README.md

C++ example for benchmarking with Google Benchmark Framework

• Workflow for this example
• Action log of this example
• Benchmark results on GitHub pages

This directory shows how to use github-action-benchmark with Google Benchmark Framework.

Run benchmarks

Official documentation for usage of Google Benchmark Framework:

https://github.com/google/benchmark

Build and install benchmark library and write up your benchmark suites following instructions in the above repository:

#include "benchmark/benchmark.h"

static void bench1(benchmark::State &state) {
  for (auto _ : state) {
    // Your benchmark goes here
  }
}

// Register the function as a benchmark
BENCHMARK(bench1);

// Run the benchmark
BENCHMARK_MAIN();

Build the source with C++ compiler:

$ clang++ -std=c++14 -O3 -l benchmark bench.cpp

And run built executable to output the result in JSON format:

$ ./a.out --benchmark_format=json | tee benchmark_result.json

Process benchmark results

Store the benchmark results with step using the action. Please set googlecpp to tool input.

- name: Store benchmark result
  uses: benchmark-action/github-action-benchmark@v1
  with:
    tool: 'googlecpp'
    output-file-path: benchmark_result.json

Please read 'How to use' section for common usage.

Run this example

To try this example, please use make and clang++.

$ make bench

bench subcommand prepares all dependencies, compiles bench.cpp and runs benchmarks. The results are output to console.

2019-11-29 21:13:55
Running ./a.out
Run on (4 X 2700 MHz CPU s)
CPU Caches:
  L1 Data 32K (x2)
  L1 Instruction 32K (x2)
  L2 Unified 262K (x2)
  L3 Unified 3145K (x1)
Load Average: 1.66, 1.98, 2.49
-----------------------------------------------------
Benchmark           Time             CPU   Iterations
-----------------------------------------------------
fib_10            210 ns          210 ns      3239181
fib_20          27857 ns        27786 ns        25206

To get JSON output for running github-action-benchmark, please use another subcommand.

$ make json

json subcommand outputs the benchmark results in JSON format and generates benchmark_result.json file in current directory.