Method for monitoring internal memory varible rewrite based on finite-state-machine

Abstract

The method includes steps: based on monitoring parameters of memory variable to be monitored and monitoring condition, setting up monitoring units; setting up some monitoring points at different positions of Finite State Machine (FSM); when program runs to the monitoring point, determining whether the relevant monitoring condition recorded in the monitoring unit is satisfied; if yes, the monitoring point of FSM outputs monitoring information. Advantages are: when CPU hardware does not possess register for debugging data, fault of rewritten unstack variable is positioned to level of status and event so as to raise debugging efficiency. Features are: accurate positioning and good performance in real time. Further, rewritten unstack variable can be positioned to function level inside FSM.

Description

technical field [0001] The invention relates to a method for monitoring the rewriting of non-stack memory variables in the embedded software environment of the finite state machine, and provides a method for locating the rewriting of non-stack variables in a multi-task operating environment based on shared global memory, especially The invention relates to a method for monitoring memory variable rewriting based on a finite state machine. Background technique [0002] In an embedded multitasking environment, how to locate non-stack variables that have been incorrectly rewritten is the most labor-intensive task in the debugging process and version running process. When it is wrongly rewritten, by whom, and how to catch the wrong rewrite are the first issues to be considered in software debugging or software fault location. [0003] In the existing non-stack memory variable reading and writing monitoring method, the fault that the non-stack memory variable is wrongly rewritten...

AI Technical Summary

Problems solved by technology

The advantage of this method is accurate positioning and good real-time performance, but this method also has defects: it depends on the CPU hardware. When the CPU hardware does not provide data debugging registers, it cannot complete the monitoring of non-stack variables being rewritten; In addition, this method is also limited by the number of data breakpoint registers of the CPU, and the number of variables monitored at one time cannot exceed the number of data breakpoint registers, so its application range is limited

The defect of this method is that in the multitasking environment of shared global memory, since multiple tasks are in the address space of uniform addressing, when one task changes the non-stack state variable of another task by mistake, it is not necessarily Will or will not immediately cause CPU memory read and write exceptions, often after a task has been running for a long time, the CPU may be abnormally interrupted due to other parts of the memory read and write

Due to this hysteresis effect, it is more difficult to locate faults where non-stack variables are incorrectly overwritten

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