Fix Preview concurrencies

Linphone/core/CMakeLists.txt

@@ -14,6 +14,7 @@ list(APPEND _LINPHONEAPP_SOURCES
 	core/call-history/CallHistoryProxy.cpp
 	core/camera/CameraGui.cpp
 	core/camera/CameraDummy.cpp
+	core/camera/PreviewManager.cpp
 	core/fps-counter/FPSCounter.cpp
 	core/friend/FriendCore.cpp
 	core/friend/FriendGui.cpp

Linphone/core/camera/CameraGui.cpp

@@ -25,6 +25,7 @@
 
 #include "CameraDummy.hpp"
 #include "CameraGui.hpp"
+#include "PreviewManager.hpp"
 #include "core/App.hpp"
 #include "core/call/CallCore.hpp"
 #include "core/call/CallGui.hpp"
@@ -33,9 +34,6 @@
 
 DEFINE_ABSTRACT_OBJECT(CameraGui)
 
-QMutex CameraGui::gPreviewCounterMutex;
-int CameraGui::gPreviewCounter = 0;
-
 // =============================================================================
 CameraGui::CameraGui(QQuickItem *parent) : QQuickFramebufferObject(parent) {
 	mustBeInMainThread(getClassName());
@@ -52,7 +50,6 @@ CameraGui::~CameraGui() {
 	mustBeInMainThread("~" + getClassName());
 	mRefreshTimer.stop();
 	mIsDeleting = true;
-	deactivatePreview();
 	setWindowIdLocation(None);
 }
 
@@ -72,30 +69,15 @@ QQuickFramebufferObject::Renderer *CameraGui::createRenderer(bool resetWindowId)
 	// A renderer is mandatory, we cannot wait async.
 	switch (getSourceLocation()) {
 		case CorePreview: {
-			auto f = [qmlName = mQmlName, &renderer, resetWindowId]() {
-				qInfo() << "[Camera] (" << qmlName << ") Setting Camera to Preview";
-				auto coreModel = CoreModel::getInstance();
-				if (coreModel) {
-					auto core = coreModel->getCore();
-					if (!core) return;
-					if (resetWindowId) {
-						renderer = (QQuickFramebufferObject::Renderer *)core->getNativePreviewWindowId();
-						if (renderer) core->setNativePreviewWindowId(NULL);
-					} else {
-						renderer = (QQuickFramebufferObject::Renderer *)core->createNativePreviewWindowId();
-						if (renderer) core->setNativePreviewWindowId(renderer);
-					}
-				}
-			};
-			if (mIsDeleting) {
-				App::postModelBlock(f);
-			} else App::postModelSync(f);
+			if (resetWindowId) PreviewManager::getInstance()->unsubscribe(this);
+			else renderer = PreviewManager::getInstance()->subscribe(this);
 		} break;
 		case Call: {
 			auto f = [qmlName = mQmlName, callGui = mCallGui, &renderer, resetWindowId]() {
 				auto call = callGui->getCore()->getModel()->getMonitor();
 				if (call) {
-					qInfo() << "[Camera] (" << qmlName << ") Setting Camera to CallModel";
+					qInfo() << "[Camera] (" << qmlName << ") " << (resetWindowId ? "Resetting" : "Setting")
+					        << " Camera to CallModel";
 					if (resetWindowId) {
 						renderer = (QQuickFramebufferObject::Renderer *)call->getNativeVideoWindowId();
 						if (renderer) call->setNativeVideoWindowId(NULL);
@@ -113,7 +95,8 @@ QQuickFramebufferObject::Renderer *CameraGui::createRenderer(bool resetWindowId)
 			auto f = [qmlName = mQmlName, participantDeviceGui = mParticipantDeviceGui, &renderer, resetWindowId]() {
 				auto device = participantDeviceGui->getCore()->getModel()->getMonitor();
 				if (device) {
-					qInfo() << "[Camera] (" << qmlName << ") Setting Camera to ParticipantDeviceModel";
+					qInfo() << "[Camera] (" << qmlName << ") " << (resetWindowId ? "Resetting" : "Setting")
+					        << " Camera to ParticipantDeviceModel";
 					if (resetWindowId) {
 					} else {
 						renderer = (QQuickFramebufferObject::Renderer *)device->createNativeVideoWindowId();
@@ -217,27 +200,6 @@ CameraGui::WindowIdLocation CameraGui::getSourceLocation() const {
 	return mWindowIdLocation;
 }
 
