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Java Benchmark 基準測試的實例詳解
import java.util.Arrays;
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.Scope;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Threads;
import org.openjdk.jmh.annotations.Warmup;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.RunnerException;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;
@BenchmarkMode(Mode.Throughput)//基準測試類型
@OutputTimeUnit(TimeUnit.SECONDS)//基準測試結果的時間類型
@Warmup(iterations = 3)//預熱的迭代次數
@Threads(2)//測試線程數量
@State(Scope.Thread)//該狀態為每個線程獨享
//度量:iterations進行測試的輪次，time每輪進行的時長，timeUnit時長單位,batchSize批次數量
@Measurement(iterations = 2, time = -1, timeUnit = TimeUnit.SECONDS, batchSize = -1)
public class InstructionsBenchmark{
static int staticPos = 0;
//String src = "SELECT a FROM ab , ee.ff AS f,(SELECT a FROM `schema_bb`.`tbl_bb`,(SELECT a FROM ccc AS c, `dddd`));";
final byte[] srcBytes = {83, 69, 76, 69, 67, 84, 32, 97, 32, 70, 82, 79, 77, 32, 97, 98, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 44, 32, 101, 101, 46, 102, 102, 32, 65, 83, 32, 102, 44, 40, 83, 69, 76, 69, 67, 84, 32, 97, 32, 70, 82, 79, 77, 32, 96, 115, 99, 104, 101, 109, 97, 95, 98, 98, 96, 46, 96, 116, 98, 108, 95, 98, 98, 96, 44, 40, 83, 69, 76, 69, 67, 84, 32, 97, 32, 70, 82, 79, 77, 32, 99, 99, 99, 32, 65, 83, 32, 99, 44, 32, 96, 100, 100, 100, 100, 96, 41, 41, 59};
int len = srcBytes.length;
byte[] array = new byte[8192];
int memberVariable = 0;
//run
public static void main(String[] args) throws RunnerException {
Options opt = new OptionsBuilder()
.include(InstructionsBenchmark.class.getSimpleName())
.forks(1)
// 使用之前要安裝hsdis
//-XX:-TieredCompilation 關閉分層優化 -server
//-XX:+LogCompilation 運行之后項目路徑會出現按照測試順序輸出hotspot_pid<PID>.log文件,可以使用JITWatch進行分析,可以根據最后運行的結果的順序按文件時間找到對應的hotspot_pid<PID>.log文件
.jvmArgs("-XX:+UnlockDiagnosticVMOptions", "-XX:+LogCompilation", "-XX:+TraceClassLoading", "-XX:+PrintAssembly")
// .addProfiler(CompilerProfiler.class) // report JIT compiler profiling via standard MBeans
// .addProfiler(GCProfiler.class) // report GC time
// .addProfiler(StackProfiler.class) // report method stack execution profile
// .addProfiler(PausesProfiler.class)
/*
WinPerfAsmProfiler
You must install Windows Performance Toolkit. Once installed, locate directory with xperf.exe file
and either add it to PATH environment variable, or set it to jmh.perfasm.xperf.dir system property.
*/
//.addProfiler(WinPerfAsmProfiler.class)
//更多Profiler,請看JMH介紹
//.output("InstructionsBenchmark.log")//輸出信息到文件
.build();
new Runner(opt).run();
}
//空循環 對照項
@Benchmark
public int emptyLoop() {
int pos = 0;
while (pos < len) {
++pos;
}
return pos;
}
@Benchmark
public int increment() {
int pos = 0;
int result = 0;
while (pos < len) {
++result;
++pos;
}
return result;
}
@Benchmark
public int decrement() {
int pos = 0;
int result = 0;
while (pos < len) {
--result;
++pos;
}
return result;
}
@Benchmark
public int ifElse() {
int pos = 0;
int result = 0;
while (pos < len) {
if (pos == 10) {
++result;
++pos;
} else {
++pos;
}
}
return result;
}
@Benchmark
public int ifElse2() {
int pos = 0;
int result = 0;
while (pos < len) {
if (pos == 10) {
++result;
++pos;
} else if (pos == 20) {
++result;
++pos;
} else {
++pos;
}
}
return result;
}
@Benchmark
public int ifnotElse() {
int pos = 0;
int result = 0;
while (pos < len) {
if (pos != 10) {
++pos;
} else {
++result;
++pos;
}
}
return result;
}
@Benchmark
public int ifLessthanElse() {
int pos = 0;
int result = 0;
while (pos < len) {
if (pos < 10) {
++pos;
} else {
++result;
++pos;
}
}
return result;
}
@Benchmark
public int ifGreaterthanElse() {
int pos = 0;
int result = 0;
while (pos < len) {
if (pos > 10) {
++pos;
} else {
++result;
++pos;
}
}
return result;
}
@Benchmark
public int readMemberVariable_a_byteArray() {
int pos = 0;
int result = 0;
while (pos < len) {
result = srcBytes[pos];
pos++;
}
return result;
}
}
ops/time：標識每秒鐘執行的次數
依賴jar包：
<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>
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<executions>
<execution>
<id>run-benchmarks</id>
<phase>integration-test</phase>
<goals>
<goal>exec</goal>
</goals>
<configuration>
<classpathScope>test</classpathScope>
<executable>java</executable>
<arguments>
<argument>-classpath</argument>
<classpath />
<argument>org.openjdk.jmh.Main</argument>
<argument>.*</argument>
</arguments>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
以上就是Java Benchmark 基準測試，如有疑問請留言或者到本站社區交流討論，感謝閱讀，希望能幫助到大家，謝謝大家對本站的支持！
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