__

apscheduler/jobstores/memory.py

@@ -0,0 +1,108 @@
+from __future__ import absolute_import
+
+from apscheduler.jobstores.base import BaseJobStore, JobLookupError, ConflictingIdError
+from apscheduler.util import datetime_to_utc_timestamp
+
+
+class MemoryJobStore(BaseJobStore):
+    """
+    Stores jobs in an array in RAM. Provides no persistence support.
+
+    Plugin alias: ``memory``
+    """
+
+    def __init__(self):
+        super(MemoryJobStore, self).__init__()
+        # list of (job, timestamp), sorted by next_run_time and job id (ascending)
+        self._jobs = []
+        self._jobs_index = {}  # id -> (job, timestamp) lookup table
+
+    def lookup_job(self, job_id):
+        return self._jobs_index.get(job_id, (None, None))[0]
+
+    def get_due_jobs(self, now):
+        now_timestamp = datetime_to_utc_timestamp(now)
+        pending = []
+        for job, timestamp in self._jobs:
+            if timestamp is None or timestamp > now_timestamp:
+                break
+            pending.append(job)
+
+        return pending
+
+    def get_next_run_time(self):
+        return self._jobs[0][0].next_run_time if self._jobs else None
+
+    def get_all_jobs(self):
+        return [j[0] for j in self._jobs]
+
+    def add_job(self, job):
+        if job.id in self._jobs_index:
+            raise ConflictingIdError(job.id)
+
+        timestamp = datetime_to_utc_timestamp(job.next_run_time)
+        index = self._get_job_index(timestamp, job.id)
+        self._jobs.insert(index, (job, timestamp))
+        self._jobs_index[job.id] = (job, timestamp)
+
+    def update_job(self, job):
+        old_job, old_timestamp = self._jobs_index.get(job.id, (None, None))
+        if old_job is None:
+            raise JobLookupError(job.id)
+
+        # If the next run time has not changed, simply replace the job in its present index.
+        # Otherwise, reinsert the job to the list to preserve the ordering.
+        old_index = self._get_job_index(old_timestamp, old_job.id)
+        new_timestamp = datetime_to_utc_timestamp(job.next_run_time)
+        if old_timestamp == new_timestamp:
+            self._jobs[old_index] = (job, new_timestamp)
+        else:
+            del self._jobs[old_index]
+            new_index = self._get_job_index(new_timestamp, job.id)
+            self._jobs.insert(new_index, (job, new_timestamp))
+
+        self._jobs_index[old_job.id] = (job, new_timestamp)
+
+    def remove_job(self, job_id):
+        job, timestamp = self._jobs_index.get(job_id, (None, None))
+        if job is None:
+            raise JobLookupError(job_id)
+
+        index = self._get_job_index(timestamp, job_id)
+        del self._jobs[index]
+        del self._jobs_index[job.id]
+
+    def remove_all_jobs(self):
+        self._jobs = []
+        self._jobs_index = {}
+
+    def shutdown(self):
+        self.remove_all_jobs()
+
+    def _get_job_index(self, timestamp, job_id):
+        """
+        Returns the index of the given job, or if it's not found, the index where the job should be
+        inserted based on the given timestamp.
+
+        :type timestamp: int
+        :type job_id: str
+
+        """
+        lo, hi = 0, len(self._jobs)
+        timestamp = float('inf') if timestamp is None else timestamp
+        while lo < hi:
+            mid = (lo + hi) // 2
+            mid_job, mid_timestamp = self._jobs[mid]
+            mid_timestamp = float('inf') if mid_timestamp is None else mid_timestamp
+            if mid_timestamp > timestamp:
+                hi = mid
+            elif mid_timestamp < timestamp:
+                lo = mid + 1
+            elif mid_job.id > job_id:
+                hi = mid
+            elif mid_job.id < job_id:
+                lo = mid + 1
+            else:
+                return mid
+
+        return lo

apscheduler/jobstores/mongodb.py

@@ -0,0 +1,141 @@
+from __future__ import absolute_import
+import warnings
+
+from apscheduler.jobstores.base import BaseJobStore, JobLookupError, ConflictingIdError
+from apscheduler.util import maybe_ref, datetime_to_utc_timestamp, utc_timestamp_to_datetime
+from apscheduler.job import Job
+
+try:
+    import cPickle as pickle
+except ImportError:  # pragma: nocover
+    import pickle
+
+try:
+    from bson.binary import Binary
+    from pymongo.errors import DuplicateKeyError
+    from pymongo import MongoClient, ASCENDING
+except ImportError:  # pragma: nocover
+    raise ImportError('MongoDBJobStore requires PyMongo installed')
+
+
+class MongoDBJobStore(BaseJobStore):
+    """
+    Stores jobs in a MongoDB database. Any leftover keyword arguments are directly passed to
+    pymongo's `MongoClient
+    <http://api.mongodb.org/python/current/api/pymongo/mongo_client.html#pymongo.mongo_client.MongoClient>`_.
+
+    Plugin alias: ``mongodb``
+
+    :param str database: database to store jobs in
+    :param str collection: collection to store jobs in
+    :param client: a :class:`~pymongo.mongo_client.MongoClient` instance to use instead of
+        providing connection arguments
+    :param int pickle_protocol: pickle protocol level to use (for serialization), defaults to the
+        highest available
+    """
+
+    def __init__(self, database='apscheduler', collection='jobs', client=None,
+                 pickle_protocol=pickle.HIGHEST_PROTOCOL, **connect_args):
+        super(MongoDBJobStore, self).__init__()
+        self.pickle_protocol = pickle_protocol
+
+        if not database:
+            raise ValueError('The "database" parameter must not be empty')
+        if not collection:
+            raise ValueError('The "collection" parameter must not be empty')
+
+        if client:
+            self.client = maybe_ref(client)
+        else:
+            connect_args.setdefault('w', 1)
+            self.client = MongoClient(**connect_args)
+
+        self.collection = self.client[database][collection]
+
+    def start(self, scheduler, alias):
+        super(MongoDBJobStore, self).start(scheduler, alias)
+        self.collection.create_index('next_run_time', sparse=True)
+
+    @property
+    def connection(self):
+        warnings.warn('The "connection" member is deprecated -- use "client" instead',
+                      DeprecationWarning)
+        return self.client
+
+    def lookup_job(self, job_id):
+        document = self.collection.find_one(job_id, ['job_state'])
+        return self._reconstitute_job(document['job_state']) if document else None
+
+    def get_due_jobs(self, now):
+        timestamp = datetime_to_utc_timestamp(now)
+        return self._get_jobs({'next_run_time': {'$lte': timestamp}})
+
+    def get_next_run_time(self):
+        document = self.collection.find_one({'next_run_time': {'$ne': None}},
+                                            projection=['next_run_time'],
+                                            sort=[('next_run_time', ASCENDING)])
+        return utc_timestamp_to_datetime(document['next_run_time']) if document else None
+
+    def get_all_jobs(self):
+        jobs = self._get_jobs({})
+        self._fix_paused_jobs_sorting(jobs)
+        return jobs
+
+    def add_job(self, job):
+        try:
+            self.collection.insert_one({
+                '_id': job.id,
+                'next_run_time': datetime_to_utc_timestamp(job.next_run_time),
+                'job_state': Binary(pickle.dumps(job.__getstate__(), self.pickle_protocol))
+            })
+        except DuplicateKeyError:
+            raise ConflictingIdError(job.id)
+
+    def update_job(self, job):
+        changes = {
+            'next_run_time': datetime_to_utc_timestamp(job.next_run_time),
+            'job_state': Binary(pickle.dumps(job.__getstate__(), self.pickle_protocol))
+        }
+        result = self.collection.update_one({'_id': job.id}, {'$set': changes})
+        if result and result.matched_count == 0:
+            raise JobLookupError(job.id)
+
+    def remove_job(self, job_id):
+        result = self.collection.delete_one({'_id': job_id})
+        if result and result.deleted_count == 0:
+            raise JobLookupError(job_id)
+
+    def remove_all_jobs(self):
+        self.collection.delete_many({})
+
+    def shutdown(self):
+        self.client.close()
+
+    def _reconstitute_job(self, job_state):
+        job_state = pickle.loads(job_state)
+        job = Job.__new__(Job)
+        job.__setstate__(job_state)
+        job._scheduler = self._scheduler
+        job._jobstore_alias = self._alias
+        return job
+
+    def _get_jobs(self, conditions):
+        jobs = []
+        failed_job_ids = []
+        for document in self.collection.find(conditions, ['_id', 'job_state'],
+                                             sort=[('next_run_time', ASCENDING)]):
+            try:
+                jobs.append(self._reconstitute_job(document['job_state']))
+            except BaseException:
+                self._logger.exception('Unable to restore job "%s" -- removing it',
+                                       document['_id'])
+                failed_job_ids.append(document['_id'])
+
+        # Remove all the jobs we failed to restore
+        if failed_job_ids:
+            self.collection.delete_many({'_id': {'$in': failed_job_ids}})
+
+        return jobs
+
+    def __repr__(self):
+        return '<%s (client=%s)>' % (self.__class__.__name__, self.client)

