com.netflix.spectator.gc.HelperFunctions Maven / Gradle / Ivy
/*
* Copyright 2014-2021 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.netflix.spectator.gc;
import com.sun.management.GcInfo;
import java.lang.management.MemoryUsage;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
/** Utility functions for GC. */
final class HelperFunctions {
private static final Map KNOWN_COLLECTOR_NAMES = knownCollectors();
private HelperFunctions() {
}
private static Map knownCollectors() {
Map m = new HashMap<>();
m.put("ConcurrentMarkSweep", GcType.OLD);
m.put("Copy", GcType.YOUNG);
m.put("G1 Old Generation", GcType.OLD);
m.put("G1 Young Generation", GcType.YOUNG);
m.put("MarkSweepCompact", GcType.OLD);
m.put("PS MarkSweep", GcType.OLD);
m.put("PS Scavenge", GcType.YOUNG);
m.put("ParNew", GcType.YOUNG);
m.put("ZGC", GcType.OLD);
m.put("ZGC Cycles", GcType.OLD);
m.put("ZGC Pauses", GcType.OLD);
m.put("Shenandoah Cycles", GcType.OLD);
m.put("Shenandoah Pauses", GcType.OLD);
return Collections.unmodifiableMap(m);
}
/** Determine the type, old or young, based on the name of the collector. */
static GcType getGcType(String name) {
GcType t = KNOWN_COLLECTOR_NAMES.get(name);
return (t == null) ? GcType.UNKNOWN : t;
}
/** Return true if it is an old GC type. */
static boolean isOldGcType(String name) {
return getGcType(name) == GcType.OLD;
}
/** Returns true if memory pool name matches an old generation pool. */
static boolean isOldGenPool(String name) {
return name.endsWith("Old Gen")
|| name.endsWith("Tenured Gen")
|| "Shenandoah".equals(name)
|| "ZHeap".equals(name);
}
/** Returns true if memory pool name matches an young generation pool. */
static boolean isYoungGenPool(String name) {
return name.endsWith("Eden Space")
|| "Shenandoah".equals(name)
|| "ZHeap".equals(name);
}
/** Compute the total usage across all pools. */
static long getTotalUsage(Map usages) {
long sum = 0L;
for (Map.Entry e : usages.entrySet()) {
sum += e.getValue().getUsed();
}
return sum;
}
/** Compute the max usage across all pools. */
static long getTotalMaxUsage(Map usages) {
long sum = 0L;
for (Map.Entry e : usages.entrySet()) {
long max = e.getValue().getMax();
if (max > 0) {
sum += e.getValue().getMax();
}
}
return sum;
}
/** Compute the amount of data promoted during a GC event. */
static long getPromotionSize(GcInfo info) {
long totalBefore = getTotalUsage(info.getMemoryUsageBeforeGc());
long totalAfter = getTotalUsage(info.getMemoryUsageAfterGc());
return totalAfter - totalBefore;
}
}