[v2,2/2] libcamera: camera_manager: Add environment variable to order pipelines match
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Message ID 20240308110056.453320-3-julien.vuillaumier@nxp.com
State New
Headers show
Series
  • Add environment variable to order pipelines match
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Commit Message

Julien Vuillaumier March 8, 2024, 11 a.m. UTC
To match the enumerated media devices, each pipeline handler registered
is used in no specific order. It is a limitation when several pipelines
can match the devices, and user has to select a specific pipeline.

For this purpose, environment variable LIBCAMERA_PIPELINES_MATCH_LIST is
created that gives the option to define an ordered list of pipelines
to invoke during the match process.

LIBCAMERA_PIPELINES_MATCH_LIST="<name1>[,<name2>[,<name3>...]]]"

Example:
LIBCAMERA_PIPELINES_MATCH_LIST="PipelineHandlerRkISP1,SimplePipelineHandler"

Signed-off-by: Julien Vuillaumier <julien.vuillaumier@nxp.com>
---
 Documentation/environment_variables.rst     |  5 ++
 include/libcamera/internal/camera_manager.h |  1 +
 src/libcamera/camera_manager.cpp            | 57 ++++++++++++++++-----
 3 files changed, 51 insertions(+), 12 deletions(-)

Comments

Jacopo Mondi March 20, 2024, 12:53 p.m. UTC | #1
Hi Julien

On Fri, Mar 08, 2024 at 12:00:56PM +0100, Julien Vuillaumier wrote:
> To match the enumerated media devices, each pipeline handler registered

s/pipeline handler registered/registered pipeline handler/

> is used in no specific order. It is a limitation when several pipelines
> can match the devices, and user has to select a specific pipeline.
>
> For this purpose, environment variable LIBCAMERA_PIPELINES_MATCH_LIST is
> created that gives the option to define an ordered list of pipelines

s/that gives/to give/

> to invoke during the match process.

Or just: "to match on."

>
> LIBCAMERA_PIPELINES_MATCH_LIST="<name1>[,<name2>[,<name3>...]]]"
>
> Example:
> LIBCAMERA_PIPELINES_MATCH_LIST="PipelineHandlerRkISP1,SimplePipelineHandler"
>
> Signed-off-by: Julien Vuillaumier <julien.vuillaumier@nxp.com>
> ---
>  Documentation/environment_variables.rst     |  5 ++
>  include/libcamera/internal/camera_manager.h |  1 +
>  src/libcamera/camera_manager.cpp            | 57 ++++++++++++++++-----
>  3 files changed, 51 insertions(+), 12 deletions(-)
>
> diff --git a/Documentation/environment_variables.rst b/Documentation/environment_variables.rst
> index a9b230bc..ea4da3c9 100644
> --- a/Documentation/environment_variables.rst
> +++ b/Documentation/environment_variables.rst
> @@ -37,6 +37,11 @@ LIBCAMERA_IPA_MODULE_PATH
>
>     Example value: ``${HOME}/.libcamera/lib:/opt/libcamera/vendor/lib``
>
> +LIBCAMERA_PIPELINES_MATCH_LIST
> +   Define an ordered list of pipeline names to be used to match the media devices in the system.

long line over 80 cols which could eaily be broken in 2 lines

> +
> +   Example value: ``PipelineHandlerRkISP1,SimplePipelineHandler``

These are the names of the PipelineHandlers classes, which is fine,
but maybe for users it is better to use something they can more easily
reference, like the meson option associated with the pipeline ?

This will require a map though...

> +
>  LIBCAMERA_RPI_CONFIG_FILE
>     Define a custom configuration file to use in the Raspberry Pi pipeline handler.
>
> diff --git a/include/libcamera/internal/camera_manager.h b/include/libcamera/internal/camera_manager.h
> index 33ebe069..c57e509a 100644
> --- a/include/libcamera/internal/camera_manager.h
> +++ b/include/libcamera/internal/camera_manager.h
> @@ -45,6 +45,7 @@ private:
>  	int init();
>  	void createPipelineHandlers();
>  	void cleanup() LIBCAMERA_TSA_EXCLUDES(mutex_);
> +	void pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory);

Please move this one line up to match the function definition order in
the .cpp file

>
>  	/*
>  	 * This mutex protects
> diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
> index 355f3ada..620be1c8 100644
> --- a/src/libcamera/camera_manager.cpp
> +++ b/src/libcamera/camera_manager.cpp
> @@ -99,13 +99,36 @@ int CameraManager::Private::init()
>
>  void CameraManager::Private::createPipelineHandlers()
>  {
> -	CameraManager *const o = LIBCAMERA_O_PTR();
> -
>  	/*
>  	 * \todo Try to read handlers and order from configuration
> -	 * file and only fallback on all handlers if there is no
> -	 * configuration file.
> +	 * file and only fallback on environment variable or all handlers, if
> +	 * there is no configuration file.
> +	 */
> +
> +	/*
> +	 * When a list of preferred pipelines is defined, iterate through the
> +	 * ordered list to match the devices enumerated.

s/devices enumerated/enumerated devices/

> +	 * Otherwise, device matching is done in no specific order with each
> +	 * registered pipeline handler.
>  	 */

What about moving this comment block in the below if (pipesList)
branch ?

> +	const char *pipesList =
> +		utils::secure_getenv("LIBCAMERA_PIPELINES_MATCH_LIST");
> +	if (pipesList) {
> +		for (const auto &pipeName : utils::split(pipesList, ",")) {
> +			const PipelineHandlerFactoryBase *factory;
> +			factory = PipelineHandlerFactoryBase::getFactoryByName(pipeName);
> +			if (!factory)
> +				continue;
> +
> +			LOG(Camera, Debug)
> +				<< "Found listed pipeline handler '"
> +				<< pipeName << "'";
> +			pipelineFactoryMatch(factory);
> +		}
> +
> +		return;
> +	}
> +
>  	const std::vector<PipelineHandlerFactoryBase *> &factories =
>  		PipelineHandlerFactoryBase::factories();
>
> @@ -117,15 +140,25 @@ void CameraManager::Private::createPipelineHandlers()
>  		 * Try each pipeline handler until it exhaust
>  		 * all pipelines it can provide.
>  		 */
> -		while (1) {
> -			std::shared_ptr<PipelineHandler> pipe = factory->create(o);
> -			if (!pipe->match(enumerator_.get()))
> -				break;
> +		pipelineFactoryMatch(factory);
> +	}
> +}
>
> -			LOG(Camera, Debug)
> -				<< "Pipeline handler \"" << factory->name()
> -				<< "\" matched";
> -		}
> +void CameraManager::Private::pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory)
> +{
> +	CameraManager *const o = LIBCAMERA_O_PTR();
> +
> +	/*
> +	 * Provide as many matching pipelines as possible
> +	 */

Fits on a single line

Also, I would
        /* Match all the registed pipeline handlers. */

> +	while (1) {
> +		std::shared_ptr<PipelineHandler> pipe = factory->create(o);
> +		if (!pipe->match(enumerator_.get()))
> +			break;
> +
> +		LOG(Camera, Debug)
> +			<< "Pipeline handler \"" << factory->name()
> +			<< "\" matched";
>  	}
>  }

Overall, I concur this is an useful addition. I know there are ideas
about assigning a priority to pipeline handlers at creation time as
currently the only conflict is on the ISI which can be
matched both by the imx8-isi pipeline and the simple pipeline.

For the time being, with the above issues fixed
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>

Thanks
  j

>
> --
> 2.34.1
>
Julien Vuillaumier March 21, 2024, 7:26 p.m. UTC | #2
Hi Jacopo,

Your comments will be integrated in v3.

But I have a couple of questions to confirm I have the correct 
understanding.

Thank you,
Julien

On 20/03/2024 13:53, Jacopo Mondi wrote:
> Caution: This is an external email. Please take care when clicking links or opening attachments. When in doubt, report the message using the 'Report this email' button
> 
> 
> Hi Julien
> 
> On Fri, Mar 08, 2024 at 12:00:56PM +0100, Julien Vuillaumier wrote:
>> To match the enumerated media devices, each pipeline handler registered
> 
> s/pipeline handler registered/registered pipeline handler/
> 
>> is used in no specific order. It is a limitation when several pipelines
>> can match the devices, and user has to select a specific pipeline.
>>
>> For this purpose, environment variable LIBCAMERA_PIPELINES_MATCH_LIST is
>> created that gives the option to define an ordered list of pipelines
> 
> s/that gives/to give/
> 
>> to invoke during the match process.
> 
> Or just: "to match on."
> 
>>
>> LIBCAMERA_PIPELINES_MATCH_LIST="<name1>[,<name2>[,<name3>...]]]"
>>
>> Example:
>> LIBCAMERA_PIPELINES_MATCH_LIST="PipelineHandlerRkISP1,SimplePipelineHandler"
>>
>> Signed-off-by: Julien Vuillaumier <julien.vuillaumier@nxp.com>
>> ---
>>   Documentation/environment_variables.rst     |  5 ++
>>   include/libcamera/internal/camera_manager.h |  1 +
>>   src/libcamera/camera_manager.cpp            | 57 ++++++++++++++++-----
>>   3 files changed, 51 insertions(+), 12 deletions(-)
>>
>> diff --git a/Documentation/environment_variables.rst b/Documentation/environment_variables.rst
>> index a9b230bc..ea4da3c9 100644
>> --- a/Documentation/environment_variables.rst
>> +++ b/Documentation/environment_variables.rst
>> @@ -37,6 +37,11 @@ LIBCAMERA_IPA_MODULE_PATH
>>
>>      Example value: ``${HOME}/.libcamera/lib:/opt/libcamera/vendor/lib``
>>
>> +LIBCAMERA_PIPELINES_MATCH_LIST
>> +   Define an ordered list of pipeline names to be used to match the media devices in the system.
> 
> long line over 80 cols which could eaily be broken in 2 lines
> 
>> +
>> +   Example value: ``PipelineHandlerRkISP1,SimplePipelineHandler``
> 
> These are the names of the PipelineHandlers classes, which is fine,
> but maybe for users it is better to use something they can more easily
> reference, like the meson option associated with the pipeline ?
> 
> This will require a map though...

