AsyncTaskManager

from acron.core import AsyncTaskManager

class AsyncTaskManager

Bases:

Bases: TypedReferenceCount, Namable

A class to manage a loose queue of isolated tasks, which can be performed either synchronously (in the foreground thread) or asynchronously (by a background thread).

The AsyncTaskManager is actually a collection of AsyncTaskChains, each of which maintains a list of tasks. Each chain can be either foreground or background (it may run only in the main thread, or it may be serviced by one or more background threads). See AsyncTaskChain for more information.

If you do not require background processing, it is perfectly acceptable to create only one AsyncTaskChain, which runs in the main thread. This is a common configuration.

Inheritance diagram

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__init__()

property active_tasks → AsyncTaskCollection

Returns the set of tasks that are active (and not sleeping) on the task manager, at the time of the call.

add()

Adds the indicated task to the active queue. It is an error if the task is already added to this or any other active queue.

cleanup()

Stops all threads and messily empties the task list. This is intended to be called on destruction only.

property clock → ClockObject

Getter

Returns the clock pointer used within the AsyncTaskManager. See set_clock().

Setter

Replaces the clock pointer used within the AsyncTaskManager. This is used to control when tasks with a set_delay() specified will be scheduled. It can also be ticked automatically each epoch, if set_tick_clock() is true.

The default is the global clock pointer.

find_task()

Returns the first task found with the indicated name, or NULL if there is no task with the indicated name.

If there are multiple tasks with the same name, returns one of them arbitrarily.

find_task_chain()

Searches a new AsyncTaskChain of the indicated name and returns it if it exists, or NULL otherwise.

find_tasks()

Returns the list of tasks found with the indicated name.

find_tasks_matching()

Returns the list of tasks found whose name matches the indicated glob pattern, e.g. “my_task_*”.

get_active_tasks()

Returns the set of tasks that are active (and not sleeping) on the task manager, at the time of the call.

static get_class_type()

get_clock()

Returns the clock pointer used within the AsyncTaskManager. See set_clock().

static get_global_ptr()

Returns a pointer to the global AsyncTaskManager. This is the AsyncTaskManager that most code should use for queueing tasks and suchlike.

get_next_wake_time()

Returns the scheduled time (on the manager’s clock) of the next sleeping task, on any task chain, to awaken. Returns -1 if there are no sleeping tasks.

get_num_task_chains()

Returns the number of different task chains.

get_num_tasks()

Returns the number of tasks that are currently active or sleeping within the task manager.

get_sleeping_tasks()

Returns the set of tasks that are sleeping (and not active) on the task manager, at the time of the call.

get_task_chain()

Returns the nth task chain.

get_task_chains() → list

get_tasks()

Returns the set of tasks that are active or sleeping on the task manager, at the time of the call.

has_task()

Returns true if the indicated task has been added to this AsyncTaskManager, false otherwise.

make_task_chain()

Creates a new AsyncTaskChain of the indicated name and stores it within the AsyncTaskManager. If a task chain with this name already exists, returns it instead.

Creates a new threaded AsyncTaskChain of the indicated name and stores it within the AsyncTaskManager. If a task chain with this name already exists, returns it instead.

property next_wake_time → float

Returns the scheduled time (on the manager’s clock) of the next sleeping task, on any task chain, to awaken. Returns -1 if there are no sleeping tasks.

output()

poll()

Runs through all the tasks in the task list, once, if the task manager is running in single-threaded mode (no threads available). This method does nothing in threaded mode, so it may safely be called in either case.

remove()

Removes the indicated task from the active queue. Returns true if the task is successfully removed, or false if it wasn’t there.

Removes all of the tasks in the AsyncTaskCollection. Returns the number of tasks removed.

remove_task_chain()

Removes the AsyncTaskChain of the indicated name. If the chain still has tasks, this will block until all tasks are finished.

Returns true if successful, or false if the chain did not exist.

set_clock()

Replaces the clock pointer used within the AsyncTaskManager. This is used to control when tasks with a set_delay() specified will be scheduled. It can also be ticked automatically each epoch, if set_tick_clock() is true.

The default is the global clock pointer.

property sleeping_tasks → AsyncTaskCollection

Returns the set of tasks that are sleeping (and not active) on the task manager, at the time of the call.

start_threads()

Starts any requested threads to service the tasks on the queue. This is normally not necessary, since adding a task will start the threads automatically.

stop_threads()

Stops any threads that are currently running. If any tasks are still pending and have not yet been picked up by a thread, they will not be serviced unless poll() or start_threads() is later called.

property tasks → AsyncTaskCollection

Returns the set of tasks that are active or sleeping on the task manager, at the time of the call.

wait_for_tasks()

Blocks until the task list is empty.

write()