---
title: "os_signpost(_:dso:log:name:signpostID:_:_:)"
framework: os
role: symbol
role_heading: Function
path: "os/os_signpost(_:dso:log:name:signpostid:_:_:)-2om9b"
---

# os_signpost(_:dso:log:name:signpostID:_:_:)

Logs a point of interest in your code as a time interval or as an event for debugging performance in Instruments, and includes a detailed message.

## Declaration

```swift
func os_signpost(_ type: OSSignpostType, dso: UnsafeRawPointer = #dsohandle, log: OSLog, name: StaticString, signpostID: OSSignpostID = .exclusive, _ format: StaticString, _ arguments: any CVarArg...)
```

## Parameters

- `type`: The type of signpost to log.
- `log`: A log object to log the signpost to.
- `name`: The name of the signpost.
- `signpostID`: A signpost identifier you use to disambiguate between signposts with the same name.
- `format`: A constant string or format string that produces a human-readable log message.
- `arguments`: Additional arguments to substitute into the format string parameter. Pass the expected number of arguments in the order that they appear in the string. If format is a constant string, don’t include any additional arguments.

## See Also

### Measure Events

- [os_signpost(_:dso:log:name:signpostID:)](os/os_signpost(_:dso:log:name:signpostid:)-2oz8u.md)
- [OSSignpostType](os/ossignposttype.md)
- [os_signpost(_:dso:log:name:signpostID:)](os/os_signpost(_:dso:log:name:signpostid:)-12m3v.md)
- [os_signpost(_:dso:log:name:signpostID:_:_:)](os/os_signpost(_:dso:log:name:signpostid:_:_:)-nez5.md)
- [OSSignpostAnimationBegin](os/ossignpostanimationbegin.md)
- [AnimationFormatString](os/animationformatstring.md)
- [os_signpost_id_t](os/os_signpost_id_t.md)