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test/jdk/java/lang/management/MemoryMXBean/ResetPeakMemoryUsage.java
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@@ -46,10 +46,11 @@
import java.lang.management.*;
import java.lang.ref.WeakReference;
import java.util.*;
import sun.hotspot.code.Compiler;
+import sun.hotspot.WhiteBox;
public class ResetPeakMemoryUsage {
private static MemoryMXBean mbean = ManagementFactory.getMemoryMXBean();
// make public so that it can't be optimized away easily
public static Object[] obj;
@@ -65,11 +66,14 @@
final String mn = "-Xmn8m";
if (!Compiler.isGraalEnabled()) { // Graal does not support CMS
RunUtil.runTestClearGcOpts(main, ms, mn, "-XX:+UseConcMarkSweepGC");
}
RunUtil.runTestClearGcOpts(main, ms, mn, "-XX:+UseParallelGC");
- RunUtil.runTestClearGcOpts(main, ms, mn, "-XX:+UseG1GC", "-XX:G1HeapRegionSize=1m");
+ RunUtil.runTestClearGcOpts(main, ms, mn, "-XX:+UseG1GC", "-XX:-G1UseLegacyMonitoring",
+ "-XX:G1HeapRegionSize=1m");
+ RunUtil.runTestClearGcOpts(main, ms, mn, "-XX:+UseG1GC", "-XX:+G1UseLegacyMonitoring",
+ "-XX:G1HeapRegionSize=1m");
RunUtil.runTestClearGcOpts(main, ms, mn, "-XX:+UseSerialGC",
"-XX:MarkSweepAlwaysCompactCount=1");
}
private static class TestMain {
@@ -77,20 +81,35 @@
List pools = ManagementFactory.getMemoryPoolMXBeans();
ListIterator iter = pools.listIterator();
boolean found = false;
while (iter.hasNext()) {
MemoryPoolMXBean p = (MemoryPoolMXBean) iter.next();
- // only check heap pools that support usage threshold
- // this is typically only the old generation space
- // since the other spaces are expected to get filled up
+ // Only check heap pools that support a usage threshold.
+ // This is typically only the old generation space
+ // since the other spaces are expected to get filled up.
if (p.getType() == MemoryType.HEAP &&
- p.isUsageThresholdSupported())
- {
+ p.isUsageThresholdSupported()) {
+ // In all collectors except G1, only the old generation supports a
+ // usage threshold. The G1 legacy mode "G1 Old Gen" also does. In
+ // G1 default mode, both the old space ("G1 Old Space": it's not
+ // really a generation in the non-G1 collector sense) and the
+ // humongous space ("G1 Humongous Space"), support a usage threshold.
+ // So, the following condition is true for all non-G1 old generations,
+ // for the G1 legacy old gen, and for the G1 default humongous space.
+ // It is not true for the G1 default old gen.
+ //
+ // We're allocating humongous objects in this test, so the G1 default
+ // mode "G1 Old Space" occupancy doesn't change, because humongous
+ // objects are allocated in the "G1 Humongous Space". If we allowed
+ // the G1 default mode "G1 Old Space", notification would never
+ // happen because no objects are allocated there.
+ if (!p.getName().equals("G1 Old Space")) {
found = true;
testPool(p);
}
}
+ }
if (!found) {
throw new RuntimeException("No heap pool found");
}
}
}
@@ -129,17 +148,15 @@
formatSize("Before allocation: peak", peak0.getUsed()) +
" expected to be < " +
formatSize("After allocation: peak", peak1.getUsed()));
}
-
- // The object is now garbage and do a GC
- // memory usage should drop
+ // The object is now garbage and do a GC. Memory usage should drop.
obj = null;
- //This will cause sure shot GC unlike Runtime.gc() invoked by mbean.gc()
- while(weakRef.get() != null) {
+ // This will cause a sure shot GC unlike Runtime.gc() invoked by mbean.gc()
+ while (weakRef.get() != null) {
mbean.gc();
}
MemoryUsage usage2 = mpool.getUsage();
MemoryUsage peak2 = mpool.getPeakUsage();
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