Compile-Based Intermediate Code Key Variable Fault-Tolerant Technology

With the rise of worldwide space exploration activities, the reliability of board computers is getting more and more important. In the space environment, computer reliability problems caused by the hardware transient failure on-board are very important. Especially the single-event upset on board computer constitutes a major threat to security. Traditionally, radiation-hard devices are used to build on board computer. However, radiation-hard devices are expensive, and the computing performance is low. Compared with radiation hardened components, COTS components have very high performance, lower price and lower power dissipations. SHIFT (SHIFT, Software Implemented Hardware Fault Tolerance) on COTS components can provide space computers with high reliability, high performance, low cost and low power dissipations.Generally, SHIFT detects hardware transient faults by duplicate instruction and comparing the result. Inserting instructions for redundant computing can realize fault tolerance simply and effectively during compiling. Fault tolerance by compiler is a good implementation of SHIFT. So fault-tolerant by compiler is more popular.Firstly, this paper in-depth analysis the current fault-tolerant techniques and its advantages, disadvantages. Proposed a static analysis based analysis of the key variables and variable selection techniques. Analysis the variable vulnerability factors influence to system reliability. Concepts and models of the inherent vulnerability factors and dependency vulnerability factors are given. And the way to calculation, some examples verify the correctness of the calculation model.We depth analysis the principle of compiled based intermediate code key variable fault-tolerant algorithm, and got the conclusion that the key variable duplicate in the intermediate code is effective.We proposed two different variable duplicate strategies for error detection and one strategy for error recovery. Take the comparison of advantages and disadvantages of these strategies. The compiled based intermediate code key variable fault-tolerant algorithm has the adnantages of both the source to source fault-talerant and the fault-talerants on assembly instructions. It can be applied to a variety of high-level languages and hardware platforms. Finally, we verified the principle of compile based intermediate code key variable fault-tolerant algorithm by the method of fault injection experiments. The experiments results show that:1) The key variables selected technology can effectively be calculated and analyzed the variables impact on system reliability based on static analysis. The calculation of the variable vulnerability factors flexibility, and can be effectively use the compiler program analysis information.2) The compile based intermediate code key variable fault-tolerant technology achieves the expectation purpose, and it have better behaves on performance overhead and fault tolerance.