As of today the pipeline name, defined as PipelineHandler class name, is 
presented to the user (log=DEBUG), during the match procedure:
"Found registered pipeline handler <xyz>"
"Pipeline handler <xyz> matched"

Thus, reusing that same name to define the ordered list of pipelines for 
the match seemed fairly consistent.

But agreed, PipelineHandler names could be simpler. Currently, apart 
from those logs during match, pipeline name looks to be used only in an 
ipa interface test.
If deemed useful, we could change the current names of each 
PipelineHandler to replace the class name, as you suggested, by the 
meson option name associated with that pipeline.

A simple way of doing that would be adding to the existing 
REGISTER_PIPELINE_HANDLER(handler) a parameter 'name' to be passed to 
PipelineHandlerFactory constructor, instead of the stringified class name.
Registration of each existing pipelines would need to be updated 
accordingly.

Do you recommend changing PipelineHandler name used in the context of 
that change?
In that case, does the above proposal (add a short name to the register 
macro) makes sense?

>> +
>>   LIBCAMERA_RPI_CONFIG_FILE
>>      Define a custom configuration file to use in the Raspberry Pi pipeline handler.
>>
>> diff --git a/include/libcamera/internal/camera_manager.h b/include/libcamera/internal/camera_manager.h
>> index 33ebe069..c57e509a 100644
>> --- a/include/libcamera/internal/camera_manager.h
>> +++ b/include/libcamera/internal/camera_manager.h
>> @@ -45,6 +45,7 @@ private:
>>        int init();
>>        void createPipelineHandlers();
>>        void cleanup() LIBCAMERA_TSA_EXCLUDES(mutex_);
>> +     void pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory);
> 
> Please move this one line up to match the function definition order in
> the .cpp file
> 
>>
>>        /*
>>         * This mutex protects
>> diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
>> index 355f3ada..620be1c8 100644
>> --- a/src/libcamera/camera_manager.cpp
>> +++ b/src/libcamera/camera_manager.cpp
>> @@ -99,13 +99,36 @@ int CameraManager::Private::init()
>>
>>   void CameraManager::Private::createPipelineHandlers()
>>   {
>> -     CameraManager *const o = LIBCAMERA_O_PTR();
>> -
>>        /*
>>         * \todo Try to read handlers and order from configuration
>> -      * file and only fallback on all handlers if there is no
>> -      * configuration file.
>> +      * file and only fallback on environment variable or all handlers, if
>> +      * there is no configuration file.
>> +      */
>> +
>> +     /*
>> +      * When a list of preferred pipelines is defined, iterate through the
>> +      * ordered list to match the devices enumerated.
> 
> s/devices enumerated/enumerated devices/
> 
>> +      * Otherwise, device matching is done in no specific order with each
>> +      * registered pipeline handler.
>>         */
> 
> What about moving this comment block in the below if (pipesList)
> branch ?
> 
>> +     const char *pipesList =
>> +             utils::secure_getenv("LIBCAMERA_PIPELINES_MATCH_LIST");
>> +     if (pipesList) {
>> +             for (const auto &pipeName : utils::split(pipesList, ",")) {
>> +                     const PipelineHandlerFactoryBase *factory;
>> +                     factory = PipelineHandlerFactoryBase::getFactoryByName(pipeName);
>> +                     if (!factory)
>> +                             continue;
>> +
>> +                     LOG(Camera, Debug)
>> +                             << "Found listed pipeline handler '"
>> +                             << pipeName << "'";
>> +                     pipelineFactoryMatch(factory);
>> +             }
>> +
>> +             return;
>> +     }
>> +
>>        const std::vector<PipelineHandlerFactoryBase *> &factories =
>>                PipelineHandlerFactoryBase::factories();
>>
>> @@ -117,15 +140,25 @@ void CameraManager::Private::createPipelineHandlers()
>>                 * Try each pipeline handler until it exhaust
>>                 * all pipelines it can provide.
>>                 */
>> -             while (1) {
>> -                     std::shared_ptr<PipelineHandler> pipe = factory->create(o);
>> -                     if (!pipe->match(enumerator_.get()))
>> -                             break;
>> +             pipelineFactoryMatch(factory);
>> +     }
>> +}
>>
>> -                     LOG(Camera, Debug)
>> -                             << "Pipeline handler \"" << factory->name()
>> -                             << "\" matched";
>> -             }
>> +void CameraManager::Private::pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory)
>> +{
>> +     CameraManager *const o = LIBCAMERA_O_PTR();
>> +
>> +     /*
>> +      * Provide as many matching pipelines as possible
>> +      */
> 
> Fits on a single line
> 
> Also, I would
>          /* Match all the registed pipeline handlers. */
> 
>> +     while (1) {
>> +             std::shared_ptr<PipelineHandler> pipe = factory->create(o);
>> +             if (!pipe->match(enumerator_.get()))
>> +                     break;
>> +
>> +             LOG(Camera, Debug)
>> +                     << "Pipeline handler \"" << factory->name()
>> +                     << "\" matched";
>>        }
>>   }
> 
> Overall, I concur this is an useful addition. I know there are ideas
> about assigning a priority to pipeline handlers at creation time as
> currently the only conflict is on the ISI which can be
> matched both by the imx8-isi pipeline and the simple pipeline.

As you mentioned, imx8-isi and simple pipelines are concurrent. With 
imx9 family, there is an additional cause of concurrency as platforms 
can/will use topologies with both ISI + ISP. And depending on the use 
case, user may want to use either simple, or imx8-isi or the isi+isp 
pipeline.

This change is a basic way to dynamically assign relative priorities to 
the pipelines. It was suggested in v1 review comments to also have a 
similar configuration possible from a global config file.

> 
> For the time being, with the above issues fixed
> Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> 
> Thanks
>    j
> 
>>
>> --
>> 2.34.1
>>
Jacopo Mondi March 22, 2024, 8:50 a.m. UTC | #3
Hi Julien

On Thu, Mar 21, 2024 at 08:26:06PM +0100, Julien Vuillaumier wrote:
> Hi Jacopo,
>
> Your comments will be integrated in v3.
>
> But I have a couple of questions to confirm I have the correct
> understanding.
>
> Thank you,
> Julien
>
> On 20/03/2024 13:53, Jacopo Mondi wrote:
> > Caution: This is an external email. Please take care when clicking links or opening attachments. When in doubt, report the message using the 'Report this email' button
> >
> >
> > Hi Julien
> >
> > On Fri, Mar 08, 2024 at 12:00:56PM +0100, Julien Vuillaumier wrote:
> > > To match the enumerated media devices, each pipeline handler registered
> >
> > s/pipeline handler registered/registered pipeline handler/
> >
> > > is used in no specific order. It is a limitation when several pipelines
> > > can match the devices, and user has to select a specific pipeline.
> > >
> > > For this purpose, environment variable LIBCAMERA_PIPELINES_MATCH_LIST is
> > > created that gives the option to define an ordered list of pipelines
> >
> > s/that gives/to give/
> >
> > > to invoke during the match process.
> >
> > Or just: "to match on."
> >
> > >
> > > LIBCAMERA_PIPELINES_MATCH_LIST="<name1>[,<name2>[,<name3>...]]]"
> > >
> > > Example:
> > > LIBCAMERA_PIPELINES_MATCH_LIST="PipelineHandlerRkISP1,SimplePipelineHandler"
> > >
> > > Signed-off-by: Julien Vuillaumier <julien.vuillaumier@nxp.com>
> > > ---
> > >   Documentation/environment_variables.rst     |  5 ++
> > >   include/libcamera/internal/camera_manager.h |  1 +
> > >   src/libcamera/camera_manager.cpp            | 57 ++++++++++++++++-----
> > >   3 files changed, 51 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/Documentation/environment_variables.rst b/Documentation/environment_variables.rst
> > > index a9b230bc..ea4da3c9 100644
> > > --- a/Documentation/environment_variables.rst
> > > +++ b/Documentation/environment_variables.rst
> > > @@ -37,6 +37,11 @@ LIBCAMERA_IPA_MODULE_PATH
> > >
> > >      Example value: ``${HOME}/.libcamera/lib:/opt/libcamera/vendor/lib``
> > >
> > > +LIBCAMERA_PIPELINES_MATCH_LIST
> > > +   Define an ordered list of pipeline names to be used to match the media devices in the system.
> >
> > long line over 80 cols which could eaily be broken in 2 lines
> >
> > > +
> > > +   Example value: ``PipelineHandlerRkISP1,SimplePipelineHandler``
> >
> > These are the names of the PipelineHandlers classes, which is fine,
> > but maybe for users it is better to use something they can more easily
> > reference, like the meson option associated with the pipeline ?
> >
> > This will require a map though...
>
> As of today the pipeline name, defined as PipelineHandler class name, is
> presented to the user (log=DEBUG), during the match procedure:
> "Found registered pipeline handler <xyz>"
> "Pipeline handler <xyz> matched"
>
> Thus, reusing that same name to define the ordered list of pipelines for the
> match seemed fairly consistent.
>

Yes, it's consistent indeed

> But agreed, PipelineHandler names could be simpler. Currently, apart from

I'm just a bit concerned about the fact users should either inspect
the code or debug logs, while using something like the meson option is
easier to access ?

