#67468# unloading api

1 files changed, 396 insertions, 0 deletions

diff --git a/sal/rtl/source/unload.cxx b/sal/rtl/source/unload.cxx
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+++ b/sal/rtl/source/unload.cxx
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+/*************************************************************************
+ *
+ *  $RCSfile: unload.cxx,v $
+ *
+ *  $Revision: 1.1 $
+ *
+ *  last change: $Author: jl $ $Date: 2001-06-07 09:28:33 $
+ *
+ *  The Contents of this file are made available subject to the terms of
+ *  either of the following licenses
+ *
+ *         - GNU Lesser General Public License Version 2.1
+ *         - Sun Industry Standards Source License Version 1.1
+ *
+ *  Sun Microsystems Inc., October, 2000
+ *
+ *  GNU Lesser General Public License Version 2.1
+ *  =============================================
+ *  Copyright 2000 by Sun Microsystems, Inc.
+ *  901 San Antonio Road, Palo Alto, CA 94303, USA
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License version 2.1, as published by the Free Software Foundation.
+ *
+ *  This library 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
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ *  MA  02111-1307  USA
+ *
+ *
+ *  Sun Industry Standards Source License Version 1.1
+ *  =================================================
+ *  The contents of this file are subject to the Sun Industry Standards
+ *  Source License Version 1.1 (the "License"); You may not use this file
+ *  except in compliance with the License. You may obtain a copy of the
+ *  License at http://www.openoffice.org/license.html.
+ *
+ *  Software provided under this License is provided on an "AS IS" basis,
+ *  WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
+ *  WITHOUT LIMITATION, WARRANTIES THAT THE SOFTWARE IS FREE OF DEFECTS,
+ *  MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE, OR NON-INFRINGING.
+ *  See the License for the specific provisions governing your rights and
+ *  obligations concerning the Software.
+ *
+ *  The Initial Developer of the Original Code is: Sun Microsystems, Inc.
+ *
+ *  Copyright: 2000 by Sun Microsystems, Inc.
+ *
+ *  All Rights Reserved.
+ *
+ *  Contributor(s): _______________________________________
+ *
+ *
+ ************************************************************************/
+#ifndef _RTL_UNLOAD_H_
+#include <rtl/unload.h>
+#endif
+#ifndef _RTL_USTRING_HXX_
+#include <rtl/ustring.hxx>
+#endif
+#ifndef _OSL_MUTEX_HXX_
+#include <osl/mutex.hxx>
+#endif
+
+#include <hash_map>
+#include <list>
+#include <queue>
+
+using namespace ::std;
+using namespace ::rtl;
+using namespace ::osl;
+
+static void rtl_notifyUnloadingListeners();
+
+static sal_Bool isEqualTimeValue ( const TimeValue* time1,  const TimeValue* time2)
+{
+    if( time1->Seconds == time2->Seconds &&
+        time1->Nanosec == time2->Nanosec)
+        return sal_True;
+    else
+        return sal_False;
+}
+
+static sal_Bool isGreaterTimeValue(  const TimeValue* time1,  const TimeValue* time2)
+{
+    sal_Bool retval;
+    if ( time1->Seconds > time2->Seconds)
+        retval= sal_True;
+    else if ( time1->Seconds == time2->Seconds)
+    {
+        if( time1->Nanosec > time2->Nanosec)
+            retval= sal_True;
+    }
+    else
+        retval= sal_False;
+    return retval;
+}
+
+static sal_Bool isGreaterEqualTimeValue( const TimeValue* time1, const TimeValue* time2)
+{
+    if( isEqualTimeValue( time1, time2) )
+        return sal_True;
+    else if( isGreaterTimeValue( time1, time2))
+        return sal_True;
+    else
+        return sal_False;
+}
+
+static void addTimeValue( const TimeValue* value1, const TimeValue* value2, TimeValue* result)
+{
+    sal_uInt64 sum;
+    result->Nanosec=0;
+    result->Seconds=0;
+
+    sum= value1->Nanosec + value2->Nanosec;
