[PATCH] API CHANGE: remove some of useless rtl/unload.h functionalit...

Hi,

I have submitted a patch for review:

    https://gerrit.libreoffice.org/3317

To pull it, you can do:

    git pull ssh://gerrit.libreoffice.org:29418/core refs/changes/17/3317/1

API CHANGE: remove some of useless rtl/unload.h functionality

Change-Id: If32923e35ef97f42d5203975362e5c76948ff327
---
M sal/inc/rtl/unload.h
M sal/osl/all/compat.cxx
M sal/rtl/unload.cxx
3 files changed, 23 insertions(+), 551 deletions(-)



diff --git a/sal/inc/rtl/unload.h b/sal/inc/rtl/unload.h
index 9de17b4..0bbc414 100644
--- a/sal/inc/rtl/unload.h
+++ b/sal/inc/rtl/unload.h
@@ -27,209 +27,12 @@
 #include "sal/saldllapi.h"
 #include "sal/types.h"
 
-/** @file
-The API enables an effective way of unloading libraries in a centralized way.
-The mechanism ensures that used libraries are not unloaded. This prevents
-crashes if library code is being used after unloading the library.
-The unloading mechanism currently only works with libraries which contain
-UNO services. A library cannot be unloaded if one of the following conditions
-apply
-
-<ul>
-<li>An instance is still referenced </li>
-<li>A module has been loaded without registering it </li>
-<li>The service manager has created a one instance service </li>
-<li>A service instance has been added to an UNO context </li>
-</ul>
-
-<b>Notification Mechanism</b>
-The API provides a notification mechanism. Clients can use it to do clean up,
-such as releasing cached references, in order to allow modules to be unloaded.
-As long as someone holds a reference to an object whose housing module
-supports unloading the module cannot be unloaded.<p>
-
-Because of the inherent danger of crashing the application by using this API
-all instances which control threads should be registered listeners. On
-notification they have to ensure that their threads assume a safe state, that
-is, they run outside of modules which could be unloaded and do not jump
-back into module code as a result of a finished function call. In other words,
-there must not be an address of the module on the thread's stack.
-<p>
-Since current operating systems lack APIs in respect to controlling the
-position of threads within libraries, it would be a major effort to comply with
-that recommendation. The best and most efficient way of handling the unloading
-scenario is to let all threads, except for the main thread, die in case of a
-notification.
-<p>
-Use this API with great care because it might crash the application. See the
-respective documentation (Library Unloading) on the udk.openoffice.org web site.
-*/
-
-
-/**
-A library which supports unloading has to implement and export a function
-called <code>component_canUnload</code>. <p>
-If the function returns <code>sal_True</code> then the module can be safely unloaded.
-That is the case when there are no external references to code within the
-library. In case a module houses UNO components then the function must return
-<code>sal_False</code> after the first factory has been handed out. The function then
-continues to return <code>sal_False</code> as long as there is at least one object (factory
-or service instance)  which originated from the module.<p>
-
-Libraries which not only contain UNO components (or none at all) have to
-provide a means to control whether they can be unloaded or not, e.g. However,
-there is no concept yet. <p>
-
-The argument <code>pTime</code> is an optional out-parameter. If the return value is
-<code>sal_True</code> then <code>pTime</code> reflects a point in time since
-when the module could have
-been unloaded. Since that time the function would have continually returned
-<code>sal_True</code> up to the present. The value of <code>pTime</code> is
-important for the decision
-as to a module will be unloaded. When someone initiates the unloading of
-modules by calling <code>rtl_unloadUnusedModules</code> then the caller can specify a time
-span with the effect that only those modules are unloaded which are unused at
-least for that amount of time. If <code>component_canUnload</code> does not
-fill in <code>pTime</code>
-then the module is unloaded immediately.<p>
-
-<code>component_canUnload</code> is implicitly called by <code>rtl_unloadUnusedModules
-</code>. There is no need to call the function directly.
-*/
-#define COMPONENT_CANUNLOAD         "component_canUnload"
-typedef sal_Bool (SAL_CALL * component_canUnloadFunc)( TimeValue* pTime);
-
-
 /** C-interface for a module reference counting
  */
 #ifdef __cplusplus
 extern "C"
 {
 #endif
-
-/**
-By registering a module, one declares that a module supports the
-unloading mechanism. One registers a module by calling this function.<p>
-
-A module can only be unloaded from memory when it has been registered
-as many times as it has been loaded. The reason is that a library can
-be &quot;loaded&quot; several times by <code>osl_loadModule</code>
-within the same process. The
-function will then return the same module handle because the library will
-effectively only be loaded once. To remove the library from memory it is
-necessary to call <code>osl_unloadModule</code> as often as <code>
-osl_loadModule</code> was called. The
-function <code>rtl_unloadUnusedModules</code> calls <code>osl_unloadModule</code>
-for a module as many
-times as it was registered. If, for example, a module has been registered one
-time less then <code>osl_loadModule</code> has been called and the module can be unloaded
-then it needs a call to <code>rtl_unloadUnusedModules</code> and an explicit call to
-<code>osl_unloadModule</code> to remove the module from memory. <p>
-
-A module must be registered every time it has been loaded otherwise the
-unloading mechanism is not effective.<p>
-
