Using ExtensionList.lookup consistently.

core/src/main/java/hudson/FilePath.java

@@ -900,14 +900,9 @@ public final class FilePath implements Serializable {
             // run this on a remote system
             try {
                 DelegatingCallable<T,IOException> wrapper = new FileCallableWrapper<T>(callable, cl);
-                Jenkins instance = Jenkins.getInstance();
-                if (instance != null) { // this happens during unit tests
-                    ExtensionList<FileCallableWrapperFactory> factories = instance.getExtensionList(FileCallableWrapperFactory.class);
-                    for (FileCallableWrapperFactory factory : factories) {
-                        wrapper = factory.wrap(wrapper);
-                    }
+                for (FileCallableWrapperFactory factory : ExtensionList.lookup(FileCallableWrapperFactory.class)) {
+                    wrapper = factory.wrap(wrapper);
                 }
-
                 return channel.call(wrapper);
             } catch (TunneledInterruptedException e) {
                 throw (InterruptedException)new InterruptedException(e.getMessage()).initCause(e);
@@ -985,14 +980,9 @@ public final class FilePath implements Serializable {
     public <T> Future<T> actAsync(final FileCallable<T> callable) throws IOException, InterruptedException {
         try {
             DelegatingCallable<T,IOException> wrapper = new FileCallableWrapper<T>(callable);
-            Jenkins instance = Jenkins.getInstance();
-            if (instance != null) { // this happens during unit tests
-                ExtensionList<FileCallableWrapperFactory> factories = instance.getExtensionList(FileCallableWrapperFactory.class);
-                for (FileCallableWrapperFactory factory : factories) {
-                    wrapper = factory.wrap(wrapper);
-                }
+            for (FileCallableWrapperFactory factory : ExtensionList.lookup(FileCallableWrapperFactory.class)) {
+                wrapper = factory.wrap(wrapper);
             }
-
             return (channel!=null ? channel : localChannel)
                 .callAsync(wrapper);
         } catch (IOException e) {

core/src/main/java/hudson/Functions.java

@@ -913,7 +913,7 @@ public class Functions {
      * @since 1.494
      */
     public static Collection<Descriptor> getSortedDescriptorsForGlobalConfig(Predicate<GlobalConfigurationCategory> predicate) {
-        ExtensionList<Descriptor> exts = Jenkins.getInstance().getExtensionList(Descriptor.class);
+        ExtensionList<Descriptor> exts = ExtensionList.lookup(Descriptor.class);
         List<Tag> r = new ArrayList<Tag>(exts.size());
 
         for (ExtensionComponent<Descriptor> c : exts.getComponents()) {

core/src/main/java/hudson/LauncherDecorator.java

@@ -45,6 +45,6 @@ public abstract class LauncherDecorator implements ExtensionPoint {
      * Returns all the registered {@link LauncherDecorator}s.
      */
     public static ExtensionList<LauncherDecorator> all() {
-        return Jenkins.getInstance().getExtensionList(LauncherDecorator.class);
+        return ExtensionList.lookup(LauncherDecorator.class);
     }
 }

core/src/main/java/hudson/PluginManager.java

@@ -1170,7 +1170,7 @@ public abstract class PluginManager extends AbstractModelObject implements OnMas
          * @return this monitor.
          */
         public static final PluginUpdateMonitor getInstance() {
-            return Jenkins.getInstance().getExtensionList(PluginUpdateMonitor.class).get(0);
+            return ExtensionList.lookup(PluginUpdateMonitor.class).get(0);
         }
         
         /**

core/src/main/java/hudson/UDPBroadcastFragment.java

@@ -54,6 +54,6 @@ public abstract class UDPBroadcastFragment implements ExtensionPoint {
      * Returns all the registered {@link UDPBroadcastFragment}s.
      */
     public static ExtensionList<UDPBroadcastFragment> all() {
-        return Jenkins.getInstance().getExtensionList(UDPBroadcastFragment.class);
+        return ExtensionList.lookup(UDPBroadcastFragment.class);
     }
 }

core/src/main/java/hudson/URLConnectionDecorator.java

@@ -46,6 +46,6 @@ public abstract class URLConnectionDecorator implements ExtensionPoint {
      * Returns all the registered {@link URLConnectionDecorator}s.
      */
     public static ExtensionList<URLConnectionDecorator> all() {
-        return Jenkins.getInstance().getExtensionList(URLConnectionDecorator.class);
+        return ExtensionList.lookup(URLConnectionDecorator.class);
     }
 }

core/src/main/java/hudson/cli/CLICommand.java

@@ -489,7 +489,7 @@ public abstract class CLICommand implements ExtensionPoint, Cloneable {
      * Returns all the registered {@link CLICommand}s.
      */
     public static ExtensionList<CLICommand> all() {
-        return Jenkins.getInstance().getExtensionList(CLICommand.class);
+        return ExtensionList.lookup(CLICommand.class);
     }
 
