Re: [Boost-bugs] [Boost C++ Libraries] #9601: Unable to load archives with pointer instances which contain self reference cycles in 1.55

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #9601: Unable to load archives with pointer instances which contain self reference cycles in 1.55
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-01-30 01:57:43

#9601: Unable to load archives with pointer instances which contain self reference
cycles in 1.55
-------------------------------+---------------------------
  Reporter:  brandon.kohn      |      Owner:  ramey
      Type:  Bugs              |     Status:  assigned
 Milestone:  To Be Determined  |  Component:  serialization
   Version:  Boost 1.55.0      |   Severity:  Problem
Resolution:                    |   Keywords:
-------------------------------+---------------------------

Comment (by blkohn@…):

 I've read your last comment, and it seems to make sense if I switch the
 two code blocks (and add make it pph.m_ph = '''&'''ph.) Is this what you
 intended?

 Assuming it is, I believe the code in the first block was well behaved in
 1.53 and prior versions. Otherwise we would have seen this issue in our
 own archives which apparently do a lot of this. I have a version of 1.53
 handy so I can test it tomorrow.

 I agree the fix I proposed is specific to the all heap allocated case. I
 don't think there is a general solution which handles both of these use
 cases. My understanding of the library is that whenever a pointer is
 serialized, it will be heap allocated on the read unless it is tracked and
 has already been loaded (in which case it will simply assign the
 previously loaded value.) In order to support consistency between pointers
 to a stack allocated object, there would have to be something to tell the
 archive that the original stack allocated object's address needs to be
 tracked. I could imagine a wrapper for it which tells the archive to put
 the address into the pointer tracking system (something along those
 lines.) That might work, maybe it's worth a discussion with other users on
 the list.

 Still, IMO the stack allocated case seems less likely than the heap case.
 Perhaps it makes sense to fix the heap case and add documentation about
 the issue with serialization of pointers to stack allocated objects that
 informs that cycles would be broken on deserialization in those instances.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/9601#comment:8>
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