{"id":16501,"url":"https://patchwork.libcamera.org/api/1.1/patches/16501/?format=json","web_url":"https://patchwork.libcamera.org/patch/16501/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/1.1/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20220701084521.31831-10-tomi.valkeinen@ideasonboard.com>","date":"2022-07-01T08:45:13","name":"[libcamera-devel,v3,09/17] py: Switch to non-blocking eventfd","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"7542f65cb2257be81370da9d64b31c49ee6f7bcd","submitter":{"id":109,"url":"https://patchwork.libcamera.org/api/1.1/people/109/?format=json","name":"Tomi Valkeinen","email":"tomi.valkeinen@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/16501/mbox/","series":[{"id":3241,"url":"https://patchwork.libcamera.org/api/1.1/series/3241/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=3241","date":"2022-07-01T08:45:04","name":"Python bindings event handling","version":3,"mbox":"https://patchwork.libcamera.org/series/3241/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/16501/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/16501/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 1D934BD808\n\tfor ;\n\tFri, 1 Jul 2022 08:45:53 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 595F7656A6;\n\tFri, 1 Jul 2022 10:45:52 +0200 (CEST)","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 E0B6D6565E\n\tfor ;\n\tFri, 1 Jul 2022 10:45:44 +0200 (CEST)","from deskari.lan (91-158-154-79.elisa-laajakaista.fi\n\t[91.158.154.79])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 5EC8325C;\n\tFri, 1 Jul 2022 10:45:44 +0200 (CEST)"],"DKIM-Signature":["v=1; a=rsa-sha256; c=relaxed/simple; d=libcamera.org;\n\ts=mail; t=1656665152;\n\tbh=t3z1boBAErV4KT5ni+tiw18/p6GL+055t+oTd6lKo60=;\n\th=To:Date:In-Reply-To:References:Subject:List-Id:List-Unsubscribe:\n\tList-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:\n\tFrom;\n\tb=OWNNLFPnVGspMGFHjZqSAlfXI2L6jscIdndblp/erm2S82IYo0FYnpITOBSSqYJ97\n\t+V+9UydUxf1AZysvxY9VyHwiyetfeWXhk/JsLAon7KprEQVtupegZXJbrXTSwVFAww\n\tinDIfN39sywjs2twuRV5NifxMZgyysaMUUF/sAon+/Rz8SKwJUhuP6smBEOVOs3eK9\n\tQFY9S48XFQj7MonqLX7tbJCulqBdjdKSNz4BHSAwV0LmZJRLqGjnaPpPgWq4QmYFxQ\n\tyKfvt+A6Dp5+dYMDAPEuTXpdxaI26byurk1pVNAZd177WzhWMkC4hTMYl71dkYy6Di\n\tLG6nwn661IPog==","v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1656665144;\n\tbh=t3z1boBAErV4KT5ni+tiw18/p6GL+055t+oTd6lKo60=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=LgmvwpaHqfkOnk9nD8c7/fy6NAfJKKwdoIttKomG40Bo89pTpvx8pESxVsvQhM/jz\n\tnS5KqkQW6uq+YjmqodsFHSksQ+ALtKCfUx9aNdOpFXCrNuZ+rIAvwBBsl1k7iS7IBe\n\taMrFxmoIy3VBjhBN6mFC640erznRH4DGoi/nr8xw="],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key; \n\tunprotected) header.d=ideasonboard.com\n\theader.i=@ideasonboard.com\n\theader.b=\"LgmvwpaH\"; dkim-atps=neutral","To":"libcamera-devel@lists.libcamera.org,\n\tDavid Plowman ,\n\tKieran Bingham ,\n\tLaurent Pinchart ,\n\tJacopo Mondi ","Date":"Fri, 1 Jul 2022 11:45:13 +0300","Message-Id":"<20220701084521.31831-10-tomi.valkeinen@ideasonboard.com>","X-Mailer":"git-send-email 2.34.1","In-Reply-To":"<20220701084521.31831-1-tomi.valkeinen@ideasonboard.com>","References":"<20220701084521.31831-1-tomi.valkeinen@ideasonboard.com>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH v3 09/17] py: Switch to non-blocking\n\teventfd","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","From":"Tomi Valkeinen via libcamera-devel\n\t","Reply-To":"Tomi Valkeinen ","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"Blocking wait can be easily implemented on top in Python, so rather than\nsupporting only blocking reads, or supporting both non-blocking and\nblocking reads, let's support only non-blocking reads.\n\nSigned-off-by: Tomi Valkeinen \n---\n src/py/examples/simple-cam.py | 5 +++--\n src/py/examples/simple-capture.py | 12 +++++++++--\n src/py/examples/simple-continuous-capture.py | 5 +++--\n src/py/libcamera/py_camera_manager.cpp | 22 +++++++++++++-------\n src/py/libcamera/py_camera_manager.h | 2 +-\n test/py/unittests.py | 7 +++++++\n 6 files changed, 39 insertions(+), 14 deletions(-)","diff":"diff --git a/src/py/examples/simple-cam.py b/src/py/examples/simple-cam.py\nindex 2b81bb65..b3e97ca7 100755\n--- a/src/py/examples/simple-cam.py\n+++ b/src/py/examples/simple-cam.py\n@@ -19,8 +19,9 @@ TIMEOUT_SEC = 3\n \n \n def handle_camera_event(cm):\n- # cm.get_ready_requests() will not block here, as we know there is an event\n- # to read.