ComFlex: Composable and Flexible Resource Management for the IoT

The Internet of Things (IoT) enables new services, such as smart home and smart healthcare integrating various resources of networked devices. However, managing IoT resources is very challenging because a device may have multiple different resources and the service accesses subsets of the resources in multiple devices. To simplify the resource management, the existing IoT frameworks provide resource models and protocols for manufacturers and programmers, but their access granularity is too coarse grained causing overprivilege problems, or too fine grained causing management overheads. To avoid the overprivilege problems without the management overheads, this work proposes a new composable and flexible resource management scheme and implements its prototype compiler-runtime framework called ComFlex. The ComFlex compiler allows manufacturers to register their devices as composition of fine-grained resources by inheriting the existing interfaces of the resources, and programmers to define their own access granularity as a virtual resource that consists of the fine-grained resources of multiple devices. The ComFlex runtime supports fine-grained access control without additional overheads by mapping the fine-grained resources of the virtual resource into physical resources of different devices. To evaluate the ComFlex framework, this work implements 52 resources on 14 devices and six IoT services with ComFlex and an existing fine-grained resource management scheme. Compared to the existing scheme, the ComFlex framework supports the IoT services with 40.2% fewer lines of code and 80.9% less discovery time, without any overprivilege problem and response time delay.