JPH0566966A - Test procedure generating method for parallel program - Google Patents

Abstract

PURPOSE:To reduce the memory capacity and the calculation time required for generation of a black box test procedure for a parallel program and to obtain this test procedure with high efficiency by generating a control flow graph which contains all stable start states of each test procedure and expresses only the actions that can be recognized as the test items. CONSTITUTION:A means which converts a parallel program into a control flow flag 12 selects a global event consisting of a pair of events where each process can be carried out in the present state with higher preference given to the internal transmission/reception events of a system and the local event of each process over an external input event. Then the selected global event is sequentially carried out from an intial state for generation of the graph 12 which defines an entire area state as a spot and the transition caused by the global event as a branch respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of generating a procedure when a black box test is performed by using a system composed of a plurality of processes as a parallel program.

[0002]

2. Description of the Related Art Conventionally, various methods have been proposed for conformity testing methods for protocol machines and the like, but all of them are intended to test a single process. For example, OSI (Open Systems Interconne
ction: open system interconnection) etc., active discussions have been conducted on conformity testing methods for protocol machines (reference, “Formal Methods for Protocol Test”).
ing, A Detailed Study ”D. P. Shdhu et al., IEEE
Transaction on Software Engineering 15 pp.
413-426 (1987)). Therefore, it is difficult to apply them to a black box test of a parallel program such as a coupling test of an exchange program and an interconnection test of an application layer protocol such as OSI. By the way, a black box test of a parallel system such as an exchange is a test performed under the following assumptions. (A) A FIFO is used for the inter-process communication channel. (B) The relative execution speed between processes cannot be foreseen. (C) The system starts operation triggered by an input from the outside, gives an observable output, and repeats the transition to a stable state. Further, the test item is generated under the following conditions. (A) The observation in the test does not distinguish the difference caused by the operation timing in the system. (B) Only a single external input is provided in each stable state. That is, a plurality of simultaneous external inputs and external inputs during transition between stable states are prohibited. It should be noted that the stable state here is an entire state in which only reception of an input from the outside can be executed. Conventionally, a black box test of a parallel system such as an exchange has been manually created with reference to specifications, so it takes a considerable amount of time and work, and there are problems such as quality variations depending on the creator of the test procedure. there were.

FIG. 2 is an explanatory view of a conventional test procedure generation method for a parallel program, and FIG. 3 is a flow chart showing an operation algorithm of the control flow graph generation section in FIG. In FIG. 2, 11 is a system specification, 21 is a degenerate reachability analysis unit, 12 is a control flow chart, 13 is a test specification, 22 is a test procedure generation unit, and 14 is a test procedure. For example, the document “Towards analyzing a
nd synthesizing protocols ”P. Zafiropulo et al., I
EEE Transactions on Communication 28, pp.
651 to 660 (1980)), a control flow chart (sequential program) that represents a global operation of a concurrent program to be tested, as shown in FIG.
The test procedure generation method for the sequential program is applied to the control flow chart. First, event candidates are generated (step 1), then the reachable tree is updated (step 2), and the process returns to the original. That is, first, the state Sp of all processes is set to the initial state, and all reception buffers are set to 0 (301). It is judged whether Sp has ended for all p (302), and if not completed yet, an executable event set Esp in the current state Sp is obtained for all processes p (303). ). Next, it is judged whether or not Esp = 0 for all p (304), and 0
If not, the logical sum E of all Esp is calculated (30
5). Next, the event included in the generated E is executed, the next global state is generated, and a branch to it is added (3
06). Then, it returns to the operation 302 again to continue the processing.

[0004]

However, in the conventional method shown in FIGS. 2 and 3, the memory capacity required for the control flow graph generation and the calculation time are enormous.
It was impossible to generate efficient test items. An object of the present invention is to solve such a conventional problem and to provide an efficient method of generating a black box test procedure of a parallel program by reducing both the memory capacity required for generating the test procedure and the calculation time. Especially.

[0005]

In order to achieve the above object, a test procedure generation method for a concurrent program according to the present invention converts a concurrent program into a control flow chart and then generates a test procedure from the control flow chart. In a test procedure generation system for a concurrent program, when converting a concurrent program into a control flow chart, a group consisting of a set of events that each process can execute in the current state.
The global event is selected by giving priority to the transmission / reception event between processes and the local event of each process over the input event from the outside, and the events are sequentially executed from the initial global state, and the global state is set as a point. -It is characterized in that a control flow graph having a transition due to a bar event as a branch is generated.