-Before a module is registered, one has to make sure that the module is in a
-state that prevents it from being unloaded. In other words,
-<code>component_canUnload</code> must return <code>sal_False</code>. Assuming that
-<code>component_canUnload</code>
-returns <code>sal_True</code> and it is registered regardless, then a call to
-<code>rtl_unloadUnusedModules</code> causes the module to be unloaded. This unloading can
-be set off by a different thread and the thread which registered the module is
-&quot;unaware&quot; of this. Then when the first thread tries to obtain a factory or
-calls another function in the module, the application will crash, because the
-module has been unloaded before. Therefore one has to ensure that the module
-cannot be unloaded before it is registered. This is simply done by obtaining a
-factory from the module. As long as a factory or some other object, which has
-been created by the factory, is alive, the <code>component_canUnload</code> function will
-return <code>sal_False</code>.<p>
-Loading and registering have to be in this order:<br>
-<ul>
-<li>load a library (<code>osl_loadModule</code>)</li>
-<li>get the <code>component_getFactory</code> function and get a factory</li>
-<li>register the module (rtl_registerModuleForUnloading</li>
-</ul>
-Usually the service manager is used to obtain an instance of a service.
-The service manager registers all modules which support the unloading mechanism.
-When the service manager is used to get service instances than one does not
-have to bother about registering.
-
-@param module a module handle as is obtained by osl_loadModule
-@return sal_True - the module could be registered for unloading, sal_False otherwise
-*/
-SAL_DLLPUBLIC sal_Bool SAL_CALL rtl_registerModuleForUnloading( oslModule module);
-
-/**
-The function revokes the registration of a module. By calling the function for
-a previously registered module one prevents the module from being unloaded by
-this unloading mechanism. However, in order to completely unregister the module
-it is necessary to call the function as often as the module has been registered.
-<p>
-<code>rtl_unloadUnusedModules</code> unregisters the modules which it unloads. Therefore
-there is no need to call this function unless one means to prevent the unloading of a module.
-
-@param module a module handle as is obtained by osl_loadModule
-*/
-SAL_DLLPUBLIC void SAL_CALL rtl_unregisterModuleForUnloading( oslModule module);
-/**
-This function sets off the unloading mechanism. At first it notifies the
-unloading listeners in order to give them a chance to do cleanup and get
-their threads in a safe state. Then all registered modules are asked if they
-can be unloaded. That is, the function calls component_canUnload on every
-registered module. If <code>sal_True</code> is returned then <code>osl_unloadModule</code>
-is called for the belonging module as often as it is registered.
-<p>
-A call to <code>osl_unloadModule</code> does not guarantee that the module is unloaded even
-if its <code>component_canUnload</code> function returns <code>sal_True</code>.
-<p>
-The optional in-parameter <code>libUnused</code> specifies a period of time which a library
-must be unused in order to qualify for being unloaded. By using this argument
-one can counter the multithreading problem as described further above. It is in
-the responsibility of the user of this function to provide a timespan big enough
-to ensure that all threads are out of modules (see <code>component_canUnload</code>).
-<p>
-The service managers which have been created by functions such as
-<code>createRegistryServiceFactory</code> (declared in cppuhelper/servicefactory.hxx) are
-registered listeners and release the references to factories on notification.
-
-
-@param libUnused span of time that a module must be unused to be unloaded. the
-argument is optional.
-*/
-SAL_DLLPUBLIC void SAL_CALL rtl_unloadUnusedModules( TimeValue* libUnused);
-
-/**
-rtl_addUnloadingListener takes an argument of this type.
-
-@param id - The value that has been passed as second argument to rtl_addUnloadingListener
-*/
-typedef void (SAL_CALL *rtl_unloadingListenerFunc)(void* id);
-/**
-The function registered an unloading listener. The callback argument is a
-function which is called  when the unloading procedure has been initiated by a call to
-<code>rtl_unloadUnusedLibraries</code>. The second argument is used to distinguish between 
different
-listener instances and may be <code>NULL</code>. It will be passed as argument when the callback
-function is being called. The return value identifies the registered listener and will
-be used for removing the listener later on. If the same listener is added more then
-once then every registration is treated as if made for a different listener. That is,
-a different cookie is returned and the callback function will be called as many times
-as it has been registered.
-@param callback - a function that is called to notify listeners.
-@param _this  - a value to distinguish different listener instances
-@return identifier which is used in rtl_removeUnloadingListener
-*/
-SAL_DLLPUBLIC sal_Int32 SAL_CALL rtl_addUnloadingListener( rtl_unloadingListenerFunc callback, 
void* _this);
-
-/**
-Listeners (the callback functions) must be unregistered before the listener code
-becomes invalid. That is, if a module contains listener code, namely callback
-functions of type <code>rtl_unloadingListenerFunc</code>, then those functions must not be
-registered when <code>component_canUnload</code> returns <code>sal_True</code>.
-
-@param cookie is an identifier as returned by <code>rtl_addUnloadingListener</code> function.
-*/
-SAL_DLLPUBLIC void SAL_CALL rtl_removeUnloadingListener( sal_Int32 cookie );
-
 
