Add benchmark for Sentinel

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

pom.xml

@@ -67,6 +67,7 @@
         <module>sentinel-dashboard</module>
 
         <module>sentinel-demo</module>
+        <module>sentinel-benchmark</module>
     </modules>
 
     <dependencyManagement>

sentinel-benchmark/pom.xml

@@ -0,0 +1,98 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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">
+    <parent>
+        <artifactId>sentinel-parent</artifactId>
+        <groupId>com.alibaba.csp</groupId>
+        <version>0.2.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>sentinel-benchmark</artifactId>
+    <packaging>jar</packaging>
+
+    <name>Sentinel JMH benchmark</name>
+
+    <prerequisites>
+        <maven>3.0</maven>
+    </prerequisites>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-core</artifactId>
+        </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>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <jmh.version>1.21</jmh.version>
+        <javac.target>1.8</javac.target>
+        <uberjar.name>benchmarks</uberjar.name>
+    </properties>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.8.0</version>
+                <configuration>
+                    <compilerVersion>${javac.target}</compilerVersion>
+                    <source>${javac.target}</source>
+                    <target>${javac.target}</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>3.1.1</version>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                            <finalName>${uberjar.name}</finalName>
+                            <transformers>
+                                <transformer
+                                        implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                    <mainClass>org.openjdk.jmh.Main</mainClass>
+                                </transformer>
+                            </transformers>
+                            <filters>
+                                <filter>
+                                    <!--
+                                        Shading signed JARs will fail without this.
+                                        http://stackoverflow.com/questions/999489/invalid-signature-file-when-attempting-to-run-a-jar
+                                    -->
+                                    <artifact>*:*</artifact>
+                                    <excludes>
+                                        <exclude>META-INF/*.SF</exclude>
+                                        <exclude>META-INF/*.DSA</exclude>
+                                        <exclude>META-INF/*.RSA</exclude>
+                                    </excludes>
+                                </filter>
+                            </filters>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

sentinel-benchmark/src/main/java/com/alibaba/csp/sentinel/benchmark/SentinelEntryBenchmark.java

@@ -0,0 +1,140 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * 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.alibaba.csp.sentinel.benchmark;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.TimeUnit;
+
+import com.alibaba.csp.sentinel.Entry;
+import com.alibaba.csp.sentinel.SphU;
+import com.alibaba.csp.sentinel.slots.block.BlockException;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+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.Threads;
+import org.openjdk.jmh.annotations.Warmup;
+
+/**
+ * Benchmark for Sentinel entries.
+ *
+ * @author Eric Zhao
+ */
+@Warmup(iterations = 10)
+@BenchmarkMode(Mode.Throughput)
+@OutputTimeUnit(TimeUnit.SECONDS)
+@State(Scope.Thread)
+public class SentinelEntryBenchmark {
+
+    @Param({"25", "50", "100", "200", "500", "1000"})
+    private int length;
+
+    private List<Integer> numbers;
+
+    @Setup
+    public void prepare() {
+        numbers = new ArrayList<>();
+        for (int i = 0; i < length; i++) {
+            numbers.add(ThreadLocalRandom.current().nextInt());
+        }
+    }
+
+    private void doSomething() {
+        Collections.shuffle(numbers);
+        Collections.sort(numbers);
+    }
+
+    private void doSomethingWithEntry() {
+        Entry e0 = null;
+        try {
+            e0 = SphU.entry("benchmark");
+            doSomething();
+        } catch (BlockException e) {
+        } finally {
+            if (e0 != null) {
+                e0.exit();
+            }
+        }
+    }
+
+    @Benchmark
+    @Threads(1)
+    public void testSingleThreadDirectly() {
+        doSomething();
+    }
+
+    @Benchmark
+    @Threads(1)
+    public void testSingleThreadSingleEntry() {
+        doSomethingWithEntry();
+    }
+
+    @Benchmark
+    @Threads(2)
+    public void test2ThreadsSingleEntry() {
+        doSomethingWithEntry();
+    }
+
+    @Benchmark
+    @Threads(3)
+    public void test3ThreadsSingleEntry() {
+        doSomethingWithEntry();
+    }
+
+    @Benchmark
+    @Threads(4)
+    public void test4ThreadsDirectly() {
+        doSomething();
+    }
+
+    @Benchmark
+    @Threads(4)
+    public void test4ThreadsSingleEntry() {
+        doSomethingWithEntry();
+    }
+
+    @Benchmark
+    @Threads(8)
+    public void test8ThreadsDirectly() {
+        doSomething();
+    }
+
+    @Benchmark
+    @Threads(8)
+    public void test8ThreadsSingleEntry() {
+        doSomethingWithEntry();
+    }
+
+    @Benchmark
+    @Threads(16)
+    public void test16ThreadsDirectly() {
+        doSomething();
+    }
+
+    @Benchmark
+    @Threads(16)
+    public void test16ThreadsSingleEntry() {
+        doSomethingWithEntry();
+    }
+}