     /**

core/src/main/java/hudson/cli/CliTransportAuthenticator.java

@@ -49,6 +49,6 @@ public abstract class CliTransportAuthenticator implements ExtensionPoint {
     public abstract void authenticate(String protocol, Channel channel, Connection con);
 
     public static ExtensionList<CliTransportAuthenticator> all() {
-        return Jenkins.getInstance().getExtensionList(CliTransportAuthenticator.class);
+        return ExtensionList.lookup(CliTransportAuthenticator.class);
     }
 }

core/src/main/java/hudson/console/ConsoleAnnotatorFactory.java

@@ -127,6 +127,6 @@ public abstract class ConsoleAnnotatorFactory<T> implements ExtensionPoint {
      * All the registered instances.
      */
     public static ExtensionList<ConsoleAnnotatorFactory> all() {
-        return Jenkins.getInstance().getExtensionList(ConsoleAnnotatorFactory.class);
+        return ExtensionList.lookup(ConsoleAnnotatorFactory.class);
     }
 }

core/src/main/java/hudson/console/ConsoleLogFilter.java

@@ -55,6 +55,6 @@ public abstract class ConsoleLogFilter implements ExtensionPoint {
      * All the registered {@link ConsoleLogFilter}s.
      */
     public static ExtensionList<ConsoleLogFilter> all() {
-        return Jenkins.getInstance().getExtensionList(ConsoleLogFilter.class);
+        return ExtensionList.lookup(ConsoleLogFilter.class);
     }
 }

core/src/main/java/hudson/diagnosis/HudsonHomeDiskUsageMonitor.java

@@ -134,7 +134,7 @@ public final class HudsonHomeDiskUsageMonitor extends AdministrativeMonitor {
          * All registered {@link Solution}s.
          */
         public static ExtensionList<Solution> all() {
-            return Jenkins.getInstance().getExtensionList(Solution.class);
+            return ExtensionList.lookup(Solution.class);
         }
     }
 }

core/src/main/java/hudson/model/AbstractProject.java

@@ -32,6 +32,7 @@ import com.infradna.tool.bridge_method_injector.WithBridgeMethods;
 import hudson.AbortException;
 import hudson.CopyOnWrite;
 import hudson.EnvVars;
+import hudson.ExtensionList;
 import hudson.ExtensionPoint;
 import hudson.FeedAdapter;
 import hudson.FilePath;
@@ -547,7 +548,7 @@ public abstract class AbstractProject<P extends AbstractProject<P,R>,R extends A
     public final @CheckForNull FilePath getSomeWorkspace() {
         R b = getSomeBuildWithWorkspace();
         if (b!=null) return b.getWorkspace();
-        for (WorkspaceBrowser browser : Jenkins.getInstance().getExtensionList(WorkspaceBrowser.class)) {
+        for (WorkspaceBrowser browser : ExtensionList.lookup(WorkspaceBrowser.class)) {
             FilePath f = browser.getWorkspace(this);
             if (f != null) return f;
         }
@@ -1369,7 +1370,7 @@ public abstract class AbstractProject<P extends AbstractProject<P,R>,R extends A
             WorkspaceOfflineReason workspaceOfflineReason = workspaceOffline( b );
             if ( workspaceOfflineReason != null ) {
                 // workspace offline
-                for (WorkspaceBrowser browser : Jenkins.getInstance().getExtensionList(WorkspaceBrowser.class)) {
+                for (WorkspaceBrowser browser : ExtensionList.lookup(WorkspaceBrowser.class)) {
                     ws = browser.getWorkspace(this);
                     if (ws != null) {
                         return pollWithWorkspace(listener, scm, b, ws, browser.getWorkspaceList());
@@ -2039,6 +2040,9 @@ public abstract class AbstractProject<P extends AbstractProject<P,R>,R extends A
                         Messages.AbstractProject_AssignedLabelString_InvalidBooleanExpression(e.getMessage()));
             }
             Jenkins j = Jenkins.getInstance();
+            if (j == null) {
+                return FormValidation.ok(); // ?
+            }
             Label l = j.getLabel(value);
             if (l.isEmpty()) {
                 for (LabelAtom a : l.listAtoms()) {

core/src/main/java/hudson/model/Actionable.java

@@ -23,13 +23,13 @@
  */
 package hudson.model;
 
+import hudson.ExtensionList;
 import hudson.Util;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
-import jenkins.model.Jenkins;
 import jenkins.model.ModelObjectWithContextMenu;
 import jenkins.model.TransientActionFactory;
 import org.kohsuke.stapler.StaplerRequest;
@@ -89,12 +89,9 @@ public abstract class Actionable extends AbstractModelObject implements ModelObj
     @Exported(name="actions")
     public final List<? extends Action> getAllActions() {
         List<Action> _actions = new ArrayList<Action>(getActions());
-        Jenkins jenkins = Jenkins.getInstance();
-        if (jenkins != null) {
-            for (TransientActionFactory<?> taf : jenkins.getExtensionList(TransientActionFactory.class)) {
-                if (taf.type().isInstance(this)) {
-                    _actions.addAll(createFor(taf));
-                }
+        for (TransientActionFactory<?> taf : ExtensionList.lookup(TransientActionFactory.class)) {
+            if (taf.type().isInstance(this)) {
+                _actions.addAll(createFor(taf));
             }
         }
         return Collections.unmodifiableList(_actions);

core/src/main/java/hudson/model/AdministrativeMonitor.java

@@ -153,6 +153,6 @@ public abstract class AdministrativeMonitor extends AbstractModelObject implemen
      * All registered {@link AdministrativeMonitor} instances.
      */
     public static ExtensionList<AdministrativeMonitor> all() {
-        return Jenkins.getInstance().getExtensionList(AdministrativeMonitor.class);
+        return ExtensionList.lookup(AdministrativeMonitor.class);
     }
 }

core/src/main/java/hudson/model/AperiodicWork.java

@@ -105,7 +105,7 @@ public abstract class AperiodicWork extends SafeTimerTask implements ExtensionPo
      * Returns all the registered {@link AperiodicWork}s.
      */
     public static ExtensionList<AperiodicWork> all() {
-        return Jenkins.getInstance().getExtensionList(AperiodicWork.class);
+        return ExtensionList.lookup(AperiodicWork.class);
     }
 
     private static final Random RANDOM = new Random();

core/src/main/java/hudson/model/Api.java

@@ -23,6 +23,7 @@
  */
 package hudson.model;
 
