Benchmarking is a way to inspect and monitor the performance of your application. You can regularly run benchmarks to help analyze and debug performance problems and ensure that you don't introduce regressions in recent changes.
Android offers two benchmarking libraries and approaches for analyzing and testing different kinds of situations in your application: Macrobenchmark and Microbenchmark.
Macrobenchmark
The Macrobenchmark library measures larger end-user interactions, such as startup, interacting with the UI, and animations. The library provides direct control over the performance environment you're testing. It allows you to control compiling, starting and stopping your application to directly measure actual app startup or scrolling, instead of only the specific jitted, hot functions, with all disk accesses cached.
The Macrobenchmark library injects events and monitors results externally from a test application that is built with your tests. Therefore, when writing the benchmarks, you don’t call your application code directly and instead navigate within your application as a user would.
Microbenchmark
The Microbenchmark library lets you benchmark app code directly in a loop. This is designed for measuring CPU work that assesses best-case performance (warmed up Just in Time (JIT), disk accesses cached), that you might see with an inner-loop or a specific hot function. The library can only measure the code you can call directly in isolation.
If your app needs to process a complex data structure, or have some specific
computation-heavy algorithm that is called multiple times during the application
run, these may be good examples for benchmarking. You can also measure parts of
your UI. For example, you can measure the cost of the RecyclerView item
binding, how long it takes to inflate a layout, or how demanding the
layout-and-measure pass of your View class is from a performance perspective.
However, you won’t be able to measure how the benchmarked cases contribute to the overall user experience. In some scenarios, benchmarking won’t tell you if you’re improving a bottleneck like jank or application startup time. For that reason, it’s crucial to identify those bottlenecks first with the Android Profiler. After you have found the code you want to investigate and optimize, the benchmarked loop can run repeatedly, in a quick and easy fashion to create less noisy results, which lets you focus on one area of improvement.
The Microbenchmark library only reports information about your application, not about the system overall. Therefore, it’s best at analyzing performance of situations specific to the app, not ones that might relate to overall system issues.
Benchmarking library comparison
| Macrobenchmark | Microbenchmark | |
|---|---|---|
| Function | Measure high-level entry points or interactions (for example, activity launch or scrolling a list) | Measure individual functions |
| Scope | Out-of-process test of full app | In-process test of CPU work |
| Speed | Medium iteration speed (can exceed a minute) | Fast iteration speed (often less than 10 seconds) |
| Tracing | Results come with profiling traces | Optional method sampling and tracing |
| Min API version | 23 | 14 |