thread dump now reports all the threads from all the slaves, not just

the master.

changelog.html

@@ -58,7 +58,8 @@ Upcoming changes</a>
 <!-- Record your changes in the trunk here. -->
 <div id="trunk" style="display:none"><!--=TRUNK-BEGIN=-->
 <ul class=image>
-  <li class=>
+  <li class=rfe>
+    thread dump now reports all the threads from all the slaves, not just the master.
 </ul>
 </div><!--=TRUNK-END=-->
 

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

@@ -189,6 +189,7 @@ import java.io.FileFilter;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.net.BindException;
 import java.net.URL;
 import java.nio.charset.Charset;
@@ -2631,6 +2632,38 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
         rsp.sendRedirect2("threadDump");
     }
 
+    /**
+     * Obtains the thread dump of all slaves (including the master.)
+     *
+     * <p>
+     * Since this is for diagnostics, it has a built-in precautionary measure against hang slaves.
+     */
+    public Map<String,Map<String,String>> getAllThreadDumps() throws IOException, InterruptedException {
+        checkPermission(ADMINISTER);
+
+        // issue the requests all at once
+        Map<String,Future<Map<String,String>>> future = new HashMap<String, Future<Map<String, String>>>();
+        for (Computer c : getComputers()) {
+            future.put(c.getName(), RemotingDiagnostics.getThreadDumpAsync(c.getChannel()));
+        }
+
+        // if the result isn't available in 5 sec, ignore that.
+        // this is a precaution against hang nodes
+        long endTime = System.currentTimeMillis() + 5000;
+
+        Map<String,Map<String,String>> r = new HashMap<String, Map<String, String>>();
+        for (Entry<String, Future<Map<String, String>>> e : future.entrySet()) {
+            try {
+                r.put(e.getKey(), e.getValue().get(endTime-System.currentTimeMillis(), TimeUnit.MILLISECONDS));
+            } catch (Exception x) {
+                StringWriter sw = new StringWriter();
+                x.printStackTrace(new PrintWriter(sw,true));
+                r.put(e.getKey(), Collections.singletonMap("Failed to retrieve thread dump",sw.toString()));
+            }
+        }
+        return r;
+    }
+
     public synchronized Item doCreateItem( StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException {
         return itemGroupMixIn.createTopLevelItem(req, rsp);
     }

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

@@ -27,8 +27,10 @@ import groovy.lang.GroovyShell;
 import hudson.FilePath;
 import hudson.Functions;
 import hudson.model.Hudson;
+import hudson.remoting.AsyncFutureImpl;
 import hudson.remoting.Callable;
 import hudson.remoting.DelegatingCallable;
+import hudson.remoting.Future;
 import hudson.remoting.VirtualChannel;
 import hudson.security.AccessControlled;
 import org.kohsuke.stapler.StaplerRequest;
@@ -78,6 +80,12 @@ public final class RemotingDiagnostics {
         return channel.call(new GetThreadDump());
     }
 
+    public static Future<Map<String,String>> getThreadDumpAsync(VirtualChannel channel) throws IOException, InterruptedException {
+        if(channel==null)
+            return new AsyncFutureImpl<Map<String, String>>(Collections.singletonMap("N/A","offline"));
+        return channel.callAsync(new GetThreadDump());
+    }
+
     private static final class GetThreadDump implements Callable<Map<String,String>,RuntimeException> {
         public Map<String,String> call() {
             Map<String,String> r = new LinkedHashMap<String,String>();

core/src/main/resources/hudson/model/Hudson/threadDump.jelly

 <!--
 The MIT License
 
-Copyright (c) 2004-2010, Sun Microsystems, Inc., Kohsuke Kawaguchi, Tom Huybrechts
+Copyright (c) 2004-2010, Sun Microsystems, Inc., Kohsuke Kawaguchi, Tom Huybrechts, CloudBees, Inc.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -31,9 +31,15 @@ THE SOFTWARE.
 
     <l:main-panel>
       <h1>${%Thread Dump}</h1>
-      <j:forEach var="t" items="${it.toComputer().getThreadDump().entrySet()}">
-        <h2>${t.key}</h2>
-        <pre>${t.value}</pre>
+      <j:forEach var="e" items="${it.getAllThreadDumps().entrySet()}" varStatus="loop">
+        <j:if test="${!loop.first}">
+          <hr style="margin-bottom:6em"/>
+        </j:if>
+        <h1>${e.key}</h1>
+        <j:forEach var="t" items="${e.value.entrySet()}">
+          <h2>${t.key}</h2>
+          <pre>${t.value}</pre>
+        </j:forEach>
       </j:forEach>
     </l:main-panel>
   </l:layout>

remoting/src/main/java/hudson/remoting/AsyncFutureImpl.java

 /*
  * The MIT License
  * 
- * Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi
+ * Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi, CloudBees, Inc.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -48,6 +48,14 @@ public class AsyncFutureImpl<V> implements Future<V> {
     private Throwable problem;
     private boolean cancelled;
 
+    public AsyncFutureImpl() {}
+    public AsyncFutureImpl(V value) {
+        set(value);
+    }
+    public AsyncFutureImpl(Throwable value) {
+        set(value);
+    }
+
     public boolean cancel(boolean mayInterruptIfRunning) {
         return false;
     }