org.wildfly.common.cpu.CacheInfo Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* JBoss, Home of Professional Open Source.
* Copyright 2015 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* 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 org.wildfly.common.cpu;
import static java.security.AccessController.doPrivileged;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.charset.StandardCharsets;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Locale;
/**
* A class which exposes any available cache line information for the current CPU.
*
* @author David M. Lloyd
*/
public final class CacheInfo {
private static final CacheLevelInfo[] cacheLevels;
/**
* Get the number of CPU cache level entries. If no cache information could be gathered, 0 is returned.
*
* @return the number of CPU cache levels, or 0 if unknown
*/
public static int getLevelEntryCount() {
return cacheLevels.length;
}
/**
* Get the CPU cache level information for a cache level. The {@code index} argument must be greater than zero and
* less than the number of levels returned by {@link #getLevelEntryCount()}.
*
* @param index the cache level index
* @return the CPU cache level information
*/
public static CacheLevelInfo getCacheLevelInfo(int index) {
return cacheLevels[index];
}
/**
* Get the smallest known data cache line size. If no cache line sizes are known, 0 is returned. Note that smaller
* cache lines may exist if one or more cache line sizes are unknown.
*
* @return the smallest cache line size, or 0 if unknown
*/
public static int getSmallestDataCacheLineSize() {
int minSize = Integer.MAX_VALUE;
for (CacheLevelInfo cacheLevel : cacheLevels) {
if (cacheLevel.getCacheType().isData()) {
final int cacheLineSize = cacheLevel.getCacheLineSize();
if (cacheLineSize != 0 && cacheLineSize < minSize) {
minSize = cacheLineSize;
}
}
}
return minSize == Integer.MAX_VALUE ? 0 : minSize;
}
/**
* Get the smallest known instruction cache line size. If no cache line sizes are known, 0 is returned. Note that smaller
* cache lines may exist if one or more cache line sizes are unknown.
*
* @return the smallest cache line size, or 0 if unknown
*/
public static int getSmallestInstructionCacheLineSize() {
int minSize = Integer.MAX_VALUE;
for (CacheLevelInfo cacheLevel : cacheLevels) {
if (cacheLevel.getCacheType().isInstruction()) {
final int cacheLineSize = cacheLevel.getCacheLineSize();
if (cacheLineSize != 0 && cacheLineSize < minSize) {
minSize = cacheLineSize;
}
}
}
return minSize == Integer.MAX_VALUE ? 0 : minSize;
}
static {
cacheLevels = doPrivileged((PrivilegedAction) () -> {
try {
String osArch = System.getProperty("os.name", "unknown").toLowerCase(Locale.US);
if (osArch.contains("linux")) {
// try to read /sys fs
final File cpu0 = new File("/sys/devices/system/cpu/cpu0/cache");
if (cpu0.exists()) {
// great!
final File[] files = cpu0.listFiles();
if (files != null) {
ArrayList indexes = new ArrayList();
for (File file : files) {
if (file.getName().startsWith("index")) {
indexes.add(file);
}
}
final CacheLevelInfo[] levelInfoArray = new CacheLevelInfo[indexes.size()];
for (int i = 0; i < indexes.size(); i++) {
File file = indexes.get(i);
int index = parseIntFile(new File(file, "level"));
final CacheType type;
switch (parseStringFile(new File(file, "type"))) {
case "Data": type = CacheType.DATA; break;
case "Instruction": type = CacheType.INSTRUCTION; break;
case "Unified": type = CacheType.UNIFIED; break;
default: type = CacheType.UNKNOWN; break;
}
int size = parseIntKBFile(new File(file, "size"));
int lineSize = parseIntFile(new File(file, "coherency_line_size"));
levelInfoArray[i] = new CacheLevelInfo(index, type, size, lineSize);
}
return levelInfoArray;
}
}
} else if (osArch.contains("mac os x")) {
// cache line size
final int lineSize = safeParseInt(parseProcessOutput("/usr/sbin/sysctl", "-n", "hw.cachelinesize"));