apscheduler/jobstores/redis.py

@@ -0,0 +1,150 @@
+from __future__ import absolute_import
+from datetime import datetime
+
+from pytz import utc
+import six
+
+from apscheduler.jobstores.base import BaseJobStore, JobLookupError, ConflictingIdError
+from apscheduler.util import datetime_to_utc_timestamp, utc_timestamp_to_datetime
+from apscheduler.job import Job
+
+try:
+    import cPickle as pickle
+except ImportError:  # pragma: nocover
+    import pickle
+
+try:
+    from redis import Redis
+except ImportError:  # pragma: nocover
+    raise ImportError('RedisJobStore requires redis installed')
+
+
+class RedisJobStore(BaseJobStore):
+    """
+    Stores jobs in a Redis database. Any leftover keyword arguments are directly passed to redis's
+    :class:`~redis.StrictRedis`.
+
+    Plugin alias: ``redis``
+
+    :param int db: the database number to store jobs in
+    :param str jobs_key: key to store jobs in
+    :param str run_times_key: key to store the jobs' run times in
+    :param int pickle_protocol: pickle protocol level to use (for serialization), defaults to the
+        highest available
+    """
+
+    def __init__(self, db=0, jobs_key='apscheduler.jobs', run_times_key='apscheduler.run_times',
+                 pickle_protocol=pickle.HIGHEST_PROTOCOL, **connect_args):
+        super(RedisJobStore, self).__init__()
+
+        if db is None:
+            raise ValueError('The "db" parameter must not be empty')
+        if not jobs_key:
+            raise ValueError('The "jobs_key" parameter must not be empty')
+        if not run_times_key:
+            raise ValueError('The "run_times_key" parameter must not be empty')
+
+        self.pickle_protocol = pickle_protocol
+        self.jobs_key = jobs_key
+        self.run_times_key = run_times_key
+        self.redis = Redis(db=int(db), **connect_args)
+
+    def lookup_job(self, job_id):
+        job_state = self.redis.hget(self.jobs_key, job_id)
+        return self._reconstitute_job(job_state) if job_state else None
+
+    def get_due_jobs(self, now):
+        timestamp = datetime_to_utc_timestamp(now)
+        job_ids = self.redis.zrangebyscore(self.run_times_key, 0, timestamp)
+        if job_ids:
+            job_states = self.redis.hmget(self.jobs_key, *job_ids)
+            return self._reconstitute_jobs(six.moves.zip(job_ids, job_states))
+        return []
+
+    def get_next_run_time(self):
+        next_run_time = self.redis.zrange(self.run_times_key, 0, 0, withscores=True)
+        if next_run_time:
+            return utc_timestamp_to_datetime(next_run_time[0][1])
+
+    def get_all_jobs(self):
+        job_states = self.redis.hgetall(self.jobs_key)
+        jobs = self._reconstitute_jobs(six.iteritems(job_states))
+        paused_sort_key = datetime(9999, 12, 31, tzinfo=utc)
+        return sorted(jobs, key=lambda job: job.next_run_time or paused_sort_key)
+
+    def add_job(self, job):
+        if self.redis.hexists(self.jobs_key, job.id):
+            raise ConflictingIdError(job.id)
+
+        with self.redis.pipeline() as pipe:
+            pipe.multi()
+            pipe.hset(self.jobs_key, job.id, pickle.dumps(job.__getstate__(),
+                                                          self.pickle_protocol))
+            if job.next_run_time:
+                pipe.zadd(self.run_times_key,
+                          {job.id: datetime_to_utc_timestamp(job.next_run_time)})
+
+            pipe.execute()
+
+    def update_job(self, job):
+        if not self.redis.hexists(self.jobs_key, job.id):
+            raise JobLookupError(job.id)
+
+        with self.redis.pipeline() as pipe:
+            pipe.hset(self.jobs_key, job.id, pickle.dumps(job.__getstate__(),
+                                                          self.pickle_protocol))
+            if job.next_run_time:
+                pipe.zadd(self.run_times_key,
+                          {job.id: datetime_to_utc_timestamp(job.next_run_time)})
+            else:
+                pipe.zrem(self.run_times_key, job.id)
+
+            pipe.execute()
+
+    def remove_job(self, job_id):
+        if not self.redis.hexists(self.jobs_key, job_id):
+            raise JobLookupError(job_id)
+
+        with self.redis.pipeline() as pipe:
+            pipe.hdel(self.jobs_key, job_id)
+            pipe.zrem(self.run_times_key, job_id)
+            pipe.execute()
+
+    def remove_all_jobs(self):
+        with self.redis.pipeline() as pipe:
+            pipe.delete(self.jobs_key)
+            pipe.delete(self.run_times_key)
+            pipe.execute()
+
+    def shutdown(self):
+        self.redis.connection_pool.disconnect()
+
+    def _reconstitute_job(self, job_state):
+        job_state = pickle.loads(job_state)
+        job = Job.__new__(Job)
+        job.__setstate__(job_state)
+        job._scheduler = self._scheduler
+        job._jobstore_alias = self._alias
+        return job
+
+    def _reconstitute_jobs(self, job_states):
+        jobs = []
+        failed_job_ids = []
+        for job_id, job_state in job_states:
+            try:
+                jobs.append(self._reconstitute_job(job_state))
+            except BaseException:
+                self._logger.exception('Unable to restore job "%s" -- removing it', job_id)
+                failed_job_ids.append(job_id)
+
+        # Remove all the jobs we failed to restore
+        if failed_job_ids:
+            with self.redis.pipeline() as pipe:
+                pipe.hdel(self.jobs_key, *failed_job_ids)
+                pipe.zrem(self.run_times_key, *failed_job_ids)
+                pipe.execute()
+
+        return jobs
+
+    def __repr__(self):
+        return '<%s>' % self.__class__.__name__

apscheduler/jobstores/rethinkdb.py

@@ -0,0 +1,155 @@
+from __future__ import absolute_import
+
+from apscheduler.jobstores.base import BaseJobStore, JobLookupError, ConflictingIdError
+from apscheduler.util import maybe_ref, datetime_to_utc_timestamp, utc_timestamp_to_datetime
+from apscheduler.job import Job
+
+try:
+    import cPickle as pickle
+except ImportError:  # pragma: nocover
+    import pickle
+
+try:
+    from rethinkdb import RethinkDB
+except ImportError:  # pragma: nocover
+    raise ImportError('RethinkDBJobStore requires rethinkdb installed')
+
+
+class RethinkDBJobStore(BaseJobStore):
+    """
+    Stores jobs in a RethinkDB database. Any leftover keyword arguments are directly passed to
+    rethinkdb's `RethinkdbClient <http://www.rethinkdb.com/api/#connect>`_.
+
+    Plugin alias: ``rethinkdb``
+
+    :param str database: database to store jobs in
+    :param str collection: collection to store jobs in
+    :param client: a :class:`rethinkdb.net.Connection` instance to use instead of providing
+        connection arguments
+    :param int pickle_protocol: pickle protocol level to use (for serialization), defaults to the
+        highest available
+    """
+
+    def __init__(self, database='apscheduler', table='jobs', client=None,
+                 pickle_protocol=pickle.HIGHEST_PROTOCOL, **connect_args):
+        super(RethinkDBJobStore, self).__init__()
+
+        if not database:
+            raise ValueError('The "database" parameter must not be empty')
+        if not table:
+            raise ValueError('The "table" parameter must not be empty')
+
+        self.database = database
+        self.table_name = table
+        self.table = None
+        self.client = client
+        self.pickle_protocol = pickle_protocol
+        self.connect_args = connect_args
+        self.r = RethinkDB()
+        self.conn = None
+
+    def start(self, scheduler, alias):
+        super(RethinkDBJobStore, self).start(scheduler, alias)
+
+        if self.client:
+            self.conn = maybe_ref(self.client)
+        else:
+            self.conn = self.r.connect(db=self.database, **self.connect_args)
+
+        if self.database not in self.r.db_list().run(self.conn):
+            self.r.db_create(self.database).run(self.conn)
+
+        if self.table_name not in self.r.table_list().run(self.conn):
+            self.r.table_create(self.table_name).run(self.conn)
+
+        if 'next_run_time' not in self.r.table(self.table_name).index_list().run(self.conn):
+            self.r.table(self.table_name).index_create('next_run_time').run(self.conn)
+
+        self.table = self.r.db(self.database).table(self.table_name)
+
+    def lookup_job(self, job_id):
+        results = list(self.table.get_all(job_id).pluck('job_state').run(self.conn))
+        return self._reconstitute_job(results[0]['job_state']) if results else None
+
+    def get_due_jobs(self, now):
+        return self._get_jobs(self.r.row['next_run_time'] <= datetime_to_utc_timestamp(now))
+
+    def get_next_run_time(self):
+        results = list(
+            self.table
+            .filter(self.r.row['next_run_time'] != None)  # noqa
+            .order_by(self.r.asc('next_run_time'))
+            .map(lambda x: x['next_run_time'])
+            .limit(1)
+            .run(self.conn)
+        )
+        return utc_timestamp_to_datetime(results[0]) if results else None
+
+    def get_all_jobs(self):
+        jobs = self._get_jobs()
+        self._fix_paused_jobs_sorting(jobs)
+        return jobs
+
+    def add_job(self, job):
+        job_dict = {
+            'id': job.id,
+            'next_run_time': datetime_to_utc_timestamp(job.next_run_time),
+            'job_state': self.r.binary(pickle.dumps(job.__getstate__(), self.pickle_protocol))
+        }
+        results = self.table.insert(job_dict).run(self.conn)
+        if results['errors'] > 0:
+            raise ConflictingIdError(job.id)
+
+    def update_job(self, job):
+        changes = {
+            'next_run_time': datetime_to_utc_timestamp(job.next_run_time),
+            'job_state': self.r.binary(pickle.dumps(job.__getstate__(), self.pickle_protocol))
+        }
+        results = self.table.get_all(job.id).update(changes).run(self.conn)
+        skipped = False in map(lambda x: results[x] == 0, results.keys())
+        if results['skipped'] > 0 or results['errors'] > 0 or not skipped:
+            raise JobLookupError(job.id)
+
+    def remove_job(self, job_id):
+        results = self.table.get_all(job_id).delete().run(self.conn)
+        if results['deleted'] + results['skipped'] != 1:
+            raise JobLookupError(job_id)
+
+    def remove_all_jobs(self):
+        self.table.delete().run(self.conn)
+
+    def shutdown(self):
+        self.conn.close()
+
+    def _reconstitute_job(self, job_state):
+        job_state = pickle.loads(job_state)
+        job = Job.__new__(Job)
+        job.__setstate__(job_state)
+        job._scheduler = self._scheduler
+        job._jobstore_alias = self._alias
+        return job
+
+    def _get_jobs(self, predicate=None):
+        jobs = []
+        failed_job_ids = []
+        query = (self.table.filter(self.r.row['next_run_time'] != None).filter(predicate)  # noqa
+                 if predicate else self.table)
+        query = query.order_by('next_run_time', 'id').pluck('id', 'job_state')
+
+        for document in query.run(self.conn):
+            try:
+                jobs.append(self._reconstitute_job(document['job_state']))
+            except Exception:
+                self._logger.exception('Unable to restore job "%s" -- removing it', document['id'])
+                failed_job_ids.append(document['id'])
+
+        # Remove all the jobs we failed to restore
+        if failed_job_ids:
+            self.r.expr(failed_job_ids).for_each(
+                lambda job_id: self.table.get_all(job_id).delete()).run(self.conn)
+
+        return jobs
+
+    def __repr__(self):
+        connection = self.conn
+        return '<%s (connection=%s)>' % (self.__class__.__name__, connection)