> those logs during match, pipeline name looks to be used only in an ipa
> interface test.
> If deemed useful, we could change the current names of each PipelineHandler
> to replace the class name, as you suggested, by the meson option name
> associated with that pipeline.

No wait, I was suggesting using the meson option to populate the
LIBCAMERA_PIPELINES_MATCH_LIST env variable.

>
> A simple way of doing that would be adding to the existing
> REGISTER_PIPELINE_HANDLER(handler) a parameter 'name' to be passed to
> PipelineHandlerFactory constructor, instead of the stringified class name.
> Registration of each existing pipelines would need to be updated
> accordingly.
>
> Do you recommend changing PipelineHandler name used in the context of that
> change?
> In that case, does the above proposal (add a short name to the register
> macro) makes sense?
>

Maybe I'm just over-concerned. A way out could be to expand the env
variable description to clearly indicate what identifiers to use as
pipeline handler names. Something like:

LIBCAMERA_PIPELINES_MATCH_LIST
   Define an ordered list of pipeline handlers to be used to match the media
   devices in the system. The pipeline handler names used to populate
   the variable are the ones passed to the the
   REGISTER_PIPELINE_HANDLER() macro in the source code.

   Example value: ``PipelineHandlerRkISP1,SimplePipelineHandler``

Alternatively what I was proposing was to use the identifiers for
the 'pipelines' meson option

        option('pipelines',
                type : 'array',
                value : ['auto'],
                choices : [
                    'all',
                    'auto',
                    'imx8-isi',
                    'ipu3',
                    'rkisp1',
                    'rpi/vc4',
                    'simple',
                    'uvcvideo',
                    'vimc'
                ],


LIBCAMERA_PIPELINES_MATCH_LIST=``rkisp1,simple,imx8-isi``

and keep a map in CameraManager class, but this indeed requires more
maintainership.

Now that I wrote this, isn't it easier to just compile only the
pipeline handler you need ? I presume this doesn't apply to generic
distro though


> > > +
> > >   LIBCAMERA_RPI_CONFIG_FILE
> > >      Define a custom configuration file to use in the Raspberry Pi pipeline handler.
> > >
> > > diff --git a/include/libcamera/internal/camera_manager.h b/include/libcamera/internal/camera_manager.h
> > > index 33ebe069..c57e509a 100644
> > > --- a/include/libcamera/internal/camera_manager.h
> > > +++ b/include/libcamera/internal/camera_manager.h
> > > @@ -45,6 +45,7 @@ private:
> > >        int init();
> > >        void createPipelineHandlers();
> > >        void cleanup() LIBCAMERA_TSA_EXCLUDES(mutex_);
> > > +     void pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory);
> >
> > Please move this one line up to match the function definition order in
> > the .cpp file
> >
> > >
> > >        /*
> > >         * This mutex protects
> > > diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
> > > index 355f3ada..620be1c8 100644
> > > --- a/src/libcamera/camera_manager.cpp
> > > +++ b/src/libcamera/camera_manager.cpp
> > > @@ -99,13 +99,36 @@ int CameraManager::Private::init()
> > >
> > >   void CameraManager::Private::createPipelineHandlers()
> > >   {
> > > -     CameraManager *const o = LIBCAMERA_O_PTR();
> > > -
> > >        /*
> > >         * \todo Try to read handlers and order from configuration
> > > -      * file and only fallback on all handlers if there is no
> > > -      * configuration file.
> > > +      * file and only fallback on environment variable or all handlers, if
> > > +      * there is no configuration file.
> > > +      */
> > > +
> > > +     /*
> > > +      * When a list of preferred pipelines is defined, iterate through the
> > > +      * ordered list to match the devices enumerated.
> >
> > s/devices enumerated/enumerated devices/
> >
> > > +      * Otherwise, device matching is done in no specific order with each
> > > +      * registered pipeline handler.
> > >         */
> >
> > What about moving this comment block in the below if (pipesList)
> > branch ?
> >
> > > +     const char *pipesList =
> > > +             utils::secure_getenv("LIBCAMERA_PIPELINES_MATCH_LIST");
> > > +     if (pipesList) {
> > > +             for (const auto &pipeName : utils::split(pipesList, ",")) {
> > > +                     const PipelineHandlerFactoryBase *factory;
> > > +                     factory = PipelineHandlerFactoryBase::getFactoryByName(pipeName);
> > > +                     if (!factory)
> > > +                             continue;
> > > +
> > > +                     LOG(Camera, Debug)
> > > +                             << "Found listed pipeline handler '"
> > > +                             << pipeName << "'";
> > > +                     pipelineFactoryMatch(factory);
> > > +             }
> > > +
> > > +             return;
> > > +     }
> > > +
> > >        const std::vector<PipelineHandlerFactoryBase *> &factories =
> > >                PipelineHandlerFactoryBase::factories();
> > >
> > > @@ -117,15 +140,25 @@ void CameraManager::Private::createPipelineHandlers()
> > >                 * Try each pipeline handler until it exhaust
> > >                 * all pipelines it can provide.
> > >                 */
> > > -             while (1) {
> > > -                     std::shared_ptr<PipelineHandler> pipe = factory->create(o);
> > > -                     if (!pipe->match(enumerator_.get()))
> > > -                             break;
> > > +             pipelineFactoryMatch(factory);
> > > +     }
> > > +}
> > >
> > > -                     LOG(Camera, Debug)
> > > -                             << "Pipeline handler \"" << factory->name()
> > > -                             << "\" matched";
> > > -             }
> > > +void CameraManager::Private::pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory)
> > > +{
> > > +     CameraManager *const o = LIBCAMERA_O_PTR();
> > > +
> > > +     /*
> > > +      * Provide as many matching pipelines as possible
> > > +      */
> >
> > Fits on a single line
> >
> > Also, I would
> >          /* Match all the registed pipeline handlers. */
> >
> > > +     while (1) {
> > > +             std::shared_ptr<PipelineHandler> pipe = factory->create(o);
> > > +             if (!pipe->match(enumerator_.get()))
> > > +                     break;
> > > +
> > > +             LOG(Camera, Debug)
> > > +                     << "Pipeline handler \"" << factory->name()
> > > +                     << "\" matched";
> > >        }
> > >   }
> >
> > Overall, I concur this is an useful addition. I know there are ideas
> > about assigning a priority to pipeline handlers at creation time as
> > currently the only conflict is on the ISI which can be
> > matched both by the imx8-isi pipeline and the simple pipeline.
>
> As you mentioned, imx8-isi and simple pipelines are concurrent. With imx9
> family, there is an additional cause of concurrency as platforms can/will
> use topologies with both ISI + ISP. And depending on the use case, user may
> want to use either simple, or imx8-isi or the isi+isp pipeline.
>
> This change is a basic way to dynamically assign relative priorities to the
> pipelines. It was suggested in v1 review comments to also have a similar
> configuration possible from a global config file.
>
> >
> > For the time being, with the above issues fixed
> > Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> >
> > Thanks
> >    j
> >
> > >
> > > --
> > > 2.34.1
> > >
>
Julien Vuillaumier March 22, 2024, 2:15 p.m. UTC | #4
Hi Jacopo,

