Minor fixes to main app

server/sonar-main/src/main/java/org/sonar/application/AppStateImpl.java

@@ -25,7 +25,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.atomic.AtomicBoolean;
-import javax.annotation.Nonnull;
 import org.sonar.process.NetworkUtilsImpl;
 import org.sonar.process.ProcessId;
 
@@ -36,7 +35,7 @@ public class AppStateImpl implements AppState {
   private final AtomicBoolean webLeaderLocked = new AtomicBoolean(false);
 
   @Override
-  public void addListener(@Nonnull AppStateListener listener) {
+  public void addListener(AppStateListener listener) {
     this.listeners.add(listener);
   }
 

server/sonar-main/src/main/java/org/sonar/application/NodeLifecycle.java

@@ -69,7 +69,7 @@ class NodeLifecycle {
     res.put(OPERATIONAL, toSet(STOPPING, STOPPED));
     res.put(STOPPING, toSet(STOPPED));
     res.put(STOPPED, toSet(STARTING));
-    return res;
+    return Collections.unmodifiableMap(res);
   }
 
   private static Set<State> toSet(State... states) {

server/sonar-main/src/main/java/org/sonar/application/SchedulerImpl.java

@@ -51,7 +51,7 @@ public class SchedulerImpl implements Scheduler, ProcessEventListener, ProcessLi
   private final AppState appState;
   private final NodeLifecycle nodeLifecycle = new NodeLifecycle();
 
-  private final CountDownLatch keepAlive = new CountDownLatch(1);
+  private final CountDownLatch awaitTermination = new CountDownLatch(1);
   private final AtomicBoolean firstWaitingEsLog = new AtomicBoolean(true);
   private final AtomicBoolean restartRequested = new AtomicBoolean(false);
   private final AtomicBoolean restartDisabled = new AtomicBoolean(false);
@@ -63,8 +63,7 @@ public class SchedulerImpl implements Scheduler, ProcessEventListener, ProcessLi
   private long processWatcherDelayMs = SQProcess.DEFAULT_WATCHER_DELAY_MS;
 
   public SchedulerImpl(AppSettings settings, AppReloader appReloader, CommandFactory commandFactory,
-    ProcessLauncher processLauncher,
-    AppState appState) {
+    ProcessLauncher processLauncher, AppState appState) {
     this.settings = settings;
     this.appReloader = appReloader;
     this.commandFactory = commandFactory;
@@ -203,13 +202,13 @@ public class SchedulerImpl implements Scheduler, ProcessEventListener, ProcessLi
     if (restarterThread != null) {
       restarterThread.interrupt();
     }
-    keepAlive.countDown();
+    awaitTermination.countDown();
   }
 
   @Override
   public void awaitTermination() {
     try {
-      keepAlive.await();
+      awaitTermination.await();
     } catch (InterruptedException e) {
       Thread.currentThread().interrupt();
     }

server/sonar-main/src/main/java/org/sonar/application/cluster/ClusterAppStateImpl.java

@@ -34,7 +34,6 @@ import java.util.EnumMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
-import java.util.concurrent.locks.Lock;
 import org.elasticsearch.cluster.health.ClusterHealthStatus;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -122,21 +121,7 @@ public class ClusterAppStateImpl implements ClusterAppState {
   @Override
   public boolean tryToLockWebLeader() {
     IAtomicReference<String> leader = hzMember.getAtomicReference(LEADER);
-    if (leader.get() == null) {
-      Lock lock = hzMember.getLock(LEADER);
-      lock.lock();
-      try {
-        if (leader.get() == null) {
-          leader.set(hzMember.getUuid());
-          return true;
-        }
-        return false;
-      } finally {
-        lock.unlock();
-      }
-    } else {
-      return false;
-    }
+    return leader.compareAndSet(null, hzMember.getUuid());
   }
 
   @Override
@@ -147,44 +132,28 @@ public class ClusterAppStateImpl implements ClusterAppState {
   @Override
   public void registerSonarQubeVersion(String sonarqubeVersion) {
     IAtomicReference<String> sqVersion = hzMember.getAtomicReference(SONARQUBE_VERSION);
-    if (sqVersion.get() == null) {
-      Lock lock = hzMember.getLock(SONARQUBE_VERSION);
-      lock.lock();
-      try {
-        if (sqVersion.get() == null) {
-          sqVersion.set(sonarqubeVersion);
-        }
-      } finally {
-        lock.unlock();
-      }
-    }
+    boolean wasSet = sqVersion.compareAndSet(null, sonarqubeVersion);
 
-    String clusterVersion = sqVersion.get();
-    if (!sqVersion.get().equals(sonarqubeVersion)) {
-      throw new IllegalStateException(
-        format("The local version %s is not the same as the cluster %s", sonarqubeVersion, clusterVersion));
+    if (!wasSet) {
+      String clusterVersion = sqVersion.get();
+      if (!sqVersion.get().equals(sonarqubeVersion)) {
+        throw new IllegalStateException(
+          format("The local version %s is not the same as the cluster %s", sonarqubeVersion, clusterVersion));
+      }
     }
   }
 
