Failure free restart of the launcher and a comment

why we do that

3 files changed, 28 insertions, 0 deletions

diff --git a/core/launcher/serverapp.cpp b/core/launcher/serverapp.cpp
index 522ef07..28316a4 100644
--- a/core/launcher/serverapp.cpp
+++ b/core/launcher/serverapp.cpp
@@ -678,99 +678,118 @@ void ServerApplication::clearSafeMode()
 
 
 void ServerApplication::shutdown()
 {
     if ( type() != GuiServer )
         return;
     ShutdownImpl *sd = new ShutdownImpl( 0, 0, WDestructiveClose );
     connect( sd, SIGNAL(shutdown(ShutdownImpl::Type)),
              this, SLOT(shutdown(ShutdownImpl::Type)) );
     sd->showMaximized();
 }
 
 void ServerApplication::shutdown( ShutdownImpl::Type t )
 {
     char *opt = 0;
 
     switch ( t ) {
     case ShutdownImpl::ShutdownSystem:
         opt = "-h";
         // fall through
     case ShutdownImpl::RebootSystem:
         if ( opt == 0 )
             opt = "-r";
 
         if ( execl( "/sbin/shutdown", "shutdown", opt, "now", ( void* ) 0) < 0 )
             perror("shutdown");
         //                              ::syslog ( LOG_ERR, "Erroring execing shutdown\n" );
 
         break;
     case ShutdownImpl::RestartDesktop:
         restart();
         break;
     case ShutdownImpl::TerminateDesktop:
         prepareForTermination( FALSE );
 
         // This is a workaround for a Qt bug
         // clipboard applet has to stop its poll timer, or Qt/E
         // will hang on quit() right before it emits aboutToQuit()
         emit aboutToQuit ( );
 
         quit();
         break;
     }
 }
 
 void ServerApplication::restart()
 {
     if ( allowRestart ) {
+
+        /*
+         * Applets and restart is a problem. Some applets delete
+         * their widgets even if ownership gets transfered to the
+         * parent (Systray ) but deleting the applet may be unsafe
+         * as well ( double deletion ). Some have topLevel widgets
+         * and when we dlclose and then delete the widget we will
+         * crash and an crash during restart is not nice
+         */
+#ifdef ALL_APPLETS_ON_THIS_WORLD_ARE_FIXED
+        /* same as above */
+        emit aboutToQuit();
         prepareForTermination(TRUE);
         doRestart = TRUE;
         quit();
+#else
+        prepareForTermination( true );
+        for ( int fd = 3; fd < 100; fd++ )
+                close( fd );
+        execl( ( qpeDir() + "/bin/qpe" ).latin1(), "qpe", 0 );
+        exit( 1 );
+#endif
     }
 }
 
 void ServerApplication::rereadVolumes()
 {
     Config cfg( "qpe" );
     cfg. setGroup ( "Volume" );
 
     m_screentap_sound = cfg. readBoolEntry ( "TouchSound" );
     m_keyclick_sound  = cfg. readBoolEntry ( "KeySound" );
     m_alarm_sound     = cfg. readBoolEntry ( "AlarmSound" );
 }
 
 
 void ServerApplication::checkMemory()
 {
 #if defined(QPE_HAVE_MEMALERTER)
     static bool ignoreNormal=TRUE;
     static bool existingMessage=FALSE;
 
     if(existingMessage)
         return; // don't show a second message while still on first
 
     existingMessage = TRUE;
     switch ( memstate ) {
         case MemUnknown:
             break;
         case MemLow:
             memstate = MemUnknown;
             if ( !recoverMemory() ) {
                 QMessageBox::warning( 0 , tr("Memory Status"),
                     tr("Memory Low\nPlease save data.") );
                 ignoreNormal = FALSE;
             }
             break;
         case MemNormal:
             memstate = MemUnknown;
             if ( !ignoreNormal ) {
                 ignoreNormal = TRUE;
                 QMessageBox::information ( 0 , tr("Memory Status"),
                     "Memory OK" );
             }
             break;
         case MemVeryLow:
             memstate = MemUnknown;
             QMessageBox::critical( 0 , tr("Memory Status"),
                 tr("Critical Memory Shortage\n"
                 "Please end this application\n"
diff --git a/core/launcher/systray.cpp b/core/launcher/systray.cpp
index 64356ca..6122770 100644
--- a/core/launcher/systray.cpp
+++ b/core/launcher/systray.cpp
@@ -24,96 +24,104 @@
 
 #include <qlayout.h>
 #include <qdir.h>
 #include <qmessagebox.h>
 #include <qtranslator.h>
 
 #include "systray.h"
 
 #include <stdlib.h>
 
 /* ### Single build floppies ### */
 #if 0
 #ifdef QT_NO_COMPONENTS
 #include "../plugins/applets/clockapplet/clockappletimpl.h"
 #endif
 #endif
 