[0006]

Under the constraints (a) and (b) described above, the black box equivalence concept is introduced in order to show the relationship between operation sequences that cannot be distinguished as a test procedure. That is, the action sequence is generally divided into sets of partial sequences of events executed by each process. Here, the above set will be referred to as a multilog. When the following conditions (A) and (B) are satisfied, the two operation sequences IS and IS 'are called black box equivalence. (A) Subsequence focusing only on external input of IS, IS ′,
ex (IS) and ex (IS ') match. (B) IS and IS 'are divided into the same multilog. In the present invention, a global event sequence (a degenerate action sequence R) that represents a set of black box equivalent action sequences.
By forming a control flow chart consisting only of (IS), a minimum control flow chart expressing only operations that can be distinguished as a test procedure is constructed. (B) The expansion event sequence serves as the route of the control flow chart generated by the conventional method. (B) There is a control flow graph path which generates a black box equivalent expansion event sequence with an arbitrary path of the control flow graph generated by the conventional method. Here, the expanded event sequence is an event sequence formed by arranging each event in the global event in parallel in an arbitrary process order from the path of the control flow graph. In the present invention, in order to generate a control flow graph including all stable states, a global event composed of a set of events that can be executed in the current state is set as an internal event (excluding an external input event) rather than an external input event. (Event) is preferentially selected, and it is sequentially executed from the initial whole state to generate a control flow chart. Therefore, the control flow chart generated by the present invention has the following properties. (A) The expansion event sequence generated from different routes is
Not black box equivalent (minimal). (B) All stable states are generated (coverage). That is, the generated control flow chart is a minimum control flow chart that includes all stable states, which are the starting states of each test procedure, and that expresses only the operations that can be distinguished as the test procedure. And the calculation time can be reduced.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a functional block diagram of a test procedure generation system for a parallel program showing an embodiment of the present invention. In this embodiment, the control flow is changed from the system specification 11.
The control flow chart generation unit (degenerate reachability analysis unit) 21 that generates the graph 12 and the test procedure generation unit 22 that generates the test procedure 14 from the generated control flow graph 12 and the test specifications 13 are configured. Here, since the test procedure generation unit 23 may use a method similar to the test procedure generation method for the sequential program, the details of the control flow generation unit 21 will be described below. Control flow chart generation unit 2
1 is an execution state management unit 23 that manages the overall execution state,
An event executability determination unit 25 that determines the executability of each event, a global event generation unit 26 that calculates global events, and a control flow that updates the control flow graph with the generated global events. -It is composed of the graph updating unit 24. 1 is different from the conventional system shown in FIG. 2 in that a global event generation unit 26 is newly provided in the control flow generation unit 21.

FIGS. 4 (a) and 4 (b) show an example of a protocol specification that simplifies the two-party call service applicable to the present invention, and the meaning of the predicate as a general example.
In FIG. 4A, a signal with a left internal arrow is an external reception event, a target (signal) with a right internal arrow is a reception event, a target (signal) with a right external arrow is a transmission event, and both ends of an external arrow are A certain free is a conditional branch event, and a ring with double-ended arrows is an autonomous event (see FIG. 4 (b)).
In addition, start is operation start, onhk is on-hook, and ofhk is off-hook. As shown in FIG. 4A, this specification is composed of three processes of the subscriber terminals T1 and T2 and the exchange EX. Each process is described in a notation similar to the CCITT specification description language drawing SLD / GR. Subscriber terminals T1, T2 and exchange EX of FIG. 4 (a)
In contrast to the specification of, the event series IS ₁ and IS ₂ are the system operation series of this specification and are paths on the reachable tree. In addition, T ₁ , T ₂ , EX added at the end of each term in the following equation is
It means the processes of the subscriber terminals T ₁ and T ₂ and the exchange EX, respectively. IS ₁ = [+ (ofhk) T ₁ , −T2 (start) T ₁ , + T1 (start) T ₂ , if (free: Y) T ₂ , −T1 (Ack) T ₂ , + T2 (Ack) T ₁ , Ring_back () T ₁ , Ring () T ₂ , + (ofhk) T ₂ , -EX (cnnect) T ₂ ,, T2 (connect) EX, -T1 (connect) T ₂ ,, + T 2 (connect) T ₁ ,, set_speachpath (T1, T2) EX, ······ , + T1 (term) T2, Busy () T 2, + (onhk) T 2 ] IS ₂ = _{[+ (ofhk) T 1, -T2} (start) T ₁ , + T1 (start) T ₂ , if (free: N) T ₂ , -T1 (Nack) T ₂ , + T2 (Nack) T ₁ , Busy () T ₁ , + (onhk) T ₁ ]