if (lineSize != 0) {
// cache sizes
final int l1d = safeParseInt(parseProcessOutput("/usr/sbin/sysctl", "-n", "hw.l1dcachesize"));
final int l1i = safeParseInt(parseProcessOutput("/usr/sbin/sysctl", "-n", "hw.l1icachesize"));
final int l2 = safeParseInt(parseProcessOutput("/usr/sbin/sysctl", "-n", "hw.l2cachesize"));
final int l3 = safeParseInt(parseProcessOutput("/usr/sbin/sysctl", "-n", "hw.l3cachesize"));
ArrayList list = new ArrayList();
if (l1d != 0) {
list.add(new CacheLevelInfo(1, CacheType.DATA, l1d / 1024, lineSize));
}
if (l1i != 0) {
list.add(new CacheLevelInfo(1, CacheType.INSTRUCTION, l1i / 1024, lineSize));
}
if (l2 != 0) {
list.add(new CacheLevelInfo(2, CacheType.UNIFIED, l2 / 1024, lineSize));
}
if (l3 != 0) {
list.add(new CacheLevelInfo(3, CacheType.UNIFIED, l3 / 1024, lineSize));
}
if (list.size() > 0) {
return list.toArray(new CacheLevelInfo[list.size()]);
}
}
} else if (osArch.contains("windows")) {
// TODO: use the wmic utility to get cache line info
}
} catch (Throwable ignored) {}
// all has failed
return new CacheLevelInfo[0];
});
}
static int parseIntFile(final File file) {
return safeParseInt(parseStringFile(file));
}
static int safeParseInt(final String string) {
try {
return Integer.parseInt(string);
} catch (Throwable ignored) {
return 0;
}
}
static int parseIntKBFile(final File file) {
try {
final String s = parseStringFile(file);
if (s.endsWith("K")) {
return Integer.parseInt(s.substring(0, s.length() - 1));
} else if (s.endsWith("M")) {
return Integer.parseInt(s.substring(0, s.length() - 1)) * 1024;
} else if (s.endsWith("G")) {
return Integer.parseInt(s.substring(0, s.length() - 1)) * 1024 * 1024;
} else {
return Integer.parseInt(s);
}
} catch (Throwable ignored) {
return 0;
}
}
static String parseStringFile(final File file) {
try (FileInputStream is = new FileInputStream(file)) {
return parseStringStream(is);
} catch (Throwable ignored) {
return "";
}
}
static String parseStringStream(final InputStream is) {
try (Reader r = new InputStreamReader(is, StandardCharsets.UTF_8)) {
StringBuilder b = new StringBuilder();
char[] cb = new char[64];
int res;
while ((res = r.read(cb)) != -1) {
b.append(cb, 0, res);
}
return b.toString().trim();
} catch (Throwable ignored) {
return "";
}
}
static String parseProcessOutput(final String... args) {
final ProcessBuilder processBuilder = new ProcessBuilder(args);
try {
final Process process = processBuilder.start();
process.getOutputStream().close();
final InputStream errorStream = process.getErrorStream();
final Thread errorThread = new Thread(null, new StreamConsumer(errorStream), "Process thread", 32768L);
errorThread.start();
final String result;
try (final InputStream inputStream = process.getInputStream()) {
result = parseStringStream(inputStream);
}
boolean intr = false;
try {
process.waitFor();
} catch (InterruptedException e) {
intr = true;
return null;
} finally {
try {
errorThread.join();
} catch (InterruptedException e) {
intr = true;
} finally {
if (intr) {
Thread.currentThread().interrupt();
}
}
}
return result;
} catch (IOException e) {
return "";
}
}
static class StreamConsumer implements Runnable {
private final InputStream stream;
StreamConsumer(final InputStream stream) {
this.stream = stream;
}
public void run() {
byte[] buffer = new byte[128];
try {
while (stream.read(buffer) != -1) ;
} catch (IOException ignored) {
} finally {
try {
stream.close();
} catch (IOException ignored) {
}
}
}
}
public static void main(String[] args) {
System.out.println("Detected cache info:");
for (CacheLevelInfo levelInfo : cacheLevels) {
System.out.printf("Level %d cache: type %s, size %d KiB, cache line is %d bytes%n",
Integer.valueOf(levelInfo.getCacheLevel()),
levelInfo.getCacheType(),
Integer.valueOf(levelInfo.getCacheLevelSizeKB()),
Integer.valueOf(levelInfo.getCacheLineSize())
);
}
}
}