[Python-Dev] patch-finalizer vs Zope3

[Tim Peters]

[Tim Peters]
> FYI, and without taking time for non-trivial analysis.  I ran the non-ZEO
> Zope3 tests with a Python patched to treat weakrefs with callbacks as
> reachable (this was patch-finalizer.txt, attached to a msg I sent to
> python-dev last night).
> 
> The first test to leave stuff in gc.garbage then:
> 
>    The following test left garbage:
>    test_created (bugtracker.browser.tests.test_bug.BugBaseViewTest)
>    65
> 
> where 65 is len(gc.garbage) after the test finished.

OK, that actually wasn't the first test to produce garbage, it was
just the first time test.py *noticed* gc.garbage wasn't empty.  The
first test to produce garbage was BuddyCityState, and it produces
garbage in isolation:

C:\Code\Zope3>\code\python\PCbuild\python_d.exe test.py -vv . BuddyCityState
Configuration file found.
Running UNIT tests at level 1
Running UNIT tests from C:\Code\Zope3
BuddyCityState (buddydemo.buddy) ... ok
The following test left garbage:
BuddyCityState (buddydemo.buddy)
28 entries in gc.garbage:
  0: <weakref at 03C86F20; to 'InterfaceClass' at 012B5930 (IWriteContainer)>
      0x12B5930 is <InterfaceClass
zope.app.container.interfaces.IWriteContainer>
  1: <weakref at 03C8E080; to 'InterfaceClass' at 00B5EAB8 (Interface)>
      0xB5EAB8 is <InterfaceClass zope.interface.Interface>
  2: <weakref at 03C8E1A0; to 'Surrogate' at 03C8D4D0>
      0x3C8D4D0 is <Surrogate(<InterfaceClass
zope.app.container.interfaces.IWriteContainer>)>
  3: <weakref at 03C8E278; to 'InterfaceClass' at 012B5578 (IObjectEvent)>
      0x12B5578 is <InterfaceClass zope.app.event.interfaces.IObjectEvent>
  4: <weakref at 03C8E398; to 'Surrogate' at 03C8D6C8>
      0x3C8D6C8 is <Surrogate(<InterfaceClass
zope.app.event.interfaces.IObjectEvent>)>
  5: <weakref at 03C8E3E0; to 'InterfaceClass' at 01197230 (IHTTPRequest)>
      0x1197230 is <InterfaceClass zope.publisher.interfaces.http.IHTTPRequest>
  6: <weakref at 03C8E500; to 'InterfaceClass' at 0118ACE8 (IRequest)>
      0x118ACE8 is <InterfaceClass zope.publisher.interfaces.IRequest>
  7: <weakref at 03C8E620; to 'InterfaceClass' at 0118A818 (IPublisherRequest)>
      0x118A818 is <InterfaceClass zope.publisher.interfaces.IPublisherRequest>
  8: <weakref at 03C8E740; to 'InterfaceClass' at 0118A5E8
(IPublicationRequest)>
      0x118A5E8 is <InterfaceClass
zope.publisher.interfaces.IPublicationRequest>
  9: <weakref at 03C8E860; to 'InterfaceClass' at 00DB9690
(IPresentationRequest)>
      0xDB9690 is <InterfaceClass
zope.component.interfaces.IPresentationRequest>
 10: <weakref at 03C8E980; to 'Surrogate' at 03C8DAB8>
      0x3C8DAB8 is <Surrogate(<InterfaceClass
zope.component.interfaces.IPresentationRequest>)>
 11: <weakref at 03C8E9C8; to 'InterfaceClass' at 00DA0188 (IParticipation)>
      0xDA0188 is <InterfaceClass zope.security.interfaces.IParticipation>
 12: <weakref at 03C8EAE8; to 'Surrogate' at 03C8DB28>
      0x3C8DB28 is <Surrogate(<InterfaceClass
zope.security.interfaces.IParticipation>)>
 13: <weakref at 03C8EB30; to 'Surrogate' at 03C8DA10>
      0x3C8DA10 is <Surrogate(<InterfaceClass
zope.publisher.interfaces.IPublicationRequest>)>
 14: <weakref at 03C8EB78; to 'Surrogate' at 03C8DA10>
      0x3C8DA10 is <Surrogate(<InterfaceClass
zope.publisher.interfaces.IPublicationRequest>)>
 15: <weakref at 03C8EBC0; to 'Surrogate' at 03C8D968>
      0x3C8D968 is <Surrogate(<InterfaceClass
zope.publisher.interfaces.IPublisherRequest>)>
 16: <weakref at 03C8EC08; to 'InterfaceClass' at 0118AC08
(IApplicationRequest)>
      0x118AC08 is <InterfaceClass
zope.publisher.interfaces.IApplicationRequest>
 17: <weakref at 03C8ED28; to 'InterfaceClass' at 01177F18 (IEnumerableMapping)>
      0x1177F18 is <InterfaceClass
zope.interface.common.mapping.IEnumerableMapping>
 18: <weakref at 03C8EE48; to 'InterfaceClass' at 01177D58 (IReadMapping)>
      0x1177D58 is <InterfaceClass zope.interface.common.mapping.IReadMapping>
 19: <weakref at 03C8EF68; to 'InterfaceClass' at 01177C40 (IItemMapping)>
      0x1177C40 is <InterfaceClass zope.interface.common.mapping.IItemMapping>
 20: <weakref at 03C8F0C8; to 'Surrogate' at 03C8DD20>
      0x3C8DD20 is <Surrogate(<InterfaceClass
zope.interface.common.mapping.IItemMapping>)>
 21: <weakref at 03C8F110; to 'Surrogate' at 03C8DC78>
      0x3C8DC78 is <Surrogate(<InterfaceClass
zope.interface.common.mapping.IReadMapping>)>
 22: <weakref at 03C8F158; to 'Surrogate' at 03C8DBD0>
      0x3C8DBD0 is <Surrogate(<InterfaceClass
zope.interface.common.mapping.IEnumerableMapping>)>
 23: <weakref at 03C8F1A0; to 'Surrogate' at 03C8D9D8>
      0x3C8D9D8 is <Surrogate(<InterfaceClass
zope.publisher.interfaces.IApplicationRequest>)>
 24: <weakref at 03C8F1E8; to 'Surrogate' at 03C8D8C0>
      0x3C8D8C0 is <Surrogate(<InterfaceClass
zope.publisher.interfaces.IRequest>)>
 25: <weakref at 03C8F230; to 'Surrogate' at 03C8D8C0>
      0x3C8D8C0 is <Surrogate(<InterfaceClass
zope.publisher.interfaces.IRequest>)>
 26: <weakref at 03C8F278; to 'Surrogate' at 03C8D8C0>
      0x3C8D8C0 is <Surrogate(<InterfaceClass
zope.publisher.interfaces.IRequest>)>
 27: <weakref at 03C8F2C0; to 'Surrogate' at 03C8D818>
      0x3C8D818 is <Surrogate(<InterfaceClass
zope.publisher.interfaces.http.IHTTPRequest>)>
[703156 refs]

C:\Code\Zope3>

It appears generally true that, like in that test, gc.garbage gets
filled with (hundreds of thousands of) weakrefs specifically due to
adaptation machinery.  By inspection, there are a lot of weakrefs
flying around there <wink>.