+import hudson.ExtensionList;
 import jenkins.model.Jenkins;
 import jenkins.security.SecureRequester;
 
@@ -216,7 +217,7 @@ public class Api extends AbstractModelObject {
     }
 
     private boolean permit(StaplerRequest req) {
-        for (SecureRequester r : Jenkins.getInstance().getExtensionList(SecureRequester.class)) {
+        for (SecureRequester r : ExtensionList.lookup(SecureRequester.class)) {
             if (r.permit(req, bean)) {
                 return true;
             }

core/src/main/java/hudson/model/BuildStepListener.java

@@ -27,6 +27,6 @@ public abstract class BuildStepListener implements ExtensionPoint {
      */
     public static ExtensionList<BuildStepListener> all() {
         // TODO should have a null-safe version when Jenkins.getInstance() is null; would require changes in ExtensionList
-        return Jenkins.getInstance().getExtensionList(BuildStepListener.class);
+        return ExtensionList.lookup(BuildStepListener.class);
     }
 }

core/src/main/java/hudson/model/BuildVariableContributor.java

@@ -70,6 +70,6 @@ public abstract class BuildVariableContributor implements ExtensionPoint {
      * Returns all the registered {@link BuildVariableContributor}s.
      */
     public static ExtensionList<BuildVariableContributor> all() {
-        return Jenkins.getInstance().getExtensionList(BuildVariableContributor.class);
+        return ExtensionList.lookup(BuildVariableContributor.class);
     }
 }

core/src/main/java/hudson/model/ComputerPanelBox.java

 package hudson.model;
 
+import hudson.ExtensionList;
 import hudson.ExtensionPoint;
 import java.util.ArrayList;
 import java.util.List;
@@ -38,7 +39,7 @@ public abstract class ComputerPanelBox implements ExtensionPoint{
      */
     public static List<ComputerPanelBox> all(Computer computer) {
         List<ComputerPanelBox> boxs = new ArrayList<ComputerPanelBox>();
-        for(ComputerPanelBox box:  Jenkins.getInstance().getExtensionList(ComputerPanelBox.class)){
+        for(ComputerPanelBox box:  ExtensionList.lookup(ComputerPanelBox.class)){
             box.setComputer(computer);
             boxs.add(box);
         }

core/src/main/java/hudson/model/ComputerPinger.java

@@ -27,7 +27,7 @@ public abstract class ComputerPinger implements ExtensionPoint {
      * Get all registered instances.
      */
     public static ExtensionList<ComputerPinger> all() {
-        return Jenkins.getInstance().getExtensionList(ComputerPinger.class);
+        return ExtensionList.lookup(ComputerPinger.class);
     }
 
     /**

core/src/main/java/hudson/model/Descriptor.java

@@ -28,6 +28,7 @@ import hudson.PluginWrapper;
 import hudson.RelativePath;
 import hudson.XmlFile;
 import hudson.BulkChange;
+import hudson.ExtensionList;
 import hudson.Util;
 import hudson.model.listeners.SaveableListener;
 import hudson.util.FormApply;
@@ -937,7 +938,7 @@ public abstract class Descriptor<T extends Describable<T>> implements Saveable {
     }
 
     public static @CheckForNull Descriptor find(String className) {
-        return find(Jenkins.getInstance().getExtensionList(Descriptor.class),className);
+        return find(ExtensionList.lookup(Descriptor.class),className);
     }
 
     public static final class FormException extends Exception implements HttpResponse {

core/src/main/java/hudson/model/DescriptorVisibilityFilter.java

@@ -42,7 +42,7 @@ public abstract class DescriptorVisibilityFilter implements ExtensionPoint {
     public abstract boolean filter(Object context, Descriptor descriptor);
 
     public static ExtensionList<DescriptorVisibilityFilter> all() {
-        return Jenkins.getInstance().getExtensionList(DescriptorVisibilityFilter.class);
+        return ExtensionList.lookup(DescriptorVisibilityFilter.class);
     }
 
     public static <T extends Descriptor> List<T> apply(Object context, Iterable<T> source) {

core/src/main/java/hudson/model/DownloadService.java

@@ -324,7 +324,7 @@ public class DownloadService extends PageDecorator {
          * Returns all the registered {@link Downloadable}s.
          */
         public static ExtensionList<Downloadable> all() {
-            return Jenkins.getInstance().getExtensionList(Downloadable.class);
+            return ExtensionList.lookup(Downloadable.class);
         }
 
         /**

core/src/main/java/hudson/model/EnvironmentContributor.java

@@ -115,7 +115,7 @@ public abstract class EnvironmentContributor implements ExtensionPoint {
      * Returns all the registered {@link EnvironmentContributor}s.
      */
     public static ExtensionList<EnvironmentContributor> all() {
-        return Jenkins.getInstance().getExtensionList(EnvironmentContributor.class);
+        return ExtensionList.lookup(EnvironmentContributor.class);
     }
 
