Re: [Boost-users] Building and testing smart pointers using HP-UX/G++

From: David M Garza (David.M.Garza_at_[hidden])
Date: 2005-12-14 12:06:32

Ben Hutchings wrote:
...
>> I grabbed the CVS instead of using the 1.33.0 package I was working
>> with before.  I assume this was what you intended?
>> 
>> 
> 
> Did you also apply the patch I attached? I won't commit that change
> to CVS unless and until you confirm that it works in an ILP32
> configuration.

This was with the patch already applied.  I wasn't very specific in what
I wrote--I meant I applied the patch to what I got from CVS as opposed
to applying it to 1.33.0.  Sorry.

> 
> 
>> As an aside, do I gather correctly from the presence of
>> "-D_REENTRANT -pthread" the smart pointer code is multithreaded?
>> 
> 
> It's intended to be thread-safe if necessary. The purpose of the 
> assembly-language code is to do reference-counting in a thread-safe
> and efficient way (use of mutexes for reference-counting is quite
> expensive).
> 
> 
>> Anything I write using smart pointers, regardless of whether or not
>> my code is multithreaded, will require the flags?
>> 
>> 
> 
> If BOOST_DISABLE_THREADS is defined then you will get a
> non-thread-safe and more efficient version of sp_counted_base. You
> must ensure that all translation units that use sp_counted_base get a
> consistent definition (the One Definition Rule). So you should choose
> either "-D_REENTRANT -pthread" or "-DBOOST_DISABLE_THREADS" and use
> it consistently.

Okay.  I'm thinking right now I'll end up using BOOST_DISABLE_THREADS 
since I don't intend to spawn multiple threads myself--my project is a 
serial numerical analysis code.

Once I was doing a project involving Java and I read a Java programer 
still had to consider thread safety regardless of whether or not the 
program code explicitly spawned multiple threads because, while the 
program's code might not explicitly spawn many threads, Java class 
library methods could spawn multiple threads when called.  I think this 
came up in particular when I was doing Java-C++-Fortran cross-language 
programming.

David