[{"id":3579,"web_url":"https://patchwork.libcamera.org/comment/3579/","msgid":"<20200122163719.GY1124294@oden.dyn.berto.se>","date":"2020-01-22T16:37:19","subject":"Re: [libcamera-devel] [PATCH 17/19] libcamera: pipeline_handler:\n\tImplement the threading model","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 work.\n\nOn 2020-01-20 02:24:35 +0200, Laurent Pinchart wrote:\n> Document the threading model of the PipelineHandler class (and all its\n> derived classes). The model is already enforced by the Camera class, so\n> not much is required. As for the Camera class, disconnection is\n> currently left out.\n> \n> Signed-off-by: Laurent Pinchart \n\ns/Implement/Document/ in the patch subject, whit this fixed,\n\nReviewed-by: Niklas Söderlund \n\n> ---\n> src/libcamera/pipeline_handler.cpp | 36 ++++++++++++++++++++++++++++++\n> 1 file changed, 36 insertions(+)\n> \n> diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp\n> index 3091971d5da0..2ebf73b76e6b 100644\n> --- a/src/libcamera/pipeline_handler.cpp\n> +++ b/src/libcamera/pipeline_handler.cpp\n> @@ -166,6 +166,8 @@ PipelineHandler::~PipelineHandler()\n> * If this function returns true, a new instance of the pipeline handler will\n> * be created and its match() function called.\n> *\n> + * \\context This function is called from the CameraManager thread.\n> + *\n> * \\return true if media devices have been acquired and camera instances\n> * created, or false otherwise\n> */\n> @@ -182,6 +184,8 @@ PipelineHandler::~PipelineHandler()\n> * device explicitly, it will be automatically released when the pipeline\n> * handler is destroyed.\n> *\n> + * \\context This function shall be called from the CameraManager thread.\n> + *\n> * \\return A pointer to the matching MediaDevice, or nullptr if no match is found\n> */\n> MediaDevice *PipelineHandler::acquireMediaDevice(DeviceEnumerator *enumerator,\n> @@ -205,6 +209,8 @@ MediaDevice *PipelineHandler::acquireMediaDevice(DeviceEnumerator *enumerator,\n> * This method shall not be called from pipeline handler implementation, as the\n> * Camera class handles locking directly.\n> *\n> + * \\context This function is \\threadsafe.\n> + *\n> * \\return True if the devices could be locked, false otherwise\n> * \\sa unlock()\n> * \\sa MediaDevice::lock()\n> @@ -227,6 +233,8 @@ bool PipelineHandler::lock()\n> * This method shall not be called from pipeline handler implementation, as the\n> * Camera class handles locking directly.\n> *\n> + * \\context This function is \\threadsafe.\n> + *\n> * \\sa lock()\n> */\n> void PipelineHandler::unlock()\n> @@ -238,6 +246,7 @@ void PipelineHandler::unlock()\n> /**\n> * \\brief Retrieve the list of controls for a camera\n> * \\param[in] camera The camera\n> + * \\context This function is \\threadsafe.\n> * \\return A ControlInfoMap listing the controls support by \\a camera\n> */\n> const ControlInfoMap &PipelineHandler::controls(Camera *camera)\n> @@ -261,6 +270,10 @@ const ControlInfoMap &PipelineHandler::controls(Camera *camera)\n> * The intended companion to this is \\a configure() which can be used to change\n> * the group of streams parameters.\n> *\n> + * \\context This function may be called from any thread and shall be\n> + * \\threadsafe. It shall not modify the state of the \\a camera in the pipeline\n> + * handler.\n> + *\n> * \\return A valid CameraConfiguration if the requested roles can be satisfied,\n> * or a null pointer otherwise. The ownership of the returned configuration is\n> * passed to the caller.\n> @@ -286,6 +299,8 @@ const ControlInfoMap &PipelineHandler::controls(Camera *camera)\n> * instance to each StreamConfiguration entry in the CameraConfiguration using\n> * the StreamConfiguration::setStream() method.\n> *\n> + * \\context This function is called from the CameraManager thread.\n> + *\n> * \\return 0 on success or a negative error code otherwise\n> */\n> \n> @@ -316,6 +331,8 @@ const ControlInfoMap &PipelineHandler::controls(Camera *camera)\n> *\n> * The only intended caller is Camera::exportFrameBuffers().\n> *\n> + * \\context This function is called from the CameraManager thread.\n> + *\n> * \\return 0 on success or a negative error code otherwise\n> */\n> \n> @@ -343,6 +360,8 @@ const ControlInfoMap &PipelineHandler::controls(Camera *camera)\n> *\n> * The only intended caller is Camera::start().