[Development] 32bit linux build of qt5.10.0 w/ webengine

[Toan Pham]

I am suspecting that the reason why qtwebengineview did not render because
it could not establish IPC connection to qtwebengineprocess.  As seen in
the error below, qtwebengineview aborted when it received unexpected number
of bytes from the IPC initialization call (recvmsg): "unexpected number of
handles".  The second error is related to QT not able to allocate more
memory: "FATAL:memory.cc(22)] Out of memory. size=262144".  The system had
more than 1.8G of RAM, so I do not see how it is possible.



Reference: Error and stack trace of application:

>> [13118:13122:0112/095238.425618:ERROR:broker_posix.cc(46)] Received
unexpected number of handles

My assumption here is that qt could not establish IPC connection with
webengineprocess!



>>
[13118:13122:0112/095238.425832:WARNING:client_shared_bitmap_manager.cc(98)]
Browser failed to allocate shared memory
>> [13118:13122:0112/095238.425986:FATAL:memory.cc(22)] Out of memory.
size=262144
>> #0 0x0000412c4f36 <unknown>
>> #1 0x0000412c4c5d <unknown>
>>  #2 0x0000412d6c4d <unknown>

Obviously, bitmap manager could not allocate memory.  The question is why?
system had pretty of RAM.



On Thu, Jan 11, 2018 at 12:49 PM, Toan Pham <tpham3783 at gmail.com> wrote:

>
> Thiago,
>
> I managed to get the build completed by performing these steps:
>
>   1.  Followed your advise on enabling sse2 because it is a
> hard-requirement.
>   2.  Patched libvpx heavily to disable avx+avx2/sse3+ (see attached patch)
>   3.  Patched libyuv (see attached patch)
>   4.  Patched qwebengine/src/core/Makefile.gn_run to launch ninja in
> single thread - otherwise build w/ terminate by Out-Of-Memory manager.
>   5.  Used 32bit native linker even though you recommended a 64bit linker.
>
> Step# 2 and 3 were needed because the compiler I was using was optimized
> for pentium4, it wouldn't be able to compile/link-in SIMD instructions
> beyond SSE2.
>
>
> After all that hard work, minimal webengine browser (located at
> qtwebengine/examples/webengine/minimal) did not show anything when I
> launched it (see attached screenshot).  I also launched the same browser
> which worked fine under lxc-ubuntu16.04-32bit; but did not show anything
> within the chroot environment of the pentium4 build.  OnPageLoad event of
> qtwebengine showed that webpage loaded successfully; so it made me to
> believe that this is an issue with qwebenginewidget.  FYI, within the same
> build environment, I was able to run QtWebKit from Qt-5.x a few months
> back.  Please help if you know what possibly happened to qwebengineview not
> rendering anything on the view.
>
>
> Thank you,
>
> TP
>
>
>
>
> On Mon, Jan 8, 2018 at 3:21 AM, Lars Knoll <lars.knoll at qt.io> wrote:
>
>> >
>> >> For me, it's quite simple:
>> >> No (opensource/commercial) Qt CI = No (opensource/commercial) Qt
>> >> binaries = No (opensource/commercial) support.
>> >
>> > No CI, see above.
>> > No binaries, build from sources.
>> > No support, sorry, I can't comment.
>>
>> Just a quick comment from TQtC’s perspective on this: We do commercially
>> support more platforms than we create binaries for. Linux/32bit is
>> certainly one of those.
>>
>> But as Thiago pointed out, those platforms are not always tested quite as
>> well (unfortunately we can’t possibly test all combinations of OS/CPU
>> architecture/distribution in our CI).
>>
>> Cheers,
>> Lars
>>
>> >
>> >> If you don't build and test on a regular basis, it can break at any
>> >> moment without anyone noticing (and it did happened at least once)
>> >
>> > You're right, but given all the other permutations, we're very likely
>> covered
>> > at a good 99% certainty.
>> >
>> >> PS: In case you think I'm ranting for free here, i would like to say
>> >> (again) that I think Qt is a great piece of (opensource/commercial)
>> >> SW, and big thumb up to anyone behind this, The Qt Project, The Qt
>> >> Company, Intel, ICS, KDAB, KDE, ... and everyone else, individual or
>> >> corporate.
>> >
>> > We're having a constructive conversation, don't worry.
>> >
>> > --
>> > Thiago Macieira - thiago.macieira (AT) intel.com
>> >  Software Architect - Intel Open Source Technology Center
>> >
>> > _______________________________________________
>> > Development mailing list
>> > Development at qt-project.org
>> > http://lists.qt-project.org/mailman/listinfo/development
>>
>> _______________________________________________
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>>
>
>
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