apscheduler/jobstores/sqlalchemy.py

@@ -0,0 +1,154 @@
+from __future__ import absolute_import
+
+from apscheduler.jobstores.base import BaseJobStore, JobLookupError, ConflictingIdError
+from apscheduler.util import maybe_ref, datetime_to_utc_timestamp, utc_timestamp_to_datetime
+from apscheduler.job import Job
+
+try:
+    import cPickle as pickle
+except ImportError:  # pragma: nocover
+    import pickle
+
+try:
+    from sqlalchemy import (
+        create_engine, Table, Column, MetaData, Unicode, Float, LargeBinary, select, and_)
+    from sqlalchemy.exc import IntegrityError
+    from sqlalchemy.sql.expression import null
+except ImportError:  # pragma: nocover
+    raise ImportError('SQLAlchemyJobStore requires SQLAlchemy installed')
+
+
+class SQLAlchemyJobStore(BaseJobStore):
+    """
+    Stores jobs in a database table using SQLAlchemy.
+    The table will be created if it doesn't exist in the database.
+
+    Plugin alias: ``sqlalchemy``
+
+    :param str url: connection string (see
+        :ref:`SQLAlchemy documentation <sqlalchemy:database_urls>` on this)
+    :param engine: an SQLAlchemy :class:`~sqlalchemy.engine.Engine` to use instead of creating a
+        new one based on ``url``
+    :param str tablename: name of the table to store jobs in
+    :param metadata: a :class:`~sqlalchemy.schema.MetaData` instance to use instead of creating a
+        new one
+    :param int pickle_protocol: pickle protocol level to use (for serialization), defaults to the
+        highest available
+    :param str tableschema: name of the (existing) schema in the target database where the table
+        should be
+    :param dict engine_options: keyword arguments to :func:`~sqlalchemy.create_engine`
+        (ignored if ``engine`` is given)
+    """
+
+    def __init__(self, url=None, engine=None, tablename='apscheduler_jobs', metadata=None,
+                 pickle_protocol=pickle.HIGHEST_PROTOCOL, tableschema=None, engine_options=None):
+        super(SQLAlchemyJobStore, self).__init__()
+        self.pickle_protocol = pickle_protocol
+        metadata = maybe_ref(metadata) or MetaData()
+
+        if engine:
+            self.engine = maybe_ref(engine)
+        elif url:
+            self.engine = create_engine(url, **(engine_options or {}))
+        else:
+            raise ValueError('Need either "engine" or "url" defined')
+
+        # 191 = max key length in MySQL for InnoDB/utf8mb4 tables,
+        # 25 = precision that translates to an 8-byte float
+        self.jobs_t = Table(
+            tablename, metadata,
+            Column('id', Unicode(191, _warn_on_bytestring=False), primary_key=True),
+            Column('next_run_time', Float(25), index=True),
+            Column('job_state', LargeBinary, nullable=False),
+            schema=tableschema
+        )
+
+    def start(self, scheduler, alias):
+        super(SQLAlchemyJobStore, self).start(scheduler, alias)
+        self.jobs_t.create(self.engine, True)
+
+    def lookup_job(self, job_id):
+        selectable = select([self.jobs_t.c.job_state]).where(self.jobs_t.c.id == job_id)
+        job_state = self.engine.execute(selectable).scalar()
+        return self._reconstitute_job(job_state) if job_state else None
+
+    def get_due_jobs(self, now):
+        timestamp = datetime_to_utc_timestamp(now)
+        return self._get_jobs(self.jobs_t.c.next_run_time <= timestamp)
+
+    def get_next_run_time(self):
+        selectable = select([self.jobs_t.c.next_run_time]).\
+            where(self.jobs_t.c.next_run_time != null()).\
+            order_by(self.jobs_t.c.next_run_time).limit(1)
+        next_run_time = self.engine.execute(selectable).scalar()
+        return utc_timestamp_to_datetime(next_run_time)
+
+    def get_all_jobs(self):
+        jobs = self._get_jobs()
+        self._fix_paused_jobs_sorting(jobs)
+        return jobs
+
+    def add_job(self, job):
+        insert = self.jobs_t.insert().values(**{
+            'id': job.id,
+            'next_run_time': datetime_to_utc_timestamp(job.next_run_time),
+            'job_state': pickle.dumps(job.__getstate__(), self.pickle_protocol)
+        })
+        try:
+            self.engine.execute(insert)
+        except IntegrityError:
+            raise ConflictingIdError(job.id)
+
+    def update_job(self, job):
+        update = self.jobs_t.update().values(**{
+            'next_run_time': datetime_to_utc_timestamp(job.next_run_time),
+            'job_state': pickle.dumps(job.__getstate__(), self.pickle_protocol)
+        }).where(self.jobs_t.c.id == job.id)
+        result = self.engine.execute(update)
+        if result.rowcount == 0:
+            raise JobLookupError(job.id)
+
+    def remove_job(self, job_id):
+        delete = self.jobs_t.delete().where(self.jobs_t.c.id == job_id)
+        result = self.engine.execute(delete)
+        if result.rowcount == 0:
+            raise JobLookupError(job_id)
+
+    def remove_all_jobs(self):
+        delete = self.jobs_t.delete()
+        self.engine.execute(delete)
+
+    def shutdown(self):
+        self.engine.dispose()
+
+    def _reconstitute_job(self, job_state):
+        job_state = pickle.loads(job_state)
+        job_state['jobstore'] = self
+        job = Job.__new__(Job)
+        job.__setstate__(job_state)
+        job._scheduler = self._scheduler
+        job._jobstore_alias = self._alias
+        return job
+
+    def _get_jobs(self, *conditions):
+        jobs = []
+        selectable = select([self.jobs_t.c.id, self.jobs_t.c.job_state]).\
+            order_by(self.jobs_t.c.next_run_time)
+        selectable = selectable.where(and_(*conditions)) if conditions else selectable
+        failed_job_ids = set()
+        for row in self.engine.execute(selectable):
+            try:
+                jobs.append(self._reconstitute_job(row.job_state))
+            except BaseException:
+                self._logger.exception('Unable to restore job "%s" -- removing it', row.id)
+                failed_job_ids.add(row.id)
+
+        # Remove all the jobs we failed to restore
+        if failed_job_ids:
+            delete = self.jobs_t.delete().where(self.jobs_t.c.id.in_(failed_job_ids))
+            self.engine.execute(delete)
+
+        return jobs
+
+    def __repr__(self):
+        return '<%s (url=%s)>' % (self.__class__.__name__, self.engine.url)

apscheduler/jobstores/zookeeper.py

@@ -0,0 +1,178 @@
+from __future__ import absolute_import
+
+from datetime import datetime
+
+from pytz import utc
+from kazoo.exceptions import NoNodeError, NodeExistsError
+
+from apscheduler.jobstores.base import BaseJobStore, JobLookupError, ConflictingIdError
+from apscheduler.util import maybe_ref, datetime_to_utc_timestamp, utc_timestamp_to_datetime
+from apscheduler.job import Job
+
+try:
+    import cPickle as pickle
+except ImportError:  # pragma: nocover
+    import pickle
+
+try:
+    from kazoo.client import KazooClient
+except ImportError:  # pragma: nocover
+    raise ImportError('ZooKeeperJobStore requires Kazoo installed')
+
+
+class ZooKeeperJobStore(BaseJobStore):
+    """
+    Stores jobs in a ZooKeeper tree. Any leftover keyword arguments are directly passed to
+    kazoo's `KazooClient
+    <http://kazoo.readthedocs.io/en/latest/api/client.html>`_.
+
+    Plugin alias: ``zookeeper``
+
+    :param str path: path to store jobs in
+    :param client: a :class:`~kazoo.client.KazooClient` instance to use instead of
+        providing connection arguments
+    :param int pickle_protocol: pickle protocol level to use (for serialization), defaults to the
+        highest available
+    """
+
+    def __init__(self, path='/apscheduler', client=None, close_connection_on_exit=False,
+                 pickle_protocol=pickle.HIGHEST_PROTOCOL, **connect_args):
+        super(ZooKeeperJobStore, self).__init__()
+        self.pickle_protocol = pickle_protocol
+        self.close_connection_on_exit = close_connection_on_exit
+
+        if not path:
+            raise ValueError('The "path" parameter must not be empty')
+
+        self.path = path
+
+        if client:
+            self.client = maybe_ref(client)
+        else:
+            self.client = KazooClient(**connect_args)
+        self._ensured_path = False
+
+    def _ensure_paths(self):
+        if not self._ensured_path:
+            self.client.ensure_path(self.path)
+        self._ensured_path = True
+
+    def start(self, scheduler, alias):
+        super(ZooKeeperJobStore, self).start(scheduler, alias)
+        if not self.client.connected:
+            self.client.start()
+
+    def lookup_job(self, job_id):
+        self._ensure_paths()
+        node_path = self.path + "/" + str(job_id)
+        try:
+            content, _ = self.client.get(node_path)
+            doc = pickle.loads(content)
+            job = self._reconstitute_job(doc['job_state'])
+            return job
+        except BaseException:
+            return None
+
+    def get_due_jobs(self, now):
+        timestamp = datetime_to_utc_timestamp(now)
+        jobs = [job_def['job'] for job_def in self._get_jobs()
+                if job_def['next_run_time'] is not None and job_def['next_run_time'] <= timestamp]
+        return jobs
+
+    def get_next_run_time(self):
+        next_runs = [job_def['next_run_time'] for job_def in self._get_jobs()
+                     if job_def['next_run_time'] is not None]
+        return utc_timestamp_to_datetime(min(next_runs)) if len(next_runs) > 0 else None
+
+    def get_all_jobs(self):
+        jobs = [job_def['job'] for job_def in self._get_jobs()]
+        self._fix_paused_jobs_sorting(jobs)
+        return jobs
+
+    def add_job(self, job):
+        self._ensure_paths()
+        node_path = self.path + "/" + str(job.id)
+        value = {
+            'next_run_time': datetime_to_utc_timestamp(job.next_run_time),
+            'job_state': job.__getstate__()
+        }
+        data = pickle.dumps(value, self.pickle_protocol)
+        try:
+            self.client.create(node_path, value=data)
+        except NodeExistsError:
+            raise ConflictingIdError(job.id)
+
+    def update_job(self, job):
+        self._ensure_paths()
+        node_path = self.path + "/" + str(job.id)
+        changes = {
+            'next_run_time': datetime_to_utc_timestamp(job.next_run_time),
+            'job_state': job.__getstate__()
+        }
+        data = pickle.dumps(changes, self.pickle_protocol)
+        try:
+            self.client.set(node_path, value=data)
+        except NoNodeError:
+            raise JobLookupError(job.id)
+
+    def remove_job(self, job_id):
+        self._ensure_paths()
+        node_path = self.path + "/" + str(job_id)
+        try:
+            self.client.delete(node_path)
+        except NoNodeError:
+            raise JobLookupError(job_id)
+
+    def remove_all_jobs(self):
+        try:
+            self.client.delete(self.path, recursive=True)
+        except NoNodeError:
+            pass
+        self._ensured_path = False
+
+    def shutdown(self):
+        if self.close_connection_on_exit:
+            self.client.stop()
+            self.client.close()
+
+    def _reconstitute_job(self, job_state):
+        job_state = job_state
+        job = Job.__new__(Job)
+        job.__setstate__(job_state)
+        job._scheduler = self._scheduler
+        job._jobstore_alias = self._alias
+        return job
+
+    def _get_jobs(self):
+        self._ensure_paths()
+        jobs = []
+        failed_job_ids = []
+        all_ids = self.client.get_children(self.path)
+        for node_name in all_ids:
+            try:
+                node_path = self.path + "/" + node_name
+                content, _ = self.client.get(node_path)
+                doc = pickle.loads(content)
+                job_def = {
+                    'job_id': node_name,
+                    'next_run_time': doc['next_run_time'] if doc['next_run_time'] else None,
+                    'job_state': doc['job_state'],
+                    'job': self._reconstitute_job(doc['job_state']),
+                    'creation_time': _.ctime
+                }
+                jobs.append(job_def)
+            except BaseException:
+                self._logger.exception('Unable to restore job "%s" -- removing it' % node_name)
+                failed_job_ids.append(node_name)
+
+        # Remove all the jobs we failed to restore
+        if failed_job_ids:
+            for failed_id in failed_job_ids:
+                self.remove_job(failed_id)
+        paused_sort_key = datetime(9999, 12, 31, tzinfo=utc)
+        return sorted(jobs, key=lambda job_def: (job_def['job'].next_run_time or paused_sort_key,
+                                                 job_def['creation_time']))
+
+    def __repr__(self):
+        self._logger.exception('<%s (client=%s)>' % (self.__class__.__name__, self.client))
+        return '<%s (client=%s)>' % (self.__class__.__name__, self.client)

apscheduler/schedulers/__init__.py

@@ -0,0 +1,12 @@
+class SchedulerAlreadyRunningError(Exception):
+    """Raised when attempting to start or configure the scheduler when it's already running."""
+
+    def __str__(self):
+        return 'Scheduler is already running'
+
+
+class SchedulerNotRunningError(Exception):
+    """Raised when attempting to shutdown the scheduler when it's not running."""
+
+    def __str__(self):
+        return 'Scheduler is not running'

