[FFmpeg-devel] [PATCH v2 01/14] vvcdec: add thread executor

[Michael Niedermayer]

On Tue, Jul 18, 2023 at 07:53:09PM +0800, Nuo Mi wrote:
> On Tue, Jul 18, 2023 at 6:14 AM Michael Niedermayer <michael at niedermayer.cc>
> wrote:
> 
> > On Sun, Jul 16, 2023 at 02:28:53PM +0800, Nuo Mi wrote:
> > > On Mon, Jul 10, 2023 at 3:41 PM Nuo Mi <nuomi2021 at gmail.com> wrote:
> > >
> > > >
> > > >
> > > > On Sun, Jul 9, 2023 at 5:52 AM Michael Niedermayer <
> > michael at niedermayer.cc>
> > > > wrote:
> > > >
> > > >> On Fri, Jul 07, 2023 at 10:05:27PM +0800, Nuo Mi wrote:
> > > >> > The executor design pattern was inroduced by java
> > > >> > <
> > > >>
> > https://docs.oracle.com/en/java/javase/20/docs/api/java.base/java/util/concurrent/Executor.html
> > > >> >
> > > >> > it also adapted by python
> > > >> > <https://docs.python.org/3/library/concurrent.futures.html>
> > > >> > Compared to handcrafted thread pool management, it greatly
> > simplifies
> > > >> the thread code.
> > > >> > ---
> > > >> >  libavcodec/Makefile     |   1 +
> > > >> >  libavcodec/executor.c   | 182
> > ++++++++++++++++++++++++++++++++++++++++
> > > >> >  libavcodec/executor.h   |  67 +++++++++++++++
> > > >> >  libavcodec/vvc/Makefile |   4 +
> > > >> >  4 files changed, 254 insertions(+)
> > > >> >  create mode 100644 libavcodec/executor.c
> > > >> >  create mode 100644 libavcodec/executor.h
> > > >> >  create mode 100644 libavcodec/vvc/Makefile
> > > >>
> > > >> This seems to need some fallback if pthreads are unavailable
> > > >>
> > > >> src/libavcodec/executor.c: In function ‘executor_worker_task’:
> > > >> src/libavcodec/executor.c:64:5: error: implicit declaration of
> > function
> > > >> ‘pthread_mutex_lock’; did you mean ‘ff_mutex_lock’?
> > > >> [-Werror=implicit-function-declaration]
> > > >>      pthread_mutex_lock(&e->lock);
> > > >>      ^~~~~~~~~~~~~~~~~~
> > > >>      ff_mutex_lock
> > > >> ...
> > > >> cc1: some warnings being treated as errors
> > > >> ffmpeg/ffbuild/common.mak:81: recipe for target
> > 'libavcodec/executor.o'
> > > >> failed
> > > >> make: *** [libavcodec/executor.o] Error 1
> > > >> make: *** Waiting for unfinished jobs....
> > > >>
> > > >> thx
> > > >>
> > > >> [...]
> > > >> --
> > > >> Michael     GnuPG fingerprint:
> > 9FF2128B147EF6730BADF133611EC787040B0FAB
> > > >>
> > > >> Why not whip the teacher when the pupil misbehaves? -- Diogenes of
> > Sinope
> > > >> _______________________________________________
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> > > >> ffmpeg-devel at ffmpeg.org
> > > >> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> > > >>
> > > >> To unsubscribe, visit link above, or email
> > > >> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
> > > >>
> > > > Hi Michael,
> > > > Thank you for the information. I will fixed it
> > > >
> > >
> > > Hi Michael,
> > > FFmpeg application has a dependency on threads
> > > Once I --disable-pthreads, I can't build ffmpeg for the decoder md5 test.
> > > Could you share with me how to test the decoder when we disabled threads?
> >
> > it seems this failure occurred on a ppc cross compile
> > ../configure --target-os=linux --enable-cross-compile --disable-iconv
> > --disable-pthreads && make -j32
> 
> 
> 
> 
> > but its reproduceable on ubuntu x86-64 with a simple
> >  make distclean ; ./configure   --disable-pthreads && make -j32
> >
> I used a similar configuration, but both my configuration and the one you
> provided do not generate the ffmpeg executable. We only get the ffprobe.
> However, I need the ffmpeg executable to obtain the MD5 for the conformance
> test.

I dont understand fully

the command results in a build failure of libavcodec, theres no need to build
the ffmpeg excutable, it should fail before

Its true that once the build failure is corrected that testing this without pthreads
would be impossible with tools depending on pthreads and build in the same pass.
I dont think testing beyond build is critical here.
But you can test it likely either with older ffmpeg or with a bit of "duct tape"
building with shared libs building ffmpeg with threads and linking to libs build
without. Again, iam not asking fr that to be done, iam happy if the build failure is
fixed and its believed to work.

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

While the State exists there can be no freedom; when there is freedom there
will be no State. -- Vladimir Lenin
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