Creating

Creating a custom input source involves defining the following:

• The information you want your input source to process.
• A scheduler routine to let interested clients know how to contact your input source.

Signaling the Input Source

• After it hands off its data to the input source, a client must signal the source and wake up its run loop.
• Signaling the source lets the run loop know that the source is ready to be processed

• you should always wake up the run loop explicitly

  tips

• when the allotted time expires,the run loop call CFRunLoopSourceInvalidate to invalidate all the source0(at the same time invoke cancellation routine to inform the client)

• CFRunLoopSourceInvalidate removes source from all the run loop modes in which it was registered.