gssettingsuis/Gs/GSFramework/inc/GSWatchDog.h
branchRCL_3
changeset 54 7e0eff37aedb
parent 0 8c5d936e5675
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gssettingsuis/Gs/GSFramework/inc/GSWatchDog.h	Wed Sep 01 12:20:44 2010 +0100
@@ -0,0 +1,293 @@
+/*
+* Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description: 
+*
+*/
+
+
+#ifndef GSWATCHDOG_H
+#define GSWATCHDOG_H
+
+// System includes
+#include <e32base.h>
+#include <mgswatchdog.h>
+
+// CONSTANTS
+
+
+/**
+* Maximum number of GS runs during which plugin is held in blacklist. After
+* this plugin is allowed normal execution unless it crashes again.
+*
+* Used only in case no CenRep value is defined.
+*/
+const TInt KGSDefaultMaxPluginBlackListedRuns = 5;
+
+
+/**
+* Defines how many crashes are observed before watchdog is activated. The
+* bigger the value, more tolerant behaviour towards crashing plugins.
+*
+* -1 = Watchdog is completely disabled regardless any crash
+*      (KGSWatchdogActivationDisabled).
+*  1 = In practise, the fastest reaction, meaning watchdog is enabled the next
+*      run GS starts after a crash.
+*  2 = GS can have 1 crash without watchdog being enabled = 2nd GS crash in a
+*      row will enable watchdog.
+*  n = GS can have n-1 crashes before watchdog being activated etc.
+*
+* Used only in case no CenRep value is defined.
+*/
+const TInt KGSDefaultWatchdogActivationLimit = 1;
+
+/**
+* Watchdog is completely disabled.
+*/
+const TInt KGSWatchdogActivationDisabled = -1;
+
+
+// FORWARD DECLARATIONS
+class CRepository;
+class RReadStream;
+class RWriteStream;
+
+// CLASS DECLARATION
+
+
+
+/**
+* Container class for quarantined plugin data.
+*/
+class TGSPluginQuarantine
+    {
+    public:
+        /**
+        * Read data from aStream.
+        * @param aStream read stream.
+        */
+        void InternalizeL( RReadStream& aStream );
+
+        /**
+        * Write data to aStream.
+        * @param aStream write stream.
+        */
+        void ExternalizeL( RWriteStream& aStream ) const;
+
+    public:
+
+        /**
+        * Uid of the plugin.
+        */
+        TUid iUid;
+
+        /**
+        * Counter which is incremented each time GS is started and the plugin
+        * is in blacklist. This is used for removing plugin from blacklist
+        * after certain number of GS runs (iMaxPluginBlackListedRuns). This
+        * means plugins are not in blacklist for ever but it is possible to try
+        * running the plugin after a number of GS runs. This is needed in case
+        * of ramdom crash while some essential plugin is in quarantine.
+        */
+        TInt iRunsAfterCrash;
+    };
+
+/**
+*  CGSWatchDog is responsible for quarantining plugins and updating blacklist
+*  for crashing GS plugins. This is the class responsible for keeping GS
+*  application functional even if some plugin to panics all the time.
+*
+*  @since Series60_3.2
+*/
+NONSHARABLE_CLASS( CGSWatchDog ) : public CBase,
+                                   public MGSWatchDog
+    {
+    public: // Constructor and destructor
+
+        /**
+        * Symbian OS two-phased constructor
+        * @return CGSWatchDog.
+        */
+        static CGSWatchDog* NewL();
+
+        /**
+        * Destructor.
+        */
+        ~CGSWatchDog();
+
+    public: // From MGSWatchDog
+
+        /**
+        * Adds plugin to quarantine. In case GS crashes, quarantined plugin
+        * will be blacklisted so it is not loaded in next GS run. Same plugin
+        * can be quarantined multiple times or even have several uid instances
+        * in quarantine if needed as long as all these are removed
+        * correspondingly.
+        *
+        * NOTE: Plugin must ALWAYS be removed from quarantine after plugin's
+        * function execution.
+        * 1. QuarantineL().
+        * 2. Call quarantined plugin function.
+        * 3. RemoveFromQuarantineL().
+        *
+        * @param aPluginUid uid of the quarantined plugin.
+        */
+        void QuarantineL( TUid aPluginUid );
+
+        /**
+        * Removes plugin from quarantine. In case plugin is not removed from
+        * quarantine before GS exits, the plugin will be blacklisted during
+        * next GS startup.
