TaskKit.Scheduler | index /usr/local/share/webware/TaskKit/Scheduler.py

`This is the task manager Python package.
It provides a system for running any number of predefined tasks in separate
threads in an organized and controlled manner.
A task in this package is a class derived from the Task class. The task
should have a run method that, when called, performs some task.
The Scheduler class is the organizing object. It manages the addition,
execution, deletion, and well being of a number of tasks. Once you have
created your task class, you call the Scheduler to get it added to the
tasks to be run.`

Classes

``

threading.Thread(threading._Verbose)
  Scheduler

class Scheduler(threading.Thread)
`` | `The top level class of the task manager system. The Scheduler is a thread that handles organizing and running tasks. The Scheduler class should be instantiated to start a task manager session. Its start method should be called to start the task manager. Its stop method should be called to end the task manager session.`

Method resolution order:
  Scheduler
  threading.Thread
  threading._Verbose
  __builtin__.object

Methods defined here:

__init__(self, daemon=True, exceptionHandler=None)

addActionOnDemand(self, task, name)
  `Add a task to be run only on demand.
  Adds a task to the scheduler that will not be scheduled
  until specifically requested.`

addDailyAction(self, hour, minute, task, name)
  `Add an action to be run every day at a specific time.
  If a task with the given name is already registered with the
  scheduler, that task will be removed from the scheduling queue
  and registered anew as a periodic task.
  Can we make this addCalendarAction? What if we want to run
  something once a week? We probably don't need that for Webware,
  but this is a more generally useful module. This could be a
  difficult function, though. Particularly without mxDateTime.`

addPeriodicAction(self, start, period, task, name)
  `Add a task to be run periodically.
  Adds an action to be run at a specific initial time,
  and every period thereafter.
  The scheduler will not reschedule a task until the last
  scheduled instance of the task has completed.
  If a task with the given name is already registered with
  the scheduler, that task will be removed from the scheduling
  queue and registered anew as a periodic task.`

addTimedAction(self, time, task, name)
  `Add a task to be run once, at a specific time.`

delOnDemand(self, name)
  `Delete a task with the given name from the on demand list.`

delRunning(self, name)
  `Delete a task from the running list.
  Used internally.`

delScheduled(self, name)
  `Delete a task with the given name from the scheduled list.`

demandTask(self, name)
  `Demand execution of a task.
  Allow the server to request that a task listed as being registered
  on-demand be run as soon as possible.
  If the task is currently running, it will be flagged to run again
  as soon as the current run completes.
  Returns False if the task name could not be found on the on-demand
  or currently running lists.`

disableTask(self, name)
  `Specify that a task be suspended.
  Suspended tasks will not be scheduled until later enabled.
  If the task is currently running, it will not be interfered
  with, but the task will not be scheduled for execution in
  future until re-enabled.
  Returns True if the task was found and disabled.`

enableTask(self, name)
  `Enable a task again.
  This method is provided to specify that a task be re-enabled
  after a suspension. A re-enabled task will be scheduled for
  execution according to its original schedule, with any runtimes
  that would have been issued during the time the task was suspended
  simply skipped.
  Returns True if the task was found and enabled.`

hasOnDemand(self, name)
  `Checks whether task with given name is in the on demand list.`

hasRunning(self, name)
  `Check to see if a task with the given name is currently running.`

hasScheduled(self, name)
  `Checks whether task with given name is in the scheduled list.`

isRunning(self)
  `Check whether thread is running.`

nextTime(self)
  `Get next execution time.`

notify(self)
  `Wake up scheduler by sending a notify even.`

notifyCompletion(self, handle)
  `Notify completion of a task.
  Used by instances of TaskHandler to let the Scheduler thread know
  when their tasks have run to completion. This method is responsible
  for rescheduling the task if it is a periodic task.`

notifyFailure(self, handle)
  `Notify failure of a task.
  Used by instances of TaskHandler to let the Scheduler thread know
  if an exception has occurred within the task thread.`

onDemand(self, name, default=None)
  `Return a task from the onDemand list.`

onDemandTasks(self)
  `Return all on demand tasks.`

run(self)
  `The main method of the scheduler running as a background thread.
  This method is responsible for carrying out the scheduling work of
  this class on a background thread. The basic logic is to wait until
  the next action is due to run, move the task from our scheduled
  list to our running list, and run it. Other synchronized methods
  such as runTask(), scheduleTask(), and notifyCompletion(), may
  be called while this method is waiting for something to happen.
  These methods modify the data structures that run() uses to
  determine its scheduling needs.`

