[startkde] Move kwin launching to systemd / plasma-session

Currently we have a whole daisy-chain of startplasmawayland-> kwin ->
startplasmawaylandsession -> launching the session.

This was needed as we needed environment variables which previously we
only knew after kwin started.

After some kwin refactoring this is no longer the case, and
kwin_wayland_wrapper will sync it's environment variables to the
appropriate startup environments.

This allows us to move starting kwin_wayland to be systemd managed,
brining resource control, alongside it's classic counterpart
plasma-session.

ksmserver/plasma-ksmserver.service.in

@@ -1,7 +1,7 @@
 [Unit]
 Description=KDE Session Management Server
-Wants=plasma-kcminit.service
 PartOf=graphical-session.target
+After=plasma-kwin_wayland.service plasma-kcminit.service
 
 [Service]
 ExecStart=@CMAKE_INSTALL_FULL_BINDIR@/ksmserver

startkde/CMakeLists.txt

@@ -30,7 +30,6 @@ target_link_libraries(startplasma PUBLIC
 
 add_executable(startplasma-x11 ${START_PLASMA_COMMON_SRCS} startplasma-x11.cpp kcheckrunning/kcheckrunning.cpp)
 add_executable(startplasma-wayland ${START_PLASMA_COMMON_SRCS} startplasma-wayland.cpp)
-add_executable(startplasma-waylandsession ${START_PLASMA_COMMON_SRCS} startplasma-waylandsession.cpp)
 
 target_link_libraries(startplasma-x11 PRIVATE
     startplasma
@@ -41,9 +40,6 @@ target_link_libraries(startplasma-wayland PRIVATE
     startplasma
 )
 
-target_link_libraries(startplasma-waylandsession PRIVATE
-    startplasma
-)
 add_subdirectory(plasma-session)
 add_subdirectory(plasma-shutdown)
 
@@ -57,6 +53,5 @@ configure_file(config-startplasma.h.cmake ${CMAKE_CURRENT_BINARY_DIR}/config-sta
 
 install(TARGETS startplasma-x11 ${KDE_INSTALL_TARGETS_DEFAULT_ARGS})
 install(TARGETS startplasma-wayland ${KDE_INSTALL_TARGETS_DEFAULT_ARGS})
-install(TARGETS startplasma-waylandsession DESTINATION ${KDE_INSTALL_LIBEXECDIR})
 install(PROGRAMS plasma-sourceenv.sh DESTINATION ${KDE_INSTALL_LIBEXECDIR})
 install(PROGRAMS plasma-dbus-run-session-if-needed DESTINATION ${KDE_INSTALL_LIBEXECDIR})

startkde/kcminit/plasma-kcminit.service.in

@@ -1,6 +1,7 @@
 [Unit]
 Description=KDE Config Module Initialization
 PartOf=graphical-session.target
+After=plasma-kwin_wayland.service
 
 [Service]
 ExecStart=@CMAKE_INSTALL_FULL_BINDIR@/kcminit_startup

startkde/plasma-session/startup.cpp

@@ -148,10 +148,7 @@ Startup::Startup(QObject *parent)
 
     const AutoStart autostart;
 
-    // Keep for KF5; remove in KF6 (KInit will be gone then)
-    QProcess::execute(QStringLiteral(CMAKE_INSTALL_FULL_LIBEXECDIR_KF5 "/start_kdeinit_wrapper"), QStringList());
-
-    KJob *windowManagerJob = nullptr;
+    KJob *x11WindowManagerJob = nullptr;
     if (qEnvironmentVariable("XDG_SESSION_TYPE") != QLatin1String("wayland")) {
         QString windowManager;
         if (qEnvironmentVariableIsSet("KDEWM")) {
@@ -162,19 +159,38 @@ Startup::Startup(QObject *parent)
         }
 
         if (windowManager == QLatin1String(KWIN_BIN)) {
-            windowManagerJob = new StartServiceJob(windowManager, {}, QStringLiteral("org.kde.KWin"));
+            x11WindowManagerJob = new StartServiceJob(windowManager, {}, QStringLiteral("org.kde.KWin"));
         } else {
-            windowManagerJob = new StartServiceJob(windowManager, {}, {});
+            x11WindowManagerJob = new StartServiceJob(windowManager, {}, {});
+        }
+    } else {
+        // This must block until started as it sets the WAYLAND_DISPLAY/DISPLAY env variables needed for the rest of the boot
+        // fortunately it's very fast as it's just starting a wrapper
+        StartServiceJob kwinWaylandJob(QStringLiteral("kwin_wayland_wrapper"), {QStringLiteral("--xwayland")}, QStringLiteral("org.kde.KWinWrapper"));
+        kwinWaylandJob.exec();
+        // kslpash is only launched in plasma-session from the wayland mode, for X it's in startplasma-x11
+
+        const KConfig cfg(QStringLiteral("ksplashrc"));
+        // the splashscreen and progress indicator
+        KConfigGroup ksplashCfg = cfg.group("KSplash");
+        if (ksplashCfg.readEntry("Engine", QStringLiteral("KSplashQML")) == QLatin1String("KSplashQML")) {
+            QProcess::startDetached(QStringLiteral("ksplashqml"), {ksplashCfg.readEntry("Theme", QStringLiteral("Breeze"))});
         }
+        // FIXME 1: this code path is missing setupFontDpi() after X has started. Move to kcminit?
+        // FIXME 2: the systemd path has no concept of kslpash
+        // FIXME 3: the systemd code path is missing setupFontDpi
     }
 