apscheduler/schedulers/asyncio.py

@@ -0,0 +1,74 @@
+from __future__ import absolute_import
+from functools import wraps, partial
+
+from apscheduler.schedulers.base import BaseScheduler
+from apscheduler.util import maybe_ref
+
+try:
+    import asyncio
+except ImportError:  # pragma: nocover
+    try:
+        import trollius as asyncio
+    except ImportError:
+        raise ImportError(
+            'AsyncIOScheduler requires either Python 3.4 or the asyncio package installed')
+
+
+def run_in_event_loop(func):
+    @wraps(func)
+    def wrapper(self, *args, **kwargs):
+        wrapped = partial(func, self, *args, **kwargs)
+        self._eventloop.call_soon_threadsafe(wrapped)
+    return wrapper
+
+
+class AsyncIOScheduler(BaseScheduler):
+    """
+    A scheduler that runs on an asyncio (:pep:`3156`) event loop.
+
+    The default executor can run jobs based on native coroutines (``async def``).
+
+    Extra options:
+
+    ============== =============================================================
+    ``event_loop`` AsyncIO event loop to use (defaults to the global event loop)
+    ============== =============================================================
+    """
+
+    _eventloop = None
+    _timeout = None
+
+    def start(self, paused=False):
+        if not self._eventloop:
+            self._eventloop = asyncio.get_event_loop()
+
+        super(AsyncIOScheduler, self).start(paused)
+
+    @run_in_event_loop
+    def shutdown(self, wait=True):
+        super(AsyncIOScheduler, self).shutdown(wait)
+        self._stop_timer()
+
+    def _configure(self, config):
+        self._eventloop = maybe_ref(config.pop('event_loop', None))
+        super(AsyncIOScheduler, self)._configure(config)
+
+    def _start_timer(self, wait_seconds):
+        self._stop_timer()
+        if wait_seconds is not None:
+            self._timeout = self._eventloop.call_later(wait_seconds, self.wakeup)
+
+    def _stop_timer(self):
+        if self._timeout:
+            self._timeout.cancel()
+            del self._timeout
+
+    @run_in_event_loop
+    def wakeup(self):
+        self._stop_timer()
+        wait_seconds = self._process_jobs()
+        self._start_timer(wait_seconds)
+
+    def _create_default_executor(self):
+        from apscheduler.executors.asyncio import AsyncIOExecutor
+        return AsyncIOExecutor()

apscheduler/schedulers/background.py

@@ -0,0 +1,43 @@
+from __future__ import absolute_import
+
+from threading import Thread, Event
+
+from apscheduler.schedulers.base import BaseScheduler
+from apscheduler.schedulers.blocking import BlockingScheduler
+from apscheduler.util import asbool
+
+
+class BackgroundScheduler(BlockingScheduler):
+    """
+    A scheduler that runs in the background using a separate thread
+    (:meth:`~apscheduler.schedulers.base.BaseScheduler.start` will return immediately).
+
+    Extra options:
+
+    ========== =============================================================================
+    ``daemon`` Set the ``daemon`` option in the background thread (defaults to ``True``, see
+               `the documentation
+               <https://docs.python.org/3.4/library/threading.html#thread-objects>`_
+               for further details)
+    ========== =============================================================================
+    """
+
+    _thread = None
+
+    def _configure(self, config):
+        self._daemon = asbool(config.pop('daemon', True))
+        super(BackgroundScheduler, self)._configure(config)
+
+    def start(self, *args, **kwargs):
+        if self._event is None or self._event.is_set():
+            self._event = Event()
+
+        BaseScheduler.start(self, *args, **kwargs)
+        self._thread = Thread(target=self._main_loop, name='APScheduler')
+        self._thread.daemon = self._daemon
+        self._thread.start()
+
+    def shutdown(self, *args, **kwargs):
+        super(BackgroundScheduler, self).shutdown(*args, **kwargs)
+        self._thread.join()
+        del self._thread

apscheduler/schedulers/blocking.py

@@ -0,0 +1,35 @@
+from __future__ import absolute_import
+
+from threading import Event
+
+from apscheduler.schedulers.base import BaseScheduler, STATE_STOPPED
+from apscheduler.util import TIMEOUT_MAX
+
+
+class BlockingScheduler(BaseScheduler):
+    """
+    A scheduler that runs in the foreground
+    (:meth:`~apscheduler.schedulers.base.BaseScheduler.start` will block).
+    """
+    _event = None
+
+    def start(self, *args, **kwargs):
+        if self._event is None or self._event.is_set():
+            self._event = Event()
+
+        super(BlockingScheduler, self).start(*args, **kwargs)
+        self._main_loop()
+
+    def shutdown(self, wait=True):
+        super(BlockingScheduler, self).shutdown(wait)
+        self._event.set()
+
+    def _main_loop(self):
+        wait_seconds = TIMEOUT_MAX
+        while self.state != STATE_STOPPED:
+            self._event.wait(wait_seconds)
+            self._event.clear()
+            wait_seconds = self._process_jobs()
+
+    def wakeup(self):
+        self._event.set()

apscheduler/schedulers/gevent.py

@@ -0,0 +1,35 @@
+from __future__ import absolute_import
+
+from apscheduler.schedulers.blocking import BlockingScheduler
+from apscheduler.schedulers.base import BaseScheduler
+
+try:
+    from gevent.event import Event
+    from gevent.lock import RLock
+    import gevent
+except ImportError:  # pragma: nocover
+    raise ImportError('GeventScheduler requires gevent installed')
+
+
+class GeventScheduler(BlockingScheduler):
+    """A scheduler that runs as a Gevent greenlet."""
+
+    _greenlet = None
+
+    def start(self, *args, **kwargs):
+        self._event = Event()
+        BaseScheduler.start(self, *args, **kwargs)
+        self._greenlet = gevent.spawn(self._main_loop)
+        return self._greenlet
+
+    def shutdown(self, *args, **kwargs):
+        super(GeventScheduler, self).shutdown(*args, **kwargs)
+        self._greenlet.join()
+        del self._greenlet
+
+    def _create_lock(self):
+        return RLock()
+
+    def _create_default_executor(self):
+        from apscheduler.executors.gevent import GeventExecutor
+        return GeventExecutor()

apscheduler/schedulers/qt.py

@@ -0,0 +1,50 @@
+from __future__ import absolute_import
+
+from apscheduler.schedulers.base import BaseScheduler
+
+try:
+    from PyQt5.QtCore import QObject, QTimer
+except (ImportError, RuntimeError):  # pragma: nocover
+    try:
+        from PyQt4.QtCore import QObject, QTimer
+    except ImportError:
+        try:
+            from PySide6.QtCore import QObject, QTimer  # noqa
+        except ImportError:
+            try:
+                from PySide2.QtCore import QObject, QTimer  # noqa
+            except ImportError:
+                try:
+                    from PySide.QtCore import QObject, QTimer  # noqa
+                except ImportError:
+                    raise ImportError('QtScheduler requires either PyQt5, PyQt4, PySide6, PySide2 '
+                                      'or PySide installed')
+
+
+class QtScheduler(BaseScheduler):
+    """A scheduler that runs in a Qt event loop."""
+
+    _timer = None
+
+    def shutdown(self, *args, **kwargs):
+        super(QtScheduler, self).shutdown(*args, **kwargs)
+        self._stop_timer()
+
+    def _start_timer(self, wait_seconds):
+        self._stop_timer()
+        if wait_seconds is not None:
+            wait_time = min(wait_seconds * 1000, 2147483647)
+            self._timer = QTimer.singleShot(wait_time, self._process_jobs)
+
+    def _stop_timer(self):
+        if self._timer:
+            if self._timer.isActive():
+                self._timer.stop()
+            del self._timer
+
+    def wakeup(self):
+        self._start_timer(0)
+
+    def _process_jobs(self):
+        wait_seconds = super(QtScheduler, self)._process_jobs()
+        self._start_timer(wait_seconds)

apscheduler/schedulers/tornado.py

@@ -0,0 +1,63 @@
+from __future__ import absolute_import
+
+from datetime import timedelta
+from functools import wraps
+
+from apscheduler.schedulers.base import BaseScheduler
+from apscheduler.util import maybe_ref
+
+try:
+    from tornado.ioloop import IOLoop
+except ImportError:  # pragma: nocover
+    raise ImportError('TornadoScheduler requires tornado installed')
+
+
+def run_in_ioloop(func):
+    @wraps(func)
+    def wrapper(self, *args, **kwargs):
+        self._ioloop.add_callback(func, self, *args, **kwargs)
+    return wrapper
+
+
+class TornadoScheduler(BaseScheduler):
+    """
+    A scheduler that runs on a Tornado IOLoop.
+
+    The default executor can run jobs based on native coroutines (``async def``).
+
+    =========== ===============================================================
+    ``io_loop`` Tornado IOLoop instance to use (defaults to the global IO loop)
+    =========== ===============================================================
+    """
+
+    _ioloop = None
+    _timeout = None
+
+    @run_in_ioloop
+    def shutdown(self, wait=True):
+        super(TornadoScheduler, self).shutdown(wait)
+        self._stop_timer()
+
+    def _configure(self, config):
+        self._ioloop = maybe_ref(config.pop('io_loop', None)) or IOLoop.current()
+        super(TornadoScheduler, self)._configure(config)
+
+    def _start_timer(self, wait_seconds):
+        self._stop_timer()
+        if wait_seconds is not None:
+            self._timeout = self._ioloop.add_timeout(timedelta(seconds=wait_seconds), self.wakeup)
+
+    def _stop_timer(self):
+        if self._timeout:
+            self._ioloop.remove_timeout(self._timeout)
+            del self._timeout
+
+    def _create_default_executor(self):
+        from apscheduler.executors.tornado import TornadoExecutor
+        return TornadoExecutor()
+
+    @run_in_ioloop
+    def wakeup(self):
+        self._stop_timer()
+        wait_seconds = self._process_jobs()
+        self._start_timer(wait_seconds)

apscheduler/schedulers/twisted.py

@@ -0,0 +1,62 @@
+from __future__ import absolute_import
+
+from functools import wraps
+
+from apscheduler.schedulers.base import BaseScheduler
+from apscheduler.util import maybe_ref
+
+try:
+    from twisted.internet import reactor as default_reactor
+except ImportError:  # pragma: nocover
+    raise ImportError('TwistedScheduler requires Twisted installed')
+
+
+def run_in_reactor(func):
+    @wraps(func)
+    def wrapper(self, *args, **kwargs):
+        self._reactor.callFromThread(func, self, *args, **kwargs)
+    return wrapper
+
+
+class TwistedScheduler(BaseScheduler):
+    """
+    A scheduler that runs on a Twisted reactor.
+
+    Extra options:
+
+    =========== ========================================================
+    ``reactor`` Reactor instance to use (defaults to the global reactor)
+    =========== ========================================================
+    """
+
+    _reactor = None
+    _delayedcall = None
+
+    def _configure(self, config):
+        self._reactor = maybe_ref(config.pop('reactor', default_reactor))
+        super(TwistedScheduler, self)._configure(config)
+
+    @run_in_reactor
+    def shutdown(self, wait=True):
+        super(TwistedScheduler, self).shutdown(wait)
+        self._stop_timer()
+
+    def _start_timer(self, wait_seconds):
+        self._stop_timer()
+        if wait_seconds is not None:
+            self._delayedcall = self._reactor.callLater(wait_seconds, self.wakeup)
+
+    def _stop_timer(self):
+        if self._delayedcall and self._delayedcall.active():
+            self._delayedcall.cancel()
+            del self._delayedcall
+
+    @run_in_reactor
+    def wakeup(self):
+        self._stop_timer()
+        wait_seconds = self._process_jobs()
+        self._start_timer(wait_seconds)
+
+    def _create_default_executor(self):
+        from apscheduler.executors.twisted import TwistedExecutor
+        return TwistedExecutor()

apscheduler/triggers/base.py

@@ -0,0 +1,37 @@
+from abc import ABCMeta, abstractmethod
+from datetime import timedelta
+import random
+
+import six
+
+
+class BaseTrigger(six.with_metaclass(ABCMeta)):
+    """Abstract base class that defines the interface that every trigger must implement."""
+
+    __slots__ = ()
+
+    @abstractmethod
+    def get_next_fire_time(self, previous_fire_time, now):
+        """
+        Returns the next datetime to fire on, If no such datetime can be calculated, returns
+        ``None``.
+
+        :param datetime.datetime previous_fire_time: the previous time the trigger was fired
+        :param datetime.datetime now: current datetime
+        """
+
+    def _apply_jitter(self, next_fire_time, jitter, now):
+        """
+        Randomize ``next_fire_time`` by adding a random value (the jitter).
+
+        :param datetime.datetime|None next_fire_time: next fire time without jitter applied. If
+            ``None``, returns ``None``.
+        :param int|None jitter: maximum number of seconds to add to ``next_fire_time``
+            (if ``None`` or ``0``, returns ``next_fire_time``)
+        :param datetime.datetime now: current datetime
+        :return datetime.datetime|None: next fire time with a jitter.
+        """
+        if next_fire_time is None or not jitter:
+            return next_fire_time
+
+        return next_fire_time + timedelta(seconds=random.uniform(0, jitter))

