WRLqueue: A Lock-Free Queue For Embedded Real-Time System.

Data synchronization across tasks and devices are crucial for any system supporting multi-task. The standard lock-based blocking mechanism in the aforementioned process may have unpredictable latency overhead thus is not suitable for real time applications, and is prone to deadlock. As a result, lock-free and wait-free algorithms with worst-case latency and progress assurance are crucial for real time cases. Existing lock-free algorithms need to frequently allocate new storage buffers during execution, and design a series of complex memory recovery strategies and help mechanisms. It results in a high worst-case latency, complicated algorithm design, and poor embedded device adaptability. This work proposes a new lock-free method WRLqueue (write to read lock-free queue) for multi-producer and single consumer situation, which considerably enhances the real-time performance guarantee. Experimental results show that the cyclomatic complexity is reduced by 85% compared with existing algorithms. The worst-case latency of enqueue operation decreases by 90% in the case of no competition and 60% in the case of competition.