TaskPool

GEvent Pool.

Attributes

Attribute	Type	Description
Timer	class = Timer	Reference to the Timer class used for scheduling timed events within the pool.
signal_safe	boolean = false	Boolean flag indicating if the pool can safely handle POSIX signals, set to False for gevent compatibility.
is_green	boolean = true	Boolean flag indicating that this pool implementation uses greenlets for concurrency.
task_join_will_block	boolean = false	Indicates whether joining a task will block the current execution thread.

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Constructor

Signature

def TaskPool(
    *args: any,
    **kwargs: any
)

Parameters

Name	Type	Description
*args	any	Variable length argument list passed to the base class constructor.
**kwargs	any	Arbitrary keyword arguments, including 'timeout' for task execution.

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Methods

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on_start()

@classmethod
def on_start() - > null

Initializes the GEvent pool and internal tracking structures required for managing greenlets.

Returns

Type	Description
null

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on_stop()

@classmethod
def on_stop() - > null

Gracefully shuts down the pool by waiting for all currently executing greenlets to complete their tasks.

Returns

Type	Description
null

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on_apply()

@classmethod
def on_apply(
    target: callable,
    args: list = None,
    kwargs: dict = None,
    callback: callable = None,
    accept_callback: callable = None,
    timeout: float = None,
    timeout_callback: callable = None,
    apply_target: callable = apply_target
) - > greenlet.greenlet

Schedules a task for execution within the greenlet pool, supporting timeouts and completion callbacks.

Parameters

Name	Type	Description
target	callable	The function or task to be executed within the pool.
args	list = None	Positional arguments to pass to the target function.
kwargs	dict = None	Keyword arguments to pass to the target function.
callback	callable = None	Function to be invoked upon successful completion of the task.
accept_callback	callable = None	Function to be invoked when the task is accepted by the pool.
timeout	float = None	Maximum time in seconds allowed for task execution before it is aborted.
timeout_callback	callable = None	Function to be invoked if the task execution exceeds the timeout limit.
apply_target	callable = apply_target	The internal wrapper used to execute the target function.

Returns

Type	Description
greenlet.greenlet	The spawned greenlet instance representing the scheduled task, augmented with a terminate method.

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grow()

@classmethod
def grow(
    n: int = 1
) - > null

Increases the capacity of the pool by a specified number of slots to allow more concurrent greenlets.

Parameters

Name	Type	Description
n	int = 1	The number of slots to add to the pool's current size.

Returns

Type	Description
null

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shrink()

@classmethod
def shrink(
    n: int = 1
) - > null

Decreases the capacity of the pool by a specified number of slots to reduce concurrency.

Parameters

Name	Type	Description
n	int = 1	The number of slots to remove from the pool's current size.

Returns

Type	Description
null

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terminate_job()

@classmethod
def terminate_job(
    pid: int,
    signal: int = None
) - > null

Immediately kills a specific running task identified by its process ID (greenlet ID).

Parameters

Name	Type	Description
pid	int	The unique identifier of the greenlet to be terminated.
signal	int = None	The signal to send; note that GEvent uses greenlet.kill rather than OS signals.

Returns

Type	Description
null

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num_processes()

@classmethod
def num_processes() - > int

Returns the current number of active greenlets running in the pool.

Returns

Type	Description
int	The count of active tasks currently managed by the pool.

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