     /**

core/src/main/java/hudson/model/FingerprintCleanupThread.java

@@ -24,6 +24,7 @@
 package hudson.model;
 
 import hudson.Extension;
+import hudson.ExtensionList;
 import jenkins.model.Jenkins;
 
 import java.io.File;
@@ -57,7 +58,7 @@ public final class FingerprintCleanupThread extends AsyncPeriodicWork {
     }
 
     private static FingerprintCleanupThread getInstance() {
-        return Jenkins.getInstance().getExtensionList(AsyncPeriodicWork.class).get(FingerprintCleanupThread.class);
+        return ExtensionList.lookup(AsyncPeriodicWork.class).get(FingerprintCleanupThread.class);
     }
 
     public void execute(TaskListener listener) {

core/src/main/java/hudson/model/LabelFinder.java

@@ -47,7 +47,7 @@ public abstract class LabelFinder implements ExtensionPoint {
      * Returns all the registered {@link LabelFinder}s.
      */
     public static ExtensionList<LabelFinder> all() {
-        return Jenkins.getInstance().getExtensionList(LabelFinder.class);
+        return ExtensionList.lookup(LabelFinder.class);
     }
 
     /**

core/src/main/java/hudson/model/ManagementLink.java

@@ -103,7 +103,7 @@ public abstract class ManagementLink implements ExtensionPoint, Action {
      * All regsitered instances.
      */
     public static ExtensionList<ManagementLink> all() {
-        return Jenkins.getInstance().getExtensionList(ManagementLink.class);
+        return ExtensionList.lookup(ManagementLink.class);
     }
 
     /**

core/src/main/java/hudson/model/PeriodicWork.java

@@ -93,7 +93,7 @@ public abstract class PeriodicWork extends SafeTimerTask implements ExtensionPoi
      * Returns all the registered {@link PeriodicWork}s.
      */
     public static ExtensionList<PeriodicWork> all() {
-        return Jenkins.getInstance().getExtensionList(PeriodicWork.class);
+        return ExtensionList.lookup(PeriodicWork.class);
     }
 
     @Initializer(after= JOB_LOADED)

core/src/main/java/hudson/model/Queue.java

@@ -1600,7 +1600,7 @@ public class Queue extends ResourceController implements Saveable {
     	 * All registered {@link QueueDecisionHandler}s
     	 */
     	public static ExtensionList<QueueDecisionHandler> all() {
-    		return Jenkins.getInstance().getExtensionList(QueueDecisionHandler.class);
+    		return ExtensionList.lookup(QueueDecisionHandler.class);
     	}
     }
     

core/src/main/java/hudson/model/RestartListener.java

@@ -30,7 +30,7 @@ public abstract class RestartListener implements ExtensionPoint {
      * Returns all the registered {@link LabelFinder}s.
      */
     public static ExtensionList<RestartListener> all() {
-        return Jenkins.getInstance().getExtensionList(RestartListener.class);
+        return ExtensionList.lookup(RestartListener.class);
     }
 
     /**

core/src/main/java/hudson/model/Run.java

@@ -2015,13 +2015,10 @@ public abstract class Run <JobT extends Job<JobT,RunT>,RunT extends Run<JobT,Run
         
         ResultTrend trend = ResultTrend.getResultTrend(this);
         
-        Jenkins j = Jenkins.getInstance();
-        if (j != null) {
-            for (StatusSummarizer summarizer : j.getExtensionList(StatusSummarizer.class)) {
-                Summary summary = summarizer.summarize(this, trend);
-                if (summary != null) {
-                    return summary;
-                }
+        for (StatusSummarizer summarizer : ExtensionList.lookup(StatusSummarizer.class)) {
+            Summary summary = summarizer.summarize(this, trend);
+            if (summary != null) {
+                return summary;
             }
         }
 

core/src/main/java/hudson/model/TransientBuildActionFactory.java

@@ -45,6 +45,6 @@ public abstract class TransientBuildActionFactory implements ExtensionPoint {
      * Returns all the registered {@link TransientBuildActionFactory}s.
      */
     public static ExtensionList<TransientBuildActionFactory> all() {
-        return Jenkins.getInstance().getExtensionList(TransientBuildActionFactory.class);
+        return ExtensionList.lookup(TransientBuildActionFactory.class);
     }
 }
\ No newline at end of file

core/src/main/java/hudson/model/TransientComputerActionFactory.java

@@ -57,7 +57,7 @@ public abstract class TransientComputerActionFactory implements ExtensionPoint {
      * Returns all the registered {@link TransientComputerActionFactory}s.
      */
     public static ExtensionList<TransientComputerActionFactory> all() {
-        return Jenkins.getInstance().getExtensionList(TransientComputerActionFactory.class);
+        return ExtensionList.lookup(TransientComputerActionFactory.class);
     }
 
