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Device drivers interface in HelenOS system
Trochtová, Lenka ; Děcký, Martin (advisor) ; Bulej, Lubomír (referee)
An introduction into device drivers, the significance of the unified interface for device drivers within the operating system. A brief description of the basic principles of hardware fromthe programmer's point of view. The HelenOS operating system overview - the description of the basic funcional blocks of microkernel, the current support of user-space device drivers, e.g. the support for accessing device's registers and interrupt processing from user-space. Common functions of the interface for device drivers and their relation to the needs of the HelenOS operating system. The problems usually solved by contemporary driver frameworks and the known ways of solving them - device-centric vs. driver-centric device-to-driver matching, device IDs, the number of supported device classes, device driver entry points, the representation of a device tree. Design and implementation - hierarchical device management, device auto-detection, predefined interfaces for access to devices, device classes, controlling the device driver's life cycle and device-to-driver matching, the installation and the configuration of a device driver. The description of device drivers in some contemporary operating system and their comparison - device drivers in Windows, Solaris and Linux. The evaluation and the possibilities of future...
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Read-Copy-Update for OpenSolaris
Podzimek, Andrej ; Děcký, Martin (advisor) ; Bulej, Lubomír (referee)
The goal of this thesis is to design and implement a RCU (Read-Copy-Update)synchronization mechanism for OpenSolaris. The main purpose of the RCU mechanism is to increase concurrency in readers-writers synchronization scenarios, especially in SMP (Symmetric Multiprocessing) environments. This improvement is achieved by keeping multiple versions of the protected data which enables readers and writers to run in parallel. The RCU synchronization has already been implemented multiple times and is used in the Linux kernel. The thesis includes analysis of existing RCU implementations, possible benefits of RCU in the ONNV (OpenSolaris) kernel and a prototype implementation in ONNV. It also suggests possible applications of RCU where lockless synchronization is already applied. The prototype implementation is compared with its counterpart in the Linux kernel.
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Mass transport routing
Bečka, Michal ; Bulej, Lubomír (advisor) ; Yaghob, Jakub (referee)
A journey planning tool accessible from a mobile device provides travel information on the move. This work studies various aspects of journey planners in order to develop a solution for this task. We analyze the connection with phone networks and the Internet for possible choices to place the tool. Then we study the development environment consisting of operating systems programming languages. Another part covers possible parameters for the journey search. Then we investigate the source and form of input traffic data along with possible algorithms for this problem. Based on this analysis we design an application, making decisions from the analyzed areas. The design is applied for the following implementation and the resulting program we describe and measure. The purpose of this work is to develop a working application for mobile devices capable of public transit journey search, and to show what development of such application entails.
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Dynamic linking, debugging and tracing in HelenOS
Svoboda, Jiří ; Bulej, Lubomír (referee) ; Děcký, Martin (advisor)
HelenOS is an operating system that originated as a software project at the Faculty of Mathematics and Physics. So far it lacks support for dynamically linked libraries as well as support for process tracing and debugging. Dynamically linked libraries enable developing individual parts of large software systems independently and linking them later together without recompilation. The linking is carried out at load-time or run-time by the dynamic linker. The linker must nd all libraries used by the program, map them into memory and relocate them. Then it must resolve external (symbolic) references between the program and libraries. A debugger and a system-call tracer are essential development tools. They use a special system interface for their operation enabling them to suspend an application when certain events occur (such as a breakpoint or a trap). Then they may examine or change the application's memory contents and resume its execution. The main goal of this thesis is to implement support for dynamically linked libraries in HelenOS, namely the dynamic linker, and also a system API for debugging and tracing processes, including a demo application.
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Parallel Processing and Software Performance
Marek, Lukáš ; Bulej, Lubomír (referee) ; Tůma, Petr (advisor)
The thesis focuses on the e ects of resource sharing on software performance for selected resources of modern processor architectures, especially shared memory caches. The thesis introduces a framework for conducting experiments that assess the impact on software performance, and, using this framework, designs, executes and evaluates the experiments. The results provide an estimate of the scale of the performance impact of resource sharing on the experimental platform.
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Deployment Planner for Heterogeneous Component-based Applications
Urban, Jaroslav ; Hnětynka, Petr (referee) ; Bulej, Lubomír (advisor)
Deployment of component applications is the process of making them available for further use by clients. The OMG Deployment & Conguration Speci cation aims at creating a uni ed deployment process independent of component models. We use the OMG speci cation to create a deployment framework able to deploy heterogeneous component applications which are implemented using multiple component models. This work focuses on the planning phase of the speci cation, which selects computer resources for components with respect to their requirements. We have implemented the planning phase via a graphical user interface utilizing an automated planning algorithm which assists the user in creating a valid planning. The planning tools are extensible to support additional technologies, component models and more advanced planning heuristics.
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Optimizing performance of software connectors code generator
Petřek, Pavel ; Bulej, Lubomír (referee) ; Bureš, Tomáš (advisor)
Software connectors are intermediary entities used to model and realize communication in component systems. In addition to the communication, connectors can also provide extra functionality, such as logging or monitoring. This variability requires generation of the connector's code according to valid functional and non-functional requirements. Some requirements cannot be specified sooner than at deployment-time. However, the deployment environment can be restrictive. The existing connector generator [32] utilizes complex external tools for generation of the connector's classes from templates. In this thesis, we propose an optimization based on a precompilation approach. Templates are precompiled at design-time into a form that can be later compiled easily using a bytecode manipulation technique.
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Influence of Resource Sharing on Performance
Babka, Vlastimil ; Bulej, Lubomír (referee) ; Tůma, Petr (advisor)
Resource sharing occurs when multiple active processes or software components compete for system resources, which influences the observed performance compared to an individual execution. Isolated benchmarking of durations of key operations for solving of performance prediction models may therefore yield imprecise results. Resource sharing also occurs between the measured code and the benchmark infrastructure for obtaining and storing samples, imposing an indirect overhead. This thesis quantifies the effects of sharing on performance for several resources that are often shared, namely the processor caches and the file systems. The highest possible performance impact of cache sharing is determined by synthetic benchmarks. Impact on practical code and its dependency on a number of factors such as cache trashing frequency and intensity are then determined by experiments with existing implementations of FFT and LZW algorithms and a video stream processing application. Effects of file system sharing are measured by experiments that read and write multiple files simultaneously. For both resources, situations with significant performance impact of sharing have been observed. Based on the results of the experiments, several suggestions for dealing with the overhead of performance monitoring infrastructure are...
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The standard SOAP and its applications in small and middle enterprises.
Lupták, Boris ; Král, Jaroslav (advisor) ; Bulej, Lubomír (referee)
SOAP standard is core protocol used in web services. Web services open new possibilities in application interaction over the network. In connection with web services there has been much discussion of service oriented architecture. The main goal of this thesis is to show possibilities of SOAP in the context of small and medium businesses. To achieve this goal SOAP and accompanying nonns are described as well as the mechanism through which SOAP can be and is extended. Several standard extensions are shown. Furthennore this thesis points out the pros and cons of such usage as well as similar alternative approaches. The usage of SOAP is docmnented on several real life exainples. Part of this thesis concerns with fundamental principles of service oriented architecture and the connection between web services and service oriented architecture. The need of web services alignment with business processes and