+    if( sum >= 1000000000 )
+    {
+        result->Seconds=1;
+        sum -= 1000000000;
+    }
+    result->Nanosec= (sal_uInt32)sum;
+    result->Seconds += value1->Seconds + value2->Seconds;
+}
+
+
+static sal_Bool hasEnoughTimePassed( const TimeValue* unusedSince, const TimeValue* timespan)
+{
+    sal_Bool retval= sal_False;
+    TimeValue currentTime;
+    if( osl_getSystemTime( &currentTime))
+    {
+        TimeValue addedTime;
+        addTimeValue( unusedSince, timespan, &addedTime);
+        if( isGreaterEqualTimeValue( &currentTime, &addedTime))
+            retval= sal_True;
+    }
+
+    return retval;
+}
+
+static Mutex* getUnloadingMutex()
+{
+    static Mutex* pMutex= NULL;
+
+    if( ! pMutex)
+    {
+        MutexGuard guard( Mutex::getGlobalMutex() );
+        if( !pMutex)
+        {
+            static Mutex aMutex;
+            pMutex= &aMutex;
+        }
+    }
+    return pMutex;
+}
+
+extern "C" void rtl_moduleCount_acquire(rtl_ModuleCount * that )
+{
+    rtl_StandardModuleCount* pMod= (rtl_StandardModuleCount*)that;
+    osl_incrementInterlockedCount( &pMod->counter);
+}
+
+extern "C" void rtl_moduleCount_release( rtl_ModuleCount * that )
+{
+    rtl_StandardModuleCount* pMod= (rtl_StandardModuleCount*)that;
+    OSL_ENSURE( pMod->counter >0 , "library counter incorrect" );
+    osl_decrementInterlockedCount( &pMod->counter);
+    if( pMod->counter == 0)
+    {
+        MutexGuard guard( getUnloadingMutex());
+
+        if( sal_False == osl_getSystemTime( &pMod->unusedSince) )
+        {// set the time to 0 if we could not get the time
+            pMod->unusedSince.Seconds= 0;
+            pMod->unusedSince.Nanosec= 0;
+        }
+    }
+}
+
+
+struct hashModule
+{
+    size_t operator()( const oslModule& rkey) const
+    {
+        return (size_t)rkey;
+    }
+};
+
+struct equalModule
+{
+    bool operator()(const oslModule& m1, const oslModule& s2) const
+    {
+        return m1 == s2;
+    }
+};
+
+typedef hash_map<oslModule,
+        pair<sal_uInt32,component_canUnloadFunc>,
+        hashModule, equalModule>
+        ModuleMap;
+typedef ModuleMap::iterator Mod_IT;
+ModuleMap g_moduleMap;
+
+
+extern "C" sal_Bool rtl_moduleCount_canUnload( rtl_StandardModuleCount * that, TimeValue * libUnused)
+{
+    sal_Bool retVal= sal_False;
+    if( that->counter== 0)
+    {
+        MutexGuard guard( getUnloadingMutex());
+        if( libUnused && that->counter == 0)
+        {
+
+            rtl_copyMemory( libUnused, &that->unusedSince,  sizeof( TimeValue));
+        }
+    }
+    return that->counter == 0;
+}
+
+
+extern "C" sal_Bool SAL_CALL rtl_registerModuleForUnloading( oslModule module)
+{
+    MutexGuard guard( getUnloadingMutex());
+    sal_Bool ret= sal_True;
+    // If the module has been registered before, then find it and increment
+    // its reference cout
+    Mod_IT it= g_moduleMap.find( module);
+    if( it != g_moduleMap.end())
+    {
+        //module already registered, increment ref count
+        it->second.first++;
+    }
+    else
+    {
+        //Test if the module supports unloading, that is, it exports
+        // component_canUnload
+        OUString name(RTL_CONSTASCII_USTRINGPARAM( COMPONENT_CANUNLOAD));
+        component_canUnloadFunc  pFunc= ( component_canUnloadFunc)osl_getSymbol( module, name.pData);
+        if( pFunc)
+        {
+            //register module for the first time, set ref count to 1
+            g_moduleMap[module]= make_pair(1, pFunc);
+        }
+        else
+            ret= sal_False;
+    }
+    return ret;
+}
+
+extern "C" void SAL_CALL rtl_unregisterModuleForUnloading( oslModule module)
+{
+    MutexGuard guard( getUnloadingMutex());
+    Mod_IT it= g_moduleMap.find( module);
+    if( it != g_moduleMap.end() )
+    {
+        // The module is registered, decrement ref count.
