The Design And Implementation Of The Measurement And Control Server Based On The High Performance Network Library Asio

The rapid development of Internet and communication technology makes great changes on exiting production way, the application which is based on network is changing the realistic producing pattern and information technology can make remote, intelligence, automation more practical. In this thesis, we will improve the software framework design of the measurement and control system of grain situation. It takes advantage of the Internet technology,3G Access and modern communication technology to build a network server model, which is based on Brower/Server service mode. It will transform the existing single service mode of the measurement and control system of grain situation and be able to support remote and intelligent centralized management mode.The existing measurement and control system for grain situation measures mostly in scene and the results of the measurement storage locally, and it can’t guarantee the security of the data. To this end, this thesis designs a new service model of measurement and control system of grain situation, which allows authorized users to access to the system in any position and at any time by a variety of ways, and get the information of the granary their concerned. This system adopts the hierarchical design method to build the overall framework and combines the modular design method to realize the concrete function of each module. In the design, the main research content involved as follows:1. To design the network data transceiver module, it adopts the asynchronous I/O model. This scheme introduces the high-performance network library boost::asio as the underlying asynchronous I/O processing engine, at the same time it combines with boost::asio::io_service as task scheduling mechanism to fulfill thread pool model. These make the entire system have an ability of providing the powerful network drive.2. To realize the message distribution module, it adopts an asynchronous callback mechanism. It makes full use of the bind and function modules’ flexibility of Boost library. Callback functions act as a mediation of network layer and business layer, it not only realizes the separation of business and data, but also connects the entire framework.3. Using object-oriented programming method designs independent functionality classes to deal with the corresponding measurement and control business.In order to improve the effectiveness of data management and the stability of the server, this thesis not only adopts a more efficient way of database access, but also adds the log management module. The design of database is based on the actual business requirements, and using the C++ template library OTL (Oracle, ODBC and DB2-CLI Template Library) to efficiently accesses database to achieve data storage and management. Log4cxx provides detailed log service for monitoring Server running status. In addition, it also adopts timeout handle which is based on time wheel, and provides a common manage methods for the objects which have life cycle.The server of the measurement and control system of grain situation designed in this thesis has been widely used in many domestic granaries and its overall functions have got many users’recognition.