apscheduler/triggers/combining.py

@@ -0,0 +1,95 @@
+from apscheduler.triggers.base import BaseTrigger
+from apscheduler.util import obj_to_ref, ref_to_obj
+
+
+class BaseCombiningTrigger(BaseTrigger):
+    __slots__ = ('triggers', 'jitter')
+
+    def __init__(self, triggers, jitter=None):
+        self.triggers = triggers
+        self.jitter = jitter
+
+    def __getstate__(self):
+        return {
+            'version': 1,
+            'triggers': [(obj_to_ref(trigger.__class__), trigger.__getstate__())
+                         for trigger in self.triggers],
+            'jitter': self.jitter
+        }
+
+    def __setstate__(self, state):
+        if state.get('version', 1) > 1:
+            raise ValueError(
+                'Got serialized data for version %s of %s, but only versions up to 1 can be '
+                'handled' % (state['version'], self.__class__.__name__))
+
+        self.jitter = state['jitter']
+        self.triggers = []
+        for clsref, state in state['triggers']:
+            cls = ref_to_obj(clsref)
+            trigger = cls.__new__(cls)
+            trigger.__setstate__(state)
+            self.triggers.append(trigger)
+
+    def __repr__(self):
+        return '<{}({}{})>'.format(self.__class__.__name__, self.triggers,
+                                   ', jitter={}'.format(self.jitter) if self.jitter else '')
+
+
+class AndTrigger(BaseCombiningTrigger):
+    """
+    Always returns the earliest next fire time that all the given triggers can agree on.
+    The trigger is considered to be finished when any of the given triggers has finished its
+    schedule.
+
+    Trigger alias: ``and``
+
+    :param list triggers: triggers to combine
+    :param int|None jitter: delay the job execution by ``jitter`` seconds at most
+    """
+
+    __slots__ = ()
+
+    def get_next_fire_time(self, previous_fire_time, now):
+        while True:
+            fire_times = [trigger.get_next_fire_time(previous_fire_time, now)
+                          for trigger in self.triggers]
+            if None in fire_times:
+                return None
+            elif min(fire_times) == max(fire_times):
+                return self._apply_jitter(fire_times[0], self.jitter, now)
+            else:
+                now = max(fire_times)
+
+    def __str__(self):
+        return 'and[{}]'.format(', '.join(str(trigger) for trigger in self.triggers))
+
+
+class OrTrigger(BaseCombiningTrigger):
+    """
+    Always returns the earliest next fire time produced by any of the given triggers.
+    The trigger is considered finished when all the given triggers have finished their schedules.
+
+    Trigger alias: ``or``
+
+    :param list triggers: triggers to combine
+    :param int|None jitter: delay the job execution by ``jitter`` seconds at most
+
+    .. note:: Triggers that depends on the previous fire time, such as the interval trigger, may
+        seem to behave strangely since they are always passed the previous fire time produced by
+        any of the given triggers.
+    """
+
+    __slots__ = ()
+
+    def get_next_fire_time(self, previous_fire_time, now):
+        fire_times = [trigger.get_next_fire_time(previous_fire_time, now)
+                      for trigger in self.triggers]
+        fire_times = [fire_time for fire_time in fire_times if fire_time is not None]
+        if fire_times:
+            return self._apply_jitter(min(fire_times), self.jitter, now)
+        else:
+            return None
+
+    def __str__(self):
+        return 'or[{}]'.format(', '.join(str(trigger) for trigger in self.triggers))

apscheduler/triggers/cron/__init__.py

@@ -0,0 +1,239 @@
+from datetime import datetime, timedelta
+
+from tzlocal import get_localzone
+import six
+
+from apscheduler.triggers.base import BaseTrigger
+from apscheduler.triggers.cron.fields import (
+    BaseField, MonthField, WeekField, DayOfMonthField, DayOfWeekField, DEFAULT_VALUES)
+from apscheduler.util import (
+    datetime_ceil, convert_to_datetime, datetime_repr, astimezone, localize, normalize)
+
+
+class CronTrigger(BaseTrigger):
+    """
+    Triggers when current time matches all specified time constraints,
+    similarly to how the UNIX cron scheduler works.
+
+    :param int|str year: 4-digit year
+    :param int|str month: month (1-12)
+    :param int|str day: day of month (1-31)
+    :param int|str week: ISO week (1-53)
+    :param int|str day_of_week: number or name of weekday (0-6 or mon,tue,wed,thu,fri,sat,sun)
+    :param int|str hour: hour (0-23)
+    :param int|str minute: minute (0-59)
+    :param int|str second: second (0-59)
+    :param datetime|str start_date: earliest possible date/time to trigger on (inclusive)
+    :param datetime|str end_date: latest possible date/time to trigger on (inclusive)
+    :param datetime.tzinfo|str timezone: time zone to use for the date/time calculations (defaults
+        to scheduler timezone)
+    :param int|None jitter: delay the job execution by ``jitter`` seconds at most
+
+    .. note:: The first weekday is always **monday**.
+    """
+
+    FIELD_NAMES = ('year', 'month', 'day', 'week', 'day_of_week', 'hour', 'minute', 'second')
+    FIELDS_MAP = {
+        'year': BaseField,
+        'month': MonthField,
+        'week': WeekField,
+        'day': DayOfMonthField,
+        'day_of_week': DayOfWeekField,
+        'hour': BaseField,
+        'minute': BaseField,
+        'second': BaseField
+    }
+
+    __slots__ = 'timezone', 'start_date', 'end_date', 'fields', 'jitter'
+
+    def __init__(self, year=None, month=None, day=None, week=None, day_of_week=None, hour=None,
+                 minute=None, second=None, start_date=None, end_date=None, timezone=None,
+                 jitter=None):
+        if timezone:
+            self.timezone = astimezone(timezone)
+        elif isinstance(start_date, datetime) and start_date.tzinfo:
+            self.timezone = start_date.tzinfo
+        elif isinstance(end_date, datetime) and end_date.tzinfo:
+            self.timezone = end_date.tzinfo
+        else:
+            self.timezone = get_localzone()
+
+        self.start_date = convert_to_datetime(start_date, self.timezone, 'start_date')
+        self.end_date = convert_to_datetime(end_date, self.timezone, 'end_date')
+
+        self.jitter = jitter
+
+        values = dict((key, value) for (key, value) in six.iteritems(locals())
+                      if key in self.FIELD_NAMES and value is not None)
+        self.fields = []
+        assign_defaults = False
+        for field_name in self.FIELD_NAMES:
+            if field_name in values:
+                exprs = values.pop(field_name)
+                is_default = False
+                assign_defaults = not values
+            elif assign_defaults:
+                exprs = DEFAULT_VALUES[field_name]
+                is_default = True
+            else:
+                exprs = '*'
+                is_default = True
+
+            field_class = self.FIELDS_MAP[field_name]
+            field = field_class(field_name, exprs, is_default)
+            self.fields.append(field)
+
+    @classmethod
+    def from_crontab(cls, expr, timezone=None):
+        """
+        Create a :class:`~CronTrigger` from a standard crontab expression.
+
+        See https://en.wikipedia.org/wiki/Cron for more information on the format accepted here.
+
+        :param expr: minute, hour, day of month, month, day of week
+        :param datetime.tzinfo|str timezone: time zone to use for the date/time calculations (
+            defaults to scheduler timezone)
+        :return: a :class:`~CronTrigger` instance
+
+        """
+        values = expr.split()
+        if len(values) != 5:
+            raise ValueError('Wrong number of fields; got {}, expected 5'.format(len(values)))
+
+        return cls(minute=values[0], hour=values[1], day=values[2], month=values[3],
+                   day_of_week=values[4], timezone=timezone)
+
+    def _increment_field_value(self, dateval, fieldnum):
+        """
+        Increments the designated field and resets all less significant fields to their minimum
+        values.
+
+        :type dateval: datetime
+        :type fieldnum: int
+        :return: a tuple containing the new date, and the number of the field that was actually
+            incremented
+        :rtype: tuple
+        """
+
+        values = {}
+        i = 0
+        while i < len(self.fields):
+            field = self.fields[i]
+            if not field.REAL:
+                if i == fieldnum:
+                    fieldnum -= 1
+                    i -= 1
+                else:
+                    i += 1
+                continue
+
+            if i < fieldnum:
+                values[field.name] = field.get_value(dateval)
+                i += 1
+            elif i > fieldnum:
+                values[field.name] = field.get_min(dateval)
+                i += 1
+            else:
+                value = field.get_value(dateval)
+                maxval = field.get_max(dateval)
+                if value == maxval:
+                    fieldnum -= 1
+                    i -= 1
+                else:
+                    values[field.name] = value + 1
+                    i += 1
+
+        difference = datetime(**values) - dateval.replace(tzinfo=None)
+        return normalize(dateval + difference), fieldnum
+
+    def _set_field_value(self, dateval, fieldnum, new_value):
+        values = {}
+        for i, field in enumerate(self.fields):
+            if field.REAL:
+                if i < fieldnum:
+                    values[field.name] = field.get_value(dateval)
+                elif i > fieldnum:
+                    values[field.name] = field.get_min(dateval)
+                else:
+                    values[field.name] = new_value
+
+        return localize(datetime(**values), self.timezone)
+
+    def get_next_fire_time(self, previous_fire_time, now):
+        if previous_fire_time:
+            start_date = min(now, previous_fire_time + timedelta(microseconds=1))
+            if start_date == previous_fire_time:
+                start_date += timedelta(microseconds=1)
+        else:
+            start_date = max(now, self.start_date) if self.start_date else now
+
+        fieldnum = 0
+        next_date = datetime_ceil(start_date).astimezone(self.timezone)
+        while 0 <= fieldnum < len(self.fields):
+            field = self.fields[fieldnum]
+            curr_value = field.get_value(next_date)
+            next_value = field.get_next_value(next_date)
+
+            if next_value is None:
+                # No valid value was found
+                next_date, fieldnum = self._increment_field_value(next_date, fieldnum - 1)
+            elif next_value > curr_value:
+                # A valid, but higher than the starting value, was found
+                if field.REAL:
+                    next_date = self._set_field_value(next_date, fieldnum, next_value)
+                    fieldnum += 1
+                else:
+                    next_date, fieldnum = self._increment_field_value(next_date, fieldnum)
+            else:
+                # A valid value was found, no changes necessary
+                fieldnum += 1
+
+            # Return if the date has rolled past the end date
+            if self.end_date and next_date > self.end_date:
+                return None
+
+        if fieldnum >= 0:
+            next_date = self._apply_jitter(next_date, self.jitter, now)
+            return min(next_date, self.end_date) if self.end_date else next_date
+
+    def __getstate__(self):
+        return {
+            'version': 2,
+            'timezone': self.timezone,
+            'start_date': self.start_date,
+            'end_date': self.end_date,
+            'fields': self.fields,
+            'jitter': self.jitter,
+        }
+
+    def __setstate__(self, state):
+        # This is for compatibility with APScheduler 3.0.x
+        if isinstance(state, tuple):
+            state = state[1]
+
+        if state.get('version', 1) > 2:
+            raise ValueError(
+                'Got serialized data for version %s of %s, but only versions up to 2 can be '
+                'handled' % (state['version'], self.__class__.__name__))
+
+        self.timezone = state['timezone']
+        self.start_date = state['start_date']
+        self.end_date = state['end_date']
+        self.fields = state['fields']
+        self.jitter = state.get('jitter')
+
+    def __str__(self):
+        options = ["%s='%s'" % (f.name, f) for f in self.fields if not f.is_default]
+        return 'cron[%s]' % (', '.join(options))
+
+    def __repr__(self):
+        options = ["%s='%s'" % (f.name, f) for f in self.fields if not f.is_default]
+        if self.start_date:
+            options.append("start_date=%r" % datetime_repr(self.start_date))
+        if self.end_date:
+            options.append("end_date=%r" % datetime_repr(self.end_date))
+        if self.jitter:
+            options.append('jitter=%s' % self.jitter)
+
+        return "<%s (%s, timezone='%s')>" % (
+            self.__class__.__name__, ', '.join(options), self.timezone)