 

core/src/main/java/hudson/model/TransientProjectActionFactory.java

@@ -68,6 +68,6 @@ public abstract class TransientProjectActionFactory implements ExtensionPoint {
      * Returns all the registered {@link TransientProjectActionFactory}s.
      */
     public static ExtensionList<TransientProjectActionFactory> all() {
-        return Jenkins.getInstance().getExtensionList(TransientProjectActionFactory.class);
+        return ExtensionList.lookup(TransientProjectActionFactory.class);
     }
 }

core/src/main/java/hudson/model/TransientUserActionFactory.java

@@ -55,6 +55,6 @@ public abstract class TransientUserActionFactory implements ExtensionPoint {
      * Returns all the registered {@link TransientUserActionFactory}s.
      */
     public static ExtensionList<TransientUserActionFactory> all() {
-        return Jenkins.getInstance().getExtensionList(TransientUserActionFactory.class);
+        return ExtensionList.lookup(TransientUserActionFactory.class);
     }
 }
\ No newline at end of file

core/src/main/java/hudson/model/TransientViewActionFactory.java

@@ -25,7 +25,7 @@ public abstract class TransientViewActionFactory implements ExtensionPoint {
      * Returns all the registered {@link TransientViewActionFactory}s.
      */
 	public static ExtensionList<TransientViewActionFactory> all() {
-		return Jenkins.getInstance().getExtensionList(TransientViewActionFactory.class);
+		return ExtensionList.lookup(TransientViewActionFactory.class);
 	}
 	
     /**

core/src/main/java/hudson/model/User.java

@@ -350,7 +350,7 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
             return null;
 
         // sort resolvers by priority
-        List<CanonicalIdResolver> resolvers = new ArrayList<CanonicalIdResolver>(Jenkins.getInstance().getExtensionList(CanonicalIdResolver.class));
+        List<CanonicalIdResolver> resolvers = new ArrayList<CanonicalIdResolver>(ExtensionList.lookup(CanonicalIdResolver.class));
         Collections.sort(resolvers);
 
         String id = null;

core/src/main/java/hudson/model/WorkspaceCleanupThread.java

@@ -24,6 +24,7 @@
 package hudson.model;
 
 import hudson.Extension;
+import hudson.ExtensionList;
 import hudson.FilePath;
 import hudson.Util;
 import java.io.IOException;
@@ -52,7 +53,7 @@ public class WorkspaceCleanupThread extends AsyncPeriodicWork {
     }
 
     public static void invoke() {
-        Jenkins.getInstance().getExtensionList(AsyncPeriodicWork.class).get(WorkspaceCleanupThread.class).run();
+        ExtensionList.lookup(AsyncPeriodicWork.class).get(WorkspaceCleanupThread.class).run();
     }
 
     @Override protected void execute(TaskListener listener) throws InterruptedException, IOException {

core/src/main/java/hudson/model/WorkspaceListener.java

@@ -29,7 +29,7 @@ public abstract class WorkspaceListener implements ExtensionPoint {
      * All registered {@link WorkspaceListener}s.
      */
     public static ExtensionList<WorkspaceListener> all() {
-        return Jenkins.getInstance().getExtensionList(WorkspaceListener.class);
+        return ExtensionList.lookup(WorkspaceListener.class);
     }
 
 }

core/src/main/java/hudson/model/listeners/ItemListener.java

@@ -148,7 +148,7 @@ public class ItemListener implements ExtensionPoint {
      * All the registered {@link ItemListener}s.
      */
     public static ExtensionList<ItemListener> all() {
-        return Jenkins.getInstance().getExtensionList(ItemListener.class);
+        return ExtensionList.lookup(ItemListener.class);
     }
 
     public static void fireOnCopied(Item src, Item result) {

core/src/main/java/hudson/model/listeners/RunListener.java

@@ -252,7 +252,7 @@ public abstract class RunListener<R extends Run> implements ExtensionPoint {
      * Returns all the registered {@link RunListener}s.
      */
     public static ExtensionList<RunListener> all() {
-        return Jenkins.getInstance().getExtensionList(RunListener.class);
+        return ExtensionList.lookup(RunListener.class);
     }
 
     private static void report(Throwable e) {

core/src/main/java/hudson/model/listeners/SCMPollListener.java

@@ -102,6 +102,6 @@ public abstract class SCMPollListener implements ExtensionPoint {
 	 * Returns all the registered {@link SCMPollListener}s.
 	 */
 	public static ExtensionList<SCMPollListener> all() {
-		return Jenkins.getInstance().getExtensionList( SCMPollListener.class );
+		return ExtensionList.lookup( SCMPollListener.class );
 	}
 }

core/src/main/java/hudson/model/queue/LoadPredictor.java

@@ -81,7 +81,7 @@ public abstract class LoadPredictor implements ExtensionPoint {
      * All the registered instances.
      */
     public static ExtensionList<LoadPredictor> all() {
-        return Jenkins.getInstance().getExtensionList(LoadPredictor.class);
+        return ExtensionList.lookup(LoadPredictor.class);
     }
 
     /**

core/src/main/java/hudson/model/queue/QueueListener.java

@@ -80,6 +80,6 @@ public abstract class QueueListener implements ExtensionPoint {
      * Returns all the registered {@link QueueListener}s.
      */
     public static ExtensionList<QueueListener> all() {
-        return Jenkins.getInstance().getExtensionList(QueueListener.class);
+        return ExtensionList.lookup(QueueListener.class);
     }
 }

core/src/main/java/hudson/model/queue/QueueSorter.java

@@ -33,7 +33,7 @@ public abstract class QueueSorter implements ExtensionPoint {
      * unless explicitly overridden by {@link Queue#setSorter(QueueSorter)}.
      */
     public static ExtensionList<QueueSorter> all() {
-        return Jenkins.getInstance().getExtensionList(QueueSorter.class);
+        return ExtensionList.lookup(QueueSorter.class);
     }
 