 SysTray::SysTray( QWidget *parent ) : QFrame( parent ), layout(0)
 {
     //setFrameStyle( QFrame::Panel | QFrame::Sunken );
     loadApplets();
 }
 
 SysTray::~SysTray()
 {
     clearApplets();
 }
 
 static int compareAppletPositions(const void *a, const void *b)
 {
     const TaskbarApplet* aa = *(const TaskbarApplet**)a;
     const TaskbarApplet* ab = *(const TaskbarApplet**)b;
     int d = ab->iface->position() - aa->iface->position();
     if ( d ) return d;
     return QString::compare(ab->name,aa->name);
 }
 
 void SysTray::loadApplets()
 {
     hide();
     clearApplets();
     addApplets();
 }
 
 void SysTray::clearApplets()
 {
 #ifndef QT_NO_COMPONENTS
 
+    /*
+     * Note on clearing. SOme applets delete their
+     * applets themselves some don't do it
+     * and on restart this can crash. If we delete it
+     * here we might end up in a double deletion. We could
+     * use QGuardedPtr but that would be one QOBject
+     * for every applet more but only useful for restart
+     */
     QValueList<TaskbarApplet>::Iterator mit;
     for ( mit = appletList.begin(); mit != appletList.end(); ++mit ) {
         (*mit).iface->release();
         (*mit).library->unload();
         delete (*mit).library;
     }
 
 #endif
     appletList.clear();
     if ( layout )
         delete layout;
     layout = new QHBoxLayout( this, 0, 1 );
     layout->setAutoAdd(TRUE);
 }
 
 void SysTray::addApplets()
 {
     hide();
 #ifndef QT_NO_COMPONENTS
     Config cfg( "Taskbar" );
     cfg.setGroup( "Applets" );
     QStringList exclude = cfg.readListEntry( "ExcludeApplets", ',' );
 
     QString lang = getenv( "LANG" );
     QString path = QPEApplication::qpeDir() + "/plugins/applets";
     QDir dir( path, "lib*.so" );
     QStringList list = dir.entryList();
     QStringList::Iterator it;
     int napplets=0;
     TaskbarApplet* *applets = new TaskbarApplet*[list.count()];
     for ( it = list.begin(); it != list.end(); ++it ) {
         if ( exclude.find( *it ) != exclude.end() )
             continue;
         TaskbarAppletInterface *iface = 0;
         QLibrary *lib = new QLibrary( path + "/" + *it );
         if (( lib->queryInterface( IID_TaskbarApplet, (QUnknownInterface**)&iface ) == QS_OK ) && iface ) {
             TaskbarApplet *applet = new TaskbarApplet;
             applets[napplets++] = applet;
             applet->library = lib;
             applet->iface = iface;
 
             QTranslator *trans = new QTranslator(qApp);
             QString type = (*it).left( (*it).find(".") );
             QString tfn = QPEApplication::qpeDir()+"/i18n/"+lang+"/"+type+".qm";
             if ( trans->load( tfn ))
                 qApp->installTranslator( trans );
             else
                 delete trans;
diff --git a/core/launcher/systray.h b/core/launcher/systray.h
index 77c581f..b989d58 100644
--- a/core/launcher/systray.h
+++ b/core/launcher/systray.h
@@ -1,61 +1,62 @@
 /**********************************************************************
 ** Copyright (C) 2000-2002 Trolltech AS.  All rights reserved.
 **
 ** This file is part of the Qtopia Environment.
 **
 ** This file may be distributed and/or modified under the terms of the
 ** GNU General Public License version 2 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.GPL included in the
 ** packaging of this file.
 **
 ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 **
 ** See http://www.trolltech.com/gpl/ for GPL licensing information.
 **
 ** Contact info@trolltech.com if any conditions of this licensing are
 ** not clear to you.
 **
 **********************************************************************/
 
 #ifndef __SYSTRAY_H__
 #define __SYSTRAY_H__
 
 #ifndef QT_NO_COMPONENT
 #include <qtopia/taskbarappletinterface.h>
 #endif
 
 #include <qframe.h>
 #include <qvaluelist.h>
+#include <qguardedptr.h>
 
 class QHBoxLayout;
 class QLibrary;
 
 struct TaskbarApplet
 {
 #ifndef QT_NO_COMPONENT
     QLibrary *library;
     TaskbarAppletInterface *iface;
 #endif
     QWidget *applet;
     QString name;
 };
 
 class SysTray : public QFrame {
     Q_OBJECT
 public:
     SysTray( QWidget *parent );
     ~SysTray();
 
     void clearApplets();
     void addApplets();
 
 private:
     void loadApplets();
     QHBoxLayout *layout;
     QValueList<TaskbarApplet> appletList;
 };
 
 
 #endif // __SYSTRAY_H__