{"id":170,"url":"https://patchwork.libcamera.org/api/1.1/patches/170/?format=json","web_url":"https://patchwork.libcamera.org/patch/170/","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":"<20190107231151.23291-8-laurent.pinchart@ideasonboard.com>","date":"2019-01-07T23:11:47","name":"[libcamera-devel,v2,07/11] libcamera: Add a poll-based event dispatcher","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"9eb8a534bb638a1a4f52285de1354e052da7c637","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/1.1/people/2/?format=json","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/170/mbox/","series":[{"id":56,"url":"https://patchwork.libcamera.org/api/1.1/series/56/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=56","date":"2019-01-07T23:11:40","name":"libcamera: Add event notification and timers","version":2,"mbox":"https://patchwork.libcamera.org/series/56/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/170/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/170/checks/","tags":{},"headers":{"Return-Path":"<laurent.pinchart@ideasonboard.com>","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 EFDD760B3A\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tTue,  8 Jan 2019 00:10:49 +0100 (CET)","from avalon.bb.dnainternet.fi\n\t(dfj612ybrt5fhg77mgycy-3.rev.dnainternet.fi\n\t[IPv6:2001:14ba:21f5:5b00:2e86:4862:ef6a:2804])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 86F16E51\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tTue,  8 Jan 2019 00:10:49 +0100 (CET)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1546902649;\n\tbh=SiRsLN0Zc/8GSpeiZorpxXuDQ+BXneo3nlJDf1BZCEM=;\n\th=From:To:Subject:Date:In-Reply-To:References:From;\n\tb=bWmuUJmmBx4zO2qDRw0R2qodq/KS2i8hluOhDMOvq1ZzQIoP1U2EtpHEmGWX/IclI\n\tj0IWFVN/b2q+skj2oP5WQnuyiLKoG1sTlnpxq/vY6mkokvAsJvIAAgrNXoqnlWb+CA\n\tM42A2Fdoj5l5KWo4JZnf+H6cROH8IbTpr0Ap3JW0=","From":"Laurent Pinchart <laurent.pinchart@ideasonboard.com>","To":"libcamera-devel@lists.libcamera.org","Date":"Tue,  8 Jan 2019 01:11:47 +0200","Message-Id":"<20190107231151.23291-8-laurent.pinchart@ideasonboard.com>","X-Mailer":"git-send-email 2.19.2","In-Reply-To":"<20190107231151.23291-1-laurent.pinchart@ideasonboard.com>","References":"<20190107231151.23291-1-laurent.pinchart@ideasonboard.com>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH v2 07/11] libcamera: Add a poll-based\n\tevent dispatcher","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.23","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":"Mon, 07 Jan 2019 23:10:50 -0000"},"content":"Provide a poll-based event dispatcher implementation as convenience for\napplications that don't need a custom event loop. The poll-based\ndispatcher is automatically instantiated if the application doesn't\nprovide its own dispatcher.\n\nSigned-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>\n---\nChanges since v1:\n\n- Fix ASSERT() condition check\n- Ignore duplicate notifiers\n- Clarify warning messages for event notifier (un)registration errors\n---\n include/libcamera/libcamera.h                 |   1 +\n src/libcamera/camera_manager.cpp              |  19 +-\n src/libcamera/event_dispatcher_poll.cpp       | 234 ++++++++++++++++++\n src/libcamera/include/event_dispatcher_poll.h |  50 ++++\n src/libcamera/meson.build                     |   2 +\n 5 files changed, 301 insertions(+), 5 deletions(-)\n create mode 100644 src/libcamera/event_dispatcher_poll.cpp\n create mode 100644 src/libcamera/include/event_dispatcher_poll.h","diff":"diff --git