     /**

core/src/main/java/hudson/model/queue/QueueTaskDispatcher.java

@@ -137,6 +137,6 @@ public abstract class QueueTaskDispatcher implements ExtensionPoint {
      * All registered {@link QueueTaskDispatcher}s.
      */
     public static ExtensionList<QueueTaskDispatcher> all() {
-        return Jenkins.getInstance().getExtensionList(QueueTaskDispatcher.class);
+        return ExtensionList.lookup(QueueTaskDispatcher.class);
     }
 }
\ No newline at end of file

core/src/main/java/hudson/model/queue/SubTaskContributor.java

@@ -50,6 +50,6 @@ public abstract class SubTaskContributor implements ExtensionPoint {
      * All registered {@link SubTaskContributor} instances.
      */
     public static ExtensionList<SubTaskContributor> all() {
-        return Jenkins.getInstance().getExtensionList(SubTaskContributor.class);
+        return ExtensionList.lookup(SubTaskContributor.class);
     }
 }

core/src/main/java/hudson/scm/ChangeLogAnnotator.java

@@ -121,6 +121,6 @@ public abstract class ChangeLogAnnotator implements ExtensionPoint {
      * Returns all the registered {@link ChangeLogAnnotator} descriptors.
      */
     public static ExtensionList<ChangeLogAnnotator> all() {
-        return Jenkins.getInstance().getExtensionList(ChangeLogAnnotator.class);
+        return ExtensionList.lookup(ChangeLogAnnotator.class);
     }
 }

core/src/main/java/hudson/search/SearchFactory.java

@@ -40,6 +40,6 @@ public abstract class SearchFactory implements ExtensionPoint {
      * Returns all the registered {@link SearchFactory} instances.
      */
     public static ExtensionList<SearchFactory> all() {
-        return Jenkins.getInstance().getExtensionList(SearchFactory.class);
+        return ExtensionList.lookup(SearchFactory.class);
     }
 }

core/src/main/java/hudson/security/FederatedLoginService.java

@@ -253,6 +253,6 @@ public abstract class FederatedLoginService implements ExtensionPoint {
     }
 
     public static ExtensionList<FederatedLoginService> all() {
-        return Jenkins.getInstance().getExtensionList(FederatedLoginService.class);
+        return ExtensionList.lookup(FederatedLoginService.class);
     }
 }

core/src/main/java/hudson/security/HudsonPrivateSecurityRealm.java

@@ -25,6 +25,7 @@ package hudson.security;
 
 import com.thoughtworks.xstream.converters.UnmarshallingContext;
 import hudson.Extension;
+import hudson.ExtensionList;
 import hudson.Util;
 import hudson.diagnosis.OldDataMonitor;
 import hudson.model.Descriptor;
@@ -287,7 +288,7 @@ public class HudsonPrivateSecurityRealm extends AbstractPasswordBasedSecurityRea
      */
     private void tryToMakeAdmin(User u) {
         AuthorizationStrategy as = Jenkins.getInstance().getAuthorizationStrategy();
-        for (PermissionAdder adder : Jenkins.getInstance().getExtensionList(PermissionAdder.class)) {
+        for (PermissionAdder adder : ExtensionList.lookup(PermissionAdder.class)) {
             if (adder.add(as, u, Jenkins.ADMINISTER)) {
                 return;
             }

core/src/main/java/hudson/security/csrf/CrumbExclusion.java

@@ -32,6 +32,6 @@ public abstract class CrumbExclusion implements ExtensionPoint {
     public abstract boolean process(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException;
 
     public static ExtensionList<CrumbExclusion> all() {
-        return Jenkins.getInstance().getExtensionList(CrumbExclusion.class);
+        return ExtensionList.lookup(CrumbExclusion.class);
     }
 }

core/src/main/java/hudson/slaves/CloudProvisioningListener.java

@@ -76,7 +76,7 @@ public abstract class CloudProvisioningListener implements ExtensionPoint {
      * All the registered {@link CloudProvisioningListener}s.
      */
     public static ExtensionList<CloudProvisioningListener> all() {
-        return Jenkins.getInstance().getExtensionList(CloudProvisioningListener.class);
+        return ExtensionList.lookup(CloudProvisioningListener.class);
     }
 }
 

core/src/main/java/hudson/slaves/ComputerListener.java

@@ -229,6 +229,6 @@ public abstract class ComputerListener implements ExtensionPoint {
      * All the registered {@link ComputerListener}s.
      */
     public static ExtensionList<ComputerListener> all() {
-        return Jenkins.getInstance().getExtensionList(ComputerListener.class);
+        return ExtensionList.lookup(ComputerListener.class);
     }
 }

core/src/main/java/hudson/tasks/UserAvatarResolver.java

@@ -114,7 +114,7 @@ public abstract class UserAvatarResolver implements ExtensionPoint {
      * Returns all the registered {@link UserAvatarResolver} descriptors.
      */
     public static ExtensionList<UserAvatarResolver> all() {
-        return Jenkins.getInstance().getExtensionList(UserAvatarResolver.class);
+        return ExtensionList.lookup(UserAvatarResolver.class);
     }
 
     private static final Logger LOGGER = Logger.getLogger(UserAvatarResolver.class.getName());

core/src/main/java/hudson/tasks/UserNameResolver.java

@@ -83,7 +83,7 @@ public abstract class UserNameResolver implements ExtensionPoint {
      * Returns all the registered {@link UserNameResolver} descriptors.
      */
     public static ExtensionList<UserNameResolver> all() {
-        return Jenkins.getInstance().getExtensionList(UserNameResolver.class);
+        return ExtensionList.lookup(UserNameResolver.class);
     }
 
