Prototype label parameterization.

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

@@ -26,6 +26,7 @@ package hudson.model;
 
 import hudson.EnvVars;
 import hudson.Util;
+import hudson.model.queue.SubTask;
 import hudson.scm.SCM;
 import hudson.slaves.OfflineCause;
 import hudson.tasks.BuildWrapper;
@@ -256,5 +257,12 @@ public abstract class ParameterValue implements Serializable {
      */
     public boolean isSensitive() {
         return false;
-}
+    }
+
+    /**
+     * @since 1.414
+     */
+    public Label getAssignedLabel(SubTask task) {
+        return null;
+    }
 }

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

@@ -27,6 +27,8 @@ import hudson.Util;
 import hudson.EnvVars;
 import hudson.diagnosis.OldDataMonitor;
 import hudson.model.Queue.QueueAction;
+import hudson.model.labels.LabelAssignmentAction;
+import hudson.model.queue.SubTask;
 import hudson.tasks.BuildStep;
 import hudson.tasks.BuildWrapper;
 import hudson.util.VariableResolver;
@@ -50,7 +52,7 @@ import java.util.Set;
  * that were specified when scheduling.
  */
 @ExportedBean
-public class ParametersAction implements Action, Iterable<ParameterValue>, QueueAction, EnvironmentContributingAction {
+public class ParametersAction implements Action, Iterable<ParameterValue>, QueueAction, EnvironmentContributingAction, LabelAssignmentAction {
 
     private final List<ParameterValue> parameters;
 
@@ -119,6 +121,14 @@ public class ParametersAction implements Action, Iterable<ParameterValue>, Queue
         return null;
     }
 
+    public Label getAssignedLabel(SubTask task) {
+        for (ParameterValue p : parameters) {
+            Label l = p.getAssignedLabel(task);
+            if (l!=null)    return l;
+        }
+        return null;
+    }
+
     public String getDisplayName() {
         return Messages.ParameterAction_DisplayName();
     }

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

@@ -36,6 +36,7 @@ import static hudson.util.Iterators.reverse;
 
 import hudson.cli.declarative.CLIMethod;
 import hudson.cli.declarative.CLIResolver;
+import hudson.model.labels.LabelAssignmentAction;
 import hudson.model.queue.AbstractQueueTask;
 import hudson.model.queue.Executables;
 import hudson.model.queue.SubTask;
@@ -678,10 +679,10 @@ public class Queue extends ResourceController implements Saveable {
     public synchronized int countBuildableItemsFor(Label l) {
         int r = 0;
         for (BuildableItem bi : buildables.values())
-            if(bi.task.getAssignedLabel()==l)
+            if(bi.getAssignedLabel()==l)
                 r++;
         for (BuildableItem bi : pendings.values())
-            if(bi.task.getAssignedLabel()==l)
+            if(bi.getAssignedLabel()==l)
                 r++;
         return r;
     }
@@ -960,7 +961,7 @@ public class Queue extends ResourceController implements Saveable {
             for (Node n : h.getNodes())
                 hash.add(n,n.getNumExecutors()*100);
 
-            Label lbl = p.task.getAssignedLabel();
+            Label lbl = p.getAssignedLabel();
             for (Node n : hash.list(p.task.getFullDisplayName())) {
                 Computer c = n.toComputer();
                 if (c==null || c.isOffline())    continue;
@@ -1215,6 +1216,14 @@ public class Queue extends ResourceController implements Saveable {
          */
         public Future<Executable> getFuture() { return future; }
 
+        public Label getAssignedLabel() {
+            for (LabelAssignmentAction laa : getActions(LabelAssignmentAction.class)) {
+                Label l = laa.getAssignedLabel(task);
+                if (l!=null)    return l;
+            }
+            return task.getAssignedLabel();
+        }
+
         /**
          * Convenience method that returns a read only view of the {@link Cause}s associated with this item in the queue.
          *
@@ -1448,7 +1457,7 @@ public class Queue extends ResourceController implements Saveable {
             if(ifBlockedByHudsonShutdown(task))
                 return CauseOfBlockage.fromMessage(Messages._Queue_HudsonIsAboutToShutDown());
 
-            Label label = task.getAssignedLabel();
+            Label label = getAssignedLabel();
             if (hudson.getNodes().isEmpty())
                 label = null;    // no master/slave. pointless to talk about nodes
 
@@ -1470,7 +1479,7 @@ public class Queue extends ResourceController implements Saveable {
 
         @Override
         public boolean isStuck() {
-            Label label = task.getAssignedLabel();
+            Label label = getAssignedLabel();
             if(label!=null && label.isOffline())
                 // no executor online to process this job. definitely stuck.
                 return true;

core/src/main/java/hudson/model/labels/LabelAssignmentAction.java

+package hudson.model.labels;
+
+import hudson.model.Action;
+import hudson.model.Label;
+import hudson.model.queue.SubTask;
+
+/**
+ * @author Kohsuke Kawaguchi
+ */
+public interface LabelAssignmentAction extends Action {
+    Label getAssignedLabel(SubTask task);
+}