ExtensionSystem: Move shutdownGuard to Utils

So it can be used inside Utils which does not depend on ExtensionSystem.

Change-Id: Iade7f2a8eb14b2fed59e10682cff9e56c29f990e
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/libs/extensionsystem/pluginmanager.cpp

@@ -8,7 +8,6 @@
 #include "optionsparser.h"
 #include "pluginmanager_p.h"
 #include "pluginspec.h"
-#include "shutdownguard.h"
 
 #include <nanotrace/nanotrace.h>
 
@@ -21,6 +20,7 @@
 #include <utils/qtcassert.h>
 #include <utils/qtcprocess.h>
 #include <utils/qtcsettings.h>
+#include <utils/shutdownguard.h>
 #include <utils/stringutils.h>
 #include <utils/threadutils.h>
 
@@ -248,26 +248,6 @@ using namespace Internal;
 
 static Internal::PluginManagerPrivate *d = nullptr;
 static PluginManager *m_instance = nullptr;
-static QObject *m_shutdownGuard = nullptr;
-
-/*!
-    Returns an object that can be used as the parent for objects that should be
-    destroyed just at the end of the applications lifetime.
-    The object is destroyed after all plugins' aboutToShutdown methods
-    have finished, just before the plugins are deleted.
-
-    Only use this from the application's main thread.
-
-    \sa ExtensionSystem::IPlugin::aboutToShutdown()
-*/
-QObject *shutdownGuard()
-{
-    if (!m_shutdownGuard) {
-        QTC_CHECK(Utils::isMainThread());
-        m_shutdownGuard = new QObject;
-    }
-    return m_shutdownGuard;
-}
 
 /*!
     Gets the unique plugin manager instance.
@@ -1092,8 +1072,7 @@ void PluginManagerPrivate::deleteAll()
         Utils::futureSynchronizer()->isCancelOnWait(),
         Utils::futureSynchronizer()->cancelAllFutures());
     Utils::futureSynchronizer()->waitForFinished(); // Synchronize all futures from all plugins
-    delete m_shutdownGuard;
+    triggerShutdownGuard();
-    m_shutdownGuard = nullptr;
     Utils::reverseForeach(loadQueue(), [this](PluginSpec *spec) {
         loadPlugin(spec, PluginSpec::Deleted);
     });

src/libs/utils/CMakeLists.txt

@@ -150,6 +150,7 @@ add_qtc_library(Utils
     set_algorithm.h
     settingsaccessor.cpp settingsaccessor.h
     settingsselector.cpp settingsselector.h
+    shutdownguard.cpp shutdownguard.h
     sizedarray.h
     smallstring.h
     smallstringfwd.h

src/libs/utils/shutdownguard.cpp

@@ -0,0 +1,73 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#include <shutdownguard.h>
+
+#include <threadutils.h>
+#include <qtcassert.h>
+
+namespace Utils {
+
+class ShutdownGuardHolder final
+{
+public:
+    ~ShutdownGuardHolder()
+    {
+        if (!m_alreadyGone)
+            triggerShutdownGuard();
+    }
+
+    QObject *shutdownGuard()
+    {
+        QTC_CHECK(!m_alreadyGone);
+        if (!m_shutdownGuard) {
+            QTC_CHECK(Utils::isMainThread());
+            m_shutdownGuard = new QObject;
+        }
+        return m_shutdownGuard;
+    }
+
+    void triggerShutdownGuard()
+    {
+        m_alreadyGone = true;
+        delete m_shutdownGuard;
+        m_shutdownGuard = nullptr;
+    }
+
+private:
+    QObject *m_shutdownGuard = nullptr;
+    bool m_alreadyGone = false;
+};
+
+static ShutdownGuardHolder theShutdownGuardHolder;
+
+/*!
+    Destroys the shutdown guard object and consequently all
+    objects guarded by it.
+
+    In a normal run of the application this function is called
+    automatically at the appropriate time.
+*/
+
+void triggerShutdownGuard()
+{
+    return theShutdownGuardHolder.triggerShutdownGuard();
+}
+
+/*!
+    Returns an object that can be used as the parent for objects that should be
+    destroyed just at the end of the applications lifetime.
+    The object is destroyed after all plugins' aboutToShutdown methods
+    have finished, just before the plugins are deleted.
+
+    Only use this from the application's main thread.
+
+    \sa ExtensionSystem::IPlugin::aboutToShutdown()
+*/
+
+QObject *shutdownGuard()
+{
+    return theShutdownGuardHolder.shutdownGuard();
+}
+
+} // Utils

src/libs/utils/shutdownguard.h

@@ -3,13 +3,16 @@
 
 #pragma once
 
-#include "extensionsystem_global.h"
+#include "utils_global.h"
 
