Cleanups: Collections.singleton(), COWAS - includes ticket #388

core/java/src/net/i2p/crypto/ElGamalAESEngine.java

@@ -10,6 +10,7 @@ package net.i2p.crypto;
  */
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
@@ -527,8 +528,6 @@ public class ElGamalAESEngine {
         return aesEncr;
     }
 
-    private final static Set EMPTY_SET = new HashSet();
-
     /**
      * For both scenarios, this method encrypts the AES area using the given key, iv
      * and making sure the resulting data is at least as long as the paddedSize and 
@@ -552,7 +551,7 @@ public class ElGamalAESEngine {
                                         long paddedSize, int prefixBytes) {
         //_log.debug("iv for encryption: " + DataHelper.toString(iv, 16));
         //_log.debug("Encrypting AES");
-        if (tagsForDelivery == null) tagsForDelivery = EMPTY_SET;
+        if (tagsForDelivery == null) tagsForDelivery = Collections.EMPTY_SET;
         int size = 2 // sizeof(tags)
                  + tagsForDelivery.size()
                  + SessionTag.BYTE_LENGTH*tagsForDelivery.size()

core/java/src/net/i2p/util/Clock.java

@@ -1,8 +1,8 @@
 package net.i2p.util;
 
-import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Set;
+import java.util.concurrent.CopyOnWriteArraySet;
 
 import net.i2p.I2PAppContext;
 import net.i2p.time.Timestamper;
@@ -19,19 +19,19 @@ import net.i2p.time.Timestamper;
  *
  */
 public class Clock implements Timestamper.UpdateListener {
-    protected I2PAppContext _context;
-    private Timestamper _timestamper;
-    protected long _startedOn;
+    protected final I2PAppContext _context;
+    private final Timestamper _timestamper;
+    protected final long _startedOn;
     protected boolean _statCreated;
+    protected volatile long _offset;
+    protected boolean _alreadyChanged;
+    private final Set _listeners;
     
     public Clock(I2PAppContext context) {
         _context = context;
-        _offset = 0;
-        _alreadyChanged = false;
-        _listeners = new HashSet(1);
+        _listeners = new CopyOnWriteArraySet();
         _timestamper = new Timestamper(context, this);
         _startedOn = System.currentTimeMillis();
-        _statCreated = false;
     }
     public static Clock getInstance() {
         return I2PAppContext.getGlobalContext().clock();
@@ -41,10 +41,6 @@ public class Clock implements Timestamper.UpdateListener {
     
     /** we fetch it on demand to avoid circular dependencies (logging uses the clock) */
     protected Log getLog() { return _context.logManager().getLog(Clock.class); }
-    
-    protected volatile long _offset;
-    protected boolean _alreadyChanged;
-    private final Set _listeners;
 
     /** if the clock is skewed by 3+ days, fuck 'em */
     public final static long MAX_OFFSET = 3 * 24 * 60 * 60 * 1000;
@@ -136,24 +132,18 @@ public class Clock implements Timestamper.UpdateListener {
     }
 
     public void addUpdateListener(ClockUpdateListener lsnr) {
-        synchronized (_listeners) {
             _listeners.add(lsnr);
-        }
     }
 
     public void removeUpdateListener(ClockUpdateListener lsnr) {
-        synchronized (_listeners) {
             _listeners.remove(lsnr);
-        }
     }
 
     protected void fireOffsetChanged(long delta) {
-        synchronized (_listeners) {
             for (Iterator iter = _listeners.iterator(); iter.hasNext();) {
                 ClockUpdateListener lsnr = (ClockUpdateListener) iter.next();
                 lsnr.offsetChanged(delta);
             }
-        }
     }
 
     public static interface ClockUpdateListener {

core/java/src/net/i2p/util/I2PAppThread.java

@@ -10,9 +10,9 @@ package net.i2p.util;
  */
 
 
-import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Set;
+import java.util.concurrent.CopyOnWriteArraySet;
 
 /**
  * Like I2PThread but with per-thread OOM listeners,
@@ -22,7 +22,7 @@ import java.util.Set;
  */
 public class I2PAppThread extends I2PThread {
 
-    private Set _threadListeners = new HashSet(0);
+    private final Set _threadListeners = new CopyOnWriteArraySet();
 
     public I2PAppThread() {
         super();

core/java/src/net/i2p/util/I2PThread.java

@@ -10,9 +10,9 @@ package net.i2p.util;
  */
 
 
-import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Set;
+import java.util.concurrent.CopyOnWriteArraySet;
 
 /**
  * In case its useful later...
@@ -21,7 +21,7 @@ import java.util.Set;
  */
 public class I2PThread extends Thread {
     private static volatile Log _log;
-    private static Set _listeners = new HashSet(4);
+    private static final Set _listeners = new CopyOnWriteArraySet();
     private String _name;
     private Exception _createdBy;