On 22/03/2024 09:50, Jacopo Mondi wrote:
> Caution: This is an external email. Please take care when clicking links or opening attachments. When in doubt, report the message using the 'Report this email' button
> 
> 
> Hi Julien
> 
> On Thu, Mar 21, 2024 at 08:26:06PM +0100, Julien Vuillaumier wrote:
>> Hi Jacopo,
>>
>> Your comments will be integrated in v3.
>>
>> But I have a couple of questions to confirm I have the correct
>> understanding.
>>
>> Thank you,
>> Julien
>>
>> On 20/03/2024 13:53, Jacopo Mondi wrote:
>>> Caution: This is an external email. Please take care when clicking links or opening attachments. When in doubt, report the message using the 'Report this email' button
>>>
>>>
>>> Hi Julien
>>>
>>> On Fri, Mar 08, 2024 at 12:00:56PM +0100, Julien Vuillaumier wrote:
>>>> To match the enumerated media devices, each pipeline handler registered
>>>
>>> s/pipeline handler registered/registered pipeline handler/
>>>
>>>> is used in no specific order. It is a limitation when several pipelines
>>>> can match the devices, and user has to select a specific pipeline.
>>>>
>>>> For this purpose, environment variable LIBCAMERA_PIPELINES_MATCH_LIST is
>>>> created that gives the option to define an ordered list of pipelines
>>>
>>> s/that gives/to give/
>>>
>>>> to invoke during the match process.
>>>
>>> Or just: "to match on."
>>>
>>>>
>>>> LIBCAMERA_PIPELINES_MATCH_LIST="<name1>[,<name2>[,<name3>...]]]"
>>>>
>>>> Example:
>>>> LIBCAMERA_PIPELINES_MATCH_LIST="PipelineHandlerRkISP1,SimplePipelineHandler"
>>>>
>>>> Signed-off-by: Julien Vuillaumier <julien.vuillaumier@nxp.com>
>>>> ---
>>>>    Documentation/environment_variables.rst     |  5 ++
>>>>    include/libcamera/internal/camera_manager.h |  1 +
>>>>    src/libcamera/camera_manager.cpp            | 57 ++++++++++++++++-----
>>>>    3 files changed, 51 insertions(+), 12 deletions(-)
>>>>
>>>> diff --git a/Documentation/environment_variables.rst b/Documentation/environment_variables.rst
>>>> index a9b230bc..ea4da3c9 100644
>>>> --- a/Documentation/environment_variables.rst
>>>> +++ b/Documentation/environment_variables.rst
>>>> @@ -37,6 +37,11 @@ LIBCAMERA_IPA_MODULE_PATH
>>>>
>>>>       Example value: ``${HOME}/.libcamera/lib:/opt/libcamera/vendor/lib``
>>>>
>>>> +LIBCAMERA_PIPELINES_MATCH_LIST
>>>> +   Define an ordered list of pipeline names to be used to match the media devices in the system.
>>>
>>> long line over 80 cols which could eaily be broken in 2 lines
>>>
>>>> +
>>>> +   Example value: ``PipelineHandlerRkISP1,SimplePipelineHandler``
>>>
>>> These are the names of the PipelineHandlers classes, which is fine,
>>> but maybe for users it is better to use something they can more easily
>>> reference, like the meson option associated with the pipeline ?
>>>
>>> This will require a map though...
>>
>> As of today the pipeline name, defined as PipelineHandler class name, is
>> presented to the user (log=DEBUG), during the match procedure:
>> "Found registered pipeline handler <xyz>"
>> "Pipeline handler <xyz> matched"
>>
>> Thus, reusing that same name to define the ordered list of pipelines for the
>> match seemed fairly consistent.
>>
> 
> Yes, it's consistent indeed
> 
>> But agreed, PipelineHandler names could be simpler. Currently, apart from
> 
> I'm just a bit concerned about the fact users should either inspect
> the code or debug logs, while using something like the meson option is
> easier to access ?
> 
>> those logs during match, pipeline name looks to be used only in an ipa
>> interface test.
>> If deemed useful, we could change the current names of each PipelineHandler
>> to replace the class name, as you suggested, by the meson option name
>> associated with that pipeline.
> 
> No wait, I was suggesting using the meson option to populate the
> LIBCAMERA_PIPELINES_MATCH_LIST env variable.
> 
>>
>> A simple way of doing that would be adding to the existing
>> REGISTER_PIPELINE_HANDLER(handler) a parameter 'name' to be passed to
>> PipelineHandlerFactory constructor, instead of the stringified class name.
>> Registration of each existing pipelines would need to be updated
>> accordingly.
>>
>> Do you recommend changing PipelineHandler name used in the context of that
>> change?
>> In that case, does the above proposal (add a short name to the register
>> macro) makes sense?
>>
> 
> Maybe I'm just over-concerned. A way out could be to expand the env
> variable description to clearly indicate what identifiers to use as
> pipeline handler names. Something like:
> 
> LIBCAMERA_PIPELINES_MATCH_LIST
>     Define an ordered list of pipeline handlers to be used to match the media
>     devices in the system. The pipeline handler names used to populate
>     the variable are the ones passed to the the
>     REGISTER_PIPELINE_HANDLER() macro in the source code.
> 
>     Example value: ``PipelineHandlerRkISP1,SimplePipelineHandler``
> 
> Alternatively what I was proposing was to use the identifiers for
> the 'pipelines' meson option
> 
>          option('pipelines',
>                  type : 'array',
>                  value : ['auto'],
>                  choices : [
>                      'all',
>                      'auto',
>                      'imx8-isi',
>                      'ipu3',
>                      'rkisp1',
>                      'rpi/vc4',
>                      'simple',
>                      'uvcvideo',
>                      'vimc'
>                  ],
> 
> 
> LIBCAMERA_PIPELINES_MATCH_LIST=``rkisp1,simple,imx8-isi``
> 
> and keep a map in CameraManager class, but this indeed requires more
> maintainership.

I share the concern that adding a map of nicknames in CameraManager 
class would add some extra maintenance.
In that respect, the option of adding an explicit name parameter to 
REGISTER_PIPELINE_HANDLER() macro in order to assign to each pipeline 
its meson option name, was looking simpler to me.

Now, your proposal to expand the env variable description, documenting 
how the pipeline handler names are assigned with the register macro, 
looks perfectly fine to me.
If that option makes it acceptable to keep the current pipeline handler 
names, and nobody objects against the principle, I propose to move 
forward with that for the v3.

> 
> Now that I wrote this, isn't it easier to just compile only the
> pipeline handler you need ? I presume this doesn't apply to generic
> distro though

It does not apply to generic distro, indeed.

But also when using a custom libcamera package, one may want to change 
pipeline handler at runtime because of different use case, camera 
(raw/smart), test purpose... Reconfiguring and rebuilding libcamera with 
the unique targeted pipeline is not a very practical option here.

> 
> 
>>>> +
>>>>    LIBCAMERA_RPI_CONFIG_FILE
>>>>       Define a custom configuration file to use in the Raspberry Pi pipeline handler.
>>>>
>>>> diff --git a/include/libcamera/internal/camera_manager.h b/include/libcamera/internal/camera_manager.h
>>>> index 33ebe069..c57e509a 100644
>>>> --- a/include/libcamera/internal/camera_manager.h
>>>> +++ b/include/libcamera/internal/camera_manager.h
>>>> @@ -45,6 +45,7 @@ private:
>>>>         int init();
>>>>         void createPipelineHandlers();
>>>>         void cleanup() LIBCAMERA_TSA_EXCLUDES(mutex_);
>>>> +     void pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory);
>>>
>>> Please move this one line up to match the function definition order in
>>> the .cpp file
>>>
>>>>
>>>>         /*
>>>>          * This mutex protects
>>>> diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
>>>> index 355f3ada..620be1c8 100644
>>>> --- a/src/libcamera/camera_manager.cpp
>>>> +++ b/src/libcamera/camera_manager.cpp
>>>> @@ -99,13 +99,36 @@ int CameraManager::Private::init()
>>>>
>>>>    void CameraManager::Private::createPipelineHandlers()
>>>>    {
>>>> -     CameraManager *const o = LIBCAMERA_O_PTR();
>>>> -
>>>>         /*
>>>>          * \todo Try to read handlers and order from configuration
>>>> -      * file and only fallback on all handlers if there is no
>>>> -      * configuration file.
>>>> +      * file and only fallback on environment variable or all handlers, if
>>>> +      * there is no configuration file.
>>>> +      */
>>>> +
>>>> +     /*
>>>> +      * When a list of preferred pipelines is defined, iterate through the
>>>> +      * ordered list to match the devices enumerated.
>>>
>>> s/devices enumerated/enumerated devices/
>>>
>>>> +      * Otherwise, device matching is done in no specific order with each
>>>> +      * registered pipeline handler.
>>>>          */
>>>
>>> What about moving this comment block in the below if (pipesList)
>>> branch ?
>>>
>>>> +     const char *pipesList =
>>>> +             utils::secure_getenv("LIBCAMERA_PIPELINES_MATCH_LIST");
>>>> +     if (pipesList) {
>>>> +             for (const auto &pipeName : utils::split(pipesList, ",")) {
>>>> +                     const PipelineHandlerFactoryBase *factory;
>>>> +                     factory = PipelineHandlerFactoryBase::getFactoryByName(pipeName);
>>>> +                     if (!factory)
>>>> +                             continue;
>>>> +
>>>> +                     LOG(Camera, Debug)
>>>> +                             << "Found listed pipeline handler '"
>>>> +                             << pipeName << "'";
>>>> +                     pipelineFactoryMatch(factory);
>>>> +             }
>>>> +
>>>> +             return;
>>>> +     }
>>>> +
>>>>         const std::vector<PipelineHandlerFactoryBase *> &factories =
>>>>                 PipelineHandlerFactoryBase::factories();
>>>>
>>>> @@ -117,15 +140,25 @@ void CameraManager::Private::createPipelineHandlers()
>>>>                  * Try each pipeline handler until it exhaust
>>>>                  * all pipelines it can provide.
>>>>                  */
>>>> -             while (1) {
>>>> -                     std::shared_ptr<PipelineHandler> pipe = factory->create(o);
>>>> -                     if (!pipe->match(enumerator_.get()))
>>>> -                             break;
>>>> +             pipelineFactoryMatch(factory);
>>>> +     }
>>>> +}
>>>>
>>>> -                     LOG(Camera, Debug)
>>>> -                             << "Pipeline handler \"" << factory->name()
>>>> -                             << "\" matched";
>>>> -             }
>>>> +void CameraManager::Private::pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory)
>>>> +{
>>>> +     CameraManager *const o = LIBCAMERA_O_PTR();
>>>> +
>>>> +     /*
>>>> +      * Provide as many matching pipelines as possible
>>>> +      */
>>>
>>> Fits on a single line
>>>
>>> Also, I would
>>>           /* Match all the registed pipeline handlers. */
>>>
>>>> +     while (1) {
>>>> +             std::shared_ptr<PipelineHandler> pipe = factory->create(o);
>>>> +             if (!pipe->match(enumerator_.get()))
>>>> +                     break;
>>>> +
>>>> +             LOG(Camera, Debug)
>>>> +                     << "Pipeline handler \"" << factory->name()
>>>> +                     << "\" matched";
>>>>         }
>>>>    }
>>>
>>> Overall, I concur this is an useful addition. I know there are ideas
>>> about assigning a priority to pipeline handlers at creation time as
>>> currently the only conflict is on the ISI which can be
>>> matched both by the imx8-isi pipeline and the simple pipeline.
>>
>> As you mentioned, imx8-isi and simple pipelines are concurrent. With imx9
>> family, there is an additional cause of concurrency as platforms can/will
>> use topologies with both ISI + ISP. And depending on the use case, user may
>> want to use either simple, or imx8-isi or the isi+isp pipeline.
>>
>> This change is a basic way to dynamically assign relative priorities to the
>> pipelines. It was suggested in v1 review comments to also have a similar
>> configuration possible from a global config file.
>>
>>>
>>> For the time being, with the above issues fixed
>>> Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
>>>
>>> Thanks
>>>     j
>>>
>>>>
>>>> --
>>>> 2.34.1
>>>>
>>
Laurent Pinchart March 27, 2024, 8:35 p.m. UTC | #5
Hi Julien,

