Source code for locust.user.task

from __future__ import annotations

from locust.exception import InterruptTaskSet, MissingWaitTimeError, RescheduleTask, RescheduleTaskImmediately, StopUser

import logging
import random
import traceback
from collections import deque
from time import time
from typing import (

import gevent
from gevent import GreenletExit

    from locust import User

logger = logging.getLogger(__name__)
TaskT = TypeVar("TaskT", Callable[..., None], type["TaskSet"])


class TaskHolder(Protocol[TaskT]):
    tasks: list[TaskT]

def task(weight: TaskT) -> TaskT: ...

def task(weight: int) -> Callable[[TaskT], TaskT]: ...

[docs]def task(weight: TaskT | int = 1) -> TaskT | Callable[[TaskT], TaskT]: """ Used as a convenience decorator to be able to declare tasks for a User or a TaskSet inline in the class. Example:: class ForumPage(TaskSet): @task(100) def read_thread(self): pass @task(7) def create_thread(self): pass @task(25) class ForumThread(TaskSet): @task def get_author(self): pass @task def get_created(self): pass """ def decorator_func(func): if func.__name__ in ["on_stop", "on_start"]: logging.warning( "You have tagged your on_stop/start function with @task. This will make the method get called both as a task AND on stop/start." ) # this is usually not what the user intended if func.__name__ == "run": raise Exception( " is a method used internally by Locust, and you must not override it or register it as a task" ) func.locust_task_weight = weight return func """ Check if task was used without parentheses (not called), like this:: @task def my_task(self) pass """ if callable(weight): func = weight weight = 1 return decorator_func(func) else: return decorator_func
[docs]def tag(*tags: str) -> Callable[[TaskT], TaskT]: """ Decorator for tagging tasks and TaskSets with the given tag name. You can then limit the test to only execute tasks that are tagged with any of the tags provided by the :code:`--tags` command-line argument. Example:: class ForumPage(TaskSet): @tag('thread') @task(100) def read_thread(self): pass @tag('thread') @tag('post') @task(7) def create_thread(self): pass @tag('post') @task(11) def comment(self): pass """ def decorator_func(decorated): if hasattr(decorated, "tasks"): decorated.tasks = list(map(tag(*tags), decorated.tasks)) else: if "locust_tag_set" not in decorated.__dict__: decorated.locust_tag_set = set() decorated.locust_tag_set |= set(tags) return decorated if len(tags) == 0 or callable(tags[0]): raise ValueError("No tag name was supplied") return decorator_func
def get_tasks_from_base_classes(bases, class_dict): """ Function used by both TaskSetMeta and UserMeta for collecting all declared tasks on the TaskSet/User class and all its base classes """ new_tasks = [] for base in bases: if hasattr(base, "tasks") and base.tasks: new_tasks += base.tasks if "tasks" in class_dict and class_dict["tasks"] is not None: tasks = class_dict["tasks"] if isinstance(tasks, dict): tasks = tasks.items() for task in tasks: if isinstance(task, tuple): task, count = task for _ in range(count): new_tasks.append(task) else: new_tasks.append(task) for item in class_dict.values(): if "locust_task_weight" in dir(item): for i in range(item.locust_task_weight): new_tasks.append(item) return new_tasks def filter_tasks_by_tags( task_holder: type[TaskHolder], tags: set[str] | None = None, exclude_tags: set[str] | None = None, checked: dict[TaskT, bool] | None = None, ): """ Function used by Environment to recursively remove any tasks/TaskSets from a TaskSet/User that shouldn't be executed according to the tag options """ new_tasks = [] if checked is None: checked = {} for task in task_holder.tasks: if task in checked: if checked[task]: new_tasks.append(task) continue passing = True if hasattr(task, "tasks"): filter_tasks_by_tags(task, tags, exclude_tags, checked) passing = len(task.tasks) > 0 else: if tags is not None: passing &= "locust_tag_set" in dir(task) and len(task.locust_tag_set & tags) > 0 if exclude_tags is not None: passing &= "locust_tag_set" not in dir(task) or len(task.locust_tag_set & exclude_tags) == 0 if passing: new_tasks.append(task) checked[task] = passing task_holder.tasks = new_tasks if not new_tasks: logging.warning(f"{task_holder.__name__} had no tasks left after filtering, instantiating it will fail!") class TaskSetMeta(type): """ Meta class for the main User class. It's used to allow User classes to specify task execution ratio using an {task:int} dict, or a [(task0,int), ..., (taskN,int)] list. """ def __new__(mcs, classname, bases, class_dict): class_dict["tasks"] = get_tasks_from_base_classes(bases, class_dict) return type.__new__(mcs, classname, bases, class_dict)
