Project Introduction: Google Benchmark
Google Benchmark is a powerful library designed to help developers measure and analyze the performance of their code snippets. It works similarly to unit tests, but instead of testing code correctness, it focuses on performance benchmarking. This capability is crucial for optimizing code efficiency and pinpointing performance bottlenecks.
Getting Started
To embark on using Google Benchmark, there are a few initial steps to follow. The library has certain requirements: it can be utilized with C++03, yet to build it, C++14 support is necessary, including both the compiler and standard library. Detailed specifications about the supported compilers can be found in the library's documentation.
Installation
Installing Google Benchmark involves several straightforward steps, using CMake as the build system. First, ensure you have git and cmake installed. To begin, clone the GitHub repository:
$ git clone https://github.com/google/benchmark.git
$ cd benchmark
Create a build directory for the build output and use CMake to generate the necessary build files and resolve dependencies:
$ cmake -E make_directory "build"
$ cmake -E chdir "build" cmake -DBENCHMARK_DOWNLOAD_DEPENDENCIES=on -DCMAKE_BUILD_TYPE=Release ../
Proceed to build the library and test its functionality:
$ cmake --build "build" --config Release
Running tests after the build helps confirm that everything is functioning correctly:
$ cmake -E chdir "build" ctest --build-config Release
If needed, you can install the library globally:
sudo cmake --build "build" --config Release --target install
Usage
Using Google Benchmark is quite straightforward. Define a function that encapsulates the code you want to measure, then register it as a benchmark using the BENCHMARK macro. An important step is ensuring that a suitable main function is present to execute the benchmarks.
Here's a simple usage example in C++:
#include <benchmark/benchmark.h>
static void BM_StringCreation(benchmark::State& state) {
for (auto _ : state)
std::string empty_string;
}
BENCHMARK(BM_StringCreation);
BENCHMARK_MAIN();
Compiling and linking this code with the Google Benchmark library will enable you to run performance tests. On UNIX systems, after building the project, you can compile your benchmark with:
$ g++ mybenchmark.cc -std=c++11 -isystem benchmark/include \
-Lbenchmark/build/src -lbenchmark -lpthread -o mybenchmark
This command results in an executable that, by default, runs all registered benchmarks. You can also pass the --help flag for additional options.
For projects that use CMake, linking against Google Benchmark is recommended via target_link_libraries. You can either find the package:
find_package(benchmark REQUIRED)
or directly integrate the library into your CMake project:
add_subdirectory(benchmark)
Link to the benchmark library by adding:
target_link_libraries(MyTarget benchmark::benchmark)
Stable and Experimental Versions
Google Benchmark's main branch contains its stable version, ensuring you get a reliable API with minimal breaking changes. For those interested in exploring new and experimental features, the v2 branch might offer intriguing options, albeit with no guarantee of API stability.
Additional Resources
Google Benchmark provides various resources to assist users, including a discussion group, IRC channels, and in-depth documentation for additional tools and testing strategies. For Python users, separate documentation is available to build and install Python bindings successfully.
Overall, Google Benchmark offers a robust solution for developers looking to make their code more efficient and responsive, playing an essential role in high-performance software development.