On Fri, Mar 22, 2024 at 03:15:50PM +0100, Julien Vuillaumier wrote:
> On 22/03/2024 09:50, Jacopo Mondi wrote:
> > On Thu, Mar 21, 2024 at 08:26:06PM +0100, Julien Vuillaumier wrote:
> >> On 20/03/2024 13:53, Jacopo Mondi wrote:
> >>> On Fri, Mar 08, 2024 at 12:00:56PM +0100, Julien Vuillaumier wrote:
> >>>> To match the enumerated media devices, each pipeline handler registered
> >>>
> >>> s/pipeline handler registered/registered pipeline handler/
> >>>
> >>>> is used in no specific order. It is a limitation when several pipelines
> >>>> can match the devices, and user has to select a specific pipeline.
> >>>>
> >>>> For this purpose, environment variable LIBCAMERA_PIPELINES_MATCH_LIST is
> >>>> created that gives the option to define an ordered list of pipelines
> >>>
> >>> s/that gives/to give/
> >>>
> >>>> to invoke during the match process.
> >>>
> >>> Or just: "to match on."
> >>>
> >>>> LIBCAMERA_PIPELINES_MATCH_LIST="<name1>[,<name2>[,<name3>...]]]"
> >>>>
> >>>> Example:
> >>>> LIBCAMERA_PIPELINES_MATCH_LIST="PipelineHandlerRkISP1,SimplePipelineHandler"
> >>>>
> >>>> Signed-off-by: Julien Vuillaumier <julien.vuillaumier@nxp.com>
> >>>> ---
> >>>>    Documentation/environment_variables.rst     |  5 ++
> >>>>    include/libcamera/internal/camera_manager.h |  1 +
> >>>>    src/libcamera/camera_manager.cpp            | 57 ++++++++++++++++-----
> >>>>    3 files changed, 51 insertions(+), 12 deletions(-)
> >>>>
> >>>> diff --git a/Documentation/environment_variables.rst b/Documentation/environment_variables.rst
> >>>> index a9b230bc..ea4da3c9 100644
> >>>> --- a/Documentation/environment_variables.rst
> >>>> +++ b/Documentation/environment_variables.rst
> >>>> @@ -37,6 +37,11 @@ LIBCAMERA_IPA_MODULE_PATH
> >>>>
> >>>>       Example value: ``${HOME}/.libcamera/lib:/opt/libcamera/vendor/lib``
> >>>>
> >>>> +LIBCAMERA_PIPELINES_MATCH_LIST
> >>>> +   Define an ordered list of pipeline names to be used to match the media devices in the system.
> >>>
> >>> long line over 80 cols which could eaily be broken in 2 lines
> >>>
> >>>> +
> >>>> +   Example value: ``PipelineHandlerRkISP1,SimplePipelineHandler``
> >>>
> >>> These are the names of the PipelineHandlers classes, which is fine,
> >>> but maybe for users it is better to use something they can more easily
> >>> reference, like the meson option associated with the pipeline ?
> >>>
> >>> This will require a map though...
> >>
> >> As of today the pipeline name, defined as PipelineHandler class name, is
> >> presented to the user (log=DEBUG), during the match procedure:
> >> "Found registered pipeline handler <xyz>"
> >> "Pipeline handler <xyz> matched"
> >>
> >> Thus, reusing that same name to define the ordered list of pipelines for the
> >> match seemed fairly consistent.
> > 
> > Yes, it's consistent indeed
> > 
> >> But agreed, PipelineHandler names could be simpler. Currently, apart from
> > 
> > I'm just a bit concerned about the fact users should either inspect
> > the code or debug logs, while using something like the meson option is
> > easier to access ?
> > 
> >> those logs during match, pipeline name looks to be used only in an ipa
> >> interface test.
> >> If deemed useful, we could change the current names of each PipelineHandler
> >> to replace the class name, as you suggested, by the meson option name
> >> associated with that pipeline.
> > 
> > No wait, I was suggesting using the meson option to populate the
> > LIBCAMERA_PIPELINES_MATCH_LIST env variable.
> > 
> >> A simple way of doing that would be adding to the existing
> >> REGISTER_PIPELINE_HANDLER(handler) a parameter 'name' to be passed to
> >> PipelineHandlerFactory constructor, instead of the stringified class name.
> >> Registration of each existing pipelines would need to be updated
> >> accordingly.
> >>
> >> Do you recommend changing PipelineHandler name used in the context of that
> >> change?
> >> In that case, does the above proposal (add a short name to the register
> >> macro) makes sense?
> > 
> > Maybe I'm just over-concerned. A way out could be to expand the env
> > variable description to clearly indicate what identifiers to use as
> > pipeline handler names. Something like:
> > 
> > LIBCAMERA_PIPELINES_MATCH_LIST
> >     Define an ordered list of pipeline handlers to be used to match the media
> >     devices in the system. The pipeline handler names used to populate
> >     the variable are the ones passed to the the
> >     REGISTER_PIPELINE_HANDLER() macro in the source code.
> > 
> >     Example value: ``PipelineHandlerRkISP1,SimplePipelineHandler``
> > 
> > Alternatively what I was proposing was to use the identifiers for
> > the 'pipelines' meson option
> > 
> >          option('pipelines',
> >                  type : 'array',
> >                  value : ['auto'],
> >                  choices : [
> >                      'all',
> >                      'auto',
> >                      'imx8-isi',
> >                      'ipu3',
> >                      'rkisp1',
> >                      'rpi/vc4',
> >                      'simple',
> >                      'uvcvideo',
> >                      'vimc'
> >                  ],
> > 
> > 
> > LIBCAMERA_PIPELINES_MATCH_LIST=``rkisp1,simple,imx8-isi``
> > 
> > and keep a map in CameraManager class, but this indeed requires more
> > maintainership.
> 
> I share the concern that adding a map of nicknames in CameraManager 
> class would add some extra maintenance.
> In that respect, the option of adding an explicit name parameter to 
> REGISTER_PIPELINE_HANDLER() macro in order to assign to each pipeline 
> its meson option name, was looking simpler to me.

If we want shorter names, that's the way to go indeed.

> Now, your proposal to expand the env variable description, documenting 
> how the pipeline handler names are assigned with the register macro, 
> looks perfectly fine to me.
> If that option makes it acceptable to keep the current pipeline handler 
> names, and nobody objects against the principle, I propose to move 
> forward with that for the v3.
> 
> > Now that I wrote this, isn't it easier to just compile only the
> > pipeline handler you need ? I presume this doesn't apply to generic
> > distro though
> 
> It does not apply to generic distro, indeed.
> 
> But also when using a custom libcamera package, one may want to change 
> pipeline handler at runtime because of different use case, camera 
> (raw/smart), test purpose... Reconfiguring and rebuilding libcamera with 
> the unique targeted pipeline is not a very practical option here.

I'm still struggling a bit to understand the use cases (besiding testing
during development). Please see below.