apscheduler/triggers/cron/expressions.py

@@ -0,0 +1,251 @@
+"""This module contains the expressions applicable for CronTrigger's fields."""
+
+from calendar import monthrange
+import re
+
+from apscheduler.util import asint
+
+__all__ = ('AllExpression', 'RangeExpression', 'WeekdayRangeExpression',
+           'WeekdayPositionExpression', 'LastDayOfMonthExpression')
+
+
+WEEKDAYS = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun']
+MONTHS = ['jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug', 'sep', 'oct', 'nov', 'dec']
+
+
+class AllExpression(object):
+    value_re = re.compile(r'\*(?:/(?P<step>\d+))?$')
+
+    def __init__(self, step=None):
+        self.step = asint(step)
+        if self.step == 0:
+            raise ValueError('Increment must be higher than 0')
+
+    def validate_range(self, field_name):
+        from apscheduler.triggers.cron.fields import MIN_VALUES, MAX_VALUES
+
+        value_range = MAX_VALUES[field_name] - MIN_VALUES[field_name]
+        if self.step and self.step > value_range:
+            raise ValueError('the step value ({}) is higher than the total range of the '
+                             'expression ({})'.format(self.step, value_range))
+
+    def get_next_value(self, date, field):
+        start = field.get_value(date)
+        minval = field.get_min(date)
+        maxval = field.get_max(date)
+        start = max(start, minval)
+
+        if not self.step:
+            next = start
+        else:
+            distance_to_next = (self.step - (start - minval)) % self.step
+            next = start + distance_to_next
+
+        if next <= maxval:
+            return next
+
+    def __eq__(self, other):
+        return isinstance(other, self.__class__) and self.step == other.step
+
+    def __str__(self):
+        if self.step:
+            return '*/%d' % self.step
+        return '*'
+
+    def __repr__(self):
+        return "%s(%s)" % (self.__class__.__name__, self.step)
+
+
+class RangeExpression(AllExpression):
+    value_re = re.compile(
+        r'(?P<first>\d+)(?:-(?P<last>\d+))?(?:/(?P<step>\d+))?$')
+
+    def __init__(self, first, last=None, step=None):
+        super(RangeExpression, self).__init__(step)
+        first = asint(first)
+        last = asint(last)
+        if last is None and step is None:
+            last = first
+        if last is not None and first > last:
+            raise ValueError('The minimum value in a range must not be higher than the maximum')
+        self.first = first
+        self.last = last
+
+    def validate_range(self, field_name):
+        from apscheduler.triggers.cron.fields import MIN_VALUES, MAX_VALUES
+
+        super(RangeExpression, self).validate_range(field_name)
+        if self.first < MIN_VALUES[field_name]:
+            raise ValueError('the first value ({}) is lower than the minimum value ({})'
+                             .format(self.first, MIN_VALUES[field_name]))
+        if self.last is not None and self.last > MAX_VALUES[field_name]:
+            raise ValueError('the last value ({}) is higher than the maximum value ({})'
+                             .format(self.last, MAX_VALUES[field_name]))
+        value_range = (self.last or MAX_VALUES[field_name]) - self.first
+        if self.step and self.step > value_range:
+            raise ValueError('the step value ({}) is higher than the total range of the '
+                             'expression ({})'.format(self.step, value_range))
+
+    def get_next_value(self, date, field):
+        startval = field.get_value(date)
+        minval = field.get_min(date)
+        maxval = field.get_max(date)
+
+        # Apply range limits
+        minval = max(minval, self.first)
+        maxval = min(maxval, self.last) if self.last is not None else maxval
+        nextval = max(minval, startval)
+
+        # Apply the step if defined
+        if self.step:
+            distance_to_next = (self.step - (nextval - minval)) % self.step
+            nextval += distance_to_next
+
+        return nextval if nextval <= maxval else None
+
+    def __eq__(self, other):
+        return (isinstance(other, self.__class__) and self.first == other.first and
+                self.last == other.last)
+
+    def __str__(self):
+        if self.last != self.first and self.last is not None:
+            range = '%d-%d' % (self.first, self.last)
+        else:
+            range = str(self.first)
+
+        if self.step:
+            return '%s/%d' % (range, self.step)
+        return range
+
+    def __repr__(self):
+        args = [str(self.first)]
+        if self.last != self.first and self.last is not None or self.step:
+            args.append(str(self.last))
+        if self.step:
+            args.append(str(self.step))
+        return "%s(%s)" % (self.__class__.__name__, ', '.join(args))
+
+
+class MonthRangeExpression(RangeExpression):
+    value_re = re.compile(r'(?P<first>[a-z]+)(?:-(?P<last>[a-z]+))?', re.IGNORECASE)
+
+    def __init__(self, first, last=None):
+        try:
+            first_num = MONTHS.index(first.lower()) + 1
+        except ValueError:
+            raise ValueError('Invalid month name "%s"' % first)
+
+        if last:
+            try:
+                last_num = MONTHS.index(last.lower()) + 1
+            except ValueError:
+                raise ValueError('Invalid month name "%s"' % last)
+        else:
+            last_num = None
+
+        super(MonthRangeExpression, self).__init__(first_num, last_num)
+
+    def __str__(self):
+        if self.last != self.first and self.last is not None:
+            return '%s-%s' % (MONTHS[self.first - 1], MONTHS[self.last - 1])
+        return MONTHS[self.first - 1]
+
+    def __repr__(self):
+        args = ["'%s'" % MONTHS[self.first]]
+        if self.last != self.first and self.last is not None:
+            args.append("'%s'" % MONTHS[self.last - 1])
+        return "%s(%s)" % (self.__class__.__name__, ', '.join(args))
+
+
+class WeekdayRangeExpression(RangeExpression):
+    value_re = re.compile(r'(?P<first>[a-z]+)(?:-(?P<last>[a-z]+))?', re.IGNORECASE)
+
+    def __init__(self, first, last=None):
+        try:
+            first_num = WEEKDAYS.index(first.lower())
+        except ValueError:
+            raise ValueError('Invalid weekday name "%s"' % first)
+
+        if last:
+            try:
+                last_num = WEEKDAYS.index(last.lower())
+            except ValueError:
+                raise ValueError('Invalid weekday name "%s"' % last)
+        else:
+            last_num = None
+
+        super(WeekdayRangeExpression, self).__init__(first_num, last_num)
+
+    def __str__(self):
+        if self.last != self.first and self.last is not None:
+            return '%s-%s' % (WEEKDAYS[self.first], WEEKDAYS[self.last])
+        return WEEKDAYS[self.first]
+
+    def __repr__(self):
+        args = ["'%s'" % WEEKDAYS[self.first]]
+        if self.last != self.first and self.last is not None:
+            args.append("'%s'" % WEEKDAYS[self.last])
+        return "%s(%s)" % (self.__class__.__name__, ', '.join(args))
+
+
+class WeekdayPositionExpression(AllExpression):
+    options = ['1st', '2nd', '3rd', '4th', '5th', 'last']
+    value_re = re.compile(r'(?P<option_name>%s) +(?P<weekday_name>(?:\d+|\w+))' %
+                          '|'.join(options), re.IGNORECASE)
+
+    def __init__(self, option_name, weekday_name):
+        super(WeekdayPositionExpression, self).__init__(None)
+        try:
+            self.option_num = self.options.index(option_name.lower())
+        except ValueError:
+            raise ValueError('Invalid weekday position "%s"' % option_name)
+
+        try:
+            self.weekday = WEEKDAYS.index(weekday_name.lower())
+        except ValueError:
+            raise ValueError('Invalid weekday name "%s"' % weekday_name)
+
+    def get_next_value(self, date, field):
+        # Figure out the weekday of the month's first day and the number of days in that month
+        first_day_wday, last_day = monthrange(date.year, date.month)
+
+        # Calculate which day of the month is the first of the target weekdays
+        first_hit_day = self.weekday - first_day_wday + 1
+        if first_hit_day <= 0:
+            first_hit_day += 7
+
+        # Calculate what day of the month the target weekday would be
+        if self.option_num < 5:
+            target_day = first_hit_day + self.option_num * 7
+        else:
+            target_day = first_hit_day + ((last_day - first_hit_day) // 7) * 7
+
+        if target_day <= last_day and target_day >= date.day:
+            return target_day
+
+    def __eq__(self, other):
+        return (super(WeekdayPositionExpression, self).__eq__(other) and
+                self.option_num == other.option_num and self.weekday == other.weekday)
+
+    def __str__(self):
+        return '%s %s' % (self.options[self.option_num], WEEKDAYS[self.weekday])
+
+    def __repr__(self):
+        return "%s('%s', '%s')" % (self.__class__.__name__, self.options[self.option_num],
+                                   WEEKDAYS[self.weekday])
+
+
+class LastDayOfMonthExpression(AllExpression):
+    value_re = re.compile(r'last', re.IGNORECASE)
+
+    def __init__(self):
+        super(LastDayOfMonthExpression, self).__init__(None)
+
+    def get_next_value(self, date, field):
+        return monthrange(date.year, date.month)[1]
+
+    def __str__(self):
+        return 'last'
+
+    def __repr__(self):
+        return "%s()" % self.__class__.__name__

