[{"id":623,"web_url":"https://patchwork.libcamera.org/comment/623/","msgid":"<20190126094855.GE4596@pendragon.ideasonboard.com>","date":"2019-01-26T09:48:55","subject":"Re: [libcamera-devel] [PATCH v2 5/7] libcamera: camera: Add\n\tacquire() and release()","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"Hi Niklas,\n\nThank you for the patch.\n\nOn Fri, Jan 25, 2019 at 04:33:38PM +0100, Niklas Söderlund wrote:\n> From: Laurent Pinchart \n> \n> Signed-off-by: Laurent Pinchart \n> Reviewed-by: Niklas Söderlund \n> Signed-off-by: Niklas Söderlund \n> ---\n> include/libcamera/camera.h | 5 +++++\n> src/libcamera/camera.cpp | 35 ++++++++++++++++++++++++++++++++++-\n> 2 files changed, 39 insertions(+), 1 deletion(-)\n> \n> diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h\n> index a2ded62de94814c4..7e358f8c0aa093cf 100644\n> --- a/include/libcamera/camera.h\n> +++ b/include/libcamera/camera.h\n> @@ -29,6 +29,9 @@ public:\n> \n> \tSignal disconnected;\n> \n> +\tint acquire();\n> +\tvoid release();\n> +\n> private:\n> \tCamera(PipelineHandler *pipe, const std::string &name);\n> \t~Camera();\n> @@ -38,6 +41,8 @@ private:\n> \n> \tstd::shared_ptr pipe_;\n> \tstd::string name_;\n> +\n> +\tbool acquired_;\n> };\n> \n> } /* namespace libcamera */\n> diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp\n> index 9cec289282e4797b..fd19e8cf6694cc1b 100644\n> --- a/src/libcamera/camera.cpp\n> +++ b/src/libcamera/camera.cpp\n> @@ -102,7 +102,7 @@ const std::string &Camera::name() const\n> */\n> \n> Camera::Camera(PipelineHandler *pipe, const std::string &name)\n> -\t: pipe_(pipe->shared_from_this()), name_(name)\n> +\t: pipe_(pipe->shared_from_this()), name_(name), acquired_(false)\n> {\n> }\n> \n> @@ -127,4 +127,37 @@ void Camera::disconnect()\n> \tdisconnected.emit(this);\n> }\n> \n> +/**\n> + * \\brief Acquire the camera device for exclusive access\n> + *\n> + * After opening the device with open(), exclusive access must be obtained\n> + * before performing operations that change the device state. This function is\n> + * not blocking, if the device has already been acquired (by the same or another\n> + * process) the -EBUSY error code is returned.\n> + *\n> + * Once exclusive access isn't needed anymore, the device should be released\n> + * with a call to the release() function.\n\nLet's add a\n\n \\todo Implement exclusive access across processes.\n\n> + *\n> + * \\return 0 on success or a negative error code on error.\n> + */\n> +int Camera::acquire()\n> +{\n> +\tif (acquired_)\n> +\t\treturn -EBUSY;\n> +\n> +\tacquired_ = true;\n> +\treturn 0;\n> +}\n> +\n> +/**\n> + * \\brief Release exclusive access to the camera device\n> + *\n> + * Releasing the camera device allows other users to acquire exclusive access\n> + * with the acquire() function.\n> + */\n> +void Camera::release()\n> +{\n> +\tacquired_ = false;\n> +}\n> +\n> } /* namespace libcamera */\n\nShould we add a warning in the destructor in case acquired_ is true,\nsimilarly to what is done in DeviceEnumerator::~DeviceEnumerator() ?","headers":{"Return-Path":"","Received":["from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id F32F160C65\n\tfor ;\n\tSat, 26 Jan 2019 10:48:58 +0100 (CET)","from pendragon.ideasonboard.com (unknown [62.119.166.9])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 4672923A;\n\tSat, 26 Jan 2019 10:48:58 +0100 (CET)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1548496138;\n\tbh=vBHfpY16CUOTCaU2YWbexRo+oU7xaq4HfkN2D8rRF74=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=PtVHV76sk7zZ1q8RP1m50aGKlykS5bBBDC+f8HdrAlKAatccqcL9GbbkvPqiNJ3+C\n\t56J5+IlRp9/NihJTkSQAhPrgJie77qGB3alhHx40l9njblzjrVvqusxGevSWoDeLDa\n\tOCH82ctNQbgHTZr9ZzNrp+Mx20+5HvFDUE9CONp4=","Date":"Sat, 26 Jan 2019 11:48:55 +0200","From":"Laurent Pinchart ","To":"Niklas =?utf-8?q?S=C3=B6derlund?