A constant-time dynamic storage allocator for real-time systems

Dynamic memory allocation has been used for decades. However, it has seldom been used in real-time systems since the worst case of spatial and temporal requirements for allocation and deallocation operations is either unbounded or bounded but with a very large bound. In this paper, a new allocator called TLSF (Two Level Segregated Fit) is presented. TLSF is designed and implemented to accommodate real-time constraints. The proposed allocator exhibits time-bounded behaviour, O(1), and maintains a very good execution time. This paper describes in detail the data structures and functions provided by TLSF. We also compare TLSF with a representative set of allocators regarding their temporal cost and fragmentation. Although the paper is mainly focused on timing analysis, a brief study and comparative analysis of fragmentation incurred by the allocators has been also included in order to provide a global view of the behavior of the allocators. The temporal and spatial results showed that TLS...

• Type: Journal
• Year: 2008
• Where: RTS
• Authors: Miguel Masmano, Ismael Ripoll, Patricia Balbastre, Alfons Crespo
• Keywords: Dynamic Memory Allocation, Real-time Systems, RTS 2008, Temporal Requirements