---
title: "traceEventStart"
description: ""
type: "function"
---

<div class='type'>Function</div>


<a id='references'></a>
<div class='sourceset sourceset-common'>Common</div>


> **Deprecated** Use the overload with \$dirty metadata instead

```kotlin
@ComposeCompilerApi
public fun traceEventStart(key: Int, info: String): Unit
```


<div class='sourceset sourceset-common'>Common</div>


```kotlin
@ComposeCompilerApi
public fun traceEventStart(key: Int, dirty1: Int, dirty2: Int, info: String)
```


Internal tracing API.

Should be called without thread synchronization with occasional information loss.

#### Parameters

| | |
| --- | --- |
| key | is a group key generated by the compiler plugin for the function being traced. This key is unique the function. |
| dirty1 | $dirty metadata: forced-recomposition and function parameters 1..10 if present |
| dirty2 | $dirty2 metadata: forced-recomposition and function parameters 11..20 if present |
| info | is a user displayable string that describes the function for which this is the start event. |