JPH04104335A - Memory stop trapper - Google Patents

Abstract

PURPOSE:To evaluate software without the need of special machinery and materials except for a target computer by using a computer system which can execute interruption at every instruction and a memory stop trapper logic constructed on the computer system. CONSTITUTION:Software being the object of evaluation integrates memory stop trapper start setting processing A logic at the head of a section having a problem. Processing A logic sets conditions X and Y given in a memory change check processing and gives the instruction generating interruption at every instruction to computer hardware. Target software 1 being the object of evaluation passes through a memory stop trapper logic at every instruction and the above processing is repeated until the conditions X and Y which are set by a memory stop trapper start setting processing are satisfied. When the conditions are satisfied, an execution address which is executed immediately before is read out from a stack and a content from a hardware register by a memory change information acquirement processing D. The information is displayed in a display device such as CRT by a memory change point information display processing E.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to - a software evaluation method in a computer system having a function of generating an interrupt on an instruction-by-instruction basis; relates to a memory stop trapper that generates an interrupt trap for changes in .

[Prior Art] Conventionally, in software evaluation in multiplex real-time software systems, in order to detect the contents of a specific memory field during software execution and check the logic points that are changing it, it is necessary to They either used other systems to monitor changes in content, or they used a function built into the target computer itself that generated a trap when accessing memory.

[Problems to be Solved by the Invention] The conventional evaluation method described above requires evaluation equipment in addition to the target computer in order to set a trap when the information in the specified memory field changes under certain conditions.
In addition, when using functions built into the target computer itself, the hardware becomes expensive, and some computers only have the function of generating a trap when reading or writing a memory field. In many cases, the drawback is that it is not possible to set conditions with a large degree of freedom for software evaluation.

[Means for Solving the Problems] The memory stop trapper of the present invention is capable of generating an interrupt for each instruction, and in a computer system having instructions for starting and stopping the interrupt, the memory stop trapper of the present invention can generate an interrupt for each instruction. To stop a program when a comparison condition matches memory contents at two points separately specified in an interrupt routine while generating an interrupt, and to specify a software address at which the memory is changed.

[Example] Next, the present invention will be explained with reference to the drawings.

FIG. 1 shows the software structure of the present invention. An interrupt gate 2 generated for each instruction and a memory stop trapper logic 3 are incorporated into the target software system at the interrupt destination. The memory stop trapper logic consists of a memory change check process C, a memory change information acquisition process, and a memory change point information display process E.

Memory change check processing C stores two points of memory address information (X, Y) and a condition (X condition Y) for comparing and checking the two points with information in the memory address. Perform comparative inspection and check based on conditions.

The comparison condition is X=Y.

xf-y, x>y, x<y, x≦Y, X≧Y; X, Y, and conditions are given by memory stop trapper activation setting processing A from external software; Memory stop trapper - Cancelled by stop setting process B.

Next, the operation will be explained in more detail.

The evaluation target software that uses the memory stop trapper logic 3 built into the target software system incorporates the memory stop trapper activation setting processing A logic at the beginning of the section having the problem. The memory stop trapper activation setting processing A logic sets the X, Y, and conditions included in the memory change check processing, and issues an instruction to the computer hardware that causes an interrupt to be generated in units of -instructions.

As described above, the target evaluation target software 1 passes through the memory stop trapper logic for each instruction and repeats it until the X, Y, and conditions set in the memory stop trapper activation setting process are satisfied. If the conditions are satisfied, the memory change information acquisition process reads the most recently executed execution address from the stack and the contents from the hardware register, and the information is displayed in C by the memory change point information display process E.
It is displayed on a display device such as RT and the software system is stopped.

Through the above processing, it is possible to identify points in the logic of the software to be evaluated that have problems, such as memory corruption on its own and settings other than expected values.

[Effects of the Invention] As explained above, the present invention uses a computer system that can interrupt each instruction, and a memory stop trapper logic built on the computer system, so that it can be used in computers other than the target computer. This has the effect that software evaluation can be realized without requiring special equipment or expensive computer systems.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the software structure of the present invention. 1... Software to be evaluated, 2... Interrupt gate, 3... Memory stop trapper logic, A.
・・Memory stop trapper - startup setting processing, B...
Memory stop trapper stop setting processing, C: memory change check processing, D: memory change information acquisition processing, E: memory change point information display processing.

Claims (1)

[Claims] In a computer system that can generate an interrupt for each instruction and has instructions to start and stop the interrupt, it is possible to generate an interrupt for each instruction and store the memory contents of two points separately specified within the interrupt routine. A memory stop trapper that stops the program when the comparison conditions match and allows you to identify the software address that changed memory.