+    // Keep for KF5; remove in KF6 (KInit will be gone then)
+    QProcess::execute(QStringLiteral(CMAKE_INSTALL_FULL_LIBEXECDIR_KF5 "/start_kdeinit_wrapper"), QStringList());
+
     KJob *phase1 = nullptr;
     m_lock.reset(new QEventLoopLocker);
 
     const QVector<KJob *> sequence = {
         new StartProcessJob(QStringLiteral("kcminit_startup"), {}),
         new StartServiceJob(QStringLiteral("kded5"), {}, QStringLiteral("org.kde.kded5"), {}),
-        windowManagerJob,
+        x11WindowManagerJob,
         new StartServiceJob(QStringLiteral("ksmserver"), QCoreApplication::instance()->arguments().mid(1), QStringLiteral("org.kde.ksmserver")),
         new StartupPhase0(autostart, this),
         phase1 = new StartupPhase1(autostart, this),

startkde/startplasma-wayland.cpp

@@ -82,16 +82,16 @@ int main(int argc, char **argv)
     // variables (e.g. LANG and LC_*)
     importSystemdEnvrionment();
 
-    QStringList args;
-    if (argc > 1) {
-        args.reserve(argc);
-        for (int i = 1; i < argc; ++i) {
-            args << QString::fromLocal8Bit(argv[i]);
-        }
-    } else {
-        args = QStringList{QStringLiteral("--xwayland"), QStringLiteral(CMAKE_INSTALL_FULL_LIBEXECDIR "/startplasma-waylandsession")};
-    }
-    runSync(QStringLiteral("kwin_wayland_wrapper"), args);
+    if (!startPlasmaSession(true))
+        return 4;
+
+    // Anything after here is logout
+    // It is not called after shutdown/restart
+    waitForKonqi();
+    out << "startplasma-wayland: Shutting down...\n";
+
+    // Keep for KF5; remove in KF6 (KInit will be gone then)
+    runSync(QStringLiteral("kdeinit5_shutdown"), {});
 
     out << "startplasmacompositor: Shutting down...\n";
     cleanupPlasmaEnvironment(oldSystemdEnvironment);

startkde/startplasma-waylandsession.cpp

@@ -1,42 +0,0 @@
-/*
-    SPDX-FileCopyrightText: 2019 Aleix Pol Gonzalez <aleixpol@kde.org>
-
-    SPDX-License-Identifier: LGPL-2.0-or-later
-*/
-
-#include "startplasma.h"
-#include <signal.h>
-
-int main(int argc, char **argv)
-{
-    QCoreApplication app(argc, argv);
-    signal(SIGTERM, sigtermHandler);
-
-    QScopedPointer<QProcess, KillBeforeDeleter> ksplash;
-
-    if (!qEnvironmentVariableIsSet("KWIN_RESTART_COUNT")) {
-        ksplash.reset(setupKSplash());
-    }
-
-    out << "startplasma-waylandsession: Starting up...\n";
-
-    if (!syncDBusEnvironment()) {
-        out << "Could not sync environment to dbus.\n";
-        return 2;
-    }
-
-    if (!startPlasmaSession(true))
-        return 4;
-
-    // Anything after here is logout
-    // It is not called after shutdown/restart
-    waitForKonqi();
-    out << "startplasma-waylandsession: Shutting down...\n";
-
-    // Keep for KF5; remove in KF6 (KInit will be gone then)
-    runSync(QStringLiteral("kdeinit5_shutdown"), {});
-
-    out << "startplasma-waylandsession: Done.\n";
-
-    return 0;
-}

startkde/systemd/plasma-core.target

@@ -2,6 +2,5 @@
 Description=KDE Plasma Workspace Core
 Wants=plasma-plasmashell.service plasma-kcminit.service plasma-kded.service plasma-kcminit-phase1.service graphical-session-pre.target
 Requires=plasma-ksmserver.service
-BindsTo=plasma-ksmserver.service
-After=graphical-session-pre.target
+After=graphical-session-pre.target plasma-kwin_wayland.service
 RefuseManualStart=yes