Merge pull request #2440 from jglick/no-dead-executors

Remove the concept of yanking dead executors

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

@@ -1039,9 +1039,6 @@ public void run() {
     /**
      * Returns true if any of the executors are {@linkplain Executor#isActive active}.
      *
-     * Note that if an executor dies, we'll leave it in {@link #executors} until
-     * the administrator yanks it out, so that we can see why it died.
-     *
      * @since 1.509
      */
     protected boolean isAlive() {

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

@@ -115,10 +115,6 @@ public class Executor extends Thread implements ModelObject {
     @GuardedBy("lock")
     private WorkUnit workUnit;
 
-    private Throwable causeOfDeath;
-
-    private boolean induceDeath;
-
     @GuardedBy("lock")
     private boolean started;
 
@@ -338,8 +334,6 @@ public void run() {
         ACL.impersonate(ACL.SYSTEM);
 
         try {
-            if (induceDeath)        throw new ThreadDeath();
-
             SubTask task;
             // transition from idle to building.
             // perform this state change as an atomic operation wrt other queue operations
@@ -434,7 +428,6 @@ public SubTask call() throws Exception {
             LOGGER.log(FINE, getName()+" interrupted",e);
             // die peacefully
         } catch(Exception | Error e) {
-            causeOfDeath = e;
             LOGGER.log(SEVERE, "Unexpected executor death", e);
         } finally {
             if (asynchronousExecution == null) {
@@ -466,9 +459,7 @@ private void finish2() {
         for (RuntimeException e1 : owner.getTerminatedBy()) {
             LOGGER.log(Level.FINE, String.format("%s termination trace", getName()), e1);
         }
-        if (causeOfDeath == null) {// let this thread die and be replaced by a fresh unstarted instance
-            owner.removeExecutor(this);
-        }
+        owner.removeExecutor(this);
         if (this instanceof OneOffExecutor) {
             owner.remove((OneOffExecutor) this);
         }
@@ -485,13 +476,6 @@ public void completedAsynchronous(@CheckForNull Throwable error) {
         asynchronousExecution = null;
     }
 
-    /**
-     * For testing only. Simulate a fatal unexpected failure.
-     */
-    public void killHard() {
-        induceDeath = true;
-    }
-
     /**
      * Returns the current build this executor is running.
      *
@@ -606,7 +590,7 @@ public boolean isBusy() {
      * on-demand creation of executor threads. Callers should use
      * this method instead of {@link #isAlive()}, which would be incorrect for
      * non-started threads or running {@link AsynchronousExecution}.
-     * @return True if the executor is available for tasks
+     * @return true if the executor is available for tasks (usually true)
      * @since 1.536
      */
     public boolean isActive() {
@@ -660,13 +644,11 @@ public boolean isParking() {
     }
 
     /**
-     * If this thread dies unexpectedly, obtain the cause of the failure.
-     *
-     * @return null if the death is expected death or the thread {@link #isActive}.
-     * @since 1.142
+     * @deprecated no longer used
      */
+    @Deprecated
     public @CheckForNull Throwable getCauseOfDeath() {
-        return causeOfDeath;
+        return null;
     }
 
     /**
@@ -870,14 +852,10 @@ public HttpResponse doStop() {
     }
 
     /**
-     * Throws away this executor and get a new one.
+     * @deprecated now a no-op
      */
-    @RequirePOST
+    @Deprecated
     public HttpResponse doYank() {
-        Jenkins.getInstance().checkPermission(Jenkins.ADMINISTER);
-        if (isActive())
-            throw new Failure("Can't yank a live executor");
-        owner.removeExecutor(this);
         return HttpResponses.redirectViaContextPath("/");
     }
 

core/src/main/resources/lib/hudson/executors.jelly

@@ -45,15 +45,6 @@ THE SOFTWARE.
               ${name}
             </td>
             <j:choose>
-              <j:when test="${!e.active}">
-                <td class="pane">
-                  <a href="${rootURL}/${c.url}${url}/causeOfDeath">
-                    <div class="error">${%Dead} (!)</div>
-                  </a>
-                </td>
-                <td class="pane"/>
-                <td class="pane"/>
-              </j:when>
               <j:when test="${e.idle}">
                 <td class="pane">
                   <j:choose>