     /**

core/src/main/java/hudson/tasks/junit/TestNameTransformer.java

@@ -37,6 +37,6 @@ public abstract class TestNameTransformer implements ExtensionPoint {
     }
 
     public static ExtensionList<TestNameTransformer> all() {
-        return Jenkins.getInstance().getExtensionList(TestNameTransformer.class);
+        return ExtensionList.lookup(TestNameTransformer.class);
     }
 }

core/src/main/java/hudson/tasks/test/TestResultParser.java

@@ -74,7 +74,7 @@ public abstract class TestResultParser implements ExtensionPoint {
      * All registered {@link TestResultParser}s
      */
     public static ExtensionList<TestResultParser> all() {
-        return Jenkins.getInstance().getExtensionList(TestResultParser.class);
+        return ExtensionList.lookup(TestResultParser.class);
     }
 
     /**

core/src/main/java/hudson/tools/ToolLocationTranslator.java

@@ -70,6 +70,6 @@ public abstract class ToolLocationTranslator implements ExtensionPoint {
      * Returns all the registered {@link ToolLocationTranslator}s.
      */
     public static ExtensionList<ToolLocationTranslator> all() {
-        return Jenkins.getInstance().getExtensionList(ToolLocationTranslator.class);
+        return ExtensionList.lookup(ToolLocationTranslator.class);
     }
 }

core/src/main/java/hudson/util/AlternativeUiTextProvider.java

@@ -70,7 +70,7 @@ public abstract class AlternativeUiTextProvider implements ExtensionPoint {
      * All the registered extension point instances.
      */
     public static ExtensionList<AlternativeUiTextProvider> all() {
-        return Jenkins.getInstance().getExtensionList(AlternativeUiTextProvider.class);
+        return ExtensionList.lookup(AlternativeUiTextProvider.class);
     }
 
     public static <T> String get(Message<T> text, T context, String defaultValue) {

core/src/main/java/hudson/util/ProcessKiller.java

@@ -62,7 +62,7 @@ public abstract class ProcessKiller implements ExtensionPoint, Serializable {
      * Returns all the registered {@link ProcessKiller} descriptors.
      */
     public static ExtensionList<ProcessKiller> all() {
-        return Jenkins.getInstance().getExtensionList(ProcessKiller.class);
+        return ExtensionList.lookup(ProcessKiller.class);
     }
 
     /**

core/src/main/java/hudson/util/io/ParserConfigurator.java

@@ -69,7 +69,7 @@ public abstract class ParserConfigurator implements ExtensionPoint, Serializable
      * Returns all the registered {@link ParserConfigurator}s.
      */
     public static ExtensionList<ParserConfigurator> all() {
-        return Jenkins.getInstance().getExtensionList(ParserConfigurator.class);
+        return ExtensionList.lookup(ParserConfigurator.class);
     }
 
     public static void applyConfiguration(SAXReader reader, Object context) throws IOException, InterruptedException {

core/src/main/java/jenkins/AgentProtocol.java

@@ -43,7 +43,7 @@ public abstract class AgentProtocol implements ExtensionPoint {
      * Returns all the registered {@link AperiodicWork}s.
      */
     public static ExtensionList<AgentProtocol> all() {
-        return Jenkins.getInstance().getExtensionList(AgentProtocol.class);
+        return ExtensionList.lookup(AgentProtocol.class);
     }
 
     public static AgentProtocol of(String protocolName) {

core/src/main/java/jenkins/ExtensionFilter.java

@@ -86,6 +86,6 @@ public abstract class ExtensionFilter implements ExtensionPoint {
      * All registered {@link ExtensionFilter} instances.
      */
     public static ExtensionList<ExtensionFilter> all() {
-        return Jenkins.getInstance().getExtensionList(ExtensionFilter.class);
+        return ExtensionList.lookup(ExtensionFilter.class);
     }
 }

core/src/main/java/jenkins/model/GlobalConfigurationCategory.java

@@ -37,7 +37,7 @@ public abstract class GlobalConfigurationCategory implements ExtensionPoint, Mod
      * Returns all the registered {@link GlobalConfiguration} descriptors.
      */
     public static ExtensionList<GlobalConfigurationCategory> all() {
-        return Jenkins.getInstance().getExtensionList(GlobalConfigurationCategory.class);
+        return ExtensionList.lookup(GlobalConfigurationCategory.class);
     }
 
     public static <T extends GlobalConfigurationCategory> T get(Class<T> type) {

core/src/main/java/jenkins/model/TransientFingerprintFacetFactory.java

@@ -48,6 +48,6 @@ public abstract class TransientFingerprintFacetFactory implements ExtensionPoint
      * Returns all the registered {@link TransientFingerprintFacetFactory}s.
      */
     public static ExtensionList<TransientFingerprintFacetFactory> all() {
-        return Jenkins.getInstance().getExtensionList(TransientFingerprintFacetFactory.class);
+        return ExtensionList.lookup(TransientFingerprintFacetFactory.class);
     }
 }

core/src/main/java/jenkins/model/Uptime.java

 package jenkins.model;
 
 import hudson.Extension;
+import hudson.ExtensionList;
 import hudson.init.InitMilestone;
 import hudson.init.Initializer;
 