a/include/libcamera/libcamera.h b/include/libcamera/libcamera.h\nindex 785babefa1c8..2dcaeda49812 100644\n--- a/include/libcamera/libcamera.h\n+++ b/include/libcamera/libcamera.h\n@@ -10,5 +10,6 @@\n #include <libcamera/camera.h>\n #include <libcamera/camera_manager.h>\n #include <libcamera/event_dispatcher.h>\n+#include <libcamera/event_dispatcher_poll.h>\n \n #endif /* __LIBCAMERA_LIBCAMERA_H__ */\ndiff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp\nindex cbfd977f1e3c..348ea2fedf64 100644\n--- a/src/libcamera/camera_manager.cpp\n+++ b/src/libcamera/camera_manager.cpp\n@@ -9,6 +9,7 @@\n #include <libcamera/event_dispatcher.h>\n \n #include \"device_enumerator.h\"\n+#include \"event_dispatcher_poll.h\"\n #include \"log.h\"\n #include \"pipeline_handler.h\"\n \n@@ -188,9 +189,10 @@ CameraManager *CameraManager::instance()\n  * \\param dispatcher Pointer to the event dispatcher\n  *\n  * libcamera requires an event dispatcher to integrate event notification and\n- * timers with the application event loop. Applications shall call this function\n- * once and only once before the camera manager is started with start() to set\n- * the event dispatcher.\n+ * timers with the application event loop. Applications that want to provide\n+ * their own event dispatcher shall call this function once and only once before\n+ * the camera manager is started with start(). If no event dispatcher is\n+ * provided, a default poll-based implementation will be used.\n  *\n  * The CameraManager takes ownership of the event dispatcher and will delete it\n  * when the application terminates.\n@@ -208,11 +210,18 @@ void CameraManager::setEventDispatcher(EventDispatcher *dispatcher)\n /**\n  * \\fn CameraManager::eventDispatcher()\n  * \\brief Retrieve the event dispatcher\n- * \\return Pointer to the event dispatcher, or nullptr if no event dispatcher\n- * has been set\n+ *\n+ * This function retrieves the event dispatcher set with setEventDispatcher().\n+ * If no dispatcher has been set, a default poll-based implementation is created\n+ * and returned.\n+ *\n+ * \\return Pointer to the event dispatcher\n  */\n EventDispatcher *CameraManager::eventDispatcher()\n {\n+\tif (!dispatcher_)\n+\t\tdispatcher_ = new EventDispatcherPoll();\n+\n \treturn dispatcher_;\n }\n \ndiff --git a/src/libcamera/event_dispatcher_poll.cpp b/src/libcamera/event_dispatcher_poll.cpp\nnew file mode 100644\nindex 000000000000..0cd08b2b4cc1\n--- /dev/null\n+++ b/src/libcamera/event_dispatcher_poll.cpp\n@@ -0,0 +1,234 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2019, Google Inc.\n+ *\n+ * event_dispatcher_poll.cpp - Poll-based event dispatcher\n+ */\n+\n+#include <algorithm>\n+#include <iomanip>\n+#include <poll.h>\n+#include <string.h>\n+\n+#include <libcamera/event_notifier.h>\n+#include <libcamera/timer.h>\n+\n+#include \"event_dispatcher_poll.h\"\n+#include \"log.h\"\n+\n+/**\n+ * \\file event_dispatcher_poll.h\n+ */\n+\n+namespace libcamera {\n+\n+static const char *notifierType(EventNotifier::Type type)\n+{\n+\tif (type == EventNotifier::Read)\n+\t\treturn \"read\";\n+\tif (type == EventNotifier::Write)\n+\t\treturn \"write\";\n+\tif (type == EventNotifier::Exception)\n+\t\treturn \"exception\";\n+\n+\treturn \"\";\n+}\n+\n+/**\n+ * \\class EventDispatcherPoll\n+ * \\brief A poll-based event dispatcher\n+ */\n+\n+EventDispatcherPoll::EventDispatcherPoll()\n+{\n+}\n+\n+EventDispatcherPoll::~EventDispatcherPoll()\n+{\n+}\n+\n+void EventDispatcherPoll::registerEventNotifier(EventNotifier *notifier)\n+{\n+\tEventNotifierSetPoll &set = notifiers_[notifier->fd()];\n+\tEventNotifier::Type type = notifier->type();\n+\n+\tif (set.notifiers[type] && set.notifiers[type] != notifier) {\n+\t\tLOG(Warning) << \"Ignoring duplicate \" << notifierType(type)\n+\t\t\t     << \" notifier for fd \" << notifier->fd();\n+\t\treturn;\n+\t}\n+\n+\tset.notifiers[type] = notifier;\n+}\n+\n+void EventDispatcherPoll::unregisterEventNotifier(EventNotifier *notifier)\n+{\n+\tauto iter = notifiers_.find(notifier->fd());\n+\tif (iter == notifiers_.end())\n+\t\treturn;\n+\n+\tEventNotifierSetPoll &set = iter->second;\n+\tEventNotifier::Type type = notifier->type();\n+\n+\tif (!set.notifiers[type])\n+\t\treturn;\n+\n+\tif (set.notifiers[type] != notifier) {\n+\t\tLOG(Warning) << notifierType(type) << \" notifier for fd \"\n+\t\t\t     << notifier->fd() << \" is not registered\";\n+\t\treturn;\n+\t}\n+\n+\tset.notifiers[type] = nullptr;\n+\tif (!set.notifiers[0] && !set.notifiers[1] && !set.notifiers[2])\n+\t\tnotifiers_.erase(iter);\n+}\n+\n+void EventDispatcherPoll::registerTimer(Timer *timer)\n+{\n+\tfor (auto iter = timers_.begin(); iter != timers_.end(); ++iter) {\n+\t\tif ((*iter)->deadline() > timer->deadline()) {\n+\t\t\ttimers_.insert(iter, timer);\n+\t\t\treturn;\n+\t\t}\n+\t}\n+\n+\ttimers_.push_back(timer);\n+}\n+\n+void EventDispatcherPoll::unregisterTimer(Timer *timer)\n+{\n+\tfor (auto iter = timers_.begin(); iter != timers_.end(); ++iter) {\n+\t\tif (*iter == timer) {\n+\t\t\ttimers_.erase(iter);\n+\t\t\treturn;\n+\t\t}\n+\n+\t\t/*\n+\t\t * As the timers list is ordered, we can stop as soon as we go\n+\t\t * past the deadline.\n+\t\t */\n+\t\tif ((*iter)->deadline() > timer->deadline())\n+\t\t\tbreak;\n+\t}\n+}\n+\n+void EventDispatcherPoll::processEvents()\n+{\n+\tint ret;\n+\n+\t/* Create the pollfd array. */\n+\tstd::vector<struct pollfd> pollfds;\n+\tpollfds.reserve(notifiers_.size());\n+\n+\tfor (auto notifier : notifiers_)\n+\t\tpollfds.push_back({ notifier.first, notifier.second.events(), 0 });\n+\n+\t/* Compute the timeout. */\n+\tTimer *nextTimer = !timers_.empty() ? timers_.front() : nullptr;\n+\tstruct timespec timeout;\n+\n+\tif (nextTimer) {\n+\t\tclock_gettime(CLOCK_MONOTONIC, &timeout);\n+\t\tuint64_t now = timeout.tv_sec * 1000000000ULL + timeout.tv_nsec;\n+\n+\t\tif (nextTimer->deadline() > now) {\n+\t\t\tuint64_t delta = nextTimer->deadline() - now;\n+\t\t\ttimeout.tv_sec = delta / 1000000000ULL;\n+\t\t\ttimeout.tv_nsec = delta % 1000000000ULL;\n+\t\t} else {\n+\t\t\ttimeout.tv_sec = 0;\n+\t\t\ttimeout.tv_nsec = 0;\n+\t\t}\n+\n+\t\tLOG(Debug) << \"timeout \" << timeout.tv_sec << \".\"\n+\t\t\t   << std::setfill('0') << std::setw(9)\n+\t\t\t   << timeout.tv_nsec;\n+\t}\n+\n+\t/* Wait for events and process notifers and timers. */\n+\tret = ppoll(pollfds.data(), pollfds.size(),\n+\t\t    nextTimer ? &timeout : nullptr, nullptr);\n+\tif (ret < 0) {\n+\t\tret = -errno;\n+\t\tLOG(Warning) << \"poll() failed with \" << strerror(-ret);\n+\t} else if (ret > 0) {\n+\t\tprocessNotifiers(pollfds);\n+\t}\n+\n+\tprocessTimers();\n+}\n+\n+short EventDispatcherPoll::EventNotifierSetPoll::events() const\n+{\n+\tshort events = 0;\n+\n+\tif (notifiers[EventNotifier::Read])\n+\t\tevents |= POLLIN;\n+\tif (notifiers[EventNotifier::Write])\n+\t\tevents |= POLLOUT;\n+\tif (notifiers[EventNotifier::Exception])\n+\t\tevents |= POLLPRI;\n+\n+\treturn events;\n+}\n+\n+void EventDispatcherPoll::processNotifiers(std::vector<struct pollfd> &pollfds)\n+{\n+\tstatic const struct {\n+\t\tEventNotifier::Type type;\n+\t\tshort events;\n+\t} events[] = {\n+\t\t{ EventNotifier::Read, POLLIN },\n+\t\t{ EventNotifier::Write, POLLOUT },\n+\t\t{ EventNotifier::Exception, POLLPRI },\n+\t};\n+\n+\tfor (const struct pollfd &pfd : pollfds) {\n+\t\tauto iter = notifiers_.find(pfd.fd);\n+\t\tASSERT(iter != notifiers_.end());\n+\n+\t\tEventNotifierSetPoll &set = iter->second;\n+\n+\t\tfor (const auto &event : events) {\n+\t\t\tEventNotifier *notifier = set.notifiers[event.type];\n+\n+\t\t\tif (!notifier)\n+\t\t\t\tcontinue;\n+\n+\t\t\t/*\n+\t\t\t * If the file descriptor is invalid, disable the\n+\t\t\t * notifier immediately.\n+\t\t\t */\n+\t\t\tif (pfd.revents & POLLNVAL) {\n+\t\t\t\tLOG(Warning) << \"Disabling \" << notifierType(event.type)\n+\t\t\t\t\t     << \" due to invalid file descriptor \"\n+\t\t\t\t\t     << pfd.fd;\n+\t\t\t\tunregisterEventNotifier(notifier);\n+\t\t\t}\n+\n+\t\t\tif (pfd.revents & event.events)\n+\t\t\t\tnotifier->activated.emit(notifier);\n+\t\t}\n+\t}\n+}\n+\n+void EventDispatcherPoll::processTimers()\n+{\n+\tstruct timespec ts;\n+\tuint64_t now;\n+\tclock_gettime(CLOCK_MONOTONIC, &ts);\n+\tnow = ts.tv_sec * 1000000000ULL + ts.tv_nsec;\n+\n+\twhile (!timers_.empty()) {\n+\t\tTimer *timer = timers_.front();\n+\t\tif (timer->deadline() > now)\n+\t\t\tbreak;\n+\n+\t\ttimers_.pop_front();\n+\t\ttimer->stop();\n+\t\ttimer->timeout.emit(timer);\n+\t}\n+}\n+\n+} /* namespace libcamera */\ndiff --git a/src/libcamera/include/event_dispatcher_poll.h b/src/libcamera/include/event_dispatcher_poll.h\nnew file mode 100644\nindex 000000000000..600289e455e2\n--- /dev/null\n+++ b/src/libcamera/include/event_dispatcher_poll.h\n@@ -0,0 +1,50 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2019, Google Inc.\n+ *\n+ * event_loop.h - Camera object interface\n+ */\n+#ifndef __LIBCAMERA_EVENT_DISPATCHER_POLL_H__\n+#define __LIBCAMERA_EVENT_DISPATCHER_POLL_H__\n+\n+#include <libcamera/event_dispatcher.h>\n+\n+#include <list>\n+#include <map>\n+#include <vector>\n+\n+namespace libcamera {\n+\n+class EventNotifier;\n+class Timer;\n+\n+class EventDispatcherPoll final : public EventDispatcher\n+{\n+public:\n+\tEventDispatcherPoll();\n+\t~EventDispatcherPoll();\n+\n+\tvoid registerEventNotifier(EventNotifier *notifier);\n+\tvoid unregisterEventNotifier(EventNotifier *notifier);\n+\n+\tvoid registerTimer(Timer *timer);\n+\tvoid unregisterTimer(Timer *timer);\n+\n+\tvoid processEvents();\n+\n+private:\n+\tstruct EventNotifierSetPoll {\n+\t\tshort events() const;\n+\t\tEventNotifier *notifiers[3];\n+\t};\n+\n+\tstd::map<int, EventNotifierSetPoll> notifiers_;\n+\tstd::list<Timer *> timers_;\n+\n+\tvoid processNotifiers(std::vector<struct pollfd> &pollfds);\n+\tvoid processTimers();\n+};\n+\n+} /* namespace libcamera */\n+\n+#endif /* __LIBCAMERA_EVENT_DISPATCHER_POLL_H__ */\ndiff --git a/src/libcamera/meson.build b/src/libcamera/meson.build\nindex 61fb93205b34..abf9a71d4172 100644\n--- a/src/libcamera/meson.build\n+++ b/src/libcamera/meson.build\n@@ -3,6 +3,7 @@ libcamera_sources = files([\n     'camera_manager.cpp',\n     'device_enumerator.cpp',\n     'event_dispatcher.cpp',\n+    'event_dispatcher_poll.cpp',\n     'event_notifier.cpp',\n     'log.cpp',\n     'media_device.cpp',\n@@ -14,6 +15,7 @@ libcamera_sources = files([\n \n libcamera_headers = files([\n     'include/device_enumerator.h',\n+    'include/event_dispatcher_poll.h',\n     'include/log.h',\n     'include/media_device.h',\n     'include/media_object.h',\n","prefixes":["libcamera-devel","v2","07/11"]}