> >>>> +
> >>>>    LIBCAMERA_RPI_CONFIG_FILE
> >>>>       Define a custom configuration file to use in the Raspberry Pi pipeline handler.
> >>>>
> >>>> diff --git a/include/libcamera/internal/camera_manager.h b/include/libcamera/internal/camera_manager.h
> >>>> index 33ebe069..c57e509a 100644
> >>>> --- a/include/libcamera/internal/camera_manager.h
> >>>> +++ b/include/libcamera/internal/camera_manager.h
> >>>> @@ -45,6 +45,7 @@ private:
> >>>>         int init();
> >>>>         void createPipelineHandlers();
> >>>>         void cleanup() LIBCAMERA_TSA_EXCLUDES(mutex_);
> >>>> +     void pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory);
> >>>
> >>> Please move this one line up to match the function definition order in
> >>> the .cpp file
> >>>
> >>>>
> >>>>         /*
> >>>>          * This mutex protects
> >>>> diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
> >>>> index 355f3ada..620be1c8 100644
> >>>> --- a/src/libcamera/camera_manager.cpp
> >>>> +++ b/src/libcamera/camera_manager.cpp
> >>>> @@ -99,13 +99,36 @@ int CameraManager::Private::init()
> >>>>
> >>>>    void CameraManager::Private::createPipelineHandlers()
> >>>>    {
> >>>> -     CameraManager *const o = LIBCAMERA_O_PTR();
> >>>> -
> >>>>         /*
> >>>>          * \todo Try to read handlers and order from configuration
> >>>> -      * file and only fallback on all handlers if there is no
> >>>> -      * configuration file.
> >>>> +      * file and only fallback on environment variable or all handlers, if
> >>>> +      * there is no configuration file.
> >>>> +      */
> >>>> +
> >>>> +     /*
> >>>> +      * When a list of preferred pipelines is defined, iterate through the
> >>>> +      * ordered list to match the devices enumerated.
> >>>
> >>> s/devices enumerated/enumerated devices/
> >>>
> >>>> +      * Otherwise, device matching is done in no specific order with each
> >>>> +      * registered pipeline handler.
> >>>>          */
> >>>
> >>> What about moving this comment block in the below if (pipesList)
> >>> branch ?
> >>>
> >>>> +     const char *pipesList =
> >>>> +             utils::secure_getenv("LIBCAMERA_PIPELINES_MATCH_LIST");
> >>>> +     if (pipesList) {
> >>>> +             for (const auto &pipeName : utils::split(pipesList, ",")) {
> >>>> +                     const PipelineHandlerFactoryBase *factory;
> >>>> +                     factory = PipelineHandlerFactoryBase::getFactoryByName(pipeName);
> >>>> +                     if (!factory)
> >>>> +                             continue;
> >>>> +
> >>>> +                     LOG(Camera, Debug)
> >>>> +                             << "Found listed pipeline handler '"
> >>>> +                             << pipeName << "'";
> >>>> +                     pipelineFactoryMatch(factory);
> >>>> +             }
> >>>> +
> >>>> +             return;
> >>>> +     }
> >>>> +
> >>>>         const std::vector<PipelineHandlerFactoryBase *> &factories =
> >>>>                 PipelineHandlerFactoryBase::factories();
> >>>>
> >>>> @@ -117,15 +140,25 @@ void CameraManager::Private::createPipelineHandlers()
> >>>>                  * Try each pipeline handler until it exhaust
> >>>>                  * all pipelines it can provide.
> >>>>                  */
> >>>> -             while (1) {
> >>>> -                     std::shared_ptr<PipelineHandler> pipe = factory->create(o);
> >>>> -                     if (!pipe->match(enumerator_.get()))
> >>>> -                             break;
> >>>> +             pipelineFactoryMatch(factory);
> >>>> +     }
> >>>> +}
> >>>>
> >>>> -                     LOG(Camera, Debug)
> >>>> -                             << "Pipeline handler \"" << factory->name()
> >>>> -                             << "\" matched";
> >>>> -             }
> >>>> +void CameraManager::Private::pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory)
> >>>> +{
> >>>> +     CameraManager *const o = LIBCAMERA_O_PTR();
> >>>> +
> >>>> +     /*
> >>>> +      * Provide as many matching pipelines as possible
> >>>> +      */
> >>>
> >>> Fits on a single line
> >>>
> >>> Also, I would
> >>>           /* Match all the registed pipeline handlers. */
> >>>
> >>>> +     while (1) {
> >>>> +             std::shared_ptr<PipelineHandler> pipe = factory->create(o);
> >>>> +             if (!pipe->match(enumerator_.get()))
> >>>> +                     break;
> >>>> +
> >>>> +             LOG(Camera, Debug)
> >>>> +                     << "Pipeline handler \"" << factory->name()
> >>>> +                     << "\" matched";
> >>>>         }
> >>>>    }
> >>>
> >>> Overall, I concur this is an useful addition. I know there are ideas
> >>> about assigning a priority to pipeline handlers at creation time as
> >>> currently the only conflict is on the ISI which can be
> >>> matched both by the imx8-isi pipeline and the simple pipeline.
> >>
> >> As you mentioned, imx8-isi and simple pipelines are concurrent.

For this very specific problem, shouldn't we simply drop imx8-isi
support from the simple pipeline handler ? It was added there before we
had a dedicated pipeline handler for the imx8-isi. Now that we have one,
all the use cases that the simple pipeline handler could cover should be
handled by the imx8-isi pipeline handler. If some are missing, that's a
bug, and the imx8-isi pipeline handler should be extended.

> >> With imx9
> >> family, there is an additional cause of concurrency as platforms can/will
> >> use topologies with both ISI + ISP. And depending on the use case, user may
> >> want to use either simple, or imx8-isi or the isi+isp pipeline.

Note that the i.MX8MP also has an ISI and 2 ISP instances. Currently, we
need to select what to route the CSIS output to in DT, which is not a
good solution, but from a libcamera point of view, it means that only
one of the imx8-isi and rkisp1 pipeline handler can ever match at
runtime.

This should be fixed in the kernel, to enable dynamic routing
configuration from userspace. That's no simple work, and I'm not aware
of anyone actively working on it, but should this be completed at some
point, we would need to also improve libcamera to cover all the use
cases with a single pipeline handler. I don't really see why users would
want to select between multiple pipeline handlers.

How does the situation differ on the i.MX9 ?

> >> This change is a basic way to dynamically assign relative priorities to the
> >> pipelines. It was suggested in v1 review comments to also have a similar
> >> configuration possible from a global config file.
> >>
> >>> For the time being, with the above issues fixed
> >>> Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Julien Vuillaumier March 28, 2024, 3:54 p.m. UTC | #6
Hi Laurent,