@@ -27,6 +28,6 @@ public class Uptime {
 
     @Initializer(after=InitMilestone.JOB_LOADED)
     public static void init() {
-        Jenkins.getInstance().getExtensionList(Uptime.class).get(0).startTime = System.currentTimeMillis();
+        ExtensionList.lookup(Uptime.class).get(0).startTime = System.currentTimeMillis();
     }
 }

core/src/main/java/jenkins/model/lazy/BuildReference.java

 package jenkins.model.lazy;
 
 import hudson.Extension;
+import hudson.ExtensionList;
 import hudson.ExtensionPoint;
 import hudson.model.Run;
 import java.lang.ref.Reference;
@@ -10,7 +11,6 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
-import jenkins.model.Jenkins;
 import jenkins.model.lazy.LazyBuildMixIn.RunMixIn;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.NoExternalUse;
@@ -111,14 +111,11 @@ public final class BuildReference<R> {
             // AbstractBuild.NONE
             return new DefaultHolderFactory.NoHolder<R>();
         }
-        Jenkins j = Jenkins.getInstance();
-        if (j != null) {
-            for (HolderFactory f : j.getExtensionList(HolderFactory.class)) {
-                Holder<R> h = f.make(referent);
-                if (h != null) {
-                    LOGGER.log(Level.FINE, "created build reference for {0} using {1}", new Object[] {referent, f});
-                    return h;
-                }
+        for (HolderFactory f : ExtensionList.lookup(HolderFactory.class)) {
+            Holder<R> h = f.make(referent);
+            if (h != null) {
+                LOGGER.log(Level.FINE, "created build reference for {0} using {1}", new Object[] {referent, f});
+                return h;
             }
         }
         return new DefaultHolderFactory().make(referent);

core/src/main/java/jenkins/security/BasicHeaderAuthenticator.java

@@ -39,6 +39,6 @@ public abstract class BasicHeaderAuthenticator implements ExtensionPoint {
     public abstract Authentication authenticate(HttpServletRequest req, HttpServletResponse rsp, String username, String password) throws IOException, ServletException;
 
     public static ExtensionList<BasicHeaderAuthenticator> all() {
-        return Jenkins.getInstance().getExtensionList(BasicHeaderAuthenticator.class);
+        return ExtensionList.lookup(BasicHeaderAuthenticator.class);
     }
 }

core/src/main/java/jenkins/security/SecurityListener.java

@@ -24,6 +24,7 @@
 
 package jenkins.security;
 
+import hudson.ExtensionList;
 import hudson.ExtensionPoint;
 import hudson.security.AbstractPasswordBasedSecurityRealm;
 import hudson.security.SecurityRealm;
@@ -134,7 +135,7 @@ public abstract class SecurityListener implements ExtensionPoint {
     }
 
     private static List<SecurityListener> all() {
-        return Jenkins.getInstance().getExtensionList(SecurityListener.class);
+        return ExtensionList.lookup(SecurityListener.class);
     }
 
 }

core/src/main/java/jenkins/slaves/JnlpAgentReceiver.java

@@ -59,6 +59,6 @@ public abstract class JnlpAgentReceiver implements ExtensionPoint {
     public abstract boolean handle(String name, JnlpSlaveHandshake handshake) throws IOException, InterruptedException;
 
     public static ExtensionList<JnlpAgentReceiver> all() {
-        return Jenkins.getInstance().getExtensionList(JnlpAgentReceiver.class);
+        return ExtensionList.lookup(JnlpAgentReceiver.class);
     }
 }

core/src/main/java/jenkins/slaves/WorkspaceLocator.java

@@ -33,6 +33,6 @@ public abstract class WorkspaceLocator implements ExtensionPoint {
      * All registered {@link WorkspaceLocator}s.
      */
     public static ExtensionList<WorkspaceLocator> all() {
-        return Jenkins.getInstance().getExtensionList(WorkspaceLocator.class);
+        return ExtensionList.lookup(WorkspaceLocator.class);
     }
 }

core/src/main/java/jenkins/slaves/restarter/SlaveRestarter.java

@@ -40,7 +40,7 @@ public abstract class SlaveRestarter implements ExtensionPoint, Serializable {
     public abstract void restart() throws Exception;
 
     public static ExtensionList<SlaveRestarter> all() {
-        return Jenkins.getInstance().getExtensionList(SlaveRestarter.class);
+        return ExtensionList.lookup(SlaveRestarter.class);
     }
 
     private static final Logger LOGGER = Logger.getLogger(SlaveRestarter.class.getName());

core/src/main/java/jenkins/slaves/systemInfo/SlaveSystemInfo.java

@@ -23,6 +23,6 @@ public abstract class SlaveSystemInfo implements ExtensionPoint {
     public abstract String getDisplayName();
 
     public static ExtensionList<SlaveSystemInfo> all() {
-        return Jenkins.getInstance().getExtensionList(SlaveSystemInfo.class);
+        return ExtensionList.lookup(SlaveSystemInfo.class);
     }
 }

core/src/main/resources/META-INF/upgrade/ExtensionList.hint

+jenkins.model.Jenkins.getInstance().getExtensionList($c) :: $c instanceof java.lang.Class => hudson.ExtensionList.lookup($c);;