# AddReportToPool Adds a memory descriptor to the report pool. ``` virtual kern_return_t AddReportToPool(IOBufferMemoryDescriptor *report); ``` ## Parameters `report` A memory descriptor large enough to hold input reports from the device. The interface writes zeros to the descriptor’s bytes before using it to store a new input report. ## Return Value on success, or another value if an error occurs. See . ## Discussion When implementing a custom driver or event service, call this method to add one or more memory descriptors to a shared resource pool. When an input report arrives from the device, the interface removes a memory descriptor from the pool, fills it with the report data, and calls the [`ReportAvailable`](/documentation/HIDDriverKit/IOHIDInterface/ReportAvailable) method of the session’s action object. You are responsible for ensuring the pool has enough memory descriptors to store incoming reports. One way to maintain a sufficient supply of memory descriptors is to recycle them. In your action object’s `ReportAvailable` method, process the report and add the provided memory descriptor back to the pool when you are done. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)