INTERNET-BASED COLLABORATIVE SYSTEM DESIGN USING MOSCITO

Transcription

1 INTERNET-BASED COLLABORATIVE SYSTEM DESIGN USING MOSCITO A. Schneider E. Ivask Fraunhofer Institute for Integrated Circuits Tallinn Technical University Branch Lab EAS Dresden Department of Computer Engineering Zeunerstraße 38, Dresden, Germany Raja 15, Tallinn, Estonia Abstract. This paper introduces a software architecture which can help that Internet-based collaboration in the field of system design becomes reality. Today many powerful tools for simulation, synthesis, test, and optimization are available. But most of them can only work as stand-alone tool on a certain platform. With MOSCITO these design tools can be encapsulated and coupled via Internet. Design engineers can remotely use the needed programs like a service and partners locating in different geographical sites can perform collaborative experiments over Internet. The author describes basic ideas and the implemented infrastructure of MOSCITO and discusses first practical experiences. Keywords. Internet-based design, simulation, optimization, test, security, firewall-protection 1 Motivation Starting from the idea to connect tools via the Internet to form an appropriate workflow for solving dedicated design problems the MOSCITO system at Fraunhofer IIS was developed and implemented [3]. The MOSCITO system works as an Internet-based multi-agent system which can be controlled and observed by the user's front end program the MOSCITO Desktop. Over the last years several approaches for coupling tools and providing services via Internet were developed. Powerful middleware such as CORBA, Java RMI, COM/DCOM or HLA is available today for implementing such distributed infrastructures. MOSCITO is mainly based on the general ideas of these approaches but it uses a very small, pure Java-based implementation. Some reasons for this design decision are: CORBA is very complex. It supports components which can be implemented in different programming languages. In MOSCITO this feature is not necessary because each tool is encapsulated in a Java wrapper class - the MOSCITO Agent. COM/DCOM is available on Microsoft platforms only. MOSCITO is needed at least on Solaris, Linux and Windows systems. Main focus of HLA is coupling of simulators. MOSCITO isn't restricted to this application area.

2 Design tools running on remote servers Internet / LAN In some systems only a white-box integration of tools is possible. MOSCITO Agent interface is targeted to support black-box integration. So also commercial tools can be encapsulated with low effort. Systems like [2] are based on very fine-grained, powerful workflow concepts. MOSCITO uses very simple, dataflow-based workflows which are controlled by the MOSCITO Agents themselves. The main emphasis in the MOSCITO tool integration was put on the following aspects: Encapsulation of design tools and adaptation of the tool-specific control and data input/ output to the MOSCITO framework Communication between the tools for data exchange to support distributed, Internet-based work. Uniform graphical user front-end program for the configuration of the tools, the control of the whole workflow and the visualization of result data. Moreover, an important goal is to provide the functionality of a tool to a potential user as a service in a local area network (LAN). This approach is similar to the Application Service Provider (ASP) idea or the recent approach of Web Services. 2 MOSCITO Architecture User s desktop Figure 1: MOSCITO allows a designer to use tools over Internet. In the present system several tools have been integrated in MOSCITO: simulators, optimization programs, test pattern generators, translators etc. All these tools can act as MOSCITO Agents and each of them provides a service. The user are empowered to combine all the services to a problem-specific workflow. That means, the needed tools have not to be installed on the users local computer. The MOSCITO framework was implemented in JAVA and can run on different computing platforms. The only prerequisite is an installed Java Virtual Machine. At the moment MOSCITO is used on SUN workstation (Solaris) and on PCs (Microsoft Windows and LINUX).

3 Tool A Tool B Tool C Tool D Tool F Tool E Figure 2: Tools available as MOSCITO agents via Internet can be coupled to workflows. 2.1 Software architecture MOSCITO consists of three software layers: kernel layer, interface layer, and user extensions. The kernel provides functionality for basic object and data management, file handling, XML processing, and communication. Due to the fact that MOSCITO is an open system a special interface layer provides programming interfaces for integration of new tools, new workflows and appropriate viewers such as for diagrams, plain text and images. Each interface is represented by a Java class which contains the basic functionality. The user only needs to extend this class and can implement its own extension. A large number of templates and example implementations helps the user to integrate a new tool or workflow in less than one or two days. 2.2 Tool encapsulation For the integration of tools with MOSCITO a sophisticated agent interface was introduced. A tool is embedded into a MOSCITO agent for: adapting the input data to the embedded tool, converting the tool-specific data (simulation results, logfiles, test vectors), mapping the control information to the embedded tool and the transfer and conversion of status information (warning and error messages) to be submitted to the user. For embedding programs into a MOSCITO agent there are three ways: Integration of the entire program: the software has to be runnable as batch job without any user interactions. In this way the integration of many commercial tools are possible. Embedding legacy code as library via the Java Native Interface (JNI): e.g. C, C++ or FOR- TRAN routines can be embedded. Direct integration of Java-classes and applications, respectively, in particular for software written in JAVA. Encapsulation of the tools as a MOSCITO agent guarantees a uniform interface to the framework. All tool-specific details are aggregated in a special agent description file. This file is necessary to create tool-specific dialogs for the configuration of the tool via the front-end program.

