Re: [Boost-bugs] [Boost C++ Libraries] #5876: Serialization - tracking of non-versioned classes

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #5876: Serialization - tracking of non-versioned classes
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-01-23 17:45:16

#5876: Serialization - tracking of non-versioned classes
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  Reporter:  ybungalobill@…          |       Owner:  ramey        
      Type:  Bugs                    |      Status:  new          
 Milestone:  To Be Determined        |   Component:  serialization
   Version:  Boost 1.47.0            |    Severity:  Showstopper  
Resolution:                          |    Keywords:               
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Comment (by ybungalobill@…):

 > But this is the intended behavior! If this wasn't true, pointers to
 objects previously serialized as objects wouldn't be restored properly.

 I find it counter-intuitive. I expect objects serialized as objects to
 mean 'by value' and not be tracked, while objects serialized by pointer to
 mean 'by reference' and be tracked. Anyway it's your choice and I won't
 criticize it.

 The problem is that you can't implement the intended behavior properly for
 object_serializable. The above code is a minimal code that reproduces the
 problem, but it's not hypothetical. The real world scenario went like
 this:

 3rd party interprocess communication library used serialization by pointer
 in generic code. It happened that we passed vector<int> between two
 processes, so it serialized it through vector<int>*. Another unrelated
 part of our codebase serialized shared_ptr<vector<int>> which in turn is
 serialized through vector<int>*. Note that nowhere the user (me) played
 with the implementation level. Each part is valid in isolation. So far so
 good.

 We updated from boost 1.33.1 to boost 1.47.0. It got broken. Why? I don't
 exactly know. My hypothesis is that because the way singletons are created
 had changed (function statics in 1.33.1 versus class statics in 1.47.0)
 the linker handles them differently.

 Whatever the reason I think that code that breaks depending on the
 existence of some unrelated other code is worse than the inability to
 serialize object_serializable object as object and then track it through a
 pointer.

 Thank you,[[BR]]
 Yakov Galka

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/5876#comment:3>
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