On 7/04/2013 9:37 AM, Mani Sarkar wrote:
Hi David,
Sorry for not getting back earlier. Here's the changes to
/jdk8_tl/jdk/test/java/lang/ref/Basic.java that you suggested earlier.
Okay but what about my comment that the latch usage is completely
unnecessary in the first place ??
David
-----
-------------------x---------------------
diff -r 16f63a94c231 test/java/lang/ref/Basic.java
--- a/test/java/lang/ref/Basic.javaFri Apr 05 18:20:12 2013 -0700
+++ b/test/java/lang/ref/Basic.javaSun Apr 07 00:27:55 2013 +0100
@@ -29,7 +29,7 @@
import java.lang.ref.*;
import java.util.Vector;
-
+import java.util.concurrent.CountDownLatch;
public class Basic {
@@ -71,10 +71,11 @@
});
}
- static void createNoise() throws InterruptedException {
+ static void createNoise(final CountDownLatch complete) throws
InterruptedException {
fork(new Runnable() {
public void run() {
keep.addElement(new PhantomReference(new Object(), q2));
+ complete.countDown();
}
});
}
@@ -101,9 +102,11 @@
for (int i = 1;; i++) {
Reference r;
- createNoise();
++ CountDownLatch noiseComplete = new CountDownLatch(1);
++ createNoise(noiseComplete);
+
System.err.println("GC " + i);
- Thread.sleep(10);
+ noiseComplete.await();
System.gc();
System.runFinalization();
-------------------x---------------------
Its still implemented with CountdownLatch, but as you suggest we
implement the above via Semaphore it will have to be the next version
from me - CountdownLatch was suggested by many at the TestFest last
month but personally I benefit from getting exposed to different
techniques. I'll back to you with a solution applied using Semaphore.
Cheers,
mani
On Fri, Apr 5, 2013 at 2:40 AM, David Holmes <david.hol...@oracle.com
<mailto:david.hol...@oracle.com>> wrote:
On 5/04/2013 11:27 AM, Mani Sarkar wrote:
Hi David,
I'll reply in more detail later but to respond to your comment on:
> I would not add the extra methods around the cdl.await() and
cdl.countDown() as they just obscure things
In general its meant to do the opposite. We come across a lot of
code
that does not express intent, and the purpose of encapsulating such
blocks (even if its a single line) is to make the flow verbose and
readable - I have seen similar code-snippets in the Hotspot (C/C++
codebase) making it easy to follow what is going on. One of the
things I
picked up from TestFest was to make the tests more legible,
logical and
easy to maintain and scale - it was our intent when we changed
this test.
Sorry, createNoiseHasFinishedAddingTo__Keep is certainly verbose but
not readable. This would be much more readable:
Countdownlatch noiseComplete = new ...
createNoise(noiseComplete);
...
noiseComplete.await();
and:
static void createNoise(final CountDownLatch complete) throws
InterruptedException {
...
complete.countDown();
}
just giving the latch a meaningful name is sufficient to convey intent.
Note: in this example a Semaphore is probably a better choice than a
CountDownLatch.
Cheers,
David
I'll come back with responses for your other comments.
Cheers
mani
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