4 MOSCITO Agent (Predecessor) MOSCITO Agent Deserialization Control information from frontend programm Files Pipes COM... Input Encapsulated Tool Output Conversion Serialization MOSCITO Agent (Successor) Figure 3: A MOSCITO Agent works data-driven. 2.3 Communication The implementation of the communication between tools (agents) is based on TCP/IP-sockets. The tools can be executed on different computers or on different computing platforms (e.g. UNIX, Windows). Similar to tool encapsulation the data are sent as encapsulated datagrams. MOSCITO provides a flexible container class MOSCITO Datagram for data objects of different types: strings, scalars and arrays of integers, floating point numbers, ascii and binary files. For data transfere between agents it is very simple to put the needed data objects in the MOSCITO Datagram container. A receiver can look in the datagram and can extract data objects as needed or can put additional result data in the container. The advantages of this solution are: any kind of data can be transferred between different agents; in tool-chain workflows data can be passed to all subsequent agents (even to agents where a direct connection doesn t exist) the implementation is based on Java object serialization; MOSCITO Datagrams work platform-independent in the entire network. "Netlist" rosafilter.cir x0=12.5 x0=12.5 "x0" : 12.5 : name data object Figure 4: MOSCITO Datagram encapsulates data objects for transferring them between agents.

5 2.4 Graphical User Interface (GUI) MOSCITO provides two solutions for application-specific user interfaces. The first one, the MOSCITO Desktop, is a Java application which must be installed locally on the user s computer. With this desktop GUI a user has access to all registered agents in a network. The MO- SCITO Desktop provides the following functionality: The problem description including all data can be read in from a MOSCITO project file. Workflows can be chosen from a set of predefined flows for the specific problem. A browser supports the choice of agents (tools) and their configuration. With buttons for start, pause, resume and stop the workflow can be controlled by the user. A console window collects all messages from the running tools and allows the observation of the proper operation or trouble shooting, respectively. The visualization module MOSCITO Scope supports the display of all result data (test vectors, statistic information). Figure 5: A MOSCITO user can control the entire workflow and observe all result data using the MOSCITO Desktop (front-end). MOSCITO also supports a pure web-based usage of remote tools and workflows. In this scenario only a regular, Java-enabled Web browser is required at user s side. Small HTML pages with included Java applets offer specialized user interfaces for certain applications. This approach is currently used for e-learning systems. A learner can perform online-experiments with remote design tools running on high performance servers. 2.5 Services for Internet-based usage MOSCITO infrastructure implements basic services for a network-wide registration of agents and a lookup service for finding appropriate services. Furthermore, the next MOSCI- TO version will also support a secure data transfer via Internet and a tunnelling of firewalls via proxy server.

6 A Learner can configure model parameters. Simulation results are shown directly in the browser. The user can zoom in to see more details. Figure 6: Online-simulation of Chua s oscillator using a MOSCITO applet. 3 Summary MOSCITO has been developed as an Internet-based tool integration platform. Based on the idea to connect tools via the Internet to form an appropriate workflow for solving dedicated design problems, MOSCITO provides many features supporting collaboration between applications for system design (tool encapsulation and tool coupling, remote simulation). MOSCITO software provides open interfaces for extensions. A user can integrate new tools via the agent interface. Furthermore, it is possible to set up new workflows an to extend the visualization features of MOSCITO Scope. In the next months online-simulations will be integrated in several Web-based training modules using MOSCITO Applets as light-weight user interfaces. 4 References [1] C-LAB: Astai(R). [2] Lavana, H.; Khetawat, A.; Brglez, F.; Kozminski, K.: Executable Workflows: A Paradigm for Collaborative Design on the Internet. Proc. DAC 97, Anaheim, [3] MOSCITO: [4] Schneider, A.; Ivask, E.; Miklos, P.; Raik, J.; Diener, K.-H.; Ubar, R.; Cibáková, T.; Gramatová, E.: Internet-based Collaborative Test Generation with MOSCITO. DATE 02, Paris, March 4-8, 2002, [5] Schneider, A.; Diener, K.-H.; Elst, G.; Ivask, E.; Raik, J.; Ubar, R.: Internet-based testability driven test generation in virtual environment MOSCITO. Proc. International Workshop on IP-Based SoC Design, Grenoble, France, October 30-31, 2002 [6] Schneider, A.; Diener, K.-H.; Ivask, E.; Ubar, R.; Gramatova, E.; Hollstein, T.; Kuzmicz, W. Peng, Z.: Integrated Design and Test Generation Under Internet Based Environment MOSCITO. EUROMICRO Symp. on Digital System Design, Dortmund, Germany, September 4-6, 2003 [7] Schneider, P.; Schneider, A.; Bastian, J.; Reitz, S.; Schwarz, P.: MOSCITO a program system for MEMS optimization. Symp. "Design, Test, Integration and Packaging of MEMS/MOEMS", Cannes, Frankreich, May 5-8, 2002,