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# CFMachPortGetContext(_:_:)

Returns the context information for a CFMachPort object.

```
func CFMachPortGetContext(_ port: CFMachPort!, _ context: UnsafeMutablePointer<CFMachPortContext>!)
```

## Parameters

`port`

The CFMachPort object to examine.

`context`

A pointer to the structure into which the context information for `port` is to be copied. The information being returned is usually the same information you passed to [`CFMachPortCreate(_:_:_:_:)`](/documentation/CoreFoundation/CFMachPortCreate(_:_:_:_:)) or [`CFMachPortCreateWithPort(_:_:_:_:_:)`](/documentation/CoreFoundation/CFMachPortCreateWithPort(_:_:_:_:_:)) when creating `port`. However, if [`CFMachPortCreateWithPort(_:_:_:_:_:)`](/documentation/CoreFoundation/CFMachPortCreateWithPort(_:_:_:_:_:)) returned a cached CFMachPort object instead of creating a new object, `context` is filled with information from the original CFMachPort object instead of the information you passed to the function.

## Discussion

The context version number for CFMachPort objects is currently `0`. Before calling this function, you need to initialize the `version` member of `context` to `0`.

---

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