+        *
+        * @param aPluginUid uid of the plugin to be removed from quarantine.
+        */
+        void RemoveFromQuarantineL( TUid aPluginUid );
+
+        /**
+        * @return ETrue if GS exited cleanly last time.
+        *         EFalse if GS crashed during last execution.
+        */
+        TBool WasCleanExitL();
+
+        /**
+        * This must be called in all the cases GS exits normally. If GS panics,
+        * this will not be called resulting in banning of all quarantined
+        * plugins.Increments iRunsAfterCrash counter for blacklisted plugins.
+        * Sets iGSAppRunning to EFalse.
+        */
+        void ReportCleanExitL();
+
+        /**
+        * Checks if plugin is in blacklist. This can be used to determine if
+        * plugin should be loaded.
+        *
+        * @return ETrue in case plugin is in blacklist and should not be loaded.
+        *         EFalse in case plugin should not be loaded
+        */
+        TBool IsInBlackList( TUid aPluginUid );
+
+    protected: // New
+
+        /**
+        * C++ constructor
+        */
+        CGSWatchDog();
+
+        /**
+        * Second phase constructor
+        */
+        void ConstructL();
+
+        /**
+        * Reads previous state from persistent data storage.
+        */
+        void ReadStateL();
+
+        /**
+        * Stores iGSAppRunning, iQuarantinedPluginUid and iBlackList data to
+        * persistent storage.
+        */
+        void StoreStateL();
+
+        /**
+        * Sets state values to default values and stores these.
+        */
+        void InitStateL();
+
+        /**
+        * Reads quarantine data from persistent storage.
+        */
+        void ReadQuarantineL();
+
+        /**
+        * Stores quarantine data to persistent storage.
+        */
+        void StoreQuarantineL();
+
+        /**
+        * Reads blacklist data from persistent storage.
+        */
+        void ReadBlackListL();
+
+        /**
+        * Stores blacklist data to persistent storage.
+        */
+        void StoreBlackListL();
+
+        /**
+        * Updates run counter of each blacklisted plugin. Removes plugin from
+        * blacklist if it has been there long enough
+        * (KGSDefaultMaxPluginBlackListedRuns).
+        */
+        void UpdateBlackListedPluginRunCounters();
+
+    private: // Data
+
+        /**
+        * ETrue if WatchDog is active (GS has crashed in previous run).
+        */
+        TBool iIsActive;
+
+        /**
+        * Counter for GS crashes in a row. This is used to customize watchdog
+        * behaviour. Defines how many crashes are observed before watchdog is
+        * activated. The bigger the value, more tolerant behaviour towards crashing
+        * plugins. See iWatchdogActivationLimit.
+        *
+        * -1 = Watchdog is completely disabled regardless any crash.
+        *  1 = In paractise the fastest reaction, meaning watchdog is enabled the next
+        *      run GS starts after a crash.
+        *  2 = GS can have 1 crash without watchdog being enabled = 2nd GS crash in a
+        *      row will enable watchdog.
+        *  n = GS can have n-1 crashes before watchdog being activated etc.
+        */
+        TInt iCrashCounter;
+
+        /**
+        * Emulates stored data. Set on when GS running, off when GS exits
+        * cleanly. Check this when starting GS to see if last exit was clean.
+        */
+        TBool iGSAppRunning;
+
+        /**
+        * Uids for plugins which should be banned. They caused GS crash in
+        * previous runs.
+        */
+        RArray<TGSPluginQuarantine> iBlackList;
+
+        /**
+        * Run time quarantine for plugins.
+        */
+        RArray<TUid> iQuarantine;
+
+        /**
+        * Persistent storage.
+        */
+        CRepository* iStore;
+
+        /**
+        * Defines how long a plugin is held in blacklist.
+        * KGSDefaultMaxPluginBlackListedRuns is used if no CenRep value is defined.
+        */
+        TInt iMaxPluginBlackListedRuns;
+
+        /**
+        * Defines how many crashes is needed to activate watchdog.
+        * KGSDefaultWatchdogActivationLimit is used in case no CenRep value is
+        * defined.
+        */
+        TInt iWatchdogActivationLimit;
+    };
+
+#endif // GSWATCHDOG_H
+// End of File