841             public Object getContext() {

   841 

   842                 return getAppContext();

   842             /**

   843             }

   843              * Returns the AppContext used for applet logging isolation, or null if

   844             public Object getExecutionContext() {

   844              * the default global context can be used.

   845                 return getExecutionAppContext();

   845              * If there's no applet, or if the caller is a stand alone application,

   846             }

   846              * or running in the main app context, returns null.

   847             public Object get(Object context, Object key) {

   847              * Otherwise, returns the AppContext of the calling applet.

   848                 return ((AppContext)context).get(key);

   848              * @return null if the global default context can be used,

   849             }

   849              *         an AppContext otherwise.

   850             public void put(Object context, Object key, Object value) {

   850              **/

   851                 ((AppContext)context).put(key, value);

   851             public Object getAppletContext() {

   852             }

   852                 // There's no AppContext: return null.

   853             public void remove(Object context, Object key) {

   853                 // No need to call getAppContext() if numAppContext == 0:

   854                 ((AppContext)context).remove(key);

   854                 // it means that no AppContext has been created yet, and

   855             }

   855                 // we don't want to trigger the creation of a main app

   856                 // context since we don't need it.

   857                 if (numAppContexts.get() == 0) return null;

   858 

   859                 // Get the context from the security manager

   860                 AppContext ecx = getExecutionAppContext();

   861 

   862                 // Not sure we really need to re-check numAppContexts here.

   863                 // If all applets have gone away then we could have a

   864                 // numAppContexts coming back to 0. So we recheck

   865                 // it here because we don't want to trigger the

   866                 // creation of a main AppContext in that case.

   867                 // This is probably not 100% MT-safe but should reduce

   868                 // the window of opportunity in which that issue could

   869                 // happen.

   870                 if (numAppContexts.get() > 0) {

   871                    // Defaults to thread group caching.

   872                    // This is probably not required as we only really need

   873                    // isolation in a deployed applet environment, in which

   874                    // case ecx will not be null when we reach here

   875                    // However it helps emulate the deployed environment,

   876                    // in tests for instance.

   877                    ecx = ecx != null ? ecx : getAppContext();

   878                 }

   879 

   880                 // getAppletContext() may be called when initializing the main

   881                 // app context - in which case mainAppContext will still be

   882                 // null. To work around this issue we simply use

   883                 // AppContext.threadGroup.getParent() == null instead, since

   884                 // mainAppContext is the only AppContext which should have

   885                 // the root TG as its thread group.

   886                 // See: JDK-8023258

   887                 final boolean isMainAppContext = ecx == null

   888                     || mainAppContext == ecx

   889                     || mainAppContext == null && ecx.threadGroup.getParent() == null;

   890 

   891                 return isMainAppContext ? null : ecx;

   892             }

   893