> From: Stephen Hemminger [mailto:step...@networkplumber.org] > Sent: Thursday, 13 March 2025 17.25 > > On Thu, 13 Mar 2025 15:41:33 +0100 > Morten Brørup <m...@smartsharesystems.com> wrote: > > > > From: Thomas Monjalon [mailto:tho...@monjalon.net] > > > > > > 13/03/2025 09:56, Bruce Richardson: > > > > On Thu, Mar 13, 2025 at 09:00:09AM +0100, Morten Brørup wrote: > > > > > > From: Stephen Hemminger [mailto:step...@networkplumber.org] > > > > > > Sent: Thursday, 13 March 2025 00.02 > > > > > > > > > > > > On Wed, 19 Feb 2025 15:55:17 +0100 > > > > > > Thomas Monjalon <tho...@monjalon.net> wrote: > > > > > > > > > > > > > 14/02/2025 18:20, Stephen Hemminger: > > > > > > > > The Linux version of sys/queue.h is frozen at an older > > > version > > > > > > > > and is missing the _SAFE macro variants. Several drivers > > > started > > > > > > > > introducing the own workarounds for this. Should be > handled > > > in EAL. > > > > > > > > > > > > > > > > Signed-off-by: Stephen Hemminger > <step...@networkplumber.org> > > > > > > > > > > > > > > We may want to unify with > lib/eal/windows/include/sys/queue.h > > > > > > > > > > > > > > > > > > > > > > > > > > Not sure, we have several options here: > > > > > > 1. Keep using Linux sys/queue.h and add enhancements in > > > rte_queue.h > > > > > > 2. Make rte_queue.h a copy of FreeBSD version of queue.h > (that > > > is > > > > > > what Windows did) > > > > > > 3. Use the bsd version of queue.h. > > > > > > On Debian/Ubuntu this in libbsd-dev package and referred > to > > > as > > > > > > bsd/sys/queue.h > > > > > > > > > > > > I chose #1 as simplest. But all of these could work. #3 means > > > DPDK has > > > > > > least new > > > > > > code, but adds another dependency to the build. > > > > > > > > > > +1 to #2: > > > > > If Linux sys/queue.h is frozen, and is a subset of FreeBSD > queue.h, > > > #2 would consolidate all the queue macros in one file. > > > > > That seems easier to navigate (for a developer/reviewer looking > at > > > the macro definitions/implementations) than including sys/queue.h, > > > queue.h or lib/eal/windows/include/sys/queue.h depending on O/S, > and > > > then defining the missing macros in rte_queue.h. > > > > > A comment at the top of the rte_queue.h file could mention that > it > > > is a copy of the FreeBSD queue.h file. > > > > > > > > > > -1 to #3; it adds an unnecessary dependency. > > > > > > > > > > > > > > > > > No matter what, should add to checkpatch to block any new > files > > > that > > > > > > include sys/queue.h > > > > > > directly. > > > > > > > > > > +1 to this. > > > > > > > > > > > > > I agree with Morten, #2 looks the best option to me too. > > > > > > It means we want to remove lib/eal/windows/include/sys/queue.h, > right? > > > > Correct. > > All queue macros are consolidated into rte_queue.h. > > > > I have been trying this, and it possible but there is some fallout. > If application includes <sys/queue.h> and other DPDK headers include > <rte_queue.h> > there are declaration conflicts. Ends up being a compilation failure. > Tedious, but not hard to fix all of DPDK to use rte_queue.h instead of > sys/queue.h > but what about user applications?
Perhaps this could work: If _SYS_QUEUE_H_ is defined in rte_queue.h, including <sys/queue.h> after <rte_queue.h> will be harmless. If each macro in rte_queue.h is surrounded by #ifndef MACRONAME, including <rte_queue.h> after <sys/queue.h> will be harmless. Alternatively, surround a group of macros in rte_queue.h by #ifndef _SYS_QUEUE_H_. > > Since that would be API break, best to put it off to 25.11. It might be impossible prohibiting user libraries from including <sys/queue.h>, especially if some 3rd party library includes <sys/queue.h> in the library's header file. The application developer would not want to modify the header files of 3rd party libraries.