\n> *\n> + * \\context This function is called from the CameraManager thread.\n> + *\n> * \\return 0 on success or a negative error code otherwise\n> */\n> \n> @@ -358,6 +377,8 @@ const ControlInfoMap &PipelineHandler::controls(Camera *camera)\n> * once per stream.\n> *\n> * The only intended callers are Camera::stop() and Camera::freeFrameBuffers().\n> + *\n> + * \\context This function is called from the CameraManager thread.\n> */\n> \n> /**\n> @@ -370,6 +391,8 @@ const ControlInfoMap &PipelineHandler::controls(Camera *camera)\n> * will in turn be called from the application to indicate that it has\n> * configured the streams and is ready to capture.\n> *\n> + * \\context This function is called from the CameraManager thread.\n> + *\n> * \\return 0 on success or a negative error code otherwise\n> */\n> \n> @@ -380,6 +403,8 @@ const ControlInfoMap &PipelineHandler::controls(Camera *camera)\n> *\n> * This method stops capturing and processing requests immediately. All pending\n> * requests are cancelled and complete immediately in an error state.\n> + *\n> + * \\context This function is called from the CameraManager thread.\n> */\n> \n> /**\n> @@ -396,6 +421,8 @@ const ControlInfoMap &PipelineHandler::controls(Camera *camera)\n> * when the pipeline handler is stopped with stop(). Request completion shall be\n> * signalled by the pipeline handler using the completeRequest() method.\n> *\n> + * \\context This function is called from the CameraManager thread.\n> + *\n> * \\return 0 on success or a negative error code otherwise\n> */\n> int PipelineHandler::queueRequest(Camera *camera, Request *request)\n> @@ -422,6 +449,8 @@ int PipelineHandler::queueRequest(Camera *camera, Request *request)\n> * parameters will be applied to the frames captured in the buffers provided in\n> * the request.\n> *\n> + * \\context This function is called from the CameraManager thread.\n> + *\n> * \\return 0 on success or a negative error code otherwise\n> */\n> \n> @@ -438,6 +467,8 @@ int PipelineHandler::queueRequest(Camera *camera, Request *request)\n> * pipeline handlers a chance to perform any operation that may still be\n> * needed. They shall complete requests explicitly with completeRequest().\n> *\n> + * \\context This function shall be called from the CameraManager thread.\n> + *\n> * \\return True if all buffers contained in the request have completed, false\n> * otherwise\n> */\n> @@ -460,6 +491,8 @@ bool PipelineHandler::completeBuffer(Camera *camera, Request *request,\n> * This method ensures that requests will be returned to the application in\n> * submission order, the pipeline handler may call it on any complete request\n> * without any ordering constraint.\n> + *\n> + * \\context This function shall be called from the CameraManager thread.\n> */\n> void PipelineHandler::completeRequest(Camera *camera, Request *request)\n> {\n> @@ -493,6 +526,8 @@ void PipelineHandler::completeRequest(Camera *camera, Request *request)\n> * is to be associated with. This is for the V4L2 compatibility layer to map\n> * device nodes to Camera instances based on the device number\n> * registered by this method in \\a devnum.\n> + *\n> + * \\context This function shall be called from the CameraManager thread.\n> */\n> void PipelineHandler::registerCamera(std::shared_ptr camera,\n> \t\t\t\t std::unique_ptr data,\n> @@ -586,6 +621,7 @@ CameraData *PipelineHandler::cameraData(const Camera *camera)\n> /**\n> * \\fn PipelineHandler::name()\n> * \\brief Retrieve the pipeline handler name\n> + * \\context This function shall be \\threadsafe.\n> * \\return The pipeline handler name\n> */\n> \n> -- \n> Regards,\n> \n> Laurent Pinchart\n> \n> _______________________________________________\n> libcamera-devel mailing list\n> libcamera-devel@lists.libcamera.org\n> https://lists.libcamera.org/listinfo/libcamera-devel","headers":{"Return-Path":"","Received":["from mail-lf1-x142.google.com (mail-lf1-x142.google.com\n\t[IPv6:2a00:1450:4864:20::142])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 092A060804\n\tfor ;\n\tWed, 22 Jan 2020 17:37:21 +0100 (CET)","by mail-lf1-x142.google.com with SMTP id i23so93557lfo.7\n\tfor ;\n\tWed, 22 Jan 2020 08:37:21 -0800 (PST)","from localhost (h-93-159.A463.priv.bahnhof.se. 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