   @Override
   public void registerClusterName(String clusterName) {
     IAtomicReference<String> property = hzMember.getAtomicReference(CLUSTER_NAME);
-    if (property.get() == null) {
-      Lock lock = hzMember.getLock(CLUSTER_NAME);
-      lock.lock();
-      try {
-        if (property.get() == null) {
-          property.set(clusterName);
-        }
-      } finally {
-        lock.unlock();
-      }
-    }
+    boolean wasSet = property.compareAndSet(null, clusterName);
 
-    String clusterValue = property.get();
-    if (!property.get().equals(clusterName)) {
-      throw new MessageException(
-        format("This node has a cluster name [%s], which does not match [%s] from the cluster", clusterName, clusterValue));
+    if (!wasSet) {
+      String clusterValue = property.get();
+      if (!property.get().equals(clusterName)) {
+        throw new MessageException(
+          format("This node has a cluster name [%s], which does not match [%s] from the cluster", clusterName, clusterValue));
+      }
     }
   }
 

server/sonar-main/src/main/java/org/sonar/application/cluster/ClusterProcess.java

@@ -20,6 +20,7 @@
 package org.sonar.application.cluster;
 
 import java.io.Serializable;
+import java.util.Objects;
 import org.sonar.process.ProcessId;
 
 import static java.util.Objects.requireNonNull;
@@ -58,8 +59,6 @@ public class ClusterProcess implements Serializable {
 
   @Override
   public int hashCode() {
-    int result = processId.hashCode();
-    result = 31 * result + nodeUuid.hashCode();
-    return result;
+    return Objects.hash(processId, nodeUuid);
   }
 }

server/sonar-main/src/main/java/org/sonar/application/process/Lifecycle.java

@@ -66,7 +66,7 @@ public class Lifecycle {
     res.put(STARTED, toSet(STOPPING, STOPPED));
     res.put(STOPPING, toSet(STOPPED));
     res.put(STOPPED, toSet());
-    return res;
+    return Collections.unmodifiableMap(res);
   }
 
   private static Set<State> toSet(State... states) {

server/sonar-main/src/main/java/org/sonar/application/process/StopRequestWatcherImpl.java

@@ -20,7 +20,6 @@
 package org.sonar.application.process;
 
 import org.sonar.application.FileSystem;
-import org.sonar.application.Scheduler;
 import org.sonar.application.config.AppSettings;
 import org.sonar.process.ProcessId;
 import org.sonar.process.sharedmemoryfile.DefaultProcessCommands;
@@ -33,24 +32,24 @@ public class StopRequestWatcherImpl extends Thread implements StopRequestWatcher
   private static final long DEFAULT_WATCHER_DELAY_MS = 500L;
 
   private final ProcessCommands commands;
-  private final Scheduler scheduler;
+  private final Runnable listener;
   private final AppSettings settings;
   private long delayMs = DEFAULT_WATCHER_DELAY_MS;
 
-  StopRequestWatcherImpl(AppSettings settings, Scheduler scheduler, ProcessCommands commands) {
+  StopRequestWatcherImpl(AppSettings settings, Runnable listener, ProcessCommands commands) {
     super("StopRequestWatcherImpl");
     this.settings = settings;
     this.commands = commands;
-    this.scheduler = scheduler;
+    this.listener = listener;
 
     // safeguard, do not block the JVM if thread is not interrupted
     // (method stopWatching() never called).
     setDaemon(true);
   }
 
-  public static StopRequestWatcherImpl create(AppSettings settings, Scheduler scheduler, FileSystem fs) {
+  public static StopRequestWatcherImpl create(AppSettings settings, Runnable listener, FileSystem fs) {
     DefaultProcessCommands commands = DefaultProcessCommands.secondary(fs.getTempDir(), ProcessId.APP.getIpcIndex());
-    return new StopRequestWatcherImpl(settings, scheduler, commands);
+    return new StopRequestWatcherImpl(settings, listener, commands);
   }
 
   long getDelayMs() {
@@ -66,7 +65,7 @@ public class StopRequestWatcherImpl extends Thread implements StopRequestWatcher
     try {
       while (true) {
         if (commands.askedForStop()) {
-          scheduler.terminate();
+          listener.run();
           return;
         }
         Thread.sleep(delayMs);
@@ -86,7 +85,7 @@ public class StopRequestWatcherImpl extends Thread implements StopRequestWatcher
 
   @Override
   public void stopWatching() {
-    // does nothing is not started
+    // does nothing if not started
     interrupt();
   }
 }

server/sonar-main/src/test/java/org/sonar/application/process/StopRequestWatcherImplTest.java

@@ -27,7 +27,6 @@ import org.junit.rules.TemporaryFolder;
 import org.junit.rules.TestRule;
 import org.junit.rules.Timeout;
 import org.sonar.application.FileSystem;
-import org.sonar.application.Scheduler;
 import org.sonar.application.config.AppSettings;
 import org.sonar.process.sharedmemoryfile.ProcessCommands;
 
