# Adding profiler markers to your code

> Add profiler markers to mark up areas of your code.

Add [profiler markers](/engine/6000.6/manual/analysis/profiler/customizing/adding-information-code/intro.md) to your code to view the samples that `ProfilerMarker.Begin`, `ProfilerMarker.End`, or `ProfilerMarker.Auto` generates in the **Timeline View** and **Hierarchy View** of the [CPU Usage module](/engine/6000.6/manual/analysis/profiler/visualizing-data/cpu/introduction.md) in the [Profiler window](/engine/6000.6/manual/analysis/profiler/window.md):


**Profiler sample with metadata in Timeline View.:**
![](/api/media?file=/engine/6000.6/media/images/profiler-marker-metadata-timeline.png)


**Profiler sample with metadata in Hierarchy View.:**
![](/api/media?file=/engine/6000.6/media/images/profiler-marker-metadata-hierarchy.png)

## Prerequisites

Some examples use [the Profiling Core package](https://docs.unity3d.com/Packages/com.unity.profiling.core@latest), which you must install before you start. The Unity Profiling Core package isn't discoverable in the Package Manager UI because it's a core package. To install the package, [add it by its name](/engine/6000.6/manual/packages-list/managing-packages-window/upm-ui-actions/upm-ui-quick.md), which is `com.unity.profiling.core`.

## Marking up your code

To use the [`ProfilerMarker` API](/engine/6000.6/script-reference/unity/profiling/profilermarker.md), place the code you want to profile between calls to `ProfilerMarker.Begin` and `ProfilerMarker.End`. For example:

```lang-cs
using UnityEngine;
using Unity.Profiling;

public class ProfilerMarkerExample
{
    static readonly ProfilerMarker k_MyCodeMarker = new ProfilerMarker("My Code");

    void Update() {
        k_MyCodeMarker.Begin();
        Debug.Log("This code is being profiled");
        k_MyCodeMarker.End();
    }
}
```

> **Note:**
>
> Avoid using the `/` character in a profiler marker’s name as this makes the Profiler window unable to highlight the marker in the CPU Profiler module’s charts view.

Make sure that the code in between the `Begin` and `End` calls doesn't exit the scope before `End` is called. If the code exits the scope before `End` is called, an error message is logged to the Console. To avoid having to call `End` before every return, use `Auto` so that the sample is ended automatically on leaving the scope. For more information, refer to the section in this documentation on [Automatically close profiler marker code blocks](#automatically-close).

Unity records and reports the profiled code block's execution time to the Profiler, and displays it in the [CPU Profiler module](/engine/6000.6/manual/analysis/profiler/visualizing-data/cpu/introduction.md) without the need to use [Deep Profiling](/engine/6000.6/manual/analysis/profiler/deep-profiling.md). It displays it as a new entry in the **Hierarchy View** of the CPU Profiler module, as follows:


**Profiler sample in the Profiler Window.:**
![](/api/media?file=/engine/6000.6/media/images/profiler-marker-full-sample.png)

### Automatically close profiler marker code blocks

Use `ProfilerMarker.Auto` to ensure that `ProfilerMarker.End` is automatically called at the end of the code block. The following calls are equivalent:

```lang-cs
using Unity.Profiling;

public class MySystemClass
{
    static readonly ProfilerMarker k_UpdatePerfMarker = new ProfilerMarker("MySystem.Update");

    public void Update()
    {
        k_UpdatePerfMarker.Begin();
        // ...
        k_UpdatePerfMarker.End();

        using (k_UpdatePerfMarker.Auto())
        {
            // ...
        }
    }
}
```

Unlike the `Begin()` and `End()` calls, Unity can't compile out the `ProfilerMarker.Auto` call in non-development (Release) builds. It will however instead return null, which only adds minimal overhead.

You can also use `ProfilerMarker.Auto` with a `using var` and the `End` call happens automatically once the current scope ends. This approach minimizes the amount of code you need to change when you add a `ProfilerMarker` instance to your code:

```lang-cs
using Unity.Profiling;

public class MySystemClass
{
    static readonly ProfilerMarker k_UpdatePerfMarker = new ProfilerMarker("MySystem.Update");

    public void Update()
    {
        using var _ = k_UpdatePerfMarker.Auto();
        // ...
    }
}
```

> **Note:**
>
> Any async `await` and any `yield` calls within an area marked up with `ProfilerMarker`'s aren't supported and log an error message in the Console, even if you use `Auto`.

## Adding integer or floating point parameters to samples

Sometimes you might want to add context to your code samples to identify specific conditions in which the code runs for a long time.

For example, if your system carries out simulations of objects, you can pass the number of objects with a Profiler sample. If the Profiler returns an abnormal number along with a long sample duration, that might mean you have to use another thread for simulation, split the CPU work across multiple frames (timeslicing), or adjust your application's design to prevent frame drops.

`ProfilerMarker` supports up to three numeric parameters: [`ProfilerMarker<TP1>`](https://docs.unity3d.com/Packages/com.unity.profiling.core@1.0/api/Unity.Profiling.ProfilerMarker-1.html), [`ProfilerMarker<TP1, TP2>`](https://docs.unity3d.com/Packages/com.unity.profiling.core@1.0/api/Unity.Profiling.ProfilerMarker-2.html) and [`ProfilerMarker<TP1, TP2, TP3>`](https://docs.unity3d.com/Packages/com.unity.profiling.core@1.0/api/Unity.Profiling.ProfilerMarker-3.html):

```lang-cs
using Unity.Profiling;

public class MySystemClass
{
  static readonly ProfilerMarker<int> k_PreparePerfMarker = new ProfilerMarker<int>("MySystem.Prepare", "Objects Count");
  static readonly ProfilerMarker<float> k_SimulatePerfMarker = new ProfilerMarker<float>(ProfilerCategory.Scripts, "MySystem.Simulate", "Objects Density");

  public void Update(int objectsCount)
  {
    k_PreparePerfMarker.Begin(objectsCount);
    // ...
    k_PreparePerfMarker.End();

    using (k_SimulatePerfMarker.Auto(objectsCount * 1.0f))
    {
      // ...
    }
  }
}
```

## Adding string parameters to samples

The `ProfilerMarker` API supports adding string parameters to your profiler markers. A string parameter can be useful if you want to display the name of the level or file when your application loads level or data files. Use [`ProfilerMarkerExtension`](https://docs.unity3d.com/Packages/com.unity.profiling.core@1.0/api/Unity.Profiling.ProfilerMarkerExtension.html) methods to pass a string parameter along with a Profiler sample:

```lang-cs
using Unity.Profiling;

public class MySystemClass
{
  static readonly ProfilerMarker k_PreparePerfMarker = new ProfilerMarker("MySystem.Prepare");

  public void Prepare(string path)
  {
    k_PreparePerfMarker.Begin(path);
    // ...
    k_PreparePerfMarker.End();
  }
}
```

## Additional resources

* [Adding profiling information to your code introduction](/engine/6000.6/manual/analysis/profiler/customizing/adding-information-code/intro.md)
* [Adding profiler counters to your code](/engine/6000.6/manual/analysis/profiler/customizing/adding-information-code/add-counters-code.md)
* [CPU Usage Profiler module introduction](/engine/6000.6/manual/analysis/profiler/visualizing-data/cpu/introduction.md)
* [`ProfilerMarker` API](/engine/6000.6/script-reference/unity/profiling/profilermarker.md)
* [Profiling Core package](https://docs.unity3d.com/Packages/com.unity.profiling.core@latest)