-void CameraGui::activatePreview() {
-	gPreviewCounterMutex.lock();
-	if (++gPreviewCounter == 1) {
-		auto f = []() { CoreModel::getInstance()->getCore()->enableVideoPreview(true); };
-		if (mIsDeleting) App::postModelBlock(f);
-		else App::postModelSync(f);
-	}
-	gPreviewCounterMutex.unlock();
-}
-
-void CameraGui::deactivatePreview() {
-	gPreviewCounterMutex.lock();
-	if (getSourceLocation() == CorePreview) {
-		if (--gPreviewCounter == 0) {
-			auto f = []() { CoreModel::getInstance()->getCore()->enableVideoPreview(false); };
-			if (mIsDeleting) App::postModelBlock(f);
-			else App::postModelSync(f);
-		}
-	}
-	gPreviewCounterMutex.unlock();
-}
 void CameraGui::setWindowIdLocation(const WindowIdLocation &location) {
 	if (mWindowIdLocation != location) {
 		qDebug() << log()
@@ -245,10 +207,10 @@ void CameraGui::setWindowIdLocation(const WindowIdLocation &location) {
 		                .arg(mQmlName)
 		                .arg(mWindowIdLocation)
 		                .arg(location);
-		if (mWindowIdLocation == CorePreview) deactivatePreview();
+		if (mWindowIdLocation == CorePreview) PreviewManager::getInstance()->unsubscribe(this);
 		resetWindowId(); // Location change: Reset old window ID.
 		mWindowIdLocation = location;
-		if (mWindowIdLocation == CorePreview) activatePreview();
+		if (mWindowIdLocation == CorePreview) PreviewManager::getInstance()->subscribe(this);
 		update();
 		//		if (mWindowIdLocation == WindowIdLocation::CorePreview) {
 		//			mLastVideoDefinition =

Linphone/core/camera/CameraGui.hpp

@@ -55,9 +55,6 @@ public:
 	Q_INVOKABLE void resetWindowId() const; // const to be used from createRenderer()
 	void checkVideoDefinition();
 
-	static QMutex gPreviewCounterMutex;
-	static int gPreviewCounter;
-
 	bool getIsReady() const;
 	void setIsReady(bool isReady);
 	void isReady();
@@ -74,8 +71,6 @@ public:
 	WindowIdLocation getSourceLocation() const;
 	void setWindowIdLocation(const WindowIdLocation &location);
 
-	void activatePreview();
-	void deactivatePreview();
 	void updateWindowIdLocation();
 	void removeParticipantDeviceModel();
 	void removeCallModel();

