[RFC weston 0/9] weston-debug protocol, API, and tool

Devadoss, Maniraj (RBEI/ECF3; ADITG/SWG) external.mdevadoss at de.adit-jv.com
Thu Jul 27 11:55:25 UTC 2017

Hello Pekka,

I integrated the patches and evaluated the protocol. Initially I faced crashing with the following call stack.

EXH /lib64/libc-2.24.so(strlen+0x10)[0xffffb6ddfcd0]
EXH /lib64/libc-2.24.so(_IO_vfprintf+0x1938)[0xffffb6dad300]
EXH /lib64/libc-2.24.so(_IO_fprintf+0x68)[0xffffb6db2e18]
EXH /usr/bin/weston(protocol_log_fn+0x7c)[0x40607c]
EXH /usr/lib64/libwayland-server.so.0.1.0(_init+0x878)[0xffffb6efeea0]

The issue is that, when we tried to pass the returned pointer from weston_debug_timestamp() API, the fprintf is crashing.
I modified to pass the local "timestr" array to be passed to fprintf. After this modification it is working fine. Have you faced any such issue?
Other than the this issue everything works fine for us. I am able to see the logs for different debug scopes.

Please find our feedback below.

i) As Emre suggested we want this protocol to be in wayland-protocols so that an external client can also use this.
ii) For getting the bootup logs before client connects, we like your idea to add the new command line to weston to stream to
the given file(s).
iii) We can add the scope names to the debug logs along with time stamps so that the grouping/greping the log messages will be easier.
iv) There could be an additional debug scope named as "all" to subscribe to all the available debug scopes.

Best regards

Maniraj Devadoss
Software Group (ADITG/SWG)

Tel. +49 5121 49 6933
-----Original Message-----
From: Ucan, Emre (ADITG/ESB) 
Sent: Montag, 24. Juli 2017 16:51
To: Pekka Paalanen
Cc: wayland-devel at lists.freedesktop.org; Friedrich, Eugen (ADITG/ESB); Devadoss, Maniraj (RBEI/ECF3; ADITG/SWG)
Subject: RE: [RFC weston 0/9] weston-debug protocol, API, and tool

Hello Pekka,

Honestly speaking, I did not have time to evaluate it yet. Because I was on vacation.
I am planning to start this week. Hopefully, I can reply to you next week.

Best regards

Emre Ucan
Engineering Software Base (ADITG/ESB)

Tel. +49 5121 49 6937

> -----Original Message-----
> From: Pekka Paalanen [mailto:ppaalanen at gmail.com]
> Sent: Montag, 24. Juli 2017 16:34
> To: Ucan, Emre (ADITG/ESB)
> Cc: wayland-devel at lists.freedesktop.org; Friedrich, Eugen (ADITG/ESB)
> Subject: Re: [RFC weston 0/9] weston-debug protocol, API, and tool
> On Fri, 9 Jun 2017 18:32:25 +0300
> Pekka Paalanen <ppaalanen at gmail.com> wrote:
> > On Fri, 9 Jun 2017 14:10:56 +0000
> > "Ucan, Emre (ADITG/ESB)" <eucan at de.adit-jv.com> wrote:
> >
> > > Hi Pekka,
> > >
> > > I like your idea with scope trees. I want to play around a little 
> > > bit with the protocol next week. Later I will finalize my proposal 
> > > for the protocol. Maybe you are right and we can use the protocol 
> > > as it is.
> Hi Emre,
> now that I have finally looked at your patches, I dare ask. ;-) How is 
> it going with the debug stuff?
> Thanks,
> pq
> > >
> > > Do you think that the RFC is mergeable to upstream ? Are there 
> > > something to address before ?
> >
> > Hi Emre,
> >
> > the two things that are missing are man-page for weston-debug and 
> > finishing the protocol pretty-printer. The are noted in the 
> > respective commit messages. After those, the series is mergeable in my opinion.
> >
> > More command line options and scope collections can well be added later.
> >
> > Do you think you want the protocol in wayland-protocols still? If 
> > yes, that could be done first. However, I'm not quite sure the 
> > weston-specific interface names good then, but I don't have better 
> > ideas at the moment.
> >
> > If in wayland-protocols, it should be an unstable protocol (see the 
> > README in wayland-protocols on how things need to be arranged).
> >
> >
> > Thanks,
> > pq

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