FIG. 5 is a diagram showing an outline of a normal control flow chart for the protocol specifications of FIG. this is,
It includes 50 global states and 1267 motion sequences. The 1267 motion sequences are multi-log (uT
1, uT2, EX) is a group 1 consisting of 1266 sequences (IS ₁ is included in this group) and a sequence represented by multilog (uT1 ', uT2'). It is divided into groups 2 consisting of IS ₂ . uT1 = [+ (ofhk),-T2 (start), + T2 (Ack), Ring_back (), + T2 (connect), + (onhk),-EX (term),-T2 (term)] uT2 = [+ T1 ( start), if (free: Y), -T1 (Ack), Ring (), + (onhk), -EX (connect), -T1 (connect), -T1 (term), Busy (), + (onhk )] UEX = [+ T2 (connect), set_speachpath (T1, T2), + T1 (term), release_speachpath (T1, T2)] uT1 ′ = [+ (ofhk), −T2 (start), + T2 (Nack), Busy (), + (onhk)] uT2 '= [+ T1 (start), if (free: N), -T1 (Nack)] The above uT1, uT2, uEX are processes T1, T2.
It is an event sequence executed by EX.

Further, since the 1266 operation sequences of group 1 have the same external input event sequence ex (IS ₁ ), the above-mentioned two groups are each a glass of an operation sequence equivalent to a black box. Is. With respect to these black box equivalent action series classes, the following degenerate operation series RIS is considered to be a global event series representing each class. RIS ₁ = [{+ (ofhk) T ₁ }, {− T2 (start) T ₁ }, {+ T1 (start) T ₂ }, {if (free: Y) T ₂ }, {− T1 (Ack) T ₂ }, {+ T2 (Ack) T ₁ , Ring () T ₂ }, {Ring_back () T ₁ }, {+ (ofhk) T ₂ }, {-EX (connect) T ₂ }, {-T1 ( connect) T ₂ , + T2 (connect) EX}, {+ T2 (connect) T ₁ , set_speachpath (T1, T 2) EX}, ..., {+ T1 (term) T ₂ }, {Busy () T ₂ }, {+ (Onhk) T ₂ }] RIS ₂ = [{+ (ofhk) T ₁ }, {− T2 (start) T ₁ }, {+ T1 (start) T ₂ }, {if (free: N) T ₂ }, {− T1 (Nack) T ₂ }, {+ T2 (Nack) T ₁ }, {Busy () T ₁ }, {+ (onhk) T ₁ }]

FIG. 6 is a flow chart showing the algorithm of the control flow graph generation unit in FIG. That is, FIG. 6 shows the operation of the control flow chart generation unit that generates the control flow chart composed only of the above-described degenerate operation series RIS. The operation generates an event candidate in step 1, generates a global event in step 2, updates the reachable tree in step 3, and returns to the original. That is, first, as a preparation, all processes are initialized and all reception buffers are emptied (6
01). It is determined whether or not Sp = end state for all p, and when it is not finished (602), the event executability determination unit 25 determines that for each process p,
Executability is determined for the internal events described in the current state Sp according to the following rules, and the executable internal event set Esp and the pseudo-possible event set Psp are determined. (A) Events other than reception and an event in which an expected signal is at the head of the reception buffer can be executed. (B) In the reception event, an event in which the corresponding reception buffer is empty can be pseudo-executed. (C) Internal events other than the above cannot be executed.

