CFMachPort

Overview

A CFMachPort object is a wrapper for a native Mach port (mach_port_t). Mach ports are the native communication channel for the macOS kernel.

CFMachPort does not provide a function to send messages, so you primarily use a CFMachPort object if you need to listen to a Mach port that you obtained by other means. You can get a callback when a message arrives on the port or when the port becomes invalid, such as when the native port dies.

To listen for messages you need to create a run loop source with CFMachPortCreateRunLoopSource(_:_:_:) and add it to a run loop with CFRunLoopAddSource(_:_:_:).

To send data, you must use the Mach APIs with the native Mach port, which is not described here. Alternatively, you can use a CFMessagePort object, which can send arbitrary data.

Mach ports only support communication on the local machine. For network communication, you have to use a CFSocket object.

Symbols

Configuring a CFMachPort Object

func CFMachPortInvalidate(CFMachPort!)

Invalidates a CFMachPort object, stopping it from receiving any more messages.

func CFMachPortCreateRunLoopSource(CFAllocator!, CFMachPort!, CFIndex)

Creates a CFRunLoopSource object for a CFMachPort object.

func CFMachPortSetInvalidationCallBack(CFMachPort!, CFMachPortInvalidationCallBack!)

Sets the callback function invoked when a CFMachPort object is invalidated.

Examining a CFMachPort Object

func CFMachPortGetContext(CFMachPort!, UnsafeMutablePointer<CFMachPortContext>!)

Returns the context information for a CFMachPort object.

func CFMachPortGetInvalidationCallBack(CFMachPort!)

Returns the invalidation callback function for a CFMachPort object.

func CFMachPortGetPort(CFMachPort!)

Returns the native Mach port represented by a CFMachPort object.

func CFMachPortIsValid(CFMachPort!)

Returns a Boolean value that indicates whether a CFMachPort object is valid and able to receive messages.

Getting the CFMachPort Type ID

func CFMachPortGetTypeID()

Returns the type identifier for the CFMachPort opaque type.

Callbacks

CFMachPortCallBack

Callback invoked to process a message received on a CFMachPort object.

CFMachPortInvalidationCallBack

Callback invoked when a CFMachPort object is invalidated.

Data Types

CFMachPortContext

A structure that contains program-defined data and callbacks with which you can configure a CFMachPort object’s behavior.

CFMachPort

A reference to a CFMachPort object.