---
title: waitUntilCompleted()
framework: coreimage
role: symbol
role_heading: Instance Method
path: coreimage/cirendertask/waituntilcompleted()
---

# waitUntilCompleted()

Waits until the CIRenderTask finishes and returns.

## Declaration

```swift
func waitUntilCompleted() throws -> CIRenderInfo
```

## Discussion

Discussion Synchronously blocks execution until the CIRenderTask either completes or fails (with error).  Calling this method after startTask(toRender:to:) or startTask(toRender:from:to:at:) makes the render task behave synchronously, as if the CPU and GPU were operating as a single unit.