https://github.com/crowdcode-de/java-benchmarks
A Collection Of Java JMH Benchmarks
https://github.com/crowdcode-de/java-benchmarks
Last synced: 12 months ago
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A Collection Of Java JMH Benchmarks
- Host: GitHub
- URL: https://github.com/crowdcode-de/java-benchmarks
- Owner: crowdcode-de
- License: apache-2.0
- Created: 2019-09-22T09:57:33.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2023-12-03T23:43:09.000Z (over 2 years ago)
- Last Synced: 2024-03-26T12:20:13.741Z (about 2 years ago)
- Language: Java
- Homepage: https://www.crowdcode.io
- Size: 27.3 KB
- Stars: 2
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Java Micro-Benchmarks With JMH
[](https://travis-ci.org/crowdcode-de/java-benchmark)
These benchmarks are build with [OpenJDK JMH](https://openjdk.java.net/projects/code-tools/jmh/).
Just another collection of typical Java Code Benchmarks.
### How To Run The Benchmarks
Build the project `mvn clean install`.
You can call `java -jar target/benchmarks.jar -help` to see available command line parameters.
For instance,
```
java -Xmx1G -jar targget/benchmarks.jar -f 1 -r 5 -i -wi 5 EmptyBenchmark
```
### Create Your Own Benchmark
```
mvn archetype:generate
-DinteractiveMode=false
-DarchetypeGroupId=org.openjdk.jmh
-DarchetypeArtifactId=jmh-java-benchmark-archetype
-DarchetypeVersion=1.21
-DgroupId=org.sample
-DartifactId=test
-Dversion=1.0-SNAPSHOT
```
## Benchmark Results
REMEMBER: The numbers below are just data. To gain reusable insights, you need to follow up on
why the numbers are the way they are. Use profilers (see -prof, -lprof), design factorial
experiments, perform baseline and negative tests that provide experimental control, make sure
the benchmarking environment is safe on JVM/OS/HW level, ask for reviews from the domain experts.
Do not assume the numbers tell you what you want them to tell.
### Use Multiply Instead Of Divide
Check `MultiplyVsDivisionBenchmark` to see that it is faster to multiply than to divide doubles.
```
double divisor = 10.0;
double a = a / divisor // repeat this 1_000 times
...
```
better use
```
double divisor = 10.0;
double factor = 1 / divisor;
double a = nextDouble() * factor; // repeat this 1_000 times
```
Results with JDK 13:
````
java -Xmx1G -jar target/benchmarks.jar -f 1 -r 1 -i 5 -w 1 -wi 5 MultiplyVsDivisionBenchmark
````
|Benchmark | Mode | Cnt | Score | Error | Units|
|:-----------------------------------------------------|:-----:|:----:|:----------:|:----------:|:----:|
|MultiplyVsDivisionBenchmark.divideDoubles | thrpt | 5 | 207619,369 | ± 2662,392 | ops/s|
|MultiplyVsDivisionBenchmark.divideDoublesWithMultiply | thrpt | 5 | 508495,675 | ± 8033,898 | ops/s|
### Random Subset Without Duplicates
`RandomSubsetBenchmark`
Results with JDK 13:
````
java -Xmx1G -jar target/benchmarks.jar -f 1 -r 1 -i 5 -w 1 -wi 5 RandomSubsetBenchmark
````
|Benchmark | Mode | Cnt | Score | Error | Units|
|:-----------------------------------------------------|:-----:|:----:|:----------:|:----------:|:----:|
|RandomSubsetBenchmark.subsetWithForLoop | thrpt | 5| 1720,292 | ± 330,771 | ops/s|
|RandomSubsetBenchmark.subsetWithParallelStreams | thrpt | 5| 779,079 | ± 23,238 | ops/s|
|RandomSubsetBenchmark.subsetWithStreams | thrpt | 5| 1200,939 | ± 140,346 | ops/s|
### Date Parsing And Adding An Hour Benchmark
`DateBenchmark`
````
java -Xmx1G -jar target/benchmarks.jar -f 1 -r 1 -i 5 -w 1 -wi 5 DateBenchmark
````
|Benchmark | Mode | Cnt | Score | Error | Units|
|:-----------------------------------------------------|:-----:|:----:|:----------:|:----------:|:----:|
|DateBenchmark.dateLong | thrpt | 5 | 386571214,471 | ± 10171784,541 | ops/s|
|DateBenchmark.dateLongWithFormat | thrpt | 5 | 3358368,673 | ± 31265,425 | ops/s|
|DateBenchmark.dateParsingWithFormat | thrpt | 5 | 728327,799 | ± 19937,432 | ops/s|
|DateBenchmark.parsingLocalDateTime | thrpt | 5 | 873308,951 | ± 97291,855 | ops/s|
### Using Initial Capacity At ArrayList
Run with JDK 12 and `java -jar target/benchmarks.jar -f 1 -r 2 -w 2 -wi 5 InitialCapacityBenchmark`
|Benchmark | Mode | Cnt | Score | Error | Units|
|:-------------------------------------------------------------|:-----:|:----:|:-----:|:--------:|:----:|
|InitialCapacityBenchmark.addWithInitialCapacity | thrpt | 5 | 29,552 | ± 13,596 | ops/s|
|InitialCapacityBenchmark.addWithInitialCapacityWithStreams | thrpt | 5 | 25,123 | ± 10,103 | ops/s|
|InitialCapacityBenchmark.addWithoutInitialCapacity | thrpt | 5 | 19,304 | ± 3,389 | ops/s|
|InitialCapacityBenchmark.addWithoutInitialCapacityWithStreams | thrpt | 5 | 19,012 | ± 6,849 | ops/s|
### Created By
[CROWDCODE GmbH & Co. KG](https://www.crowdcode.io)