+        it->second.first --;
+
+        // If the refcount == 0 then remove the module from the map
+        if( it->second.first == 0)
+            g_moduleMap.erase( it);
+    }
+
+}
+
+extern "C" void SAL_CALL rtl_unloadUnusedModules( TimeValue* libUnused)
+{
+    MutexGuard guard( getUnloadingMutex());
+    list<oslModule> unloadedModulesList;
+    Mod_IT it_e= g_moduleMap.end();
+
+    // notify all listeners
+    rtl_notifyUnloadingListeners();
+    // prepare default TimeValue if argumetn is NULL
+    TimeValue nullTime={0,0};
+    TimeValue* pLibUnused= libUnused? libUnused : &nullTime;
+    for( Mod_IT it= g_moduleMap.begin(); it != it_e; it++)
+    {
+        //can the module be unloaded?
+        component_canUnloadFunc func= it->second.second;
+        TimeValue unusedSince= {0, 0};
+        if( func( &unusedSince) )
+        {   // module can be unloaded if it has not been used at least for the time
+            // specified by the argument libUnused
+            if( hasEnoughTimePassed( &unusedSince, pLibUnused))
+            {
+                // get the reference count and unload the module as many times
+                sal_uInt32 refCount= it->second.first;
+                for ( sal_uInt32 i=0; i < refCount; i++)
+                    osl_unloadModule( it->first);
+                // mark the module for later removal
+                unloadedModulesList.push_front( it->first);
+            }
+        }
+    }
+
+    // remove all entries containing invalid (unloaded) modules
+    for( list<oslModule>::iterator un_it= unloadedModulesList.begin();
+            un_it != unloadedModulesList.end(); un_it++)
+    {
+        g_moduleMap.erase( *un_it);
+    }
+}
+
+
+// ==============================================================================
+// Unloading Listener Administration
+//===============================================================================
+struct hashListener
+{
+    size_t operator()( const sal_Int32& rkey) const
+    {
+        return (size_t)rkey;
+    }
+};
+
+struct equalListener
+{
+    bool operator()(const sal_Int32& m1, const sal_Int32& s2) const
+    {
+        return m1 == s2;
+    }
+};
+
+typedef hash_map<sal_Int32,
+        pair<rtl_unloadingListenerFunc, void*>,
+        hashListener, equalListener>
+        ListenerMap;
+typedef ListenerMap::iterator Lis_IT;
+ListenerMap g_listenerMap;
+
+
+// This queue contains cookies which have been passed out by rtl_addUnloadingListener and
+// which have been regainded by rtl_removeUnloadingListener. When rtl_addUnloadingListener
+// is called then a cookie has to be returned. First we look into the set if there is one
+// availabe. Otherwise a new cookie will be provided.
+// not a new value is returned.
+static queue<sal_Int32> g_regainedCookies;
+
+static sal_Int32 getCookie()
+{
+    static sal_Int32 cookieValue= 1;
+
+    sal_Int32 retval;
+    if( g_regainedCookies.empty() )
+        retval= cookieValue++;
+    else
+    {
+        retval= g_regainedCookies.front();
+        g_regainedCookies.pop();
+    }
+    return retval;
+}
+
+static inline void recycleCookie( sal_Int32 i)
+{
+    g_regainedCookies.push( i);
+}
+
+
+// calling the function twice with the same arguments will return tow different cookies.
+// The listener will then notified twice.
+extern "C"
+sal_Int32 SAL_CALL rtl_addUnloadingListener( rtl_unloadingListenerFunc callback, void* _this)
+{
+    MutexGuard guard( getUnloadingMutex());
+    sal_Int32 cookie= getCookie();
+    g_listenerMap[ cookie]= make_pair( callback, _this);
+    return cookie;
+}
+
+
+extern "C"
+void SAL_CALL rtl_removeUnloadingListener( sal_Int32 cookie )
+{
+    MutexGuard guard( getUnloadingMutex());
+    size_t removedElements= g_listenerMap.erase( cookie);
+    if( removedElements )
+        recycleCookie( cookie);
+}
+
+
+static void rtl_notifyUnloadingListeners()
+{
+    for( Lis_IT it= g_listenerMap.begin(); it != g_listenerMap.end(); it++)
+    {
+        rtl_unloadingListenerFunc callbackFunc= it->second.first;
+        callbackFunc( it->second.second);
+    }
+}
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