 /**
 Pointers to <code>rtl_ModuleCount</code> are passed as arguments to the default factory creator
diff --git a/sal/osl/all/compat.cxx b/sal/osl/all/compat.cxx
index f9c7129..4b64326 100644
--- a/sal/osl/all/compat.cxx
+++ b/sal/osl/all/compat.cxx
@@ -11,6 +11,8 @@
 
 #include <cstdlib>
 
+#include "osl/module.h"
+#include "osl/time.h"
 #include "sal/types.h"
 
 // Stubs for removed functionality, to be killed when we bump sal SONAME
@@ -69,6 +71,27 @@
     std::abort();
 }
 
+SAL_DLLPUBLIC_EXPORT sal_Bool SAL_CALL rtl_registerModuleForUnloading(oslModule) {
+    std::abort();
+}
+
+SAL_DLLPUBLIC_EXPORT void SAL_CALL rtl_unregisterModuleForUnloading(oslModule) {
+    std::abort();
+}
+
+SAL_DLLPUBLIC_EXPORT void SAL_CALL rtl_unloadUnusedModules(TimeValue *) {
+    std::abort();
+}
+
+typedef void (SAL_CALL *rtl_unloadingListenerFunc)(void *id);
+SAL_DLLPUBLIC_EXPORT sal_Int32 SAL_CALL rtl_addUnloadingListener(rtl_unloadingListenerFunc, void 
*) {
+    std::abort();
+}
+
+SAL_DLLPUBLIC_EXPORT void SAL_CALL rtl_removeUnloadingListener(sal_Int32) {
+    std::abort();
+}
+
 }
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/sal/rtl/unload.cxx b/sal/rtl/unload.cxx
index 4d4a414..8bfff77 100644
--- a/sal/rtl/unload.cxx
+++ b/sal/rtl/unload.cxx
@@ -37,72 +37,6 @@
 