On 27/03/2024 21:35, Laurent Pinchart wrote:
> 
> Hi Julien,
> 
> On Fri, Mar 22, 2024 at 03:15:50PM +0100, Julien Vuillaumier wrote:
>> On 22/03/2024 09:50, Jacopo Mondi wrote:
>>> On Thu, Mar 21, 2024 at 08:26:06PM +0100, Julien Vuillaumier wrote:
>>>> On 20/03/2024 13:53, Jacopo Mondi wrote:
>>>>> On Fri, Mar 08, 2024 at 12:00:56PM +0100, Julien Vuillaumier wrote:
>>>>>> To match the enumerated media devices, each pipeline handler registered
>>>>>
>>>>> s/pipeline handler registered/registered pipeline handler/
>>>>>
>>>>>> is used in no specific order. It is a limitation when several pipelines
>>>>>> can match the devices, and user has to select a specific pipeline.
>>>>>>
>>>>>> For this purpose, environment variable LIBCAMERA_PIPELINES_MATCH_LIST is
>>>>>> created that gives the option to define an ordered list of pipelines
>>>>>
>>>>> s/that gives/to give/
>>>>>
>>>>>> to invoke during the match process.
>>>>>
>>>>> Or just: "to match on."
>>>>>
>>>>>> LIBCAMERA_PIPELINES_MATCH_LIST="<name1>[,<name2>[,<name3>...]]]"
>>>>>>
>>>>>> Example:
>>>>>> LIBCAMERA_PIPELINES_MATCH_LIST="PipelineHandlerRkISP1,SimplePipelineHandler"
>>>>>>
>>>>>> Signed-off-by: Julien Vuillaumier <julien.vuillaumier@nxp.com>
>>>>>> ---
>>>>>>     Documentation/environment_variables.rst     |  5 ++
>>>>>>     include/libcamera/internal/camera_manager.h |  1 +
>>>>>>     src/libcamera/camera_manager.cpp            | 57 ++++++++++++++++-----
>>>>>>     3 files changed, 51 insertions(+), 12 deletions(-)
>>>>>>
>>>>>> diff --git a/Documentation/environment_variables.rst b/Documentation/environment_variables.rst
>>>>>> index a9b230bc..ea4da3c9 100644
>>>>>> --- a/Documentation/environment_variables.rst
>>>>>> +++ b/Documentation/environment_variables.rst
>>>>>> @@ -37,6 +37,11 @@ LIBCAMERA_IPA_MODULE_PATH
>>>>>>
>>>>>>        Example value: ``${HOME}/.libcamera/lib:/opt/libcamera/vendor/lib``
>>>>>>
>>>>>> +LIBCAMERA_PIPELINES_MATCH_LIST
>>>>>> +   Define an ordered list of pipeline names to be used to match the media devices in the system.
>>>>>
>>>>> long line over 80 cols which could eaily be broken in 2 lines
>>>>>
>>>>>> +
>>>>>> +   Example value: ``PipelineHandlerRkISP1,SimplePipelineHandler``
>>>>>
>>>>> These are the names of the PipelineHandlers classes, which is fine,
>>>>> but maybe for users it is better to use something they can more easily
>>>>> reference, like the meson option associated with the pipeline ?
>>>>>
>>>>> This will require a map though...
>>>>
>>>> As of today the pipeline name, defined as PipelineHandler class name, is
>>>> presented to the user (log=DEBUG), during the match procedure:
>>>> "Found registered pipeline handler <xyz>"
>>>> "Pipeline handler <xyz> matched"
>>>>
>>>> Thus, reusing that same name to define the ordered list of pipelines for the
>>>> match seemed fairly consistent.
>>>
>>> Yes, it's consistent indeed
>>>
>>>> But agreed, PipelineHandler names could be simpler. Currently, apart from
>>>
>>> I'm just a bit concerned about the fact users should either inspect
>>> the code or debug logs, while using something like the meson option is
>>> easier to access ?
>>>
>>>> those logs during match, pipeline name looks to be used only in an ipa
>>>> interface test.
>>>> If deemed useful, we could change the current names of each PipelineHandler
>>>> to replace the class name, as you suggested, by the meson option name
>>>> associated with that pipeline.
>>>
>>> No wait, I was suggesting using the meson option to populate the
>>> LIBCAMERA_PIPELINES_MATCH_LIST env variable.
>>>
>>>> A simple way of doing that would be adding to the existing
>>>> REGISTER_PIPELINE_HANDLER(handler) a parameter 'name' to be passed to
>>>> PipelineHandlerFactory constructor, instead of the stringified class name.
>>>> Registration of each existing pipelines would need to be updated
>>>> accordingly.
>>>>
>>>> Do you recommend changing PipelineHandler name used in the context of that
>>>> change?
>>>> In that case, does the above proposal (add a short name to the register
>>>> macro) makes sense?
>>>
>>> Maybe I'm just over-concerned. A way out could be to expand the env
>>> variable description to clearly indicate what identifiers to use as
>>> pipeline handler names. Something like:
>>>
>>> LIBCAMERA_PIPELINES_MATCH_LIST
>>>      Define an ordered list of pipeline handlers to be used to match the media
>>>      devices in the system. The pipeline handler names used to populate
>>>      the variable are the ones passed to the the
>>>      REGISTER_PIPELINE_HANDLER() macro in the source code.
>>>
>>>      Example value: ``PipelineHandlerRkISP1,SimplePipelineHandler``
>>>
>>> Alternatively what I was proposing was to use the identifiers for
>>> the 'pipelines' meson option
>>>
>>>           option('pipelines',
>>>                   type : 'array',
>>>                   value : ['auto'],
>>>                   choices : [
>>>                       'all',
>>>                       'auto',
>>>                       'imx8-isi',
>>>                       'ipu3',
>>>                       'rkisp1',
>>>                       'rpi/vc4',
>>>                       'simple',
>>>                       'uvcvideo',
>>>                       'vimc'
>>>                   ],
>>>
>>>
>>> LIBCAMERA_PIPELINES_MATCH_LIST=``rkisp1,simple,imx8-isi``
>>>
>>> and keep a map in CameraManager class, but this indeed requires more
>>> maintainership.
>>
>> I share the concern that adding a map of nicknames in CameraManager
>> class would add some extra maintenance.
>> In that respect, the option of adding an explicit name parameter to
>> REGISTER_PIPELINE_HANDLER() macro in order to assign to each pipeline
>> its meson option name, was looking simpler to me.
> 
> If we want shorter names, that's the way to go indeed.
> 
>> Now, your proposal to expand the env variable description, documenting
>> how the pipeline handler names are assigned with the register macro,
>> looks perfectly fine to me.
>> If that option makes it acceptable to keep the current pipeline handler
>> names, and nobody objects against the principle, I propose to move
>> forward with that for the v3.
>>
>>> Now that I wrote this, isn't it easier to just compile only the
>>> pipeline handler you need ? I presume this doesn't apply to generic
>>> distro though
>>
>> It does not apply to generic distro, indeed.
>>
>> But also when using a custom libcamera package, one may want to change
>> pipeline handler at runtime because of different use case, camera
>> (raw/smart), test purpose... Reconfiguring and rebuilding libcamera with
>> the unique targeted pipeline is not a very practical option here.
> 
> I'm still struggling a bit to understand the use cases (besiding testing
> during development). Please see below.
> 
>>>>>> +
>>>>>>     LIBCAMERA_RPI_CONFIG_FILE
>>>>>>        Define a custom configuration file to use in the Raspberry Pi pipeline handler.
>>>>>>
>>>>>> diff --git a/include/libcamera/internal/camera_manager.h b/include/libcamera/internal/camera_manager.h
>>>>>> index 33ebe069..c57e509a 100644
>>>>>> --- a/include/libcamera/internal/camera_manager.h
>>>>>> +++ b/include/libcamera/internal/camera_manager.h
>>>>>> @@ -45,6 +45,7 @@ private:
>>>>>>          int init();
>>>>>>          void createPipelineHandlers();
>>>>>>          void cleanup() LIBCAMERA_TSA_EXCLUDES(mutex_);
>>>>>> +     void pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory);
>>>>>
>>>>> Please move this one line up to match the function definition order in
>>>>> the .cpp file
>>>>>
>>>>>>
>>>>>>          /*
>>>>>>           * This mutex protects
>>>>>> diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
>>>>>> index 355f3ada..620be1c8 100644
>>>>>> --- a/src/libcamera/camera_manager.cpp
>>>>>> +++ b/src/libcamera/camera_manager.cpp
>>>>>> @@ -99,13 +99,36 @@ int CameraManager::Private::init()
>>>>>>
>>>>>>     void CameraManager::Private::createPipelineHandlers()
>>>>>>     {
>>>>>> -     CameraManager *const o = LIBCAMERA_O_PTR();
>>>>>> -
>>>>>>          /*
>>>>>>           * \todo Try to read handlers and order from configuration
>>>>>> -      * file and only fallback on all handlers if there is no
>>>>>> -      * configuration file.
>>>>>> +      * file and only fallback on environment variable or all handlers, if
>>>>>> +      * there is no configuration file.
>>>>>> +      */
>>>>>> +
>>>>>> +     /*
>>>>>> +      * When a list of preferred pipelines is defined, iterate through the
>>>>>> +      * ordered list to match the devices enumerated.
>>>>>
>>>>> s/devices enumerated/enumerated devices/
>>>>>
>>>>>> +      * Otherwise, device matching is done in no specific order with each
>>>>>> +      * registered pipeline handler.
>>>>>>           */
>>>>>
>>>>> What about moving this comment block in the below if (pipesList)
>>>>> branch ?
>>>>>
>>>>>> +     const char *pipesList =
>>>>>> +             utils::secure_getenv("LIBCAMERA_PIPELINES_MATCH_LIST");
>>>>>> +     if (pipesList) {
>>>>>> +             for (const auto &pipeName : utils::split(pipesList, ",")) {
>>>>>> +                     const PipelineHandlerFactoryBase *factory;
>>>>>> +                     factory = PipelineHandlerFactoryBase::getFactoryByName(pipeName);
>>>>>> +                     if (!factory)
>>>>>> +                             continue;
>>>>>> +
>>>>>> +                     LOG(Camera, Debug)
>>>>>> +                             << "Found listed pipeline handler '"
>>>>>> +                             << pipeName << "'";
>>>>>> +                     pipelineFactoryMatch(factory);
>>>>>> +             }
>>>>>> +
>>>>>> +             return;
>>>>>> +     }
>>>>>> +
>>>>>>          const std::vector<PipelineHandlerFactoryBase *> &factories =
>>>>>>                  PipelineHandlerFactoryBase::factories();
>>>>>>
>>>>>> @@ -117,15 +140,25 @@ void CameraManager::Private::createPipelineHandlers()
>>>>>>                   * Try each pipeline handler until it exhaust
>>>>>>                   * all pipelines it can provide.
>>>>>>                   */
>>>>>> -             while (1) {
>>>>>> -                     std::shared_ptr<PipelineHandler> pipe = factory->create(o);
>>>>>> -                     if (!pipe->match(enumerator_.get()))
>>>>>> -                             break;
>>>>>> +             pipelineFactoryMatch(factory);
>>>>>> +     }
>>>>>> +}
>>>>>>
>>>>>> -                     LOG(Camera, Debug)
>>>>>> -                             << "Pipeline handler \"" << factory->name()
>>>>>> -                             << "\" matched";
>>>>>> -             }
>>>>>> +void CameraManager::Private::pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory)
>>>>>> +{
>>>>>> +     CameraManager *const o = LIBCAMERA_O_PTR();
>>>>>> +
>>>>>> +     /*
>>>>>> +      * Provide as many matching pipelines as possible
>>>>>> +      */
>>>>>
>>>>> Fits on a single line
>>>>>
>>>>> Also, I would
>>>>>            /* Match all the registed pipeline handlers. */
>>>>>
>>>>>> +     while (1) {
>>>>>> +             std::shared_ptr<PipelineHandler> pipe = factory->create(o);
>>>>>> +             if (!pipe->match(enumerator_.get()))
>>>>>> +                     break;
>>>>>> +
>>>>>> +             LOG(Camera, Debug)
>>>>>> +                     << "Pipeline handler \"" << factory->name()
>>>>>> +                     << "\" matched";
>>>>>>          }
>>>>>>     }
>>>>>
>>>>> Overall, I concur this is an useful addition. I know there are ideas
>>>>> about assigning a priority to pipeline handlers at creation time as
>>>>> currently the only conflict is on the ISI which can be
>>>>> matched both by the imx8-isi pipeline and the simple pipeline.
>>>>
>>>> As you mentioned, imx8-isi and simple pipelines are concurrent.
> 
> For this very specific problem, shouldn't we simply drop imx8-isi
> support from the simple pipeline handler ? It was added there before we
> had a dedicated pipeline handler for the imx8-isi. Now that we have one,
> all the use cases that the simple pipeline handler could cover should be
> handled by the imx8-isi pipeline handler. If some are missing, that's a
> bug, and the imx8-isi pipeline handler should be extended.

