Re: [Boost-users] boost::interprocess::node_allocator problem (VC8, release build)

From: Lars Hagström (lars_at_[hidden])
Date: 2007-02-02 07:47:28

Hi,

I had some trouble with this, so I decided to try it out. The
optimizations that cause the problem with MSVC is /Og and /Ob2 together
(which are both part of /O2, optimize for speed).

As Ion says it is function inlining that is the problem, since when i
added __declspec(noinline) to set_offset it all worked like a dream.
Here is a very ugly fix for this problem (just an ifdef and a __declspec):

Index: offset_ptr.hpp
===================================================================
RCS file: /cvsroot/boost/boost/boost/interprocess/offset_ptr.hpp,v
retrieving revision 1.2
diff -u -r1.2 offset_ptr.hpp
--- offset_ptr.hpp	7 Aug 2006 13:52:22 -0000	1.2
+++ offset_ptr.hpp	2 Feb 2007 12:44:25 -0000
@@ -51,6 +51,11 @@
    void unspecified_bool_type_func() const {}
    typedef void (self_t::*unspecified_bool_type)() const;

+#if (defined _MSC_VER) && (_MSC_VER >= 1200)
+   //a bug in VC8.0 (and maybe earlier?) makes having this
+   //inlined in release mode break things.
+   __declspec(noinline)
+#endif
    void set_offset(const void *ptr)
    {
       //offset == 1 && ptr != 0 is not legal for this pointer

When I install SP1 for VC8 I will let you know if this problem disappears.

Lars

P.S. I believe this may have been the problem I mentioned before that I
had with interprocess/deque.

Ion Gaztañaga wrote:
> Hi,
> 
> I don't exactly reproduce your problem (my program just crashes in 
> release mode) but I've found something tricky in my code:
> 
> -> If we use raw pointer instead of offset_ptr there is no problem.
> -> If I make offset_ptr::set_offset function non-inline (taking it out 
> of the class definition) my problem goes away.
> 
> I suspect that function inlining in VC8 is hurting something. Can you 
> try to make offset_ptr::sey_offset non-inline and report your results?
> 
> I will try to guess if that's the only problem.
> 
> Regards,
> 
> Ion
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