# AsyncTaskManager¶

from panda3d.core import AsyncTaskManager

class AsyncTaskManager

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

__init__(name: str)
property active_tasksAsyncTaskCollection

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

add(task: AsyncTask)None

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()None

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

property clockClockObject
Getter

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

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.

findTask(name: str)AsyncTask

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.

findTaskChain(name: str)AsyncTaskChain

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

findTasks(name: str)AsyncTaskCollection

Returns the list of tasks found with the indicated name.

findTasksMatching(pattern: GlobPattern)AsyncTaskCollection

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

getActiveTasks()AsyncTaskCollection

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

static getClassType()TypeHandle
getClock()ClockObject

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

static getGlobalPtr()AsyncTaskManager

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

getNextWakeTime()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.

getNumTaskChains()int

Returns the number of different task chains.

getNumTasks()int

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

getSleepingTasks()AsyncTaskCollection

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

getTaskChain(n: int)AsyncTaskChain

Returns the nth task chain.

getTaskChains()list
getTasks()AsyncTaskCollection

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

hasTask(task: AsyncTask)bool

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

makeTaskChain(name: str)AsyncTaskChain

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.

property next_wake_timefloat

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(out: ostream)None
poll()None

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(task: AsyncTask)bool

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

remove(tasks: AsyncTaskCollection)int

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

removeTaskChain(name: str)bool

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.

setClock(clock: ClockObject)None

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_tasksAsyncTaskCollection

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

startThreads()None

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.

stopThreads()None

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 startThreads() is later called.

property tasksAsyncTaskCollection

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

waitForTasks()None

Blocks until the task list is empty.

write(out: ostream, indent_level: int)None