Fixed several reference cycles to prevent memory leaks. Added simple test f...

Kirill Kuzminykh

2017-03-01 9e94bbf80320734985e786864116fa984a0ec62c

Fixed several reference cycles to prevent memory leaks. Added simple test for detect memory leaks after application closing.

Backport #2967 to 1.8-branch.

 CONTRIBUTORS.txt

@@ -292,3 +292,5 @@
- Mikko Ohtamaa, 2016/12/6

- Martin Frlin, 2016/12/7

- Kirill Kuzminykh, 2017/03/01

 pyramid/registry.py

@@ -276,7 +276,9 @@

    @reify
    def value(self):
        return self.func()
        result = self.func()
        del self.func
        return result

    def resolve(self):
        return self.value

 pyramid/tests/test_integration.py

@@ -1,6 +1,7 @@
# -*- coding: utf-8 -*-

import datetime
import gc
import locale
import os
import unittest
@@ -8,6 +9,7 @@
from pyramid.wsgi import wsgiapp
from pyramid.view import view_config
from pyramid.static import static_view
from pyramid.testing import skip_on
from pyramid.compat import (
    text_,
    url_quote,
@@ -741,3 +743,29 @@
    data = data.replace(b'\r', b'')
    data = data.replace(b'\n', b'')
    assert(body == data)


class MemoryLeaksTest(unittest.TestCase):

    def tearDown(self):
        import pyramid.config
        pyramid.config.global_registries.empty()

    def get_gc_count(self):
        last_collected = 0
        while True:
            collected = gc.collect()
            if collected == last_collected:
                break
            last_collected = collected
        return len(gc.get_objects())

    @skip_on('pypy')
    def test_memory_leaks(self):
        from pyramid.config import Configurator
        Configurator().make_wsgi_app()  # Initialize all global objects

        initial_count = self.get_gc_count()
        Configurator().make_wsgi_app()
        current_count = self.get_gc_count()
        self.assertEqual(current_count, initial_count)

 pyramid/util.py

@@ -231,17 +231,20 @@
            self._order.remove(oid)
            self._order.append(oid)
            return
        ref = weakref.ref(item, lambda x: self.remove(item))
        ref = weakref.ref(item, lambda x: self._remove_by_id(oid))
        self._items[oid] = ref
        self._order.append(oid)

    def remove(self, item):
    def _remove_by_id(self, oid):
        """ Remove an item from the set."""
        oid = id(item)
        if oid in self._items:
            del self._items[oid]
            self._order.remove(oid)

    def remove(self, item):
        """ Remove an item from the set."""
        self._remove_by_id(id(item))

    def empty(self):
        """ Clear all objects from the set."""
        self._items = {}