From patchwork Sun Jan 6 02:33:22 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 154 Return-Path: Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 309BA60B2E for ; Sun, 6 Jan 2019 03:32:28 +0100 (CET) Received: from avalon.bb.dnainternet.fi (dfj612ybrt5fhg77mgycy-3.rev.dnainternet.fi [IPv6:2001:14ba:21f5:5b00:2e86:4862:ef6a:2804]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id C202B513 for ; Sun, 6 Jan 2019 03:32:27 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1546741947; bh=oY+skbLzSkMGki+7qahzSd6PhQrV5oiC09QvwpXNQEA=; h=From:To:Subject:Date:In-Reply-To:References:From; b=OMZLnUFvjG8Ia+ktlwsnkSiZ2WGSuESdVITNeBhKDWMEiiC0UT5IqjEtUcAdn/VMb 0FndixfZJpGn/v4Wa9/Cv3k/ox9m4yBCkqToXSxcgL/f3GLHtDWG4Yxw9DLYDbkKC2 eOTwEsUR5+UcEVlQN0UKwv33xdRzrFDahSe/OdWM= From: Laurent Pinchart To: libcamera-devel@lists.libcamera.org Date: Sun, 6 Jan 2019 04:33:22 +0200 Message-Id: <20190106023328.10989-5-laurent.pinchart@ideasonboard.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20190106023328.10989-1-laurent.pinchart@ideasonboard.com> References: <20190106023328.10989-1-laurent.pinchart@ideasonboard.com> MIME-Version: 1.0 Subject: [libcamera-devel] [PATCH 05/11] libcamera: Add signal/slot communication mechanism X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 06 Jan 2019 02:32:28 -0000 Introduce a Signal class that allows connecting event sources (signals) to event listeners (slots) without adding any boilerplate code usually associated with the observer or listener design patterns. Signed-off-by: Laurent Pinchart Reviewed-by: Niklas Söderlund --- Documentation/Doxyfile.in | 3 +- include/libcamera/meson.build | 1 + include/libcamera/signal.h | 117 ++++++++++++++++++++++++++++++++++ src/libcamera/meson.build | 1 + src/libcamera/signal.cpp | 44 +++++++++++++ 5 files changed, 165 insertions(+), 1 deletion(-) create mode 100644 include/libcamera/signal.h create mode 100644 src/libcamera/signal.cpp diff --git a/Documentation/Doxyfile.in b/Documentation/Doxyfile.in index b1a70d36eee5..558a1ce04377 100644 --- a/Documentation/Doxyfile.in +++ b/Documentation/Doxyfile.in @@ -860,7 +860,8 @@ EXCLUDE_PATTERNS = # Note that the wildcards are matched against the file with absolute path, so to # exclude all test directories use the pattern */test/* -EXCLUDE_SYMBOLS = +EXCLUDE_SYMBOLS = libcamera::SlotBase \ + libcamera::Slot # The EXAMPLE_PATH tag can be used to specify one or more files or directories # that contain example code fragments that are included (see the \include diff --git a/include/libcamera/meson.build b/include/libcamera/meson.build index 3e04557d66b1..6f87689ea528 100644 --- a/include/libcamera/meson.build +++ b/include/libcamera/meson.build @@ -2,6 +2,7 @@ libcamera_api = files([ 'camera.h', 'camera_manager.h', 'libcamera.h', + 'signal.h', ]) install_headers(libcamera_api, diff --git a/include/libcamera/signal.h b/include/libcamera/signal.h new file mode 100644 index 000000000000..fceb852158ec --- /dev/null +++ b/include/libcamera/signal.h @@ -0,0 +1,117 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2019, Google Inc. + * + * signal.h - Signal & slot implementation + */ +#ifndef __LIBCAMERA_SIGNAL_H__ +#define __LIBCAMERA_SIGNAL_H__ + +#include +#include + +namespace libcamera { + +template +class Signal; + +template +class SlotBase +{ +public: + SlotBase(void *obj) + : obj_(obj) { } + virtual ~SlotBase() { } + + virtual void invoke(Args... args) = 0; + +protected: + friend class Signal; + void *obj_; +}; + +template +class Slot : public SlotBase +{ +public: + Slot(T *obj, void(T::*func)(Args...)) + : SlotBase(obj), func_(func) { } + + void invoke(Args... args) { (reinterpret_cast(this->obj_)->*func_)(args...); } + +private: + friend class Signal; + void(T::*func_)(Args...); +}; + +template +class Signal +{ +public: + Signal() { } + ~Signal() + { + for (SlotBase *slot : slots_) + delete slot; + } + + template + void connect(T *object, void(T::*func)(Args...)) + { + slots_.push_back(new Slot(object, func)); + } + + void disconnect() + { + for (SlotBase *slot : slots_) + delete slot; + slots_.clear(); + } + + template + void disconnect(T *object) + { + for (auto iter = slots_.begin(); iter != slots_.end(); ) { + SlotBase *slot = *iter; + if (slot->obj_ == object) { + iter = slots_.erase(iter); + delete slot; + } else { + ++iter; + } + } + } + + template + void disconnect(T *object, void(T::*func)(Args...)) + { + for (auto iter = slots_.begin(); iter != slots_.end(); ) { + SlotBase *slot = *iter; + if (slot->obj_ == object && + reinterpret_cast *>(slot)->func_ == func) { + iter = slots_.erase(iter); + delete slot; + } else { + ++iter; + } + } + } + + void emit(Args... args) + { + /* + * Make a copy of the slots list as the slot could call the + * disconnect operation, invalidating the iterator. + */ + std::vector *> slots{ slots_.begin(), slots_.end() }; + for (SlotBase *slot : slots) + slot->invoke(args...); + } + +private: + std::list *> slots_; +}; + +} /* namespace libcamera */ + +#endif /* __LIBCAMERA_SIGNAL_H__ */ diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build index 78562299fc42..3ec86e75b57e 100644 --- a/src/libcamera/meson.build +++ b/src/libcamera/meson.build @@ -6,6 +6,7 @@ libcamera_sources = files([ 'media_device.cpp', 'media_object.cpp', 'pipeline_handler.cpp', + 'signal.cpp', ]) libcamera_headers = files([ diff --git a/src/libcamera/signal.cpp b/src/libcamera/signal.cpp new file mode 100644 index 000000000000..8b5a6c285c55 --- /dev/null +++ b/src/libcamera/signal.cpp @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2019, Google Inc. + * + * signal.cpp - Signal & slot implementation + */ + +namespace libcamera { + +/** + * \class Signal + * \brief Generic signal and slot communication mechanism + * + * Signals and slots are a language construct aimed at communication between + * objects through the observer pattern without the need for boilerplate code. + * See http://doc.qt.io/qt-5/signalsandslots.html for more information. + */ + +/** + * \fn Signal::connect() + * \brief Connect the signal to a slot + */ + +/** + * \fn Signal::disconnect() + * \brief Disconnect the signal from all slots + */ + +/** + * \fn Signal::disconnect(T *object) + * \brief Disconnect the signal from all slots of the \a object + */ + +/** + * \fn Signal::disconnect(T *object, void(T::*func)(Args...)) + * \brief Disconnect the signal from a slot of the \a object + */ + +/** + * \fn Signal::emit() + * \brief Emit the signal and call all connected slots + */ + +} /* namespace libcamera */