name : threading_checker.py # Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html # For details: https://github.com/PyCQA/pylint/blob/main/LICENSE # Copyright (c) https://github.com/PyCQA/pylint/blob/main/CONTRIBUTORS.txt from __future__ import annotations from typing import TYPE_CHECKING from astroid import nodes from pylint.checkers import BaseChecker from pylint.checkers.utils import only_required_for_messages, safe_infer if TYPE_CHECKING: from pylint.lint import PyLinter class ThreadingChecker(BaseChecker): """Checks for threading module. - useless with lock - locking used in wrong way that has no effect (with threading.Lock():) """ name = "threading" LOCKS = frozenset( ( "threading.Lock", "threading.RLock", "threading.Condition", "threading.Semaphore", "threading.BoundedSemaphore", ) ) msgs = { "W2101": ( "'%s()' directly created in 'with' has no effect", "useless-with-lock", "Used when a new lock instance is created by using with statement " "which has no effect. Instead, an existing instance should be used to acquire lock.", ), } @only_required_for_messages("useless-with-lock") def visit_with(self, node: nodes.With) -> None: context_managers = (c for c, _ in node.items if isinstance(c, nodes.Call)) for context_manager in context_managers: if isinstance(context_manager, nodes.Call): infered_function = safe_infer(context_manager.func) if infered_function is None: continue qname = infered_function.qname() if qname in self.LOCKS: self.add_message("useless-with-lock", node=node, args=qname) def register(linter: PyLinter) -> None: linter.register_checker(ThreadingChecker(linter))