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BAEL-3855 

Lock Striping
This commit is contained in:
Unknown 2020-02-19 23:14:00 +01:00
parent b48f01d324
commit 34d04156fc
6 changed files with 262 additions and 0 deletions
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43
lock-striping/pom.xml Normal file
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<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.baeldung.concurrent.lock</groupId>
<artifactId>lock-striping</artifactId>
<version>0.0.1-SNAPSHOT</version>
<properties>
<jmh.version>1.21</jmh.version>
<guava.version>28.2-jre</guava.version>
</properties>
<dependencies>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>${guava.version}</version>
</dependency>
<dependency>
<groupId>org.openjdk.jmh</groupId>
<artifactId>jmh-core</artifactId>
<version>${jmh.version}</version>
</dependency>
<dependency>
<groupId>org.openjdk.jmh</groupId>
<artifactId>jmh-generator-annprocess</artifactId>
<version>${jmh.version}</version>
</dependency>
</dependencies>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
</project>

66
lock-striping/src/com/baeldung/concurrent/lock/BenchMark.java Normal file
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package com.baeldung.concurrent.lock;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.TimeUnit;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Warmup;
@State(Scope.Thread)
@Warmup(iterations = 2, time = 1, timeUnit = TimeUnit.MILLISECONDS)
@Measurement(iterations = 3, time = 1, timeUnit = TimeUnit.MILLISECONDS)
public class BenchMark {
ConcurrentAccessMap accessMyMap;
@Param({"HashMap", "HashMap with Lock", "HashMap with Striped Lock",
"ConcurrentHashMap", "ConcurrentHashMap with Lock", "ConcurrentHashMap with Striped Lock"})
private String type;
@Setup
public void setup() {
switch (type) {
case "HashMap":
accessMyMap = new NoLock(getHashMap());
break;
case "ConcurrentHashMap":
accessMyMap = new NoLock(getConcurrentHashMap());
break;
case "HashMap with Lock":
accessMyMap = new CoarseGrained(getHashMap());
break;
case "ConcurrentHashMap with Lock":
accessMyMap = new CoarseGrained(getConcurrentHashMap());
break;
case "HashMap with Striped Lock":
accessMyMap = new LockStriped(getHashMap());
break;
case "ConcurrentHashMap with Striped Lock":
accessMyMap = new LockStriped(getConcurrentHashMap());
break;
}
}
private Map<String, String> getHashMap() {
return new HashMap<String,String>();
}
private Map<String, String> getConcurrentHashMap() {
return new ConcurrentHashMap<String,String>();
}
@Benchmark
@BenchmarkMode(Mode.Throughput)
@OutputTimeUnit(TimeUnit.MILLISECONDS)
public void test() throws InterruptedException {
accessMyMap.doWork(type);
}
}

39
lock-striping/src/com/baeldung/concurrent/lock/CoarseGrained.java Normal file
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package com.baeldung.concurrent.lock;
import java.util.Map;
import java.util.concurrent.locks.ReentrantLock;
import com.google.common.base.Supplier;
public class CoarseGrained extends ConcurrentAccessMap {
ReentrantLock lock;
public CoarseGrained(Map<String, String> map) {
super(map);
lock = new ReentrantLock();
}
protected Supplier<?> putSupplier(int x) {
return (()-> {
boolean done = false;
while(!done) {
done = lock.tryLock();
}
map.put("key" + x, "value" + x);
lock.unlock();
return null;
});
}
protected Supplier<?> getSupplier(int x) {
return (()-> {
boolean done = false;
while(!done) {
done = lock.tryLock();
}
map.get("key" + x);
lock.unlock();
return null;
});
}
}

33
lock-striping/src/com/baeldung/concurrent/lock/ConcurrentAccessMap.java Normal file
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package com.baeldung.concurrent.lock;
import java.util.Map;
import java.util.concurrent.CompletableFuture;
import com.google.common.base.Supplier;
public abstract class ConcurrentAccessMap {
static final int SLOTS = 4;
static final int THREADS = 10000;
static final int BUCKETS = Runtime.getRuntime().availableProcessors() * SLOTS;
private CompletableFuture<?>[] requests;
Map<String, String> map;
public ConcurrentAccessMap(Map<String, String> map) {
this.map = map;
}
public final void doWork(String type) {
requests = new CompletableFuture<?>[THREADS * SLOTS];
for (int i = 0; i < THREADS; i++) {
requests[SLOTS * i + 0] = CompletableFuture.supplyAsync(putSupplier(i));
requests[SLOTS * i + 1] = CompletableFuture.supplyAsync(getSupplier(i));
requests[SLOTS * i + 2] = CompletableFuture.supplyAsync(getSupplier(i));
requests[SLOTS * i + 3] = CompletableFuture.supplyAsync(getSupplier(i));
}
CompletableFuture.allOf(requests).join();
}
protected abstract Supplier<?> putSupplier(int x);
protected abstract Supplier<?> getSupplier(int x);
}

47
lock-striping/src/com/baeldung/concurrent/lock/LockStriped.java Normal file
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package com.baeldung.concurrent.lock;
import java.util.Map;
import java.util.concurrent.locks.Lock;
import com.google.common.base.Supplier;
import com.google.common.util.concurrent.Striped;
public class LockStriped extends ConcurrentAccessMap {
Striped<Lock> lock;
public LockStriped(Map<String, String> map) {
super(map);
lock = getStripedLock();
}
private Striped<Lock> getStripedLock() {
Striped<Lock> map = Striped.lock(BUCKETS);
return map;
}
protected Supplier<?> putSupplier(int x) {
return (()-> {
Lock currentLock = lock.get("key" + x);
boolean done = false;
while(!done) {
done = currentLock.tryLock();
}
map.put("key" + x, "value" + x);
currentLock.unlock();
return null;
});
}
protected Supplier<?> getSupplier(int x) {
return (()-> {
Lock currentLock = lock.get("key" + x);
boolean done = false;
while(!done) {
done = currentLock.tryLock();
}
map.get("key" + x);
currentLock.unlock();
return null;
});
}
}

34
lock-striping/src/com/baeldung/concurrent/lock/NoLock.java Normal file
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package com.baeldung.concurrent.lock;
import java.util.Map;
import com.google.common.base.Supplier;
public class NoLock extends ConcurrentAccessMap {
public NoLock(Map<String, String> map) {
super(map);
}
protected Supplier<?> putSupplier(int x) {
return (()-> {
boolean done = false;
while(!done) {
map.put("key" + x, "value" + x);
done = true;
}
return null;
});
}
protected Supplier<?> getSupplier(int x) {
return (()-> {
boolean done = false;
while(!done) {
map.get("key" + x);
done = true;
}
return null;
});
}
}