Issue 308 in google-collections: MemoryLeak(?) when using expiration in MapMaker

[codesite...@google.com]

Status: New
Owner: ----

New issue 308 by woidjoe: MemoryLeak(?) when using expiration in MapMaker
http://code.google.com/p/google-collections/issues/detail?id=308

Expected: Using "public MapMaker expiration(long duration, TimeUnit unit)"
should not
influence garbage collection.

Observed: In one of my junit tests, test case A asserts that an
OutOfMemoryError is thrown
under special circumstances when MapMaker and expiration are used. Test
case B, which is
executed after A and does something different with a new map instance,
unexpectedly fails
with OOME. This means the memory allocated in test case A was not released,
even though no
fields are used and an new map instance is created. If expiration is not
used, all works as
expected.

I tried to reproduce the same effect in a smaller test case, but did not
succeed. Instead
expecting an OOME already fails (with an OOME). Looking at the stacktrace,
the junit code
executed after a test, runs into an OOME (which also indicates, that the
memory allocated
in the test is not released).

Stacktrace:
java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOfRange(Arrays.java:3209)
at java.lang.String.<init>(String.java:216)
at java.lang.StringBuilder.toString(StringBuilder.java:430)
at java.net.URLStreamHandler.parseURL(URLStreamHandler.java:232)
at sun.net.www.protocol.file.Handler.parseURL(Handler.java:50)
at java.net.URL.<init>(URL.java:596)
at java.net.URL.<init>(URL.java:464)
at sun.misc.URLClassPath$FileLoader.getResource(URLClassPath.java:973)
at sun.misc.URLClassPath.getResource(URLClassPath.java:168)
at java.net.URLClassLoader$1.run(URLClassLoader.java:192)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
at
org.junit.internal.runners.model.EachTestNotifier.addFailure(EachTestNotifier.java:29)
at org.junit.runners.ParentRunner.run(ParentRunner.java:226)
at
org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46)
at
org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)


Attachments:
ExpirationMemoryLeak.java 475 bytes

--
You received this message because you are listed in the owner
or CC fields of this issue, or because you starred this issue.
You may adjust your issue notification preferences at:
http://code.google.com/hosting/settings

[codesite...@google.com]

Comment #1 on issue 308 by woidjoe: MemoryLeak(?) when using expiration in
MapMaker
http://code.google.com/p/google-collections/issues/detail?id=308

This also seems to destroy the semantic of weakValues().

To reproduce:

1. Remove "(expected = OutOfMemoryError.class)" from the test case.

2.a. remove expiration() and and add weakValues()
ConcurrentMap<String, String> map = new MapMaker().weakValues().makeMap();
Observed: Works, no OOME.

2.b. Leave expiration() in place and add weakValues()
ConcurrentMap<String, String> map = new
MapMaker().weakValues().expiration(3600,
TimeUnit.SECONDS).makeMap();
Observed: OOME (even though weakValues() was used!) What is more the number
of entries that
can be stored in this way does not differ much from not using weakValues()
at all. In my test
the combination weakValues/expiration adds ~ 550K while a normal "new
MapMaker().makeMap()"-
map adds ~ 450K.