Lol

venv/lib/python3.11/site-packages/greenlet/tests/leakcheck.py

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+# Copyright (c) 2018 gevent community
+# Copyright (c) 2021 greenlet community
+#
+# This was originally part of gevent's test suite. The main author
+# (Jason Madden) vendored a copy of it into greenlet.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+from __future__ import print_function
+
+import os
+import sys
+import gc
+
+from functools import wraps
+import unittest
+
+
+import objgraph
+
+# graphviz 0.18 (Nov 7 2021), available only on Python 3.6 and newer,
+# has added type hints (sigh). It wants to use ``typing.Literal`` for
+# some stuff, but that's only available on Python 3.9+. If that's not
+# found, it creates a ``unittest.mock.MagicMock`` object and annotates
+# with that. These are GC'able objects, and doing almost *anything*
+# with them results in an explosion of objects. For example, trying to
+# compare them for equality creates new objects. This causes our
+# leakchecks to fail, with reports like:
+#
+# greenlet.tests.leakcheck.LeakCheckError: refcount increased by [337, 1333, 343, 430, 530, 643, 769]
+# _Call          1820      +546
+# dict           4094       +76
+# MagicProxy      585       +73
+# tuple          2693       +66
+# _CallList        24        +3
+# weakref        1441        +1
+# function       5996        +1
+# type            736        +1
+# cell            592        +1
+# MagicMock         8        +1
+#
+# To avoid this, we *could* filter this type of object out early. In
+# principle it could leak, but we don't use mocks in greenlet, so it
+# doesn't leak from us. However, a further issue is that ``MagicMock``
+# objects have subobjects that are also GC'able, like ``_Call``, and
+# those create new mocks of their own too. So we'd have to filter them
+# as well, and they're not public. That's OK, we can workaround the
+# problem by being very careful to never compare by equality or other
+# user-defined operators, only using object identity or other builtin
+# functions.
+
+RUNNING_ON_GITHUB_ACTIONS = os.environ.get('GITHUB_ACTIONS')
+RUNNING_ON_TRAVIS = os.environ.get('TRAVIS') or RUNNING_ON_GITHUB_ACTIONS
+RUNNING_ON_APPVEYOR = os.environ.get('APPVEYOR')
+RUNNING_ON_CI = RUNNING_ON_TRAVIS or RUNNING_ON_APPVEYOR
+RUNNING_ON_MANYLINUX = os.environ.get('GREENLET_MANYLINUX')
+SKIP_LEAKCHECKS = RUNNING_ON_MANYLINUX or os.environ.get('GREENLET_SKIP_LEAKCHECKS')
+SKIP_FAILING_LEAKCHECKS = os.environ.get('GREENLET_SKIP_FAILING_LEAKCHECKS')
+ONLY_FAILING_LEAKCHECKS = os.environ.get('GREENLET_ONLY_FAILING_LEAKCHECKS')
+
+def ignores_leakcheck(func):
+    """
+    Ignore the given object during leakchecks.
+
+    Can be applied to a method, in which case the method will run, but
+    will not be subject to leak checks.
+
+    If applied to a class, the entire class will be skipped during leakchecks. This
+    is intended to be used for classes that are very slow and cause problems such as
+    test timeouts; typically it will be used for classes that are subclasses of a base
+    class and specify variants of behaviour (such as pool sizes).
+    """
+    func.ignore_leakcheck = True
+    return func
+
+def fails_leakcheck(func):
+    """
+    Mark that the function is known to leak.
+    """
+    func.fails_leakcheck = True
+    if SKIP_FAILING_LEAKCHECKS:
+        func = unittest.skip("Skipping known failures")(func)
+    return func
+
+class LeakCheckError(AssertionError):
+    pass
+
+if hasattr(sys, 'getobjects'):
+    # In a Python build with ``--with-trace-refs``, make objgraph
+    # trace *all* the objects, not just those that are tracked by the
+    # GC
+    class _MockGC(object):
+        def get_objects(self):
+            return sys.getobjects(0) # pylint:disable=no-member
+        def __getattr__(self, name):
+            return getattr(gc, name)
+    objgraph.gc = _MockGC()
+    fails_strict_leakcheck = fails_leakcheck
+else:
+    def fails_strict_leakcheck(func):
+        """
+        Decorator for a function that is known to fail when running
+        strict (``sys.getobjects()``) leakchecks.
+
+        This type of leakcheck finds all objects, even those, such as
+        strings, which are not tracked by the garbage collector.
+        """
+        return func
+
+class ignores_types_in_strict_leakcheck(object):
+    def __init__(self, types):
+        self.types = types
+    def __call__(self, func):
+        func.leakcheck_ignore_types = self.types
+        return func
+
+class _RefCountChecker(object):
+
+    # Some builtin things that we ignore
+    # XXX: Those things were ignored by gevent, but they're important here,
+    # presumably.
+    IGNORED_TYPES = () #(tuple, dict, types.FrameType, types.TracebackType)
+
+    def __init__(self, testcase, function):
+        self.testcase = testcase
+        self.function = function
+        self.deltas = []
+        self.peak_stats = {}
+        self.ignored_types = ()
+
+        # The very first time we are called, we have already been
+        # self.setUp() by the test runner, so we don't need to do it again.
+        self.needs_setUp = False
+
+    def _include_object_p(self, obj):
+        # pylint:disable=too-many-return-statements
+        #
+        # See the comment block at the top. We must be careful to
+        # avoid invoking user-defined operations.
