> On Mar 25, 2015, at 5:18 PM, Zachary Turner <[email protected]> wrote:
> 
> Seems reasonable, I can add something to the help.  What do you think about 
> also changing the semantics of --clean to clear the module list regardless of 
> if the modules are orphaned?  I've spent the past 2 days trying to track down 
> a refcounting bug related to the shared module list that only happens when 
> running from the test suite, even if I run the exact same sequence of 
> commands from inside LLDB.  But the gist of it is that when running from the 
> test suite, when RemoveOrphanSharedModules() is called from the 
> CommandObject, the ModuleSP for the executable has a ref count of 2, so it 
> isn't unique to the shared module list, and it doesn't get removed.

This makes it sound like some Python object that is holding onto a reference to 
the executable isn't getting garbage collected.  Is there some way to force 
Python to do this?
It seem to me like violating the function of the shared cache, particularly 
from the lldb command line, is not a great idea.  Even --clean seems a little 
unfortunate to have in the command line, since some innocent person will run 
the help command and then be worried about what this whole clean thing is and 
whether it is a good idea and etc.  Might be better, if this is necessary, to 
have it only in the SB API where we can put an appropriate comment around it.  
That way ordinary users who should 100% never have to think about this won't be 
disturbed by it.

Jim

> 
> I tested to see what happens if I change this logic to remove from the module 
> list regardless of whether it's unique, and I can't find any unintended side 
> effects other than lots of tests start passing :
> 
> shared_ptrs are shared, so in theory there shouldn't be any negative 
> consequences to just removing it.  Whoever still has a reference can still 
> continue to use it.  Alternatively I can add a --force command line option, 
> so that the semantics of specifying just --clean are unchanged.
> 
> Thoughts?
> 
> 
> http://reviews.llvm.org/D8615
> 
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