Merge pull request #7030 from mbien/fix-gradle-daemon-executor-concur…

…rency

Fixed concurrency issues in GradleDaemonExecutor

extide/gradle/src/org/netbeans/modules/gradle/execute/GradleDaemonExecutor.java

@@ -37,7 +37,9 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.swing.AbstractAction;
@@ -439,41 +441,70 @@ private static String gradleExecutable() {
         return Utilities.isWindows() ? "bin\\gradle.bat" : "bin/gradle"; //NOI18N
     }
 
-    public final ExecutorTask createTask(ExecutorTask process) {
+    // TODO one of the two methods can likely go from the API
+    // setTask is called first and signals the runnable to start
+    // the started runnable requires (!) the gradleTask so it can't be created in createTask
+    @Override
+    public void setTask(ExecutorTask task) {
         assert gradleTask == null;
-        gradleTask = new GradleTask(process);
+        gradleTask = new GradleTask(task);
+        super.setTask(task);
+    }
+
+    @Override
+    public final ExecutorTask createTask(ExecutorTask process) {
+        assert gradleTask != null;
+        assert task == process;
         return gradleTask;
     }
 
+    // task which can finish early, like a CompletableFuture
     private static final class GradleTask extends ExecutorTask {
-        private final ExecutorTask delegate;
-        private Integer result;
 
+        private final ExecutorTask delegate;
+        private volatile Integer result;
+        // is 0 when wrapper or delegate finished
+        private final CountDownLatch doneSignal = new CountDownLatch(1);
+
         GradleTask(ExecutorTask delegate) {
             super(() -> {});
             this.delegate = delegate;
+            this.delegate.addTaskListener(t -> doneSignal.countDown());
         }
 
         @Override
         public void stop() {
-            this.delegate.stop();
+            delegate.stop();
         }
 
         @Override
         public int result() {
-            if (result != null) {
-                return result;
-            }
-            return this.delegate.result();
+            waitFinished();
+            return result != null ? result : delegate.result();
         }
 
         @Override
         public InputOutput getInputOutput() {
-            return this.delegate.getInputOutput();
+            return delegate.getInputOutput();
+        }
+
+        // FIXME isFinished() is final... this is still broken
+
+        @Override
+        public boolean waitFinished(long milliseconds) throws InterruptedException {
+            return doneSignal.await(milliseconds, TimeUnit.MILLISECONDS);
+        }
+
+        @Override
+        public void waitFinished() {
+            try {
+                doneSignal.await();
+            } catch (InterruptedException ex) {}
         }
 
         public void finish(int result) {
             this.result = result;
+            doneSignal.countDown();
             notifyFinished();
         }
     }

platform/core.execution/src/org/netbeans/core/execution/ExecutionEngine.java

@@ -70,13 +70,13 @@
     private static final IOTable taskIOs = new IOTable(base, systemIO);
 
     /* table of window:threadgrp */
-    private static WindowTable wtable = new WindowTable();
+    private static final WindowTable wtable = new WindowTable();
 
     /** list of ExecutionListeners */
-    private HashSet<ExecutionListener> executionListeners = new HashSet<ExecutionListener>();
+    private final HashSet<ExecutionListener> executionListeners = new HashSet<>();
 
     /** List of running executions */
-    private List<ExecutorTask> runningTasks = Collections.synchronizedList(new ArrayList<ExecutorTask>( 5 ));
+    private final List<ExecutorTask> runningTasks = Collections.synchronizedList(new ArrayList<>(5));
 
     static {
         systemIO.out = new OutputStreamWriter(System.out);
@@ -131,13 +131,14 @@ public String getRunningTaskName( ExecutorTask task ) {
     * @param executor to start
     * @param info about class to start
     */
+    @Override
     public ExecutorTask execute(String name, Runnable run, final InputOutput inout) {
         TaskThreadGroup g = new TaskThreadGroup(base, "exec_" + name + "_" + number); // NOI18N
         g.setDaemon(true);
         ExecutorTaskImpl task = new ExecutorTaskImpl();
         synchronized (task.lock) {
             try {
-                new RunClassThread(g, name, number++, inout, this, task, Lookup.getDefault(), run);
+                new RunClassThread(g, name, number++, inout, this, task, Lookup.getDefault(), run).start();
                 task.lock.wait();
             } catch (InterruptedException e) { // #171795
                 inout.closeInputOutput();
@@ -157,6 +158,7 @@ public ExecutorTask execute(String name, Runnable run, final InputOutput inout)
     *
     * @return class path to libraries
     */
+    @Override
     protected NbClassPath createLibraryPath() {
         List<File> l = Main.getModuleSystem().getModuleJars();
         return new NbClassPath (l.toArray (new File[0]));
@@ -181,6 +183,7 @@ public final void removeExecutionListener (ExecutionListener l) {
      * @param io an InputOutput
      * @return PermissionCollection for given CodeSource and InputOutput
      */
+    @Override
     protected final PermissionCollection createPermissions(CodeSource cs, InputOutput io) {
         PermissionCollection pc = Policy.getPolicy().getPermissions(cs);
         ThreadGroup grp = Thread.currentThread().getThreadGroup();
@@ -252,6 +255,7 @@ static class SysOut extends OutputStream {
             this.std = std;
         }
 
+        @Override
         public void write(int b) throws IOException {
             if (std) {
                 getTaskIOs().getOut().write(b);

platform/core.execution/src/org/netbeans/core/execution/RunClassThread.java

@@ -71,7 +71,6 @@ public RunClassThread(TaskThreadGroup base,
         this.originalLookup = originalLookup;
         // #33789 - this thread must not be daemon otherwise it is immediately destroyed
         setDaemon(false);
-        this.start();
     }
 
     /** runs the thread
@@ -166,6 +165,7 @@ private void doRun() {
         }
     } // run method
 
+    @Override
     public InputOutput getInputOutput() {
         return io;
     }