 #ifndef DISABLE_DYNLOADING
 
-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= sal_False;
-    if ( time1->Seconds > time2->Seconds)
-        retval= sal_True;
-    else if ( time1->Seconds == time2->Seconds)
-    {
-        if( time1->Nanosec > time2->Nanosec)
-            retval= sal_True;
-    }
-    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;
-}
-
 namespace
 {
     class theUnloadingMutex : public rtl::Static<osl::Mutex, theUnloadingMutex>{};
@@ -147,43 +81,6 @@
 #endif
 }
 
-#ifndef DISABLE_DYNLOADING
-
-struct hashModule
-{
-    size_t operator()( const oslModule& rkey) const
-    {
-        return (size_t)rkey;
-    }
-};
-
-typedef boost::unordered_map<
-    oslModule,
-    std::pair<sal_uInt32, component_canUnloadFunc>,
-    hashModule,
-    std::equal_to<oslModule>,
-    rtl::Allocator<oslModule>
-> ModuleMap;
-
-typedef ModuleMap::iterator Mod_IT;
-
-static ModuleMap& getModuleMap()
-{
-    static ModuleMap * g_pMap= NULL;
-    if (!g_pMap)
-    {
-        MutexGuard guard( getUnloadingMutex() );
-        if (!g_pMap)
-        {
-            static ModuleMap g_aModuleMap;
-            g_pMap= &g_aModuleMap;
-        }
-    }
-    return *g_pMap;
-}
-
-#endif
-
 extern "C" sal_Bool rtl_moduleCount_canUnload( rtl_StandardModuleCount * that, TimeValue * 
libUnused)
 {
 #ifdef DISABLE_DYNLOADING
@@ -202,256 +99,5 @@
     return (that->counter == 0);
 #endif
 }
-
-
-extern "C" sal_Bool SAL_CALL rtl_registerModuleForUnloading( oslModule module)
-{
-#ifdef DISABLE_DYNLOADING
-    (void) module;
-    return sal_False;
-#else
-    MutexGuard guard( getUnloadingMutex());
-    ModuleMap& moduleMap= getModuleMap();
-    sal_Bool ret= sal_True;
-
-    // If the module has been registered before, then find it and increment
-    // its reference cout
-    Mod_IT it= moduleMap.find( module);
-    if( it != moduleMap.end())
-    {
-        //module already registered, increment ref count
-        it->second.first++;
-    }
-    else
-    {
-        // Test if the module supports unloading (exports component_canUnload)
-        rtl::OUString name(RTL_CONSTASCII_USTRINGPARAM( COMPONENT_CANUNLOAD));
-        component_canUnloadFunc pFunc=
-            (component_canUnloadFunc)osl_getFunctionSymbol( module, name.pData);
-        if (pFunc)
-        {
-            //register module for the first time, set ref count to 1
-            moduleMap[module]= std::make_pair((sal_uInt32)1, pFunc);
-        }
-        else
-            ret= sal_False;
-    }
-    return ret;
-#endif
-}
-
-extern "C" void SAL_CALL rtl_unregisterModuleForUnloading( oslModule module)
-{
-#ifdef DISABLE_DYNLOADING
-    (void) module;
-#else
-    MutexGuard guard( getUnloadingMutex());
-
-    ModuleMap& moduleMap= getModuleMap();
-    Mod_IT it= moduleMap.find( module);
-    if( it != 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)
-            moduleMap.erase( it);
-    }
-#endif
-}
-
-extern "C" void SAL_CALL rtl_unloadUnusedModules( TimeValue* libUnused)
-{
-#ifdef DISABLE_DYNLOADING
-    (void) libUnused;
-#else
-    MutexGuard guard( getUnloadingMutex());
-
-    typedef std::list< oslModule, rtl::Allocator<oslModule> > list_type;
-    list_type unloadedModulesList;
-
-    ModuleMap& moduleMap= getModuleMap();
-    Mod_IT it_e= moduleMap.end();
-
-    // notify all listeners
-    rtl_notifyUnloadingListeners();
-
-    // prepare default TimeValue if argumetn is NULL
-    TimeValue nullTime={0,0};
-    TimeValue* pLibUnused= libUnused? libUnused : &nullTime;
-
-    Mod_IT it= moduleMap.begin();