Libcamera users are likely familiar with simple pipeline and probably 
expect it to work on i.MX8/9 - as I understand it seems commonly used.
Also, there are features from simple pipeline not available in imx8-isi 
pipeline, for instance support for more complex topologies - agreed, 
imx8-isi could be extended to integrate that. Another example could be 
Software ISP in simple pipeline - that may be valuable for i.MX 
platforms having ISI device but no hardware ISP (i.MX93). On those 
platforms I presume that Software ISP + IPA support using simple 
pipeline could come almost for free - but not sure that extending 
imx8-isi to add the same support would be worth the effort and the extra 
maintenance cost.

Imx8-isi pipeline presumably brings value compared to simple pipeline on 
systems using a smart sensor,  when the use case requires duplicating 
the stream with rescaling / CSC.
That said, the simple pipeline supports an optional scaler. So, an ISI 
channel could possibly be setup in M2M mode to act as the scaler and 
achieve a similar functionality (though less efficient with regard to 
memory bandwidth usage).

Thus, I think we should keep support for mxc.isi device in the simple 
pipeline as it is well-known by libcamera users, and also to benefit 
from all its features.

> 
>>>> With imx9
>>>> family, there is an additional cause of concurrency as platforms can/will
>>>> use topologies with both ISI + ISP. And depending on the use case, user may
>>>> want to use either simple, or imx8-isi or the isi+isp pipeline.
> 
> Note that the i.MX8MP also has an ISI and 2 ISP instances. Currently, we
> need to select what to route the CSIS output to in DT, which is not a
> good solution, but from a libcamera point of view, it means that only
> one of the imx8-isi and rkisp1 pipeline handler can ever match at
> runtime.

On i.MX8MP indeed, depending on DT configuration, one can configure the 
topology as:
CSI->ISP (no ISI): rkisp1 pipeline match
CSI->ISI (no ISP): imx8-isi or single pipeline match
Concurrency is only about imx8-isi vs single pipeline, for the ISI case.

> 
> This should be fixed in the kernel, to enable dynamic routing
> configuration from userspace. That's no simple work, and I'm not aware
> of anyone actively working on it, but should this be completed at some
> point, we would need to also improve libcamera to cover all the use
> cases with a single pipeline handler. I don't really see why users would
> want to select between multiple pipeline handlers.

On i.MX8MP, even with dynamic routing in the kernel, I am not sure which 
unique pipeline could handle the 2 uses cases :
ISP case: would presumably remain something for rkisp1 pipeline
ISI / no-ISP case: the 2 options of simple or imx8-isi pipelines would 
still apply. Rkisp1 pipeline looks out of scope here.

> How does the situation differ on the i.MX9 ?

i.MX9 SoCs have an ISI device. Some of them also have a (new) ISP. That 
ISP has a single hardware/context instance, and multi-camera use case is 
operated via memory-to-memory operation. Camera raw frames are captured 
from ISI channels video devices, and associated buffers passed to a 
software instance of the ISP device. On the principle, the flow of 
buffers handled by the pipeline is similar to the one done by IPU3 
pipeline.

A dedicated pipeline is needed to support this ISP and its associated 
IPA. ISI device usage is a common factor between that pipeline and 
imx8-isi pipeline. However, usage and operation of the 2 pipelines being 
very different, there is very limited implementation that can be shared 
between them. Therefore, working assumption has been that evolution and 
maintenance would be simpler by keeping the 2 separated.
It may be a bit premature to discuss the details of this ISP pipeline 
right now: the ISP driver has not been posted to linux-media yet, which 
is presumably a prerequisite before addressing the libcamera pipeline 
part.

To come back to the original question, i.MX9 user may want to use simple 
or imx8-isi pipeline with a smart camera, or the ISP pipeline with a raw 
camera. But to pick the ISP pipeline, its match() procedure has to be 
invoked first so that ISI devices are not acquired by simple or imx8-isi 
pipelines.

>>>> This change is a basic way to dynamically assign relative priorities to the
>>>> pipelines. It was suggested in v1 review comments to also have a similar
>>>> configuration possible from a global config file.
>>>>
>>>>> For the time being, with the above issues fixed
>>>>> Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> 
> --
> Regards,
> 
> Laurent Pinchart

Thanks,
Julien

Patch
diff mbox series

diff --git a/Documentation/environment_variables.rst b/Documentation/environment_variables.rst
index a9b230bc..ea4da3c9 100644
--- a/Documentation/environment_variables.rst
+++ b/Documentation/environment_variables.rst
@@ -37,6 +37,11 @@  LIBCAMERA_IPA_MODULE_PATH
 
    Example value: ``${HOME}/.libcamera/lib:/opt/libcamera/vendor/lib``
 
+LIBCAMERA_PIPELINES_MATCH_LIST
+   Define an ordered list of pipeline names to be used to match the media devices in the system.
+
+   Example value: ``PipelineHandlerRkISP1,SimplePipelineHandler``
+
 LIBCAMERA_RPI_CONFIG_FILE
    Define a custom configuration file to use in the Raspberry Pi pipeline handler.
 
diff --git a/include/libcamera/internal/camera_manager.h b/include/libcamera/internal/camera_manager.h
index 33ebe069..c57e509a 100644
--- a/include/libcamera/internal/camera_manager.h
+++ b/include/libcamera/internal/camera_manager.h
@@ -45,6 +45,7 @@  private:
 	int init();
 	void createPipelineHandlers();
 	void cleanup() LIBCAMERA_TSA_EXCLUDES(mutex_);
+	void pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory);
 
 	/*
 	 * This mutex protects
diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
index 355f3ada..620be1c8 100644
--- a/src/libcamera/camera_manager.cpp
+++ b/src/libcamera/camera_manager.cpp
@@ -99,13 +99,36 @@  int CameraManager::Private::init()
 
 void CameraManager::Private::createPipelineHandlers()
 {
-	CameraManager *const o = LIBCAMERA_O_PTR();
-
 	/*
 	 * \todo Try to read handlers and order from configuration
-	 * file and only fallback on all handlers if there is no
-	 * configuration file.
+	 * file and only fallback on environment variable or all handlers, if
+	 * there is no configuration file.
+	 */
+
+	/*
+	 * When a list of preferred pipelines is defined, iterate through the
+	 * ordered list to match the devices enumerated.
+	 * Otherwise, device matching is done in no specific order with each
+	 * registered pipeline handler.
 	 */
+	const char *pipesList =
+		utils::secure_getenv("LIBCAMERA_PIPELINES_MATCH_LIST");
+	if (pipesList) {
+		for (const auto &pipeName : utils::split(pipesList, ",")) {
+			const PipelineHandlerFactoryBase *factory;
+			factory = PipelineHandlerFactoryBase::getFactoryByName(pipeName);
+			if (!factory)
+				continue;
+
+			LOG(Camera, Debug)
+				<< "Found listed pipeline handler '"
+				<< pipeName << "'";
+			pipelineFactoryMatch(factory);
+		}
+
+		return;
+	}
+
 	const std::vector<PipelineHandlerFactoryBase *> &factories =
 		PipelineHandlerFactoryBase::factories();
 
@@ -117,15 +140,25 @@  void CameraManager::Private::createPipelineHandlers()
 		 * Try each pipeline handler until it exhaust
 		 * all pipelines it can provide.
 		 */
-		while (1) {
-			std::shared_ptr<PipelineHandler> pipe = factory->create(o);
-			if (!pipe->match(enumerator_.get()))
-				break;
+		pipelineFactoryMatch(factory);
+	}
+}
 
-			LOG(Camera, Debug)
-				<< "Pipeline handler \"" << factory->name()
-				<< "\" matched";
-		}
+void CameraManager::Private::pipelineFactoryMatch(const PipelineHandlerFactoryBase *factory)
+{
+	CameraManager *const o = LIBCAMERA_O_PTR();
+
+	/*
+	 * Provide as many matching pipelines as possible
+	 */
+	while (1) {
+		std::shared_ptr<PipelineHandler> pipe = factory->create(o);
+		if (!pipe->match(enumerator_.get()))
+			break;
+
+		LOG(Camera, Debug)
+			<< "Pipeline handler \"" << factory->name()
+			<< "\" matched";
 	}
 }