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{
    "id": 2892,
    "url": "https://patchwork.libcamera.org/api/patches/2892/?format=api",
    "web_url": "https://patchwork.libcamera.org/patch/2892/",
    "project": {
        "id": 1,
        "url": "https://patchwork.libcamera.org/api/projects/1/?format=api",
        "name": "libcamera",
        "link_name": "libcamera",
        "list_id": "libcamera_core",
        "list_email": "libcamera-devel@lists.libcamera.org",
        "web_url": "",
        "scm_url": "",
        "webscm_url": ""
    },
    "msgid": "<20200227200407.490616-11-nicolas.dufresne@collabora.com>",
    "date": "2020-02-27T20:03:50",
    "name": "[libcamera-devel,v2,10/27] gst: libcamerasrc: Add a task for the streaming thread",
    "commit_ref": null,
    "pull_url": null,
    "state": "accepted",
    "archived": false,
    "hash": "8c205a7f8862298fc8eb3502b29ff9d070de6122",
    "submitter": {
        "id": 31,
        "url": "https://patchwork.libcamera.org/api/people/31/?format=api",
        "name": "Nicolas Dufresne",
        "email": "nicolas.dufresne@collabora.com"
    },
    "delegate": null,
    "mbox": "https://patchwork.libcamera.org/patch/2892/mbox/",
    "series": [
        {
            "id": 693,
            "url": "https://patchwork.libcamera.org/api/series/693/?format=api",
            "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=693",
            "date": "2020-02-27T20:03:40",
            "name": "GStreamer Element for libcamera",
            "version": 2,
            "mbox": "https://patchwork.libcamera.org/series/693/mbox/"
        }
    ],
    "comments": "https://patchwork.libcamera.org/api/patches/2892/comments/",
    "check": "pending",
    "checks": "https://patchwork.libcamera.org/api/patches/2892/checks/",
    "tags": {},
    "headers": {
        "Return-Path": "<nicolas.dufresne@collabora.com>",
        "Received": [
            "from bhuna.collabora.co.uk (bhuna.collabora.co.uk\n\t[IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 8F7926271D\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tThu, 27 Feb 2020 21:04:22 +0100 (CET)",
            "from [127.0.0.1] (localhost [127.0.0.1])\n\t(Authenticated sender: nicolas) with ESMTPSA id 127EF29654F"
        ],
        "From": "Nicolas Dufresne <nicolas.dufresne@collabora.com>",
        "To": "libcamera-devel@lists.libcamera.org",
        "Date": "Thu, 27 Feb 2020 15:03:50 -0500",
        "Message-Id": "<20200227200407.490616-11-nicolas.dufresne@collabora.com>",
        "X-Mailer": "git-send-email 2.24.1",
        "In-Reply-To": "<20200227200407.490616-1-nicolas.dufresne@collabora.com>",
        "References": "<20200227200407.490616-1-nicolas.dufresne@collabora.com>",
        "MIME-Version": "1.0",
        "Content-Transfer-Encoding": "8bit",
        "Subject": "[libcamera-devel] [PATCH v2 10/27] gst: libcamerasrc: Add a task\n\tfor the streaming thread",
        "X-BeenThere": "libcamera-devel@lists.libcamera.org",
        "X-Mailman-Version": "2.1.29",
        "Precedence": "list",
        "List-Id": "<libcamera-devel.lists.libcamera.org>",
        "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>",
        "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>",
        "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>",
        "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>",
        "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>",
        "X-List-Received-Date": "Thu, 27 Feb 2020 20:04:23 -0000"
    },