[docs]class TaskSet(metaclass=TaskSetMeta): """ Class defining a set of tasks that a User will execute. When a TaskSet starts running, it will pick a task from the *tasks* attribute, execute it, and then sleep for the number of seconds returned by its *wait_time* function. If no wait_time method has been declared on the TaskSet, it'll call the wait_time function on the User by default. It will then schedule another task for execution and so on. TaskSets can be nested, which means that a TaskSet's *tasks* attribute can contain another TaskSet. If the nested TaskSet is scheduled to be executed, it will be instantiated and called from the currently executing TaskSet. Execution in the currently running TaskSet will then be handed over to the nested TaskSet which will continue to run until it throws an InterruptTaskSet exception, which is done when :py:meth:`TaskSet.interrupt() <locust.TaskSet.interrupt>` is called. (execution will then continue in the first TaskSet). """ tasks: list[TaskSet | Callable] = [] """ Collection of python callables and/or TaskSet classes that the User(s) will run. If tasks is a list, the task to be performed will be picked randomly. If tasks is a *(callable,int)* list of two-tuples, or a {callable:int} dict, the task to be performed will be picked randomly, but each task will be weighted according to its corresponding int value. So in the following case, *ThreadPage* will be fifteen times more likely to be picked than *write_post*:: class ForumPage(TaskSet): tasks = {ThreadPage:15, write_post:1} """ min_wait: float | None = None """ Deprecated: Use wait_time instead. Minimum waiting time between the execution of user tasks. Can be used to override the min_wait defined in the root User class, which will be used if not set on the TaskSet. """ max_wait: float | None = None """ Deprecated: Use wait_time instead. Maximum waiting time between the execution of user tasks. Can be used to override the max_wait defined in the root User class, which will be used if not set on the TaskSet. """ wait_function = None """ Deprecated: Use wait_time instead. Function used to calculate waiting time between the execution of user tasks in milliseconds. Can be used to override the wait_function defined in the root User class, which will be used if not set on the TaskSet. """ _user: User _parent: User def __init__(self, parent: User) -> None: self._task_queue: deque = deque() self._time_start = time() if isinstance(parent, TaskSet): self._user = parent.user else: self._user = parent self._parent = parent # if this class doesn't have a min_wait, max_wait or wait_function defined, copy it from Locust if not self.min_wait: self.min_wait = self.user.min_wait if not self.max_wait: self.max_wait = self.user.max_wait if not self.wait_function: self.wait_function = self.user.wait_function self._cp_last_run = time() # used by constant_pacing wait_time @property def user(self) -> User: """:py:class:`User <locust.User>` instance that this TaskSet was created by""" return self._user @property def parent(self): """Parent TaskSet instance of this TaskSet (or :py:class:`User <locust.User>` if this is not a nested TaskSet)""" return self._parent
[docs] def on_start(self) -> None: """ Called when a User starts executing this TaskSet """ pass
[docs] def on_stop(self): """ Called when a User stops executing this TaskSet. E.g. when TaskSet.interrupt() is called or when the User is killed """ pass
