Abstract: The basic concurrent behavior was firstly modeled with CPN and the state space was obtained through CPN Tools.After that the complexity of the CPN was increased to show the possibly problems along with the state space quickly increasing.Secondly the phase of test generation was divided into three parts to guarantee the test coverage of concurrent behavior.Among them,the test sequences which only focused on the coverage of concurrent behaviors were generated and the other two parts were generated according to the regular path generation methods.The concurrency start(end) places were mapped with the state space nodes according to the CPN model execution and the sets of start(end) nodes in the state space were achieved.After analyzing the relationship between the nodes in the sets of start(end) nodes,the sequences sets were built according to the pre or pro relationship in the sets.The start(end) parts of the test sequences were selected from such sets,and the middle test sequences between start sequence to end sequence were generated.Furthermore,to illustrate the usage of the modeling method and the test generation,a simple P2P software system which is inherited concurrent behaviors was implemented and modeled with hierarchy CPN and the test sequences were generated to coverage the concurrent behavior.Finally,a TTCN-3 test scheme was designed according to the requirement of test sequences and a test scenario was designed.And the implemented software system and the TTCN-3 tester were deploying in one scenario to execute designed TTCN-3 testing suite.The test results show the correctness of the designed and implemented test work.

Key words: Concurrent behavior,CPN,Test sequence generation,TTCN-3