@@ -50,32 +49,32 @@ public class StopRequestWatcherImplTest {
 
   private AppSettings settings = mock(AppSettings.class, RETURNS_DEEP_STUBS);
   private ProcessCommands commands = mock(ProcessCommands.class);
-  private Scheduler scheduler = mock(Scheduler.class);
+  private Runnable listener = mock(Runnable.class);
 
   @Test
   public void do_not_watch_command_if_disabled() {
     enableSetting(false);
-    StopRequestWatcherImpl underTest = new StopRequestWatcherImpl(settings, scheduler, commands);
+    StopRequestWatcherImpl underTest = new StopRequestWatcherImpl(settings, listener, commands);
 
     underTest.startWatching();
     assertThat(underTest.isAlive()).isFalse();
 
     underTest.stopWatching();
-    verifyZeroInteractions(commands, scheduler);
+    verifyZeroInteractions(commands, listener);
   }
 
   @Test
   public void watch_stop_command_if_enabled() throws Exception {
     enableSetting(true);
-    StopRequestWatcherImpl underTest = new StopRequestWatcherImpl(settings, scheduler, commands);
+    StopRequestWatcherImpl underTest = new StopRequestWatcherImpl(settings, listener, commands);
     underTest.setDelayMs(1L);
 
     underTest.startWatching();
     assertThat(underTest.isAlive()).isTrue();
-    verify(scheduler, never()).terminate();
+    verify(listener, never()).run();
 
     when(commands.askedForStop()).thenReturn(true);
-    verify(scheduler, timeout(1_000L)).terminate();
+    verify(listener, timeout(1_000L)).run();
 
     underTest.stopWatching();
     while (underTest.isAlive()) {
@@ -88,7 +87,7 @@ public class StopRequestWatcherImplTest {
     FileSystem fs = mock(FileSystem.class);
     when(fs.getTempDir()).thenReturn(temp.newFolder());
 
-    StopRequestWatcherImpl underTest = StopRequestWatcherImpl.create(settings, scheduler, fs);
+    StopRequestWatcherImpl underTest = StopRequestWatcherImpl.create(settings, listener, fs);
 
     assertThat(underTest.getDelayMs()).isEqualTo(500L);
   }
@@ -96,7 +95,7 @@ public class StopRequestWatcherImplTest {
   @Test
   public void stop_watching_commands_if_thread_is_interrupted() throws Exception {
     enableSetting(true);
-    StopRequestWatcherImpl underTest = new StopRequestWatcherImpl(settings, scheduler, commands);
+    StopRequestWatcherImpl underTest = new StopRequestWatcherImpl(settings, listener, commands);
 
     underTest.startWatching();
     underTest.interrupt();

server/sonar-process/src/main/java/org/sonar/process/SystemExit.java

@@ -19,31 +19,29 @@
  */
 package org.sonar.process;
 
-import java.util.concurrent.atomic.AtomicBoolean;
-
 /**
  * Calls {@link System#exit(int)} except from shutdown hooks, to prevent
  * deadlocks. See http://stackoverflow.com/a/19552359/229031
  */
 public class SystemExit {
 
-  private final AtomicBoolean inShutdownHook = new AtomicBoolean(false);
+  private volatile boolean inShutdownHook = false;
 
   public void exit(int code) {
-    if (!inShutdownHook.get()) {
+    if (!inShutdownHook) {
       doExit(code);
     }
   }
 
   public boolean isInShutdownHook() {
-    return inShutdownHook.get();
+    return inShutdownHook;
   }
 
   /**
    * Declarative approach. I don't know how to get this lifecycle state from Java API.
    */
   public void setInShutdownHook() {
-    inShutdownHook.set(true);
+    inShutdownHook = true;
   }
 
   void doExit(int code) {

server/sonar-process/src/main/java/org/sonar/process/sharedmemoryfile/DefaultProcessCommands.java

@@ -38,14 +38,14 @@ public class DefaultProcessCommands implements ProcessCommands {
   /**
    * Main DefaultProcessCommands will clear the shared memory space of the specified process number when created and will
    * then write and/or read to it.
-   * Therefor there should be only one main DefaultProcessCommands.
+   * Therefore there should be only one main DefaultProcessCommands.
    */
   public static DefaultProcessCommands main(File directory, int processNumber) {
     return new DefaultProcessCommands(directory, processNumber, true);
   }
 
   /**
-   * Secondary DefaultProcessCommands will read and write to the shared memory space but will not clear it. Therefor, there
+   * Secondary DefaultProcessCommands will read and write to the shared memory space but will not clear it. Therefore, there
    * can be any number of them.
    */
   public static DefaultProcessCommands secondary(File directory, int processNumber) {

sonar-application/src/main/java/org/sonar/application/App.java

@@ -74,7 +74,7 @@ public class App {
 
         scheduler.schedule();
 
-        stopRequestWatcher = StopRequestWatcherImpl.create(settings, scheduler, fileSystem);
+        stopRequestWatcher = StopRequestWatcherImpl.create(settings, scheduler::terminate, fileSystem);
         stopRequestWatcher.startWatching();
 
         scheduler.awaitTermination();