# 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))
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