-    for (; 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
-    list_type::const_iterator un_it= unloadedModulesList.begin();
-    for (; un_it != unloadedModulesList.end(); ++un_it)
-    {
-        moduleMap.erase( *un_it);
-    }
-#endif
-}
-
-#ifndef DISABLE_DYNLOADING
-
-// ==============================================================================
-// Unloading Listener Administration
-//===============================================================================
-struct hashListener
-{
-    size_t operator()( const sal_Int32& rkey) const
-    {
-        return (size_t)rkey;
-    }
-};
-
-typedef boost::unordered_map<
-    sal_Int32,
-    std::pair<rtl_unloadingListenerFunc, void*>,
-    hashListener,
-    std::equal_to<sal_Int32>,
-    rtl::Allocator<sal_Int32>
-> ListenerMap;
-
-typedef ListenerMap::iterator Lis_IT;
-
-static ListenerMap& getListenerMap()
-{
-    static ListenerMap * g_pListeners= NULL;
-    if (!g_pListeners)
-    {
-        MutexGuard guard( getUnloadingMutex() );
-        if (!g_pListeners)
-        {
-            static ListenerMap g_aListenerMap;
-            g_pListeners= &g_aListenerMap;
-        }
-    }
-    return *g_pListeners;
-}
-
-
-// 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
-// available. Otherwise a new cookie will be provided.
-// not a new value is returned.
-
-typedef std::deque<
-    sal_Int32,
-    rtl::Allocator<sal_Int32>
-> queue_type;
-
-static queue_type& getCookieQueue()
-{
-    static queue_type * g_pCookies= NULL;
-    if (!g_pCookies)
-    {
-        MutexGuard guard( getUnloadingMutex() );
-        if (!g_pCookies)
-        {
-            static queue_type g_aCookieQueue;
-            g_pCookies= &g_aCookieQueue;
-        }
-    }
-    return *g_pCookies;
-}
-
-static sal_Int32 getCookie()
-{
-    static sal_Int32 cookieValue= 1;
-
-    sal_Int32 retval;
-    queue_type& regainedCookies= getCookieQueue();
-    if( regainedCookies.empty() )
-        retval= cookieValue++;
-    else
-    {
-        retval= regainedCookies.front();
-        regainedCookies.pop_front();
-    }
-    return retval;
-}
-
-static inline void recycleCookie( sal_Int32 i)
-{
-    getCookieQueue().push_back(i);
-}
-
-
-#endif
-
-// 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)
-{
-#ifdef DISABLE_DYNLOADING
-    (void) callback;
-    (void) _this;
-    return 0;
-#else
-    MutexGuard guard( getUnloadingMutex());
-
-    sal_Int32 cookie= getCookie();
-    ListenerMap& listenerMap= getListenerMap();
-    listenerMap[ cookie]= std::make_pair( callback, _this);
-    return cookie;
-#endif
-}
-
-
-extern "C"
-void SAL_CALL rtl_removeUnloadingListener( sal_Int32 cookie )
-{
-#ifdef DISABLE_DYNLOADING
-    (void) cookie;
-#else
-    MutexGuard guard( getUnloadingMutex());
-
-    ListenerMap& listenerMap= getListenerMap();
-    size_t removedElements= listenerMap.erase( cookie);
-    if( removedElements )
-        recycleCookie( cookie);
-#endif
-}
-
-#ifndef DISABLE_DYNLOADING
-
-static void rtl_notifyUnloadingListeners()
-{
-    ListenerMap& listenerMap= getListenerMap();
-    for( Lis_IT it= listenerMap.begin(); it != listenerMap.end(); ++it)
-    {
-        rtl_unloadingListenerFunc callbackFunc= it->second.first;
-        callbackFunc( it->second.second);
-    }
-}
-
-#endif
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

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Gerrit-MessageType: newchange
Gerrit-Change-Id: If32923e35ef97f42d5203975362e5c76948ff327
Gerrit-PatchSet: 1
Gerrit-Project: core
Gerrit-Branch: master
Gerrit-Owner: Matúš Kukan <matus.kukan@gmail.com>