Re: libobjc2 objc_setassociatedobject issue

[Doug Warren]

Followup to this,

cleanupReferenceList() is never being called, I see the hidden class created and the .cxx_destruct registered but it isn't invoked.  The problem is that I don't see how object_dispose() get's called.  In the libobjc2 Test it's called in dealloc which would explain why the libobjc2 Test works, but I don't see it invoked in gnustep-base anywhere.  Or for that matter anywhere in anyone's trunk other than libobjc2's Test.h and RuntimeTest.m.

On Fri, Dec 13, 2013 at 1:30 PM, Doug Warren <address@hidden> wrote:

Works without objc_setAssociatedObject:

E/Z2GameLog(14278): STDOUT: [----------] 1 test from objc_setAssociatedObject

E/Z2GameLog(14278): STDOUT: [ RUN      ] objc_setAssociatedObject.AssociatedObjectsAreReleased

E/Z2GameLog(14278): STDOUT: [       OK ] objc_setAssociatedObject.AssociatedObjectsAreReleased (1 ms)

E/Z2GameLog(14278): STDOUT: [----------] 1 test from objc_setAssociatedObject (1 ms total)

Code change:

    @autoreleasepool {

        associatedObjectTestAllocatedObject* object = [associatedObjectTestAllocatedObject new];

        associatedObjectTestAssociatedObject *info = [[associatedObjectTestAssociatedObject new] autorelease];

        // silence -Wunused-variable

        [info description];

//        objc_setAssociatedObject(object, &objc_setAssociatedObjectKey, info, OBJC_ASSOCIATION_RETAIN);

        [object release];

    }

The reason why I had suggested that was your original post that NSString wouldn't be an appropriate target, got me thinking that perhaps there was an optimization at some point made in the runtime to NSObject that would similarly cause it to not work.  

On Fri, Dec 13, 2013 at 11:43 AM, David Chisnall <address@hidden> wrote:

This test case looks like it should pass irrespective of whether the runtime does the right thing.  Since you're using associatedObjectTestAssociatedObject for both objects, deallocating the original autoreleased one ought to set associatedObjectDeallocCalled.  Can you confirm whether this test fails for you on GNUstep with the objc_setAssociatedObject() call removed?

David

On 13 Dec 2013, at 18:27, Doug Warren <address@hidden> wrote:

> I saw the test that you checked in to svn and modified my code to match it:
>
> static BOOL associatedObjectDeallocCalled = NO;
> static const char* objc_setAssociatedObjectKey = "objc_setAssociatedObjectKey";
>
> @interface associatedObjectTestAssociatedObject : NSObject
> @end
>
> @implementation associatedObjectTestAssociatedObject
>
> -(void) dealloc
> {
>     associatedObjectDeallocCalled = YES;
>     [super dealloc];
> }
>
> @end
>
> @interface associatedObjectTestAllocatedObject : NSObject
> @end
>
> @implementation associatedObjectTestAllocatedObject
> @end
>
> TEST(objc_setAssociatedObject, AssociatedObjectsAreReleased)
> {
> #if !Z2_APPLE
>     GSDebugAllocationActive(YES);
>     GSDebugAllocationList(YES);
> #endif
>
>     @autoreleasepool {
>         associatedObjectTestAllocatedObject* object = [associatedObjectTestAllocatedObject new];
>
>         associatedObjectTestAssociatedObject *info = [[associatedObjectTestAssociatedObject new] autorelease];
>         objc_setAssociatedObject(object, &objc_setAssociatedObjectKey, info, OBJC_ASSOCIATION_RETAIN);
>
>         [object release];
>     }
> #if !Z2_APPLE
>     EXPECT_STREQ(GSDebugAllocationList(YES), "1\tNSDataMalloc\n");
> #endif
>
>     ASSERT_TRUE(associatedObjectDeallocCalled);
> }
>
>
> On the Apple runtime it passes still:
> [----------] 1 test from objc_setAssociatedObject
> [ RUN      ] objc_setAssociatedObject.AssociatedObjectsAreReleased
> [       OK ] objc_setAssociatedObject.AssociatedObjectsAreReleased (0 ms)
> [----------] 1 test from objc_setAssociatedObject (0 ms total)
>
> On Gnustep/objc2:
> E/Z2GameLog(12157): STDOUT: [----------] 1 test from objc_setAssociatedObject
> E/Z2GameLog(12157): STDOUT: [ RUN      ] objc_setAssociatedObject.AssociatedObjectsAreReleased
> E/Z2GameLog(12157): STDOUT: /data/testnations.git/jujulib/Tests/objc-utility/objc_setAssociatedObjectTest.h:44: Failure
> E/Z2GameLog(12157): STDOUT: Value of: "1\tNSDataMalloc\n"
> E/Z2GameLog(12157): STDOUT:   Actual: "1      NSDataMalloc
> E/Z2GameLog(12157): STDOUT: "
> E/Z2GameLog(12157): STDOUT: Expected: GSDebugAllocationList(((BOOL)1))
> E/Z2GameLog(12157): STDOUT: Which is: "1      NSDataMalloc
> E/Z2GameLog(12157): STDOUT: 1 associatedObjectTestAssociatedObject
> E/Z2GameLog(12157): STDOUT: "
> E/Z2GameLog(12157): STDOUT: /data/testnations.git/jujulib/Tests/objc-utility/objc_setAssociatedObjectTest.h:47: Failure
> E/Z2GameLog(12157): STDOUT: Value of: innerObjectDeallocCalled
> E/Z2GameLog(12157): STDOUT:   Actual: false
> E/Z2GameLog(12157): STDOUT: Expected: true
> E/Z2GameLog(12157): STDOUT: [  FAILED  ] objc_setAssociatedObject.AssociatedObjectsAreReleased (1 ms)
> E/Z2GameLog(12157): STDOUT: [----------] 1 test from objc_setAssociatedObject (2 ms total)
>
> My runtime environment unfortunately isn't in a position to run the libobjc tests directly.  Do you have any suggestions as to what I should be looking for?  Perhaps there's something in the GNUStep Foundation NSObject that's causing it to fail but works with the libobjc Test object?
>
>
> On Fri, Dec 13, 2013 at 9:01 AM, Doug Warren <address@hidden> wrote:
> Thanks David,
>
> I'll investigate more on our end.  I actually had changed that from NSString to NSObject just to be sure that it wasn't related to that.  (Why in the above stupid example it was cast to NSObject though Alloced as NSString, I had intended it to just be a double dummy NSObject.) The actual case where we ran into this was more complex and I feel there's still an issue but I'll go back and confirm it.
>
> I was looking at another issue that we had with NSAutoreleasePool and trying to isolate it to a test case.  If I get that I'll construct it as a standalone program as well.
>
>
> On Fri, Dec 13, 2013 at 6:44 AM, David Chisnall <address@hidden> wrote:
> Ah, sorry, I was reading your example the other way around.  This seems to be because [[NSString alloc] init] returns a singleton on GNUstep.  I don't think this is necessarily a bug, as there's nothing in the contract for NSString that says that it needs to return a new instance for different immutable strings.
>
> In general, using associated objects on immutable objects is a bad idea, because it breaks the assumption that you can use equal instances interchangeably.
>
> David
>
> On 13 Dec 2013, at 14:03, David Chisnall <address@hidden> wrote:
>
> > I've now added a test for this to the libobjc2 test suite, but it passes and so does not appear to be the cause.  Your issue appears to be the dictionary being over-retained.  I will investigate further.
> >
> > David
> >
> > P.S. When sending test cases, it helps to send them in the format of a test suite for the thing you are testing, or as stand-alone programs.  I'd have got to this a lot sooner if I didn't have to hack on the test to make it compile.
> >
> > On 19 Nov 2013, at 01:33, Doug Warren <address@hidden> wrote:
> >
> >> Hi Guys,
> >>
> >> Was tracking a memory leak in an existing app and tracked it down to objc_setassociatedobject not working as expected from the code being developed for the Apple Runtime.  The docs around objc_setassociatedobject seem to imply it follows the Apple Runtime but this simple gtest will pass on Apple but fail on libobjc/GNUStep Base:
> >>
> >> static BOOL deallocCalled = NO;
> >> static const char* objc_setAssociatedObjectKey = "objc_setAssociatedObjectKey";
> >>
> >> @interface NSMutableDictionary(setAssociatedObjectTest)
> >> @end
> >>
> >> @implementation NSMutableDictionary(setAssociatedObjectTest)
> >>
> >> -(void) dealloc
> >> {
> >>    deallocCalled = YES;
> >>    [super dealloc];
> >> }
> >>
> >> @end
> >>
> >> TEST(objc_setAssociatedObject, AssociatedObjectsAreReleased)
> >> {
> >>   address@hidden {
> >>        NSObject* object = [[NSString alloc] init];
> >>
> >>        NSMutableDictionary *info = [NSMutableDictionary dictionaryWithCapacity:1];
> >>        objc_setAssociatedObject(object, &objc_setAssociatedObjectKey, info, OBJC_ASSOCIATION_RETAIN);
> >>
> >>        [object release];
> >>    }
> >>
> >>    ASSERT_TRUE(deallocCalled);
> >> }
> >>
> >> Adding calls to GSDebugAllocationList before/after the autorelease pool:
> >> 1    NSDataMalloc
> >> 1    GSMutableDictionary
> >>
> >> Shows that the dictionary leaks.
> >>
> >> Any thoughts?
> >> _______________________________________________
> >> Gnustep-dev mailing list
> >> address@hidden
> >> https://lists.gnu.org/mailman/listinfo/gnustep-dev
> >
> >
> > _______________________________________________
> > Gnustep-dev mailing list
> > address@hidden
> > https://lists.gnu.org/mailman/listinfo/gnustep-dev
>
>
>

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