 #include <QObject>
 
-namespace ExtensionSystem {
+namespace Utils {
 
-EXTENSIONSYSTEM_EXPORT QObject *shutdownGuard();
+QTCREATOR_UTILS_EXPORT QObject *shutdownGuard();
+
+// Called from PluginManagerPrivate::deleteAll()
+QTCREATOR_UTILS_EXPORT void triggerShutdownGuard();
 
 template <class T>
 class GuardedObject
@@ -31,4 +34,4 @@ private:
     T *m_object;
 };
 
-} // namespace ExtensionSystem
+} // namespace Utils

src/libs/utils/utils.qbs

@@ -271,6 +271,8 @@ QtcLibrary {
         "result.h",
         "savefile.cpp",
         "savefile.h",
+        "shutdownguard.cpp",
+        "shutdownguard.h",
         "scopedswap.h",
         "scopedtimer.cpp",
         "scopedtimer.h",

src/plugins/coreplugin/messagemanager.cpp

@@ -9,9 +9,8 @@
 #include "ioutputpane.h"
 #include "outputwindow.h"
 
-#include <extensionsystem/shutdownguard.h>
-
 #include <utils/qtcassert.h>
+#include <utils/shutdownguard.h>
 #include <utils/utilsicons.h>
 
 #include <QFont>
@@ -100,7 +99,7 @@ private:
 static MessageOutputWindow *messageOutputWindow()
 {
     static QPointer<MessageOutputWindow> theMessageOutputWindow
-            = new MessageOutputWindow(ExtensionSystem::shutdownGuard());
+            = new MessageOutputWindow(Utils::shutdownGuard());
     return theMessageOutputWindow.get();
 }
 
@@ -124,7 +123,7 @@ static void showOutputPane(Flag flags)
 static void writeImpl(const QString &text, Flag flags)
 {
     // Make sure this end up in the GUI thread.
-    QMetaObject::invokeMethod(ExtensionSystem::shutdownGuard(), [text, flags] {
+    QMetaObject::invokeMethod(Utils::shutdownGuard(), [text, flags] {
         QTC_ASSERT(messageOutputWindow(), return);
         showOutputPane(flags);
         messageOutputWindow()->append(text + '\n');

src/plugins/coreplugin/session.cpp

@@ -17,7 +17,6 @@
 
 #include <extensionsystem/pluginmanager.h>
 #include <extensionsystem/pluginspec.h>
-#include <extensionsystem/shutdownguard.h>
 
 #include <utils/algorithm.h>
 #include <utils/filepath.h>
@@ -27,6 +26,7 @@
 #include <utils/store.h>
 #include <utils/stringutils.h>
 #include <utils/stylehelper.h>
+#include <utils/shutdownguard.h>
 #include <utils/threadutils.h>
 
 #include <nanotrace/nanotrace.h>
@@ -114,7 +114,7 @@ static SessionManagerPrivate *d = nullptr;
 
 SessionManager *sessionManager()
 {
-    static ExtensionSystem::GuardedObject<SessionManager> theSessionManager;
+    static GuardedObject<SessionManager> theSessionManager;
     return theSessionManager.get();
 }
 

src/plugins/ios/iosdevice.cpp

@@ -13,8 +13,6 @@
 #include <coreplugin/helpmanager.h>
 #include <coreplugin/icore.h>
 
-#include <extensionsystem/shutdownguard.h>
-
 #include <projectexplorer/devicesupport/devicemanager.h>
 #include <projectexplorer/devicesupport/idevicefactory.h>
 #include <projectexplorer/devicesupport/idevicewidget.h>
@@ -23,6 +21,7 @@
 #include <utils/layoutbuilder.h>
 #include <utils/portlist.h>
 #include <utils/qtcprocess.h>
+#include <utils/shutdownguard.h>
 
 #include <solutions/tasking/tasktree.h>
 
@@ -628,7 +627,7 @@ void IosDeviceManager::updateUserModeDevices()
 
 IosDeviceManager *IosDeviceManager::instance()
 {
-    static IosDeviceManager *theInstance = new IosDeviceManager(ExtensionSystem::shutdownGuard());
+    static IosDeviceManager *theInstance = new IosDeviceManager(Utils::shutdownGuard());
     return theInstance;
 }
 

src/plugins/vcsbase/vcsbaseclient.cpp

@@ -16,14 +16,13 @@
 #include <coreplugin/editormanager/editormanager.h>
 #include <coreplugin/idocument.h>
 
-#include <extensionsystem/shutdownguard.h>
-
 #include <texteditor/textdocument.h>
 
 #include <utils/commandline.h>
 #include <utils/environment.h>
 #include <utils/qtcprocess.h>
 #include <utils/qtcassert.h>
+#include <utils/shutdownguard.h>
 
 #include <QDebug>
 #include <QStringList>
@@ -213,7 +212,7 @@ VcsCommand *VcsBaseClientImpl::createVcsCommand(const FilePath &defaultWorkingDi
                                                 const Environment &environment)
 {
     auto command = new VcsCommand(defaultWorkingDir, environment);
-    command->setParent(ExtensionSystem::shutdownGuard());
+    command->setParent(Utils::shutdownGuard());
     return command;
 }