Re: Container functionality and marshalling

From:

James Kanze <james.kanze@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Fri, 1 Feb 2008 15:30:37 -0800 (PST)

Message-ID:

<0eae2982-f479-49bd-b035-3207bbf01bc4@j78g2000hsd.googlegroups.com>

On Feb 1, 10:02 pm, c...@mailvault.com wrote:

[...]

I'm having second thoughts. I forgot that I make the assumption
that the arguments passed to a marshalling function are fixed
while the function is executing.* When marshalling a list<int>,
first the size() is marshalled and then the elements. If another
thread inserts elements into the list between those two steps it
will lead to undefined behaviour.

If any thread can modifying the list, then all threads accessing
it must use some sort of lock. Synchronous access to a
container (or any other object) is only allowed if no thread is
modifying it.

I think Boost Serialization makes this assumption also.
Probably I forgot about that because it isn't documented
anywhere.

It's a basic rule of thread safety. Individual objects only
have to document it when they don't follow the rule.

--
James Kanze (GABI Software) email:james.kanze@gmail.com
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