6882654: Remove dependency on java.util.concurrent from KeepAlive implementaion

Reviewed-by: michaelm

src/share/classes/sun/net/www/http/KeepAliveCache.java

@@ -25,12 +25,11 @@
 
 package sun.net.www.http;
 
-import java.io.InputStream;
 import java.io.IOException;
 import java.io.NotSerializableException;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.net.URL;
-import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * A class that implements a cache of idle Http connections for keep-alive
@@ -39,7 +38,7 @@ import java.util.concurrent.ConcurrentHashMap;
  * @author Dave Brown
  */
 public class KeepAliveCache
-    extends ConcurrentHashMap<KeepAliveKey, ClientVector>
+    extends HashMap<KeepAliveKey, ClientVector>
     implements Runnable {
     private static final long serialVersionUID = -2937172892064557949L;
 
@@ -163,8 +162,8 @@ public class KeepAliveCache
      * Errs on the side of caution (leave connections idle for a relatively
      * short time).
      */
+    @Override
     public void run() {
-        int total_cache;
         do {
             try {
                 Thread.sleep(LIFETIME);
@@ -311,6 +310,7 @@ class KeepAliveKey {
     /**
      * Determine whether or not two objects of this type are equal
      */
+    @Override
     public boolean equals(Object obj) {
         if ((obj instanceof KeepAliveKey) == false)
             return false;
@@ -325,6 +325,7 @@ class KeepAliveKey {
      * The hashCode() for this object is the string hashCode() of
      * concatenation of the protocol, host name and port.
      */
+    @Override
     public int hashCode() {
         String str = protocol+host+port;
         return this.obj == null? str.hashCode() :

src/share/classes/sun/net/www/http/KeepAliveStream.java

@@ -25,10 +25,7 @@
 
 package sun.net.www.http;
 
-import java.net.URL;
-import java.net.HttpURLConnection;
 import java.io.*;
-import java.util.StringTokenizer;
 import sun.net.ProgressSource;
 import sun.net.www.MeteredStream;
 
@@ -50,9 +47,8 @@ class KeepAliveStream extends MeteredStream implements Hurryable {
     // has this KeepAliveStream been put on the queue for asynchronous cleanup.
     protected boolean queuedForCleanup = false;
 
-    private static KeepAliveStreamCleaner queue = new KeepAliveStreamCleaner();
-    private static Thread cleanerThread = null;
-    private static boolean startCleanupThread;
+    private static final KeepAliveStreamCleaner queue = new KeepAliveStreamCleaner();
+    private static Thread cleanerThread; // null
 
     /**
      * Constructor
@@ -155,43 +151,46 @@ class KeepAliveStream extends MeteredStream implements Hurryable {
         }
     }
 
-    private static synchronized void queueForCleanup(KeepAliveCleanerEntry kace) {
-        if(queue != null && !kace.getQueuedForCleanup()) {
-            if (!queue.offer(kace)) {
-                kace.getHttpClient().closeServer();
-                return;
-            }
+    private static void queueForCleanup(KeepAliveCleanerEntry kace) {
+        synchronized(queue) {
+            if(!kace.getQueuedForCleanup()) {
+                if (!queue.offer(kace)) {
+                    kace.getHttpClient().closeServer();
+                    return;
+                }
 
-            kace.setQueuedForCleanup();
-        }
+                kace.setQueuedForCleanup();
+                queue.notifyAll();
+            }
 
-        startCleanupThread = (cleanerThread == null);
-        if (!startCleanupThread) {
-            if (!cleanerThread.isAlive()) {
-                startCleanupThread = true;
+            boolean startCleanupThread = (cleanerThread == null);
+            if (!startCleanupThread) {
+                if (!cleanerThread.isAlive()) {
+                    startCleanupThread = true;
+                }
             }
-        }
 
-        if (startCleanupThread) {
-            java.security.AccessController.doPrivileged(
-                new java.security.PrivilegedAction<Void>() {
-                public Void run() {
-                    // We want to create the Keep-Alive-SocketCleaner in the
-                    // system threadgroup
-                    ThreadGroup grp = Thread.currentThread().getThreadGroup();
-                    ThreadGroup parent = null;
-                    while ((parent = grp.getParent()) != null) {
-                        grp = parent;
+            if (startCleanupThread) {
+                java.security.AccessController.doPrivileged(
+                    new java.security.PrivilegedAction<Void>() {
+                    public Void run() {
+                        // We want to create the Keep-Alive-SocketCleaner in the
+                        // system threadgroup
+                        ThreadGroup grp = Thread.currentThread().getThreadGroup();
+                        ThreadGroup parent = null;
+                        while ((parent = grp.getParent()) != null) {
+                            grp = parent;
+                        }
+
+                        cleanerThread = new Thread(grp, queue, "Keep-Alive-SocketCleaner");
+                        cleanerThread.setDaemon(true);
+                        cleanerThread.setPriority(Thread.MAX_PRIORITY - 2);
+                        cleanerThread.start();
+                        return null;
                     }
-
-                    cleanerThread = new Thread(grp, queue, "Keep-Alive-SocketCleaner");
-                    cleanerThread.setDaemon(true);
-                    cleanerThread.setPriority(Thread.MAX_PRIORITY - 2);
-                    cleanerThread.start();
-                    return null;
-                }
-            });
-        }
+                });
+            }
+        } // queue
     }
 
     protected long remainingToRead() {

src/share/classes/sun/net/www/http/KeepAliveStreamCleaner.java

@@ -25,9 +25,8 @@
 
 package sun.net.www.http;
 
-import java.util.concurrent.LinkedBlockingQueue;
-import java.util.concurrent.TimeUnit;
 import java.io.IOException;
+import java.util.LinkedList;
 import sun.net.NetProperties;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
@@ -44,7 +43,9 @@ import java.security.PrivilegedAction;
  */
 
 @SuppressWarnings("serial")  // never serialized
-public class KeepAliveStreamCleaner extends LinkedBlockingQueue<KeepAliveCleanerEntry> implements Runnable
+class KeepAliveStreamCleaner
+    extends LinkedList<KeepAliveCleanerEntry>
+    implements Runnable
 {
     // maximum amount of remaining data that we will try to cleanup
     protected static int MAX_DATA_REMAINING = 512;
@@ -78,23 +79,39 @@ public class KeepAliveStreamCleaner extends LinkedBlockingQueue<KeepAliveCleaner
     }
 
 
-    public KeepAliveStreamCleaner()
-    {
-        super(MAX_CAPACITY);
-    }
+    @Override
+    public boolean offer(KeepAliveCleanerEntry e) {
+        if (size() >= MAX_CAPACITY)
+            return false;
 
-    public KeepAliveStreamCleaner(int capacity)
-    {
-        super(capacity);
+        return super.offer(e);
     }
 
+    @Override
     public void run()
     {
         KeepAliveCleanerEntry kace = null;
 
         do {
             try {
-                kace = poll((long)TIMEOUT, TimeUnit.MILLISECONDS);
+                synchronized(this) {
+                    long before = System.currentTimeMillis();
+                    long timeout = TIMEOUT;
+                    while ((kace = poll()) == null) {
+                        this.wait(timeout);
+
+                        long after = System.currentTimeMillis();
+                        long elapsed = after - before;
+                        if (elapsed > timeout) {
+                            /* one last try */
+                            kace = poll();
+                            break;
+                        }
+                        before = after;
+                        timeout -= elapsed;
+                    }
+                }
+
                 if(kace == null)
                     break;