Hadoop-18519. Backport HDFS-15383 and HADOOP-17835 to branch-3.3

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/token/delegation/AbstractDelegationTokenSecretManager.java

@@ -23,11 +23,11 @@
 import java.io.IOException;
 import java.security.MessageDigest;
 import java.util.Collection;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 
 import javax.crypto.SecretKey;
 
@@ -58,10 +58,9 @@
 
 @InterfaceAudience.Public
 @InterfaceStability.Evolving
-public abstract 
-class AbstractDelegationTokenSecretManager<TokenIdent 
-extends AbstractDelegationTokenIdentifier> 
-   extends SecretManager<TokenIdent> {
+public abstract class AbstractDelegationTokenSecretManager<TokenIdent
+    extends AbstractDelegationTokenIdentifier>
+    extends SecretManager<TokenIdent> {
   private static final Logger LOG = LoggerFactory
       .getLogger(AbstractDelegationTokenSecretManager.class);
 
@@ -80,7 +79,7 @@ private String formatTokenId(TokenIdent id) {
    * to DelegationTokenInformation. Protected by this object lock.
    */
   protected final Map<TokenIdent, DelegationTokenInformation> currentTokens 
-      = new HashMap<TokenIdent, DelegationTokenInformation>();
+      = new ConcurrentHashMap<>();
 
   /**
    * Sequence number to create DelegationTokenIdentifier.
@@ -89,17 +88,17 @@ private String formatTokenId(TokenIdent id) {
   protected int delegationTokenSequenceNumber = 0;
 
   /**
-   * Access to allKeys is protected by this object lock
+   * Access to allKeys is protected by this object lock.
    */
   protected final Map<Integer, DelegationKey> allKeys 
-      = new HashMap<Integer, DelegationKey>();
+      = new ConcurrentHashMap<>();
 
   /**
    * Access to currentId is protected by this object lock.
    */
   protected int currentId = 0;
   /**
-   * Access to currentKey is protected by this object lock
+   * Access to currentKey is protected by this object lock.
    */
   private DelegationKey currentKey;
 
@@ -122,7 +121,7 @@ private String formatTokenId(TokenIdent id) {
   protected Object noInterruptsLock = new Object();
 
   /**
-   * Create a secret manager
+   * Create a secret manager.
    * @param delegationKeyUpdateInterval the number of milliseconds for rolling
    *        new secret keys.
    * @param delegationTokenMaxLifetime the maximum lifetime of the delegation
@@ -183,8 +182,9 @@ public long getCurrentTokensSize() {
    * @throws IOException raised on errors performing I/O.
    */
   public synchronized void addKey(DelegationKey key) throws IOException {
-    if (running) // a safety check
+    if (running) { // a safety check
       throw new IOException("Can't add delegation key to a running SecretManager.");
+    }
     if (key.getKeyId() > getCurrentKeyId()) {
       setCurrentKeyId(key.getKeyId());
     }
@@ -453,8 +453,9 @@ private synchronized void removeExpiredKeys() {
         it.remove();
         // ensure the tokens generated by this current key can be recovered
         // with this current key after this current key is rolled
-        if(!e.getValue().equals(currentKey))
+        if(!e.getValue().equals(currentKey)) {
           removeStoredMasterKey(e.getValue());
+        }
       }
     }
   }
@@ -729,8 +730,9 @@ protected void logExpireTokens(
   }
 
   public void stopThreads() {
-    if (LOG.isDebugEnabled())
+    if (LOG.isDebugEnabled()) {
       LOG.debug("Stopping expired delegation token remover thread");
+    }
     running = false;
 
     if (tokenRemoverThread != null) {