Next, event candidates of the external input event Tsp are calculated (603). A pseudo-possible event is an event in which the corresponding reception buffer is empty, and there is a possibility that it will become executable if "waiting" without executing the executable event. In order to schedule the execution of this pseudo-possible event, a wait event λ that means to wait for the execution of the executable event is used. However, for the process that executed the wait event λ immediately before, the executable event and the pseudo-possible event are calculated only for the pseudo-possible event that could not be executed. Next, in step 2, the global event generation unit 26 calculates a global event. That is,
Esp is 0 for all p (604), and Ts
If p is 0 (606), the calculation ends. Esp is 0
If not, the logical sum of Psp and Tsp is taken and the result is 0
If not (605), Esp: = TspU (λ) is obtained (608), and then GE: = cp is calculated (60).
9). If the result of the logical sum of Psp and Tsp is 0 (605), GE: = cp is immediately calculated (60).
9). If Tsp is not 0 for all p (6
06), the global event GE: = (t) is calculated (607). Next, in step 3, the control flow updating unit 24 executes all the events in the global event GE in an arbitrary order to generate the next global state and add a branch to it ( 610). Then, step 1 and subsequent steps are recursively applied to each of the newly generated global states. However, only one external reception is executed at the same time. When all the processes are in the final state, the algorithm ends (602). A finite channel length is assumed to guarantee the termination of this algorithm.

FIG. 7 is a diagram showing an outline of a control flow chart in which internal communication events corresponding to the specifications of FIG. 4 are deleted. The control flow chart includes the above-described two degenerate operation series R.
IS ₁ and RIS _2, and the five stable states (0,
0,0), (4,4,0), (5,7,2), (0,
9,0), (0,9,0), (9,0,0) are included. These stable states correspond to points, and the lines connecting these points correspond to branches. What exists in the middle of the branch indicates an operation indicating what to do. This control flow chart shows global events consisting of a set of events that can be executed by each process in the current state, sending and receiving events inside the system and local events of each process rather than input events from the outside. A control flow graph is generated which is selected with priority and is sequentially executed from the initial global state so that transitions due to global events are branches with the global state as a point. In this embodiment, since the control flow chart is generated by the degenerate reachability analysis method, it is desirable to include all stable states, which are the starting states of each test procedure, and not to distinguish them as the test procedure. It is composed only of the degenerate operation sequence that represents the class. Therefore, it is possible to avoid the state explosion that would occur in the usual reachability analysis and the huge calculation time. Further, by directly applying the conventional sequential program test procedure generation method to the obtained control flow chart, it is possible to easily and automatically generate the test procedure of the parallel program.

[0014]

As described above, according to the present invention,
It is possible to generate a control flow chart that includes all stable states, which are the starting states of each test procedure, and that expresses only the operations that can be distinguished as test items, under the restriction. It is possible to save time and generate efficient parallel program black box test procedures.

[0015]

[Brief description of drawings]

FIG. 1 is a functional block diagram of a test procedure generation system for a parallel program according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of a conventional test procedure generation system for a parallel program.

3 is a flow chart showing an operation algorithm of a control flow chart generation unit in FIG.

FIG. 4 is a diagram showing an example of protocol specifications in which the present invention is used.

FIG. 5 is a schematic diagram of a control flow chart according to a conventional method.

FIG. 6 is an operation flow chart showing an algorithm of a control flow chart generation unit in FIG.

FIG. 7 is a schematic diagram of a control flow graph generated in the present invention.

[Explanation of symbols]

 11 System Specifications 12 Control Flow Graph 13 Test Specifications 14 Test Procedure 21 Control Flow Graph Generation Unit 22 Test Procedure Generation Unit 23 Execution State Management Unit 24 Control Flow Graph Updating Unit 25 Event Executability Determination Unit 26 Global Event Generator

Claims (1)

[Claims] 1. A test procedure generation system for a parallel program, which converts a parallel program into a control flow chart and then generates a test procedure from the control flow chart, when converting the parallel program into a control flow chart. A global event consisting of a set of events that can be executed by each process in the current state is selected by giving priority to a transmission / reception event between processes or a local event of each process over an input event from the outside. Events are sequentially executed from the initial global state, and the global state is set as a point
A test procedure generation method for a concurrent program, which is characterized in that a control flow graph having a transition due to a bar event as a branch is generated.