637233 - Android's VMPI atomic-integer operations return bad post-inc/dec values

Status: RESOLVED FIXED

(Tamarin Graveyard :: Virtual Machine, defect)

Description

[Simon Wilkinson]

Android's atomic-integer API returns pre-inc/dec values, whereas VMPI returns post-inc/dec values. This patch fixes VMPI's (trivial) conversion which is currently incorrect.

Comment 1

[Simon Wilkinson]

Attachment: Initial Patch. MQ rev 248

Comment 2

[Simon Wilkinson]

Attachment: Rebased. MQ rev 249

Comment 3

[Tamarin Bot]

changeset: 6009:b8166dce7f69
user:      Simon Wilkinson <siwilkin>
summary:   Bug 637233: Fixes return values for Android atomic-inc/dec-and-get (r=fklockii, r pending kpalacz)

http://hg.mozilla.org/tamarin-redux/rev/b8166dce7f69

Comment 4

[Edwin Smith]

I think my comment on bug 629435 actually applies here, not there.. copied:

> I see that VMPI_atomicIncAndGet32WithBarrier() is being called in a loop to
> make sure the right number of increments happen, in ST_vmpi_threads.st.  But
> the test doesn't check the exact correctness of the returned value (before or
> after value)
> each time.
> 
> worth adding more tests?

Comment 5

[Simon Wilkinson]

(In reply to comment #4)
> I think my comment on bug 629435 actually applies here, not there.. copied:
> 
> > I see that VMPI_atomicIncAndGet32WithBarrier() is being called in a loop to
> > make sure the right number of increments happen, in ST_vmpi_threads.st.  But
> > the test doesn't check the exact correctness of the returned value (before or
> > after value)
> > each time.
> > 
> > worth adding more tests?

Seeing as though I messed it up so royally the first time around, it's probably worth adding a selftest.