apscheduler/triggers/cron/fields.py

@@ -0,0 +1,111 @@
+"""Fields represent CronTrigger options which map to :class:`~datetime.datetime` fields."""
+
+from calendar import monthrange
+import re
+
+import six
+
+from apscheduler.triggers.cron.expressions import (
+    AllExpression, RangeExpression, WeekdayPositionExpression, LastDayOfMonthExpression,
+    WeekdayRangeExpression, MonthRangeExpression)
+
+
+__all__ = ('MIN_VALUES', 'MAX_VALUES', 'DEFAULT_VALUES', 'BaseField', 'WeekField',
+           'DayOfMonthField', 'DayOfWeekField')
+
+
+MIN_VALUES = {'year': 1970, 'month': 1, 'day': 1, 'week': 1, 'day_of_week': 0, 'hour': 0,
+              'minute': 0, 'second': 0}
+MAX_VALUES = {'year': 9999, 'month': 12, 'day': 31, 'week': 53, 'day_of_week': 6, 'hour': 23,
+              'minute': 59, 'second': 59}
+DEFAULT_VALUES = {'year': '*', 'month': 1, 'day': 1, 'week': '*', 'day_of_week': '*', 'hour': 0,
+                  'minute': 0, 'second': 0}
+SEPARATOR = re.compile(' *, *')
+
+
+class BaseField(object):
+    REAL = True
+    COMPILERS = [AllExpression, RangeExpression]
+
+    def __init__(self, name, exprs, is_default=False):
+        self.name = name
+        self.is_default = is_default
+        self.compile_expressions(exprs)
+
+    def get_min(self, dateval):
+        return MIN_VALUES[self.name]
+
+    def get_max(self, dateval):
+        return MAX_VALUES[self.name]
+
+    def get_value(self, dateval):
+        return getattr(dateval, self.name)
+
+    def get_next_value(self, dateval):
+        smallest = None
+        for expr in self.expressions:
+            value = expr.get_next_value(dateval, self)
+            if smallest is None or (value is not None and value < smallest):
+                smallest = value
+
+        return smallest
+
+    def compile_expressions(self, exprs):
+        self.expressions = []
+
+        # Split a comma-separated expression list, if any
+        for expr in SEPARATOR.split(str(exprs).strip()):
+            self.compile_expression(expr)
+
+    def compile_expression(self, expr):
+        for compiler in self.COMPILERS:
+            match = compiler.value_re.match(expr)
+            if match:
+                compiled_expr = compiler(**match.groupdict())
+
+                try:
+                    compiled_expr.validate_range(self.name)
+                except ValueError as e:
+                    exc = ValueError('Error validating expression {!r}: {}'.format(expr, e))
+                    six.raise_from(exc, None)
+
+                self.expressions.append(compiled_expr)
+                return
+
+        raise ValueError('Unrecognized expression "%s" for field "%s"' % (expr, self.name))
+
+    def __eq__(self, other):
+        return isinstance(self, self.__class__) and self.expressions == other.expressions
+
+    def __str__(self):
+        expr_strings = (str(e) for e in self.expressions)
+        return ','.join(expr_strings)
+
+    def __repr__(self):
+        return "%s('%s', '%s')" % (self.__class__.__name__, self.name, self)
+
+
+class WeekField(BaseField):
+    REAL = False
+
+    def get_value(self, dateval):
+        return dateval.isocalendar()[1]
+
+
+class DayOfMonthField(BaseField):
+    COMPILERS = BaseField.COMPILERS + [WeekdayPositionExpression, LastDayOfMonthExpression]
+
+    def get_max(self, dateval):
+        return monthrange(dateval.year, dateval.month)[1]
+
+
+class DayOfWeekField(BaseField):
+    REAL = False
+    COMPILERS = BaseField.COMPILERS + [WeekdayRangeExpression]
+
+    def get_value(self, dateval):
+        return dateval.weekday()
+
+
+class MonthField(BaseField):
+    COMPILERS = BaseField.COMPILERS + [MonthRangeExpression]

apscheduler/triggers/date.py

@@ -0,0 +1,51 @@
+from datetime import datetime
+
+from tzlocal import get_localzone
+
+from apscheduler.triggers.base import BaseTrigger
+from apscheduler.util import convert_to_datetime, datetime_repr, astimezone
+
+
+class DateTrigger(BaseTrigger):
+    """
+    Triggers once on the given datetime. If ``run_date`` is left empty, current time is used.
+
+    :param datetime|str run_date: the date/time to run the job at
+    :param datetime.tzinfo|str timezone: time zone for ``run_date`` if it doesn't have one already
+    """
+
+    __slots__ = 'run_date'
+
+    def __init__(self, run_date=None, timezone=None):
+        timezone = astimezone(timezone) or get_localzone()
+        if run_date is not None:
+            self.run_date = convert_to_datetime(run_date, timezone, 'run_date')
+        else:
+            self.run_date = datetime.now(timezone)
+
+    def get_next_fire_time(self, previous_fire_time, now):
+        return self.run_date if previous_fire_time is None else None
+
+    def __getstate__(self):
+        return {
+            'version': 1,
+            'run_date': self.run_date
+        }
+
+    def __setstate__(self, state):
+        # This is for compatibility with APScheduler 3.0.x
+        if isinstance(state, tuple):
+            state = state[1]
+
+        if state.get('version', 1) > 1:
+            raise ValueError(
+                'Got serialized data for version %s of %s, but only version 1 can be handled' %
+                (state['version'], self.__class__.__name__))
+
+        self.run_date = state['run_date']
+
+    def __str__(self):
+        return 'date[%s]' % datetime_repr(self.run_date)
+
+    def __repr__(self):
+        return "<%s (run_date='%s')>" % (self.__class__.__name__, datetime_repr(self.run_date))

apscheduler/triggers/interval.py

@@ -0,0 +1,108 @@
+from datetime import timedelta, datetime
+from math import ceil
+
+from tzlocal import get_localzone
+
+from apscheduler.triggers.base import BaseTrigger
+from apscheduler.util import (
+    convert_to_datetime, normalize, timedelta_seconds, datetime_repr,
+    astimezone)
+
+
+class IntervalTrigger(BaseTrigger):
+    """
+    Triggers on specified intervals, starting on ``start_date`` if specified, ``datetime.now()`` +
+    interval otherwise.
+
+    :param int weeks: number of weeks to wait
+    :param int days: number of days to wait
+    :param int hours: number of hours to wait
+    :param int minutes: number of minutes to wait
+    :param int seconds: number of seconds to wait
+    :param datetime|str start_date: starting point for the interval calculation
+    :param datetime|str end_date: latest possible date/time to trigger on
+    :param datetime.tzinfo|str timezone: time zone to use for the date/time calculations
+    :param int|None jitter: delay the job execution by ``jitter`` seconds at most
+    """
+
+    __slots__ = 'timezone', 'start_date', 'end_date', 'interval', 'interval_length', 'jitter'
+
+    def __init__(self, weeks=0, days=0, hours=0, minutes=0, seconds=0, start_date=None,
+                 end_date=None, timezone=None, jitter=None):
+        self.interval = timedelta(weeks=weeks, days=days, hours=hours, minutes=minutes,
+                                  seconds=seconds)
+        self.interval_length = timedelta_seconds(self.interval)
+        if self.interval_length == 0:
+            self.interval = timedelta(seconds=1)
+            self.interval_length = 1
+
+        if timezone:
+            self.timezone = astimezone(timezone)
+        elif isinstance(start_date, datetime) and start_date.tzinfo:
+            self.timezone = start_date.tzinfo
+        elif isinstance(end_date, datetime) and end_date.tzinfo:
+            self.timezone = end_date.tzinfo
+        else:
+            self.timezone = get_localzone()
+
+        start_date = start_date or (datetime.now(self.timezone) + self.interval)
+        self.start_date = convert_to_datetime(start_date, self.timezone, 'start_date')
+        self.end_date = convert_to_datetime(end_date, self.timezone, 'end_date')
+
+        self.jitter = jitter
+
+    def get_next_fire_time(self, previous_fire_time, now):
+        if previous_fire_time:
+            next_fire_time = previous_fire_time + self.interval
+        elif self.start_date > now:
+            next_fire_time = self.start_date
+        else:
+            timediff_seconds = timedelta_seconds(now - self.start_date)
+            next_interval_num = int(ceil(timediff_seconds / self.interval_length))
+            next_fire_time = self.start_date + self.interval * next_interval_num
+
+        if self.jitter is not None:
+            next_fire_time = self._apply_jitter(next_fire_time, self.jitter, now)
+
+        if not self.end_date or next_fire_time <= self.end_date:
+            return normalize(next_fire_time)
+
+    def __getstate__(self):
+        return {
+            'version': 2,
+            'timezone': self.timezone,
+            'start_date': self.start_date,
+            'end_date': self.end_date,
+            'interval': self.interval,
+            'jitter': self.jitter,
+        }
+
+    def __setstate__(self, state):
+        # This is for compatibility with APScheduler 3.0.x
+        if isinstance(state, tuple):
+            state = state[1]
+
+        if state.get('version', 1) > 2:
+            raise ValueError(
+                'Got serialized data for version %s of %s, but only versions up to 2 can be '
+                'handled' % (state['version'], self.__class__.__name__))
+
+        self.timezone = state['timezone']
+        self.start_date = state['start_date']
+        self.end_date = state['end_date']
+        self.interval = state['interval']
+        self.interval_length = timedelta_seconds(self.interval)
+        self.jitter = state.get('jitter')
+
+    def __str__(self):
+        return 'interval[%s]' % str(self.interval)
+
+    def __repr__(self):
+        options = ['interval=%r' % self.interval, 'start_date=%r' % datetime_repr(self.start_date)]
+        if self.end_date:
+            options.append("end_date=%r" % datetime_repr(self.end_date))
+        if self.jitter:
+            options.append('jitter=%s' % self.jitter)
+
+        return "<%s (%s, timezone='%s')>" % (
+            self.__class__.__name__, ', '.join(options), self.timezone)