@final def run(self): try: self.on_start() except InterruptTaskSet as e: if e.reschedule: raise RescheduleTaskImmediately(e.reschedule).with_traceback(e.__traceback__) else: raise RescheduleTask(e.reschedule).with_traceback(e.__traceback__) while True: try: if not self._task_queue: self.schedule_task(self.get_next_task()) try: if self.user._state == LOCUST_STATE_STOPPING: raise StopUser() self.execute_next_task() except RescheduleTaskImmediately: pass except RescheduleTask: self.wait() else: self.wait() except InterruptTaskSet as e: try: self.on_stop() except (StopUser, GreenletExit): raise except Exception: logging.error("Uncaught exception in on_stop: \n%s", traceback.format_exc()) if e.reschedule: raise RescheduleTaskImmediately(e.reschedule) from e else: raise RescheduleTask(e.reschedule) from e except (StopUser, GreenletExit): try: self.on_stop() except Exception: logging.error("Uncaught exception in on_stop: \n%s", traceback.format_exc()) raise except Exception as e:, exception=e, tb=e.__traceback__) if self.user.environment.catch_exceptions: logger.error("%s\n%s", e, traceback.format_exc()) self.wait() else: raise def execute_next_task(self): self.execute_task(self._task_queue.popleft()) def execute_task(self, task): # check if the function is a method bound to the current locust, and if so, don't pass self as first argument if hasattr(task, "__self__") and task.__self__ == self: # task is a bound method on self task() elif hasattr(task, "tasks") and issubclass(task, TaskSet): # task is another (nested) TaskSet class task(self).run() else: # task is a function task(self)
[docs] def schedule_task(self, task_callable, first=False): """ Add a task to the User's task execution queue. :param task_callable: User task to schedule. :param first: Optional keyword argument. If True, the task will be put first in the queue. """ if first: self._task_queue.appendleft(task_callable) else: self._task_queue.append(task_callable)
def get_next_task(self): if not self.tasks: if getattr(self, "task", None): extra_message = ", but you have set a 'task' attribute - maybe you meant to set 'tasks'?" else: extra_message = "." raise Exception( f"No tasks defined on {self.__class__.__name__}{extra_message} use the @task decorator or set the 'tasks' attribute of the TaskSet" ) return random.choice(self.tasks)
[docs] def wait_time(self): """ Method that returns the time (in seconds) between the execution of tasks. Example:: from locust import TaskSet, between class Tasks(TaskSet): wait_time = between(3, 25) """ if self.user.wait_time: return self.user.wait_time() elif self.min_wait is not None and self.max_wait is not None: return random.randint(self.min_wait, self.max_wait) / 1000.0 else: raise MissingWaitTimeError( "You must define a wait_time method on either the {type(self.user).__name__} or {type(self).__name__} class" )
[docs] def wait(self): """ Make the running user sleep for a duration defined by the Locust.wait_time function (or TaskSet.wait_time function if it's been defined). The user can also be killed gracefully while it's sleeping, so calling this method within a task makes it possible for a user to be killed mid-task, even if you've set a stop_timeout. If this behaviour is not desired you should make the user wait using gevent.sleep() instead. """ if self.user._state == LOCUST_STATE_STOPPING: raise StopUser() self.user._state = LOCUST_STATE_WAITING self._sleep(self.wait_time()) if self.user._state == LOCUST_STATE_STOPPING: raise StopUser() self.user._state = LOCUST_STATE_RUNNING
def _sleep(self, seconds): gevent.sleep(seconds)
[docs] def interrupt(self, reschedule=True): """ Interrupt the TaskSet and hand over execution control back to the parent TaskSet. If *reschedule* is True (default), the parent User will immediately re-schedule, and execute, a new task. """ raise InterruptTaskSet(reschedule)
@property def client(self): """ Shortcut to the client :py:attr:`client <locust.User.client>` attribute of this TaskSet's :py:class:`User <locust.User>` """ return self.user.client
class DefaultTaskSet(TaskSet): """ Default root TaskSet that executes tasks in User.tasks. It executes tasks declared directly on the Locust with the user instance as the task argument. """ def get_next_task(self): if not self.user.tasks: if getattr(self.user, "task", None): extra_message = ", but you have set a 'task' attribute on your class - maybe you meant to set 'tasks'?" else: extra_message = "." raise Exception( f"No tasks defined on {self.user.__class__.__name__}{extra_message} Use the @task decorator or set the 'tasks' attribute of the User (or mark it as abstract = True if you only intend to subclass it)" ) return random.choice(self.user.tasks) def execute_task(self, task): if hasattr(task, "tasks") and issubclass(task, TaskSet): # task is (nested) TaskSet class task(self.user).run() else: # task is a function task(self.user)