How to reduce CPU utilization and free up memory footprint while the AVAudioEngine is running fast scheduleBuffer?

When I use websocket to get data from the network, and use AVAudioEngine scheduleBuffer every time I get data, my CPU usage and memory will increase rapidly after the continuous fast scheduleBuffer. Will the memory be automatically released after the AVAudioEngine plays the AVAudioPCMBuffer? And how can I reduce CPU usage? Inside the link is a screenshot of some of the code and debugging data

https://github.com/J844259756/picture