apscheduler/util.py

@@ -0,0 +1,438 @@
+"""This module contains several handy functions primarily meant for internal use."""
+
+from __future__ import division
+
+from datetime import date, datetime, time, timedelta, tzinfo
+from calendar import timegm
+from functools import partial
+from inspect import isclass, ismethod
+import re
+import sys
+
+from pytz import timezone, utc, FixedOffset
+import six
+
+try:
+    from inspect import signature
+except ImportError:  # pragma: nocover
+    from funcsigs import signature
+
+try:
+    from threading import TIMEOUT_MAX
+except ImportError:
+    TIMEOUT_MAX = 4294967  # Maximum value accepted by Event.wait() on Windows
+
+try:
+    from asyncio import iscoroutinefunction
+except ImportError:
+    try:
+        from trollius import iscoroutinefunction
+    except ImportError:
+        def iscoroutinefunction(func):
+            return False
+
+__all__ = ('asint', 'asbool', 'astimezone', 'convert_to_datetime', 'datetime_to_utc_timestamp',
+           'utc_timestamp_to_datetime', 'timedelta_seconds', 'datetime_ceil', 'get_callable_name',
+           'obj_to_ref', 'ref_to_obj', 'maybe_ref', 'repr_escape', 'check_callable_args',
+           'normalize', 'localize', 'TIMEOUT_MAX')
+
+
+class _Undefined(object):
+    def __nonzero__(self):
+        return False
+
+    def __bool__(self):
+        return False
+
+    def __repr__(self):
+        return '<undefined>'
+
+
+undefined = _Undefined()  #: a unique object that only signifies that no value is defined
+
+
+def asint(text):
+    """
+    Safely converts a string to an integer, returning ``None`` if the string is ``None``.
+
+    :type text: str
+    :rtype: int
+
+    """
+    if text is not None:
+        return int(text)
+
+
+def asbool(obj):
+    """
+    Interprets an object as a boolean value.
+
+    :rtype: bool
+
+    """
+    if isinstance(obj, str):
+        obj = obj.strip().lower()
+        if obj in ('true', 'yes', 'on', 'y', 't', '1'):
+            return True
+        if obj in ('false', 'no', 'off', 'n', 'f', '0'):
+            return False
+        raise ValueError('Unable to interpret value "%s" as boolean' % obj)
+    return bool(obj)
+
+
+def astimezone(obj):
+    """
+    Interprets an object as a timezone.
+
+    :rtype: tzinfo
+
+    """
+    if isinstance(obj, six.string_types):
+        return timezone(obj)
+    if isinstance(obj, tzinfo):
+        if obj.tzname(None) == 'local':
+            raise ValueError(
+                'Unable to determine the name of the local timezone -- you must explicitly '
+                'specify the name of the local timezone. Please refrain from using timezones like '
+                'EST to prevent problems with daylight saving time. Instead, use a locale based '
+                'timezone name (such as Europe/Helsinki).')
+        return obj
+    if obj is not None:
+        raise TypeError('Expected tzinfo, got %s instead' % obj.__class__.__name__)
+
+
+_DATE_REGEX = re.compile(
+    r'(?P<year>\d{4})-(?P<month>\d{1,2})-(?P<day>\d{1,2})'
+    r'(?:[ T](?P<hour>\d{1,2}):(?P<minute>\d{1,2}):(?P<second>\d{1,2})'
+    r'(?:\.(?P<microsecond>\d{1,6}))?'
+    r'(?P<timezone>Z|[+-]\d\d:\d\d)?)?$')
+
+
+def convert_to_datetime(input, tz, arg_name):
+    """
+    Converts the given object to a timezone aware datetime object.
+
+    If a timezone aware datetime object is passed, it is returned unmodified.
+    If a native datetime object is passed, it is given the specified timezone.
+    If the input is a string, it is parsed as a datetime with the given timezone.
+
+    Date strings are accepted in three different forms: date only (Y-m-d), date with time
+    (Y-m-d H:M:S) or with date+time with microseconds (Y-m-d H:M:S.micro). Additionally you can
+    override the time zone by giving a specific offset in the format specified by ISO 8601:
+    Z (UTC), +HH:MM or -HH:MM.
+
+    :param str|datetime input: the datetime or string to convert to a timezone aware datetime
+    :param datetime.tzinfo tz: timezone to interpret ``input`` in
+    :param str arg_name: the name of the argument (used in an error message)
+    :rtype: datetime
+
+    """
+    if input is None:
+        return
+    elif isinstance(input, datetime):
+        datetime_ = input
+    elif isinstance(input, date):
+        datetime_ = datetime.combine(input, time())
+    elif isinstance(input, six.string_types):
+        m = _DATE_REGEX.match(input)
+        if not m:
+            raise ValueError('Invalid date string')
+
+        values = m.groupdict()
+        tzname = values.pop('timezone')
+        if tzname == 'Z':
+            tz = utc
+        elif tzname:
+            hours, minutes = (int(x) for x in tzname[1:].split(':'))
+            sign = 1 if tzname[0] == '+' else -1
+            tz = FixedOffset(sign * (hours * 60 + minutes))
+
+        values = {k: int(v or 0) for k, v in values.items()}
+        datetime_ = datetime(**values)
+    else:
+        raise TypeError('Unsupported type for %s: %s' % (arg_name, input.__class__.__name__))
+
+    if datetime_.tzinfo is not None:
+        return datetime_
+    if tz is None:
+        raise ValueError(
+            'The "tz" argument must be specified if %s has no timezone information' % arg_name)
+    if isinstance(tz, six.string_types):
+        tz = timezone(tz)
+
+    return localize(datetime_, tz)
+
+
+def datetime_to_utc_timestamp(timeval):
+    """
+    Converts a datetime instance to a timestamp.
+
+    :type timeval: datetime
+    :rtype: float
+
+    """
+    if timeval is not None:
+        return timegm(timeval.utctimetuple()) + timeval.microsecond / 1000000
+
+
+def utc_timestamp_to_datetime(timestamp):
+    """
+    Converts the given timestamp to a datetime instance.
+
+    :type timestamp: float
+    :rtype: datetime
+
+    """
+    if timestamp is not None:
+        return datetime.fromtimestamp(timestamp, utc)
+
+
+def timedelta_seconds(delta):
+    """
+    Converts the given timedelta to seconds.
+
+    :type delta: timedelta
+    :rtype: float
+
+    """
+    return delta.days * 24 * 60 * 60 + delta.seconds + \
+        delta.microseconds / 1000000.0
+
+
+def datetime_ceil(dateval):
+    """
+    Rounds the given datetime object upwards.
+
+    :type dateval: datetime
+
+    """
+    if dateval.microsecond > 0:
+        return dateval + timedelta(seconds=1, microseconds=-dateval.microsecond)
+    return dateval
+
+
+def datetime_repr(dateval):
+    return dateval.strftime('%Y-%m-%d %H:%M:%S %Z') if dateval else 'None'
+
+
+def get_callable_name(func):
+    """
+    Returns the best available display name for the given function/callable.
+
+    :rtype: str
+
+    """
+    # the easy case (on Python 3.3+)
+    if hasattr(func, '__qualname__'):
+        return func.__qualname__
+
+    # class methods, bound and unbound methods
+    f_self = getattr(func, '__self__', None) or getattr(func, 'im_self', None)
+    if f_self and hasattr(func, '__name__'):
+        f_class = f_self if isclass(f_self) else f_self.__class__
+    else:
+        f_class = getattr(func, 'im_class', None)
+
+    if f_class and hasattr(func, '__name__'):
+        return '%s.%s' % (f_class.__name__, func.__name__)
+
+    # class or class instance
+    if hasattr(func, '__call__'):
+        # class
+        if hasattr(func, '__name__'):
+            return func.__name__
+
+        # instance of a class with a __call__ method
+        return func.__class__.__name__
+
+    raise TypeError('Unable to determine a name for %r -- maybe it is not a callable?' % func)
+
+
+def obj_to_ref(obj):
+    """
+    Returns the path to the given callable.
+
+    :rtype: str
+    :raises TypeError: if the given object is not callable
+    :raises ValueError: if the given object is a :class:`~functools.partial`, lambda or a nested
+        function
+
+    """
+    if isinstance(obj, partial):
+        raise ValueError('Cannot create a reference to a partial()')
+
+    name = get_callable_name(obj)
+    if '<lambda>' in name:
+        raise ValueError('Cannot create a reference to a lambda')
+    if '<locals>' in name:
+        raise ValueError('Cannot create a reference to a nested function')
+
+    if ismethod(obj):
+        if hasattr(obj, 'im_self') and obj.im_self:
+            # bound method
+            module = obj.im_self.__module__
+        elif hasattr(obj, 'im_class') and obj.im_class:
+            # unbound method
+            module = obj.im_class.__module__
+        else:
+            module = obj.__module__
+    else:
+        module = obj.__module__
+    return '%s:%s' % (module, name)
+
+
+def ref_to_obj(ref):
+    """
+    Returns the object pointed to by ``ref``.
+
+    :type ref: str
+
+    """
+    if not isinstance(ref, six.string_types):
+        raise TypeError('References must be strings')
+    if ':' not in ref:
+        raise ValueError('Invalid reference')
+
+    modulename, rest = ref.split(':', 1)
+    try:
+        obj = __import__(modulename, fromlist=[rest])
+    except ImportError:
+        raise LookupError('Error resolving reference %s: could not import module' % ref)
+
+    try:
+        for name in rest.split('.'):
+            obj = getattr(obj, name)
+        return obj
+    except Exception:
+        raise LookupError('Error resolving reference %s: error looking up object' % ref)
+
+
+def maybe_ref(ref):
+    """
+    Returns the object that the given reference points to, if it is indeed a reference.
+    If it is not a reference, the object is returned as-is.
+
+    """
+    if not isinstance(ref, str):
+        return ref
+    return ref_to_obj(ref)
+
+
+if six.PY2:
+    def repr_escape(string):
+        if isinstance(string, six.text_type):
+            return string.encode('ascii', 'backslashreplace')
+        return string
+else:
+    def repr_escape(string):
+        return string
+
+
+def check_callable_args(func, args, kwargs):
+    """
+    Ensures that the given callable can be called with the given arguments.
+
+    :type args: tuple
+    :type kwargs: dict
+
+    """
+    pos_kwargs_conflicts = []  # parameters that have a match in both args and kwargs
+    positional_only_kwargs = []  # positional-only parameters that have a match in kwargs
+    unsatisfied_args = []  # parameters in signature that don't have a match in args or kwargs
+    unsatisfied_kwargs = []  # keyword-only arguments that don't have a match in kwargs
+    unmatched_args = list(args)  # args that didn't match any of the parameters in the signature
+    # kwargs that didn't match any of the parameters in the signature
+    unmatched_kwargs = list(kwargs)
+    # indicates if the signature defines *args and **kwargs respectively
+    has_varargs = has_var_kwargs = False
+
+    try:
+        if sys.version_info >= (3, 5):
+            sig = signature(func, follow_wrapped=False)
+        else:
+            sig = signature(func)
+    except ValueError:
+        # signature() doesn't work against every kind of callable
+        return
+
+    for param in six.itervalues(sig.parameters):
+        if param.kind == param.POSITIONAL_OR_KEYWORD:
+            if param.name in unmatched_kwargs and unmatched_args:
+                pos_kwargs_conflicts.append(param.name)
+            elif unmatched_args:
+                del unmatched_args[0]
+            elif param.name in unmatched_kwargs:
+                unmatched_kwargs.remove(param.name)
+            elif param.default is param.empty:
+                unsatisfied_args.append(param.name)
+        elif param.kind == param.POSITIONAL_ONLY:
+            if unmatched_args:
+                del unmatched_args[0]
+            elif param.name in unmatched_kwargs:
+                unmatched_kwargs.remove(param.name)
+                positional_only_kwargs.append(param.name)
+            elif param.default is param.empty:
+                unsatisfied_args.append(param.name)
+        elif param.kind == param.KEYWORD_ONLY:
+            if param.name in unmatched_kwargs:
+                unmatched_kwargs.remove(param.name)
+            elif param.default is param.empty:
+                unsatisfied_kwargs.append(param.name)
+        elif param.kind == param.VAR_POSITIONAL:
+            has_varargs = True
+        elif param.kind == param.VAR_KEYWORD:
+            has_var_kwargs = True
+
+    # Make sure there are no conflicts between args and kwargs
+    if pos_kwargs_conflicts:
+        raise ValueError('The following arguments are supplied in both args and kwargs: %s' %
+                         ', '.join(pos_kwargs_conflicts))
+
+    # Check if keyword arguments are being fed to positional-only parameters
+    if positional_only_kwargs:
+        raise ValueError('The following arguments cannot be given as keyword arguments: %s' %
+                         ', '.join(positional_only_kwargs))
+
+    # Check that the number of positional arguments minus the number of matched kwargs matches the
+    # argspec
+    if unsatisfied_args:
+        raise ValueError('The following arguments have not been supplied: %s' %
+                         ', '.join(unsatisfied_args))
+
+    # Check that all keyword-only arguments have been supplied
+    if unsatisfied_kwargs:
+        raise ValueError(
+            'The following keyword-only arguments have not been supplied in kwargs: %s' %
+            ', '.join(unsatisfied_kwargs))
+
+    # Check that the callable can accept the given number of positional arguments
+    if not has_varargs and unmatched_args:
+        raise ValueError(
+            'The list of positional arguments is longer than the target callable can handle '
+            '(allowed: %d, given in args: %d)' % (len(args) - len(unmatched_args), len(args)))
+
+    # Check that the callable can accept the given keyword arguments
+    if not has_var_kwargs and unmatched_kwargs:
+        raise ValueError(
+            'The target callable does not accept the following keyword arguments: %s' %
+            ', '.join(unmatched_kwargs))
+
+
+def iscoroutinefunction_partial(f):
+    while isinstance(f, partial):
+        f = f.func
+
+    # The asyncio version of iscoroutinefunction includes testing for @coroutine
+    # decorations vs. the inspect version which does not.
+    return iscoroutinefunction(f)
+
+
+def normalize(dt):
+    return datetime.fromtimestamp(dt.timestamp(), dt.tzinfo)
+
+
+def localize(dt, tzinfo):
+    if hasattr(tzinfo, 'localize'):
+        return tzinfo.localize(dt)
+
+    return normalize(dt.replace(tzinfo=tzinfo))

linspector/core/linspector.py

@@ -24,6 +24,10 @@ import importlib
 
 from logging import getLogger
 
+#from apscheduler.schedulers.background import BackgroundScheduler
+#from apscheduler.jobstores.memory import MemoryJobStore
+#from apscheduler.executors.pool import ThreadPoolExecutor, ProcessPoolExecutor
+
 logger = getLogger('linspector')