Linphone/core/camera/PreviewManager.cpp

@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2010-2024 Belledonne Communications SARL.
+ *
+ * This file is part of linphone-desktop
+ * (see https://www.linphone.org).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <QOpenGLFramebufferObject>
+#include <QQuickWindow>
+#include <QThread>
+#include <QTimer>
+
+#include "../App.hpp"
+#include "PreviewManager.hpp"
+
+// =============================================================================
+PreviewManager *PreviewManager::gInstance = nullptr;
+
+PreviewManager::PreviewManager(QObject *parent) : QObject(parent) {
+}
+
+PreviewManager::~PreviewManager() {
+}
+
+PreviewManager *PreviewManager::getInstance() {
+	if (gInstance) return gInstance;
+	else {
+		gInstance = new PreviewManager();
+		return gInstance;
+	}
+}
+
+QQuickFramebufferObject::Renderer *PreviewManager::subscribe(const CameraGui *candidate) {
+	QQuickFramebufferObject::Renderer *renderer = nullptr;
+	mCounterMutex.lock();
+
+	if (mCandidates.size() == 0) {
+		activate();
+	}
+	auto itCandidate =
+	    std::find_if(mCandidates.begin(), mCandidates.end(),
+	                 [candidate](const QPair<const CameraGui *, QQuickFramebufferObject::Renderer *> &item) {
+		                 return item.first == candidate;
+	                 });
+	if (itCandidate == mCandidates.end()) {
+		connect(candidate, &QObject::destroyed, this, qOverload<QObject *>(&PreviewManager::unsubscribe));
+		mCandidates.append({candidate, nullptr});
+		itCandidate = mCandidates.end() - 1;
+	}
+	App::postModelSync([&renderer, isFirst = (itCandidate == mCandidates.begin())]() {
+		renderer =
+		    (QQuickFramebufferObject::Renderer *)CoreModel::getInstance()->getCore()->createNativePreviewWindowId();
+		if (isFirst) CoreModel::getInstance()->getCore()->setNativePreviewWindowId(renderer);
+	});
+	itCandidate->second = renderer;
+	mCounterMutex.unlock();
+	return renderer;
+}
+
+void PreviewManager::unsubscribe(const CameraGui *candidate) { // If nullptr, Use of sender()
+	mCounterMutex.lock();
+	auto itCandidate = std::find_if(mCandidates.begin(), mCandidates.end(),
+	                                [candidate = (candidate ? candidate : sender())](
+	                                    const QPair<const CameraGui *, QQuickFramebufferObject::Renderer *> &item) {
+		                                return item.first == candidate;
+	                                });
+	if (itCandidate != mCandidates.end()) {
+		disconnect(candidate, nullptr, this, nullptr);
+		if (mCandidates.size() == 1) {
+			mCandidates.erase(itCandidate);
+			deactivate();
+		} else if (mCandidates.begin() == itCandidate) {
+			mCandidates.erase(itCandidate);
+			qWarning() << "Update " << mCandidates.first().first->getQmlName();
+			App::postModelSync([renderer = mCandidates.first().second]() {
+				CoreModel::getInstance()->getCore()->setNativePreviewWindowId(renderer);
+			});
+		} else {
+			mCandidates.erase(itCandidate);
+		}
+	}
+	mCounterMutex.unlock();
+}
+
+void PreviewManager::unsubscribe(QObject *sender) {
+	unsubscribe(dynamic_cast<CameraGui *>(sender));
+}
+
+void PreviewManager::activate() {
+	App::postModelSync([]() { CoreModel::getInstance()->getCore()->enableVideoPreview(true); });
+}
+
+void PreviewManager::deactivate() {
+	App::postModelSync([]() { CoreModel::getInstance()->getCore()->enableVideoPreview(false); });
+}

Linphone/core/camera/PreviewManager.hpp

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2024 Belledonne Communications SARL.
+ *
+ * This file is part of linphone-desktop
+ * (see https://www.linphone.org).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef PREVIEW_MANAGER_H_
+#define PREVIEW_MANAGER_H_
+
+#include "CameraGui.hpp"
+#include <QMutex>
+#include <QObject>
+#include <QPair>
+#include <QQuickFramebufferObject>
+
+// Manage the SDK preview as a singleton.
+// The goal is to process the limitation that only one preview can be displayed.
+// On asynchronized application, the destruction of a previous Preview can be done AFTER the creation on a new Preview
+// Sticker.
+
+// =============================================================================
+
+class PreviewManager : public QObject {
+	Q_OBJECT
+public:
+	PreviewManager(QObject *parent = nullptr);
+	virtual ~PreviewManager();
+
+	static PreviewManager *getInstance();
+
+	QQuickFramebufferObject::Renderer *subscribe(const CameraGui *candidate);
+	void unsubscribe(const CameraGui *candidate);
+
+	void activate();
+	void deactivate();
+public slots:
+	void unsubscribe(QObject *sender);
+
+private:
+	QMutex mCounterMutex;
+	QList<QPair<const CameraGui *, QQuickFramebufferObject::Renderer *>> mCandidates;
+	static PreviewManager *gInstance;
+	QQuickFramebufferObject::Renderer *mPreviewRenderer = nullptr;
+};
+
+#endif