Pushing the dependency computation down to another thread.

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

@@ -513,7 +513,7 @@ public abstract class AbstractItem extends Actionable implements Item, HttpDelet
             // ignore
         }
 
-        Jenkins.getInstance().rebuildDependencyGraph();
+        Jenkins.getInstance().rebuildDependencyGraphAsync();
     }
 
     /**
@@ -592,7 +592,7 @@ public abstract class AbstractItem extends Actionable implements Item, HttpDelet
             } finally {
                 Items.updatingByXml.set(false);
             }
-            Jenkins.getInstance().rebuildDependencyGraph();
+            Jenkins.getInstance().rebuildDependencyGraphAsync();
 
             // if everything went well, commit this new version
             out.commit();

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

@@ -772,7 +772,7 @@ public abstract class AbstractProject<P extends AbstractProject<P,R>,R extends A
         Jenkins.getInstance().getQueue().scheduleMaintenance();
 
         // this is to reflect the upstream build adjustments done above
-        Jenkins.getInstance().rebuildDependencyGraph();
+        Jenkins.getInstance().rebuildDependencyGraphAsync();
     }
 
     /**

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

@@ -213,7 +213,7 @@ public abstract class ItemGroupMixIn {
 
         add(result);
         ItemListener.fireOnCopied(src,result);
-        Hudson.getInstance().rebuildDependencyGraph();
+        Jenkins.getInstance().rebuildDependencyGraphAsync();
 
         return result;
     }
@@ -239,7 +239,7 @@ public abstract class ItemGroupMixIn {
             add(result);
 
             ItemListener.fireOnCreated(result);
-            Jenkins.getInstance().rebuildDependencyGraph();
+            Jenkins.getInstance().rebuildDependencyGraphAsync();
 
             return result;
         } catch (IOException e) {
@@ -270,7 +270,7 @@ public abstract class ItemGroupMixIn {
         }
         item.save();
         add(item);
-        Jenkins.getInstance().rebuildDependencyGraph();
+        Jenkins.getInstance().rebuildDependencyGraphAsync();
 
         if (notify)
             ItemListener.fireOnCreated(item);

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

@@ -136,7 +136,7 @@ public class Fingerprinter extends Recorder implements Serializable, DependencyD
             build.getActions().add(new FingerprintAction(build,record));
 
             if (enableFingerprintsInDependencyGraph) {
-                Jenkins.getInstance().rebuildDependencyGraph();
+                Jenkins.getInstance().rebuildDependencyGraphAsync();
             }
         } catch (IOException e) {
             e.printStackTrace(listener.error(Messages.Fingerprinter_Failed()));

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

@@ -3601,6 +3601,25 @@ public class Jenkins extends AbstractCIBase implements ModifiableTopLevelItemGro
         dependencyGraph = graph;
     }
 
+    /**
+     * Rebuilds the dependency map asynchronously.
+     *
+     * <p>
+     * This would keep the UI thread more responsive and helps avoid the deadlocks,
+     * as dependency graph recomputation tends to touch a lot of other things.
+     *
+     * @since 1.522
+     */
+    public Future<DependencyGraph> rebuildDependencyGraphAsync() {
+        return MasterComputer.threadPoolForRemoting.submit(new java.util.concurrent.Callable<DependencyGraph>() {
+            @Override
+            public DependencyGraph call() throws Exception {
+                rebuildDependencyGraph();
+                return dependencyGraph;
+            }
+        });
+    }
+
     public DependencyGraph getDependencyGraph() {
         return dependencyGraph;
     }

maven-plugin/src/main/java/hudson/maven/MavenModule.java

@@ -649,7 +649,7 @@ public class MavenModule extends AbstractMavenProject<MavenModule,MavenBuild> im
         goals = Util.fixEmpty(req.getParameter("goals").trim());
 
         // dependency setting might have been changed by the user, so rebuild.
-        Jenkins.getInstance().rebuildDependencyGraph();
+        Jenkins.getInstance().rebuildDependencyGraphAsync();
     }
 
     @Override