From 7d35c771c0480e1ca5942ba3c9cf09c1fde22f85 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Sun, 25 Oct 2020 14:40:50 +0200 Subject: cam: Use libevent to implement event loop MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit To prepare for removal of the EventDispatcher from the libcamera public API, switch to libevent to handle the event loop. Signed-off-by: Laurent Pinchart Reviewed-by: Kieran Bingham Reviewed-by: Niklas Söderlund --- README.rst | 3 +++ src/cam/event_loop.cpp | 34 +++++++++++++++++++++++++++------- src/cam/event_loop.h | 15 ++++++++------- src/cam/main.cpp | 16 +++++----------- src/cam/meson.build | 13 ++++++++++++- 5 files changed, 55 insertions(+), 26 deletions(-) diff --git a/README.rst b/README.rst index 5c4b6989..251291b7 100644 --- a/README.rst +++ b/README.rst @@ -78,6 +78,9 @@ for documentation: [optional] for gstreamer: [optional] libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev +for cam: [optional] + libevent-dev + for qcam: [optional] qtbase5-dev libqt5core5a libqt5gui5 libqt5widgets5 qttools5-dev-tools libtiff-dev diff --git a/src/cam/event_loop.cpp b/src/cam/event_loop.cpp index e8ab8617..13f2583d 100644 --- a/src/cam/event_loop.cpp +++ b/src/cam/event_loop.cpp @@ -5,19 +5,34 @@ * event_loop.cpp - cam - Event loop */ -#include - #include "event_loop.h" -using namespace libcamera; +#include +#include +#include + +EventLoop *EventLoop::instance_ = nullptr; -EventLoop::EventLoop(EventDispatcher *dispatcher) - : dispatcher_(dispatcher) +EventLoop::EventLoop() { + assert(!instance_); + + evthread_use_pthreads(); + event_ = event_base_new(); + instance_ = this; } EventLoop::~EventLoop() { + instance_ = nullptr; + + event_base_free(event_); + libevent_global_shutdown(); +} + +EventLoop *EventLoop::instance() +{ + return instance_; } int EventLoop::exec() @@ -26,7 +41,7 @@ int EventLoop::exec() exit_.store(false, std::memory_order_release); while (!exit_.load(std::memory_order_acquire)) - dispatcher_->processEvents(); + event_base_loop(event_, EVLOOP_NO_EXIT_ON_EMPTY); return exitCode_; } @@ -35,5 +50,10 @@ void EventLoop::exit(int code) { exitCode_ = code; exit_.store(true, std::memory_order_release); - dispatcher_->interrupt(); + interrupt(); +} + +void EventLoop::interrupt() +{ + event_base_loopbreak(event_); } diff --git a/src/cam/event_loop.h b/src/cam/event_loop.h index 581c7cba..b1c6bd10 100644 --- a/src/cam/event_loop.h +++ b/src/cam/event_loop.h @@ -9,26 +9,27 @@ #include -#include - -namespace libcamera { -class EventDispatcher; -} +struct event_base; class EventLoop { public: - EventLoop(libcamera::EventDispatcher *dispatcher); + EventLoop(); ~EventLoop(); + static EventLoop *instance(); + int exec(); void exit(int code = 0); private: - libcamera::EventDispatcher *dispatcher_; + static EventLoop *instance_; + struct event_base *event_; std::atomic exit_; int exitCode_; + + void interrupt(); }; #endif /* __CAM_EVENT_LOOP_H__ */ diff --git a/src/cam/main.cpp b/src/cam/main.cpp index b3a8d94f..e01be63a 100644 --- a/src/cam/main.cpp +++ b/src/cam/main.cpp @@ -52,7 +52,7 @@ private: CameraManager *cm_; std::shared_ptr camera_; std::unique_ptr config_; - EventLoop *loop_; + EventLoop loop_; bool strictFormats_; }; @@ -60,7 +60,7 @@ private: CamApp *CamApp::app_ = nullptr; CamApp::CamApp() - : cm_(nullptr), camera_(nullptr), config_(nullptr), loop_(nullptr), + : cm_(nullptr), camera_(nullptr), config_(nullptr), strictFormats_(false) { CamApp::app_ = this; @@ -134,16 +134,11 @@ int CamApp::init(int argc, char **argv) std::cout << "Monitoring new hotplug and unplug events" << std::endl; } - loop_ = new EventLoop(cm_->eventDispatcher()); - return 0; } void CamApp::cleanup() { - delete loop_; - loop_ = nullptr; - if (camera_) { camera_->release(); camera_.reset(); @@ -166,8 +161,7 @@ int CamApp::exec() void CamApp::quit() { - if (loop_) - loop_->exit(); + loop_.exit(); } int CamApp::parseOptions(int argc, char *argv[]) @@ -366,13 +360,13 @@ int CamApp::run() } if (options_.isSet(OptCapture)) { - Capture capture(camera_, config_.get(), loop_); + Capture capture(camera_, config_.get(), &loop_); return capture.run(options_); } if (options_.isSet(OptMonitor)) { std::cout << "Press Ctrl-C to interrupt" << std::endl; - ret = loop_->exec(); + ret = loop_.exec(); if (ret) std::cout << "Failed to run monitor loop" << std::endl; } diff --git a/src/cam/meson.build b/src/cam/meson.build index 89e124fb..f0c08589 100644 --- a/src/cam/meson.build +++ b/src/cam/meson.build @@ -1,5 +1,12 @@ # SPDX-License-Identifier: CC0-1.0 +libevent = dependency('libevent_pthreads', required : false) + +if not libevent.found() + warning('libevent_pthreads not found, \'cam\' application will not be compiled') + subdir_done() +endif + cam_sources = files([ 'buffer_writer.cpp', 'capture.cpp', @@ -10,5 +17,9 @@ cam_sources = files([ ]) cam = executable('cam', cam_sources, - dependencies : [ libatomic, libcamera_dep ], + dependencies : [ + libatomic, + libcamera_dep, + libevent, + ], install : true) -- cgit v1.2.1