Hello Torsten, On Mon, Aug 07, 2006 at 07:08:39PM +0200, Thomas Girard wrote: > > > Another way of enforcing correct flags would be to check whether symbol > > > _REENTRANT is defined, and if it is not, the header could abort > > > compilation with an #error stating _REENTRANT *must* be defined. > > > > > > I am not convinced this is better. What do you think? > > > > We first used shared_ptr's about 3 or 4 years ago. That's when > > this bug hid itself undetected in our software. We only wondered, > > why using a shared_ptr would sometimes cause our software to hang. > > > > The cause was, that mostly the shared_ptr ended up having no mutex. > > But, if a piece of code included the ace headers first, it might > > hang when using a shared_ptr, that was constructed in a different > > compilation unit. > > > > An #error stating _REENTRANT *must* be defined, or even better, > > saying -pthread(s) *must* be used, would have prevented and fixed > > our bug a long time ago. I agree, that the latter would be more > > difficult, as you would have to figure out the correct option > > for different compilers and architectures. > > > > So, I would recommend the #error. > > > > The boost library also #error's out, if it requires multithreading > > support.
I have a fix for this bug, and it seems to work. But using boost 1.33.1-7 (from unstable) on your example no longer works (with or without my patch). Indeed now boost #define _REENTRANT, because <memory> gets included to use libstdc++ allocator. If you believe that's a problem, please file a bug on boost. I am disabling the patch because with it, we would have another problem: including a boost header first works, but including an ACE header first would error out. The patch is attached to this email. What is your opinion on this? Thanks, Thomas
#! /bin/sh /usr/share/dpatch/dpatch-run ## 20-check-_REENTRANT.dpatch by Thomas Girard <[EMAIL PROTECTED]> ## ## All lines beginning with `## DP:' are a description of the patch. ## DP: Rather than #defining _REENTRANT if it's not yet defined, #error out ## DP: See Debian bug #380739. @DPATCH@ --- ACE_wrappers.orig/ace/config-lite.h 2006-09-10 21:51:38.312980000 +0200 +++ ACE_wrappers/ace/config-lite.h 2006-09-10 21:36:50.861517750 +0200 @@ -68,7 +68,7 @@ # if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0) # define ACE_MT(X) X # if !defined (_REENTRANT) -# define _REENTRANT +# error _REENTRANT has to be defined! # endif /* _REENTRANT */ # else # define ACE_MT(X)
