---
title: "CompositionTracer"
description: "Internal tracing API."
type: "interface"
---
## API Reference

> Source set: Common

```kotlin
public interface CompositionTracer
```

Internal tracing API.

Should be called without thread synchronization with occasional information loss.

## Functions

### traceEventStart

> Source set: Common

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

### traceEventEnd

> Source set: Common

```kotlin
public fun traceEventEnd(): Unit
```

### isTraceInProgress

> Source set: Common

```kotlin
public fun isTraceInProgress(): Boolean
```