\n+ # cm.get_ready_requests() returns the ready requests, which in our case\n+ # should almost always return a single Request, but in some cases there\n+ # could be multiple or none.\n \n reqs = cm.get_ready_requests()\n \ndiff --git a/src/py/examples/simple-capture.py b/src/py/examples/simple-capture.py\nindex a6a9b33e..5f93574f 100755\n--- a/src/py/examples/simple-capture.py\n+++ b/src/py/examples/simple-capture.py\n@@ -14,6 +14,7 @@\n \n import argparse\n import libcamera as libcam\n+import selectors\n import sys\n \n # Number of frames to capture\n@@ -107,11 +108,18 @@ def main():\n # The main loop. Wait for the queued Requests to complete, process them,\n # and re-queue them again.\n \n+ sel = selectors.DefaultSelector()\n+ sel.register(cm.event_fd, selectors.EVENT_READ)\n+\n while frames_done < TOTAL_FRAMES:\n- # cm.get_ready_requests() blocks until there is an event and returns\n- # all the ready requests. Here we should almost always get a single\n+ # cm.get_ready_requests() does not block, so we use a Selector to wait\n+ # for a camera event. Here we should almost always get a single\n # Request, but in some cases there could be multiple or none.\n \n+ events = sel.select()\n+ if not events:\n+ continue\n+\n reqs = cm.get_ready_requests()\n \n for req in reqs:\ndiff --git a/src/py/examples/simple-continuous-capture.py b/src/py/examples/simple-continuous-capture.py\nindex fe78a2dd..26a8060b 100755\n--- a/src/py/examples/simple-continuous-capture.py\n+++ b/src/py/examples/simple-continuous-capture.py\n@@ -88,8 +88,9 @@ class CaptureContext:\n camera_contexts: list[CameraCaptureContext] = []\n \n def handle_camera_event(self):\n- # cm.get_ready_requests() will not block here, as we know there is an event\n- # to read.\n+ # cm.get_ready_requests() returns the ready requests, which in our case\n+ # should almost always return a single Request, but in some cases there\n+ # could be multiple or none.\n \n reqs = self.cm.get_ready_requests()\n \ndiff --git a/src/py/libcamera/py_camera_manager.cpp b/src/py/libcamera/py_camera_manager.cpp\nindex 5600f661..3dd8668e 100644\n--- a/src/py/libcamera/py_camera_manager.cpp\n+++ b/src/py/libcamera/py_camera_manager.cpp\n@@ -22,7 +22,7 @@ PyCameraManager::PyCameraManager()\n \n \tcameraManager_ = std::make_unique();\n \n-\tint fd = eventfd(0, EFD_CLOEXEC);\n+\tint fd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);\n \tif (fd == -1)\n \t\tthrow std::system_error(errno, std::generic_category(),\n \t\t\t\t\t\"Failed to create eventfd\");\n@@ -60,18 +60,24 @@ py::list PyCameraManager::cameras()\n \n std::vector PyCameraManager::getReadyRequests()\n {\n-\treadFd();\n+\tint ret = readFd();\n \n-\tstd::vector ret;\n+\tif (ret == EAGAIN)\n+\t\treturn std::vector();\n+\n+\tif (ret != 0)\n+\t\tthrow std::system_error(ret, std::generic_category());\n+\n+\tstd::vector py_reqs;\n \n \tfor (Request *request : getCompletedRequests()) {\n \t\tpy::object o = py::cast(request);\n \t\t/* Decrease the ref increased in Camera.queue_request() */\n \t\to.dec_ref();\n-\t\tret.push_back(o);\n+\t\tpy_reqs.push_back(o);\n \t}\n \n-\treturn ret;\n+\treturn py_reqs;\n }\n \n /* Note: Called from another thread */\n@@ -94,12 +100,14 @@ void PyCameraManager::writeFd()\n \t\tLOG(Python, Fatal) << \"Unable to write to eventfd\";\n }\n \n-void PyCameraManager::readFd()\n+int PyCameraManager::readFd()\n {\n \tuint8_t buf[8];\n \n \tif (read(eventFd_.get(), buf, 8) != 8)\n-\t\tthrow std::system_error(errno, std::generic_category());\n+\t\treturn errno;\n+\n+\treturn 0;\n }\n \n void PyCameraManager::pushRequest(Request *req)\ndiff --git a/src/py/libcamera/py_camera_manager.h b/src/py/libcamera/py_camera_manager.h\nindex 56bea13d..3525057d 100644\n--- a/src/py/libcamera/py_camera_manager.h\n+++ b/src/py/libcamera/py_camera_manager.h\n@@ -39,7 +39,7 @@ private:\n \t\tLIBCAMERA_TSA_GUARDED_BY(completedRequestsMutex_);\n \n \tvoid writeFd();\n-\tvoid readFd();\n+\tint readFd();\n \tvoid pushRequest(Request *req);\n \tstd::vector getCompletedRequests();\n };\ndiff --git a/test/py/unittests.py b/test/py/unittests.py\nindex 9adc4337..6dea80fc 100755\n--- a/test/py/unittests.py\n+++ b/test/py/unittests.py\n@@ -207,9 +207,16 @@ class SimpleCaptureMethods(CameraTesterBase):\n reqs = None\n gc.collect()\n \n+ sel = selectors.DefaultSelector()\n+ sel.register(cm.event_fd, selectors.EVENT_READ)\n+\n reqs = []\n \n while True:\n+ events = sel.select()\n+ if not events:\n+ continue\n+\n ready_reqs = cm.get_ready_requests()\n \n reqs += ready_reqs\n","prefixes":["libcamera-devel","v3","09/17"]}