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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
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*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package gc.g1.humongousObjects;
import jdk.test.lib.Utils;
import sun.hotspot.WhiteBox;
import java.util.LinkedList;
import java.util.List;
import java.util.Random;
import java.util.stream.Collectors;
/**
* @test TestNoAllocationsInHRegions
* @summary Checks that no additional allocations are made in humongous regions
* @requires vm.gc.G1
* @library /test/lib /
* @modules java.management java.base/jdk.internal.misc
* @build sun.hotspot.WhiteBox
* @run driver ClassFileInstaller sun.hotspot.WhiteBox
* sun.hotspot.WhiteBox$WhiteBoxPermission
*
* @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
* -XX:G1HeapRegionSize=1M -Xms200m -Xmx200m -XX:MaxTenuringThreshold=0
* -Xlog:gc=trace:file=TestNoAllocationsInHRegions10.log
* gc.g1.humongousObjects.TestNoAllocationsInHRegions 30 10
*
* @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
* -XX:G1HeapRegionSize=1M -Xms200m -Xmx200m -XX:MaxTenuringThreshold=0
* -Xlog:gc=trace:file=TestNoAllocationsInHRegions50.log
* gc.g1.humongousObjects.TestNoAllocationsInHRegions 30 50
*
* @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
* -XX:G1HeapRegionSize=1M -Xms200m -Xmx200m -XX:MaxTenuringThreshold=0
* -Xlog:gc=trace:file=TestNoAllocationsInHRegions70.log
* gc.g1.humongousObjects.TestNoAllocationsInHRegions 30 70
*/
public class TestNoAllocationsInHRegions {
private static final WhiteBox WB = WhiteBox.getWhiteBox();
private static final Random RND = Utils.getRandomInstance();
private static final int G1_REGION_SIZE = WB.g1RegionSize();
private static final int[] HUMONGOUS_SIZES = {G1_REGION_SIZE / 2, G1_REGION_SIZE + 1, G1_REGION_SIZE * 2 + 1};
private static final int ALLOC_THREAD_COUNT = 5;
// We fill specified part of heap with humongous objects - we need public static to prevent escape analysis to
// collect this field
public static LinkedList<byte[]> humongousAllocations = new LinkedList<>();
private static volatile boolean shouldStop = false;
private static volatile Error error = null;
static class Allocator implements Runnable {
private final List<byte[]> liveObjects = new LinkedList<>();
private int usedMemory = 0;
public final Runnable[] actions;
/**
* Maximum size of simple allocation
*/
private static final int MAX_ALLOCATION_SIZE = (int) (G1_REGION_SIZE / 2 * 0.9);
/**
* Maximum size of dead (i.e. one which is made unreachable right after allocation) object
*/
private static final int DEAD_OBJECT_MAX_SIZE = G1_REGION_SIZE / 10;
public Allocator(int maxAllocationMemory) {
actions = new Runnable[]{
// Allocation
() -> {
if (maxAllocationMemory - usedMemory != 0) {
int arraySize = RND.nextInt(Math.min(maxAllocationMemory - usedMemory,
MAX_ALLOCATION_SIZE));
if (arraySize != 0) {
byte[] allocation = new byte[arraySize];
liveObjects.add(allocation);
usedMemory += arraySize;
// Sanity check
if (WB.g1IsHumongous(allocation)) {
String errorMessage = String.format("Test Bug: Byte array of size"
+ " %d is expected to be non-humongous but it is humongous",
allocation.length);
System.out.println(errorMessage);
error = new Error(errorMessage);
shouldStop = true;
}
// Test check
if (WB.g1BelongsToHumongousRegion(WB.getObjectAddress(allocation))) {
String errorMessage = String.format("Non-humongous allocation of byte array of "
+ "length %d and size %d with address %d was made in Humongous Region",
allocation.length, WB.getObjectSize(allocation),
WB.getObjectAddress(allocation));
System.out.println(errorMessage);
error = new Error(errorMessage);
shouldStop = true;
}
}
}
},
// Deallocation
() -> {
if (liveObjects.size() != 0) {
int elementNum = RND.nextInt(liveObjects.size());
int shouldFree = liveObjects.get(elementNum).length;
liveObjects.remove(elementNum);
usedMemory -= shouldFree;
}
},
// Dead object allocation
() -> {
int size = RND.nextInt(DEAD_OBJECT_MAX_SIZE);
byte[] deadObject = new byte[size];
},
// Check
() -> {
List<byte[]> wrongHumongousAllocations = liveObjects.stream()
.filter(WB::g1IsHumongous)
.collect(Collectors.toList());
if (wrongHumongousAllocations.size() > 0) {
wrongHumongousAllocations.stream().forEach(a ->
System.out.format("Non-humongous allocation of byte array of length %d and"
+ " size %d with address %d was made in Humongous Region",
a.length, WB.getObjectSize(a), WB.getObjectAddress(a)));
error = new Error("Some non-humongous allocations were made to humongous region");
shouldStop = true;
}
}
};
}
@Override
public void run() {
while (!shouldStop) {
actions[RND.nextInt(actions.length)].run();
Thread.yield();
}
}
}
public static void main(String[] args) {
if (args.length != 2) {
throw new Error("Test Bug: Expected duration (in seconds) and percent of allocated regions were not "
+ "provided as command line argument");
}
// test duration
long duration = Integer.parseInt(args[0]) * 1000L;
// part of heap preallocated with humongous objects (in percents)
int percentOfAllocatedHeap = Integer.parseInt(args[1]);
long startTime = System.currentTimeMillis();
long initialFreeRegionsCount = WB.g1NumFreeRegions();
int regionsToAllocate = (int) ((double) initialFreeRegionsCount / 100.0 * percentOfAllocatedHeap);
long freeRegionLeft = initialFreeRegionsCount - regionsToAllocate;
System.out.println("Regions to allocate: " + regionsToAllocate + "; regions to left free: " + freeRegionLeft);
int maxMemoryPerAllocThread = (int) ((Runtime.getRuntime().freeMemory() / 100.0
* (100 - percentOfAllocatedHeap)) / ALLOC_THREAD_COUNT * 0.5);
System.out.println("Using " + maxMemoryPerAllocThread / 1024 + "KB for each of " + ALLOC_THREAD_COUNT
+ " allocation threads");
while (WB.g1NumFreeRegions() > freeRegionLeft) {
try {
humongousAllocations.add(new byte[HUMONGOUS_SIZES[RND.nextInt(HUMONGOUS_SIZES.length)]]);
} catch (OutOfMemoryError oom) {
//We got OOM trying to fill heap with humongous objects
//It probably means that heap is fragmented which is strange since the test logic should avoid it
System.out.println("Warning: OOM while allocating humongous objects - it likely means "
+ "that heap is fragmented");
break;
}
}
System.out.println("Initial free regions " + initialFreeRegionsCount + "; Free regions left "
+ WB.g1NumFreeRegions());
LinkedList<Thread> threads = new LinkedList<>();
for (int i = 0; i < ALLOC_THREAD_COUNT; i++) {
threads.add(new Thread(new Allocator(maxMemoryPerAllocThread)));
}
threads.stream().forEach(Thread::start);
while ((System.currentTimeMillis() - startTime < duration) && error == null) {
Thread.yield();
}
shouldStop = true;
System.out.println("Finished test");
if (error != null) {
throw error;
}
}
}