= ","Cc":"libcamera-devel@lists.libcamera.org","Message-ID":"<20190126094855.GE4596@pendragon.ideasonboard.com>","References":"<20190125153340.2744-1-niklas.soderlund@ragnatech.se>\n\t<20190125153340.2744-6-niklas.soderlund@ragnatech.se>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","Content-Transfer-Encoding":"8bit","In-Reply-To":"<20190125153340.2744-6-niklas.soderlund@ragnatech.se>","User-Agent":"Mutt/1.10.1 (2018-07-13)","Subject":"Re: [libcamera-devel] [PATCH v2 5/7] libcamera: camera: Add\n\tacquire() and release()","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.23","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","X-List-Received-Date":"Sat, 26 Jan 2019 09:48:59 -0000"}},{"id":628,"web_url":"https://patchwork.libcamera.org/comment/628/","msgid":"<20190126164631.GU4127@bigcity.dyn.berto.se>","date":"2019-01-26T16:46:32","subject":"Re: [libcamera-devel] [PATCH v2 5/7] libcamera: camera: Add\n\tacquire() and release()","submitter":{"id":5,"url":"https://patchwork.libcamera.org/api/people/5/","name":"Niklas Söderlund","email":"niklas.soderlund@ragnatech.se"},"content":"Hi Laurent,\n\nThanks for your feedback.\n\nOn 2019-01-26 11:48:55 +0200, Laurent Pinchart wrote:\n> Hi Niklas,\n> \n> Thank you for the patch.\n> \n> On Fri, Jan 25, 2019 at 04:33:38PM +0100, Niklas Söderlund wrote:\n> > From: Laurent Pinchart \n> > \n> > Signed-off-by: Laurent Pinchart \n> > Reviewed-by: Niklas Söderlund \n> > Signed-off-by: Niklas Söderlund \n> > ---\n> > include/libcamera/camera.h | 5 +++++\n> > src/libcamera/camera.cpp | 35 ++++++++++++++++++++++++++++++++++-\n> > 2 files changed, 39 insertions(+), 1 deletion(-)\n> > \n> > diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h\n> > index a2ded62de94814c4..7e358f8c0aa093cf 100644\n> > --- a/include/libcamera/camera.h\n> > +++ b/include/libcamera/camera.h\n> > @@ -29,6 +29,9 @@ public:\n> > \n> > \tSignal disconnected;\n> > \n> > +\tint acquire();\n> > +\tvoid release();\n> > +\n> > private:\n> > \tCamera(PipelineHandler *pipe, const std::string &name);\n> > \t~Camera();\n> > @@ -38,6 +41,8 @@ private:\n> > \n> > \tstd::shared_ptr pipe_;\n> > \tstd::string name_;\n> > +\n> > +\tbool acquired_;\n> > };\n> > \n> > } /* namespace libcamera */\n> > diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp\n> > index 9cec289282e4797b..fd19e8cf6694cc1b 100644\n> > --- a/src/libcamera/camera.cpp\n> > +++ b/src/libcamera/camera.cpp\n> > @@ -102,7 +102,7 @@ const std::string &Camera::name() const\n> > */\n> > \n> > Camera::Camera(PipelineHandler *pipe, const std::string &name)\n> > -\t: pipe_(pipe->shared_from_this()), name_(name)\n> > +\t: pipe_(pipe->shared_from_this()), name_(name), acquired_(false)\n> > {\n> > }\n> > \n> > @@ -127,4 +127,37 @@ void Camera::disconnect()\n> > \tdisconnected.emit(this);\n> > }\n> > \n> > +/**\n> > + * \\brief Acquire the camera device for exclusive access\n> > + *\n> > + * After opening the device with open(), exclusive access must be obtained\n> > + * before performing operations that change the device state. This function is\n> > + * not blocking, if the device has already been acquired (by the same or another\n> > + * process) the -EBUSY error code is returned.\n> > + *\n> > + * Once exclusive access isn't needed anymore, the device should be released\n> > + * with a call to the release() function.\n> \n> Let's add a\n> \n> \\todo Implement exclusive access across processes.\n\nDone.\n\n> \n> > + *\n> > + * \\return 0 on success or a negative error code on error.\n> > + */\n> > +int Camera::acquire()\n> > +{\n> > +\tif (acquired_)\n> > +\t\treturn -EBUSY;\n> > +\n> > +\tacquired_ = true;\n> > +\treturn 0;\n> > +}\n> > +\n> > +/**\n> > + * \\brief Release exclusive access to the camera device\n> > + *\n> > + * Releasing the camera device allows other users to acquire exclusive access\n> > + * with the acquire() function.\n> > + */\n> > +void Camera::release()\n> > +{\n> > +\tacquired_ = false;\n> > +}\n> > +\n> > } /* namespace libcamera */\n> \n> Should we add a warning in the destructor in case acquired_ is true,\n> similarly to what is done in DeviceEnumerator::~DeviceEnumerator() ?\n\nI think this is a good idea, will do so in next version.\n\n> \n> -- \n> Regards,\n> \n> Laurent Pinchart","headers":{"Return-Path":"","Received":["from mail-lf1-x144.google.com (mail-lf1-x144.google.com\n\t[IPv6:2a00:1450:4864:20::144])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 7553160B2D\n\tfor ;\n\tSat, 26 Jan 2019 17:46:34 +0100 (CET)","by mail-lf1-x144.google.com with SMTP id u18so9026343lff.10\n\tfor ;\n\tSat, 26 Jan 2019 08:46:34 -0800 (PST)","from localhost (89-233-230-99.cust.bredband2.com. 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