runTask(self, handle)
  `Run a task.
  Used by the Scheduler thread's main loop to put a task in
  the scheduled hash onto the run hash.`

runTaskNow(self, name)
  `Allow a registered task to be immediately executed.
  Returns True if the task is either currently running or was started,
  or False if the task could not be found in the list of currently
  registered tasks.`

running(self, name, default=None)
  `Return running task with given name.
  Returns a task with the given name from the "running" list,
  if it is present there.`

runningTasks(self)
  `Return all running tasks.`

scheduleTask(self, handle)
  `Schedule a task.
  This method takes a task that needs to be scheduled and adds it
  to the scheduler. All scheduling additions or changes are handled
  by this method. This is the only Scheduler method that can notify
  the run() method that it may need to wake up early to handle a
  newly registered task.`

scheduled(self, name, default=None)
  `Return a task from the scheduled list.`

scheduledTasks(self)
  `Return all scheduled tasks.`

setNextTime(self, time)
  `Set next execution time.`

setOnDemand(self, handle)
  `Add the given task to the on demand list.`

setRunning(self, handle)
  `Add a task to the running dictionary.
  Used internally only.`

setScheduled(self, handle)
  `Add the given task to the scheduled list.`

start(self)
  `Start the scheduler's activity.`

stop(self)
  `Terminate the scheduler and its associated tasks.`

stopAllTasks(self)
  `Terminate all running tasks.`

stopTask(self, name)
  `Put an immediate halt to a running background task.
  Returns True if the task was either not running, or was
  running and was told to stop.`

unregisterTask(self, name)
  `Unregisters the named task.
  After that it can be rescheduled with different parameters,
  or simply removed.`

wait(self, seconds=None)
  `Our own version of wait().
  When called, it waits for the specified number of seconds, or until
  it is notified that it needs to wake up, through the notify event.`

Methods inherited from threading.Thread:

__repr__(self)

getName(self)

isAlive(self)
  `Return whether the thread is alive.
  This method returns True just before the run() method starts until just
  after the run() method terminates. The module function enumerate()
  returns a list of all alive threads.`

isDaemon(self)

is_alive = isAlive(self)
  `Return whether the thread is alive.
  This method returns True just before the run() method starts until just
  after the run() method terminates. The module function enumerate()
  returns a list of all alive threads.`

join(self, timeout=None)
  `Wait until the thread terminates.
  This blocks the calling thread until the thread whose join() method is
  called terminates -- either normally or through an unhandled exception
  or until the optional timeout occurs.
  When the timeout argument is present and not None, it should be a
  floating point number specifying a timeout for the operation in seconds
  (or fractions thereof). As join() always returns None, you must call
  isAlive() after join() to decide whether a timeout happened -- if the
  thread is still alive, the join() call timed out.
  When the timeout argument is not present or None, the operation will
  block until the thread terminates.
  A thread can be join()ed many times.
  join() raises a RuntimeError if an attempt is made to join the current
  thread as that would cause a deadlock. It is also an error to join() a
  thread before it has been started and attempts to do so raises the same
  exception.`

setDaemon(self, daemonic)

setName(self, name)

Data descriptors inherited from threading.Thread:

daemon
  `A boolean value indicating whether this thread is a daemon thread (True) or not (False).
  This must be set before start() is called, otherwise RuntimeError is
  raised. Its initial value is inherited from the creating thread; the
  main thread is not a daemon thread and therefore all threads created in
  the main thread default to daemon = False.
  The entire Python program exits when no alive non-daemon threads are
  left.`

ident
  `Thread identifier of this thread or None if it has not been started.
  This is a nonzero integer. See the thread.get_ident() function. Thread
  identifiers may be recycled when a thread exits and another thread is
  created. The identifier is available even after the thread has exited.`

name
  `A string used for identification purposes only.
  It has no semantics. Multiple threads may be given the same name. The
  initial name is set by the constructor.`

Data descriptors inherited from threading._Verbose:

__dict__
  `dictionary for instance variables (if defined)`

__weakref__
  `list of weak references to the object (if defined)`

Functions

``

localtime(...)
  `localtime([seconds]) -> (tm_year,tm_mon,tm_mday,tm_hour,tm_min,
  tm_sec,tm_wday,tm_yday,tm_isdst)
  Convert seconds since the Epoch to a time tuple expressing local time.
  When 'seconds' is not passed in, convert the current time instead.`

time(...)
  `time() -> floating point number
  Return the current time in seconds since the Epoch.
  Fractions of a second may be present if the system clock provides them.`