On 17.05.16 07:53, Alain Stalder wrote:
I will definitely try out the InvokerHelper.removeClass(clazz) with
added ClassInfo removal plus Introspector.flushFromCaches(clazz) and
see if I can get garbage collection before reaching the limit on
Metaspace or Heap.
Fantastic, I really got it to work :)
I took groovy master plus changes for GROOVY-7646 and GROOVY-7683 and
modified the test in ClassGCTester as follows:
--
long nanoT0 = System.nanoTime();
Class<?> clazz = classLoader.loadClass(testClassName);
long nanoT1 = System.nanoTime();
clazz.newInstance();
long nanoT2 = System.nanoTime();
loadTimeTotal += (nanoT1 - nanoT0);
createTimeTotal += (nanoT2 - nanoT1);
weakFillingClassesMap.put(clazz, "");
// added:
Class<?> invokerHelperClass =
ClassGCTester.class.getClassLoader().loadClass("org.codehaus.groovy.runtime.InvokerHelper");
Method removeClassMethod =
invokerHelperClass.getDeclaredMethod("removeClass", Class.class);
removeClassMethod.invoke(null, clazz);
//Introspector.flushFromCaches(clazz);
--
An then ran the test as follows (not using ClassValue, loading the test
class not from the same ClassLoader as Groovy itself):
$ java -XX:MaxMetaspaceSize=64m -Xmx512m -cp .:groovy-2.5.0-SNAPSHOT.jar
ClassGCTester -cp filling/ -parent tester -classes GroovyFilling
--
Secs Test classes Metaspace/PermGen Heap Load time Create
time
#loaded #remaining used committed used
committed average average
0 1 1 6.3m 6.5m 12.8m 245.5m
0.838ms 11.112ms
1 486 486 9.2m 10.5m 27.6m 245.5m
0.326ms 1.624ms
2 1404 1404 12.7m 16.1m 30.3m 245.5m
0.244ms 1.124ms
3 2308 61 7.6m 16.8m 12.2m 228.5m
0.241ms 1.014ms
4 3461 1214 12.0m 16.8m 46.4m 244.0m
0.212ms 0.908ms
5 4577 2330 16.3m 21.4m 69.1m 240.0m
0.200ms 0.860ms
6 5581 3334 20.1m 27.4m 75.1m 237.5m
0.197ms 0.847ms
7 6703 974 11.1m 18.2m 11.3m 268.0m
0.197ms 0.818ms
8 7996 2267 16.0m 23.4m 65.7m 253.5m
0.188ms 0.786ms
9 9261 3532 20.9m 28.5m 115.1m 267.5m
0.182ms 0.765ms
10 10518 960 11.0m 20.0m 10.9m 285.0m
0.181ms 0.747ms
11 11841 2283 16.1m 24.0m 68.9m 285.0m
0.177ms 0.730ms
12 13097 3539 20.9m 29.0m 113.9m 285.0m
0.173ms 0.722ms
13 14288 331 8.7m 21.3m 49.6m 314.0m
0.174ms 0.715ms
14 15640 1683 13.8m 22.9m 105.5m 316.0m
0.170ms 0.705ms
15 16923 2966 18.7m 27.9m 150.4m 315.5m
0.168ms 0.699ms
16 18128 4171 23.3m 32.6m 54.6m 316.0m
0.166ms 0.697ms
17 19360 628 9.8m 21.5m 88.6m 347.0m
0.167ms 0.692ms
18 20707 1975 15.0m 24.6m 137.6m 346.5m
0.165ms 0.685ms
19 21958 3226 19.7m 29.6m 39.1m 347.5m
0.164ms 0.683ms
20 23172 4440 24.4m 34.4m 66.4m 349.5m
0.163ms 0.682ms
21 24430 861 10.7m 21.9m 120.7m 383.5m
0.163ms 0.678ms
22 25725 2156 15.7m 25.5m 19.0m 381.0m
0.162ms 0.675ms
23 26986 3417 20.5m 30.5m 49.3m 385.0m
0.161ms 0.674ms
24 28192 4623 25.1m 35.3m 70.8m 384.5m
0.161ms 0.673ms
25 29454 956 11.1m 21.0m 134.6m 416.0m
0.161ms 0.671ms
26 30737 2239 16.0m 26.3m 25.2m 416.5m
0.160ms 0.669ms
[...]
--
Nicely garbage collects repeatedly, Metaspace stay well below the
configured maximum of 64m...
PS: Note that Introspector.flushFromCaches(clazz) was experimentally
really not necessary in this case, but maybe has to do with the simple
nature of the test script ("42") and only calling a (no-args)
constructor... In any case very promising...
Alain
