Re: RFR [9] Remove sun.misc.Queue and replace usages with standard Collections

[Sergey Bylokhov]

What is the reason to use assertion? If the problem is not theoretical,

That was tricky to spot :-) nearly missed it.
Since the queue is not "capacity-restricted" i think add(E) is the more 
appropriate choice.

+1 I think so.

—

I suspect this use of queues in AppletPanel could be cleaned up given the 
usages of with synchronised blocks (and the sun.misc.Queue style is probably a 
hangover from the java.util.Vector days). Anyway, that’s for another day if the 
AWT devs want to take that on :-)

Paul.

then probably OOM(or something like that) will be better?

I don’t think OOM is quite right. Maybe ISE, as above is better?

-Chris.

On 11/12/15 20:22, Chris Hegarty wrote:

More technical debt in sun.misc…

Java SE has had support for Queues in Collections for many major releases,
sun.misc.Queue seems to predate that. I cannot find any usages outside of the
JDK, and just one in the JDK, AppletPanel. LinkedBlockingQueue appears to
provide the necessary minimum functionality required by AppletPanel, FIFO
blocking operations.

The changes are quite small so I just included the diffs inline.

Note: we could use either add(E) or offer(E) below, I don’t have a strong 
opinion
either way.

$ hg rm src/java.base/share/classes/sun/misc/Queue.java

diff --git a/src/java.desktop/share/classes/sun/applet/AppletPanel.java 
b/src/java.desktop/share/classes/sun/applet/AppletPanel.java
--- a/src/java.desktop/share/classes/sun/applet/AppletPanel.java
+++ b/src/java.desktop/share/classes/sun/applet/AppletPanel.java
@@ -38,6 +38,7 @@
import java.security.*;
import java.util.*;
import java.util.Locale;
+import java.util.concurrent.LinkedBlockingQueue;
import sun.awt.AWTAccessor;
import sun.awt.AppContext;
import sun.awt.EmbeddedFrame;
@@ -45,7 +46,6 @@
import sun.misc.ManagedLocalsThread;
import sun.misc.MessageUtils;
import sun.misc.PerformanceLogger;
-import sun.misc.Queue;
import sun.security.util.SecurityConstants;

/**
@@ -247,8 +247,7 @@
     /**
      * AppletEvent Queue
      */
-    private Queue<Integer> queue = null;
-
+    private LinkedBlockingQueue<Integer> queue = null;

     public synchronized void addAppletListener(AppletListener l) {
         listeners = AppletEventMulticaster.add(listeners, l);
@@ -276,10 +275,10 @@
         synchronized(this) {
             if (queue == null) {
                 //System.out.println("SEND0= " + id);
-                queue = new Queue<>();
+                queue = new LinkedBlockingQueue<>();
             }
-            Integer eventId = Integer.valueOf(id);
-            queue.enqueue(eventId);
+            boolean inserted = queue.offer(id);
+            assert inserted;
             notifyAll();
         }
         if (id == APPLET_QUIT) {
@@ -303,8 +302,8 @@
         while (queue == null || queue.isEmpty()) {
             wait();
         }
-        Integer eventId = queue.dequeue();
-        return new AppletEvent(this, eventId.intValue(), null);
+        int eventId = queue.take();
+        return new AppletEvent(this, eventId, null);
     }

     boolean emptyEventQueue() {

-Chris.

--
Best regards, Sergey.

--
Best regards, Sergey.