    "content": "Use a GstTask as our internal streaming thread. Unlike GstBaseSrc, we\nwill be running a streaming thread at the element level rather than\nper pad. This is needed to combine buffer request for multiple pads.\n\nSigned-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>\n---\n src/gstreamer/gstlibcamerasrc.cpp | 49 +++++++++++++++++++++++++++++++\n 1 file changed, 49 insertions(+)",
    "diff": "diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp\nindex 0c60478..53ece26 100644\n--- a/src/gstreamer/gstlibcamerasrc.cpp\n+++ b/src/gstreamer/gstlibcamerasrc.cpp\n@@ -26,7 +26,11 @@ struct GstLibcameraSrcState {\n \n struct _GstLibcameraSrc {\n \tGstElement parent;\n+\n+\tGRecMutex stream_lock;\n+\tGstTask *task;\n \tGstPad *srcpad;\n+\n \tgchar *camera_name;\n \n \tGstLibcameraSrcState *state;\n@@ -112,6 +116,30 @@ gst_libcamera_src_open(GstLibcameraSrc *self)\n \treturn true;\n }\n \n+static void\n+gst_libcamera_src_task_run(gpointer user_data)\n+{\n+\tGstLibcameraSrc *self = GST_LIBCAMERA_SRC(user_data);\n+\n+\tGST_DEBUG_OBJECT(self, \"Streaming thread is now capturing\");\n+}\n+\n+static void\n+gst_libcamera_src_task_enter(GstTask *task, GThread *thread, gpointer user_data)\n+{\n+\tGstLibcameraSrc *self = GST_LIBCAMERA_SRC(user_data);\n+\n+\tGST_DEBUG_OBJECT(self, \"Streaming thread has started\");\n+}\n+\n+static void\n+gst_libcamera_src_task_leave(GstTask *task, GThread *thread, gpointer user_data)\n+{\n+\tGstLibcameraSrc *self = GST_LIBCAMERA_SRC(user_data);\n+\n+\tGST_DEBUG_OBJECT(self, \"Streaming thread is about to stop\");\n+}\n+\n static void\n gst_libcamera_src_close(GstLibcameraSrc *self)\n {\n@@ -182,9 +210,22 @@ gst_libcamera_src_change_state(GstElement *element, GstStateChange transition)\n \t\t\treturn GST_STATE_CHANGE_FAILURE;\n \t\tbreak;\n \tcase GST_STATE_CHANGE_READY_TO_PAUSED:\n+\t\t/* This needs to be called after pads activation.*/\n+\t\tif (!gst_task_pause(self->task))\n+\t\t\treturn GST_STATE_CHANGE_FAILURE;\n+\t\tret = GST_STATE_CHANGE_NO_PREROLL;\n+\t\tbreak;\n \tcase GST_STATE_CHANGE_PLAYING_TO_PAUSED:\n \t\tret = GST_STATE_CHANGE_NO_PREROLL;\n \t\tbreak;\n+\tcase GST_STATE_CHANGE_PAUSED_TO_READY:\n+\t\t/* \\todo this might requires some thread unblocking in the future\n+\t\t * if the streaming thread starts doing any kind of blocking\n+\t\t * operations. If this was the case, we would need to do so\n+\t\t * before pad deactivation, so before chaining to the parent\n+\t\t * change_state function. */\n+\t\tgst_task_join(self->task);\n+\t\tbreak;\n \tcase GST_STATE_CHANGE_READY_TO_NULL:\n \t\tgst_libcamera_src_close(self);\n \t\tbreak;\n@@ -201,6 +242,8 @@ gst_libcamera_src_finalize(GObject *object)\n \tGObjectClass *klass = G_OBJECT_CLASS(gst_libcamera_src_parent_class);\n \tGstLibcameraSrc *self = GST_LIBCAMERA_SRC(object);\n \n+\tg_rec_mutex_clear(&self->stream_lock);\n+\tg_clear_object(&self->task);\n \tg_free(self->camera_name);\n \tdelete self->state;\n \n@@ -213,6 +256,12 @@ gst_libcamera_src_init(GstLibcameraSrc *self)\n \tGstLibcameraSrcState *state = new GstLibcameraSrcState();\n \tGstPadTemplate *templ = gst_element_get_pad_template(GST_ELEMENT(self), \"src\");\n \n+\tg_rec_mutex_init(&self->stream_lock);\n+\tself->task = gst_task_new(gst_libcamera_src_task_run, self, nullptr);\n+\tgst_task_set_enter_callback(self->task, gst_libcamera_src_task_enter, self, nullptr);\n+\tgst_task_set_leave_callback(self->task, gst_libcamera_src_task_leave, self, nullptr);\n+\tgst_task_set_lock(self->task, &self->stream_lock);\n+\n \tself->srcpad = gst_pad_new_from_template(templ, \"src\");\n \tgst_element_add_pad(GST_ELEMENT(self), self->srcpad);\n \tself->state = state;\n",
    "prefixes": [
        "libcamera-devel",
        "v2",
        "10/27"
    ]
}