+        if obj is self:
+            return False
+        kind = type(obj)
+        # ``self._include_object_p == obj`` returns NotImplemented
+        # for non-function objects, which causes the interpreter
+        # to try to reverse the order of arguments...which leads
+        # to the explosion of mock objects. We don't want that, so we implement
+        # the check manually.
+        if kind == type(self._include_object_p):
+            try:
+                # pylint:disable=not-callable
+                exact_method_equals = self._include_object_p.__eq__(obj)
+            except AttributeError:
+                # Python 2.7 methods may only have __cmp__, and that raises a
+                # TypeError for non-method arguments
+                # pylint:disable=no-member
+                exact_method_equals = self._include_object_p.__cmp__(obj) == 0
+
+            if exact_method_equals is not NotImplemented and exact_method_equals:
+                return False
+
+        # Similarly, we need to check identity in our __dict__ to avoid mock explosions.
+        for x in self.__dict__.values():
+            if obj is x:
+                return False
+
+
+        if kind in self.ignored_types or kind in self.IGNORED_TYPES:
+            return False
+
+        return True
+
+    def _growth(self):
+        return objgraph.growth(limit=None, peak_stats=self.peak_stats,
+                               filter=self._include_object_p)
+
+    def _report_diff(self, growth):
+        if not growth:
+            return "<Unable to calculate growth>"
+
+        lines = []
+        width = max(len(name) for name, _, _ in growth)
+        for name, count, delta in growth:
+            lines.append('%-*s%9d %+9d' % (width, name, count, delta))
+
+        diff = '\n'.join(lines)
+        return diff
+
+
+    def _run_test(self, args, kwargs):
+        gc_enabled = gc.isenabled()
+        gc.disable()
+
+        if self.needs_setUp:
+            self.testcase.setUp()
+            self.testcase.skipTearDown = False
+        try:
+            self.function(self.testcase, *args, **kwargs)
+        finally:
+            self.testcase.tearDown()
+            self.testcase.doCleanups()
+            self.testcase.skipTearDown = True
+            self.needs_setUp = True
+            if gc_enabled:
+                gc.enable()
+
+    def _growth_after(self):
+        # Grab post snapshot
+        # pylint:disable=no-member
+        if 'urlparse' in sys.modules:
+            sys.modules['urlparse'].clear_cache()
+        if 'urllib.parse' in sys.modules:
+            sys.modules['urllib.parse'].clear_cache()
+
+        return self._growth()
+
+    def _check_deltas(self, growth):
+        # Return false when we have decided there is no leak,
+        # true if we should keep looping, raises an assertion
+        # if we have decided there is a leak.
+
+        deltas = self.deltas
+        if not deltas:
+            # We haven't run yet, no data, keep looping
+            return True
+
+        if gc.garbage:
+            raise LeakCheckError("Generated uncollectable garbage %r" % (gc.garbage,))
+
+
+        # the following configurations are classified as "no leak"
+        # [0, 0]
+        # [x, 0, 0]
+        # [... a, b, c, d]  where a+b+c+d = 0
+        #
+        # the following configurations are classified as "leak"
+        # [... z, z, z]  where z > 0
+
+        if deltas[-2:] == [0, 0] and len(deltas) in (2, 3):
+            return False
+
+        if deltas[-3:] == [0, 0, 0]:
+            return False
+
+        if len(deltas) >= 4 and sum(deltas[-4:]) == 0:
+            return False
+
+        if len(deltas) >= 3 and deltas[-1] > 0 and deltas[-1] == deltas[-2] and deltas[-2] == deltas[-3]:
+            diff = self._report_diff(growth)
+            raise LeakCheckError('refcount increased by %r\n%s' % (deltas, diff))
+
+        # OK, we don't know for sure yet. Let's search for more
+        if sum(deltas[-3:]) <= 0 or sum(deltas[-4:]) <= 0 or deltas[-4:].count(0) >= 2:
+            # this is suspicious, so give a few more runs
+            limit = 11
+        else:
+            limit = 7
+        if len(deltas) >= limit:
+            raise LeakCheckError('refcount increased by %r\n%s'
+                                 % (deltas,
+                                    self._report_diff(growth)))
+
+        # We couldn't decide yet, keep going
+        return True
+
+    def __call__(self, args, kwargs):
+        for _ in range(3):
+            gc.collect()
+
+        expect_failure = getattr(self.function, 'fails_leakcheck', False)
+        if expect_failure:
+            self.testcase.expect_greenlet_leak = True
+        self.ignored_types = getattr(self.function, "leakcheck_ignore_types", ())
+
+        # Capture state before; the incremental will be
+        # updated by each call to _growth_after
+        growth = self._growth()
+
+        try:
+            while self._check_deltas(growth):
+                self._run_test(args, kwargs)
+
+                growth = self._growth_after()
+
+                self.deltas.append(sum((stat[2] for stat in growth)))
+        except LeakCheckError:
+            if not expect_failure:
+                raise
+        else:
+            if expect_failure:
+                raise LeakCheckError("Expected %s to leak but it did not." % (self.function,))
+
+def wrap_refcount(method):
+    if getattr(method, 'ignore_leakcheck', False) or SKIP_LEAKCHECKS:
+        return method
+
+    @wraps(method)
+    def wrapper(self, *args, **kwargs): # pylint:disable=too-many-branches
+        if getattr(self, 'ignore_leakcheck', False):
+            raise unittest.SkipTest("This class ignored during leakchecks")
+        if ONLY_FAILING_LEAKCHECKS and not getattr(method, 'fails_leakcheck', False):
+            raise unittest.SkipTest("Only running tests that fail leakchecks.")
+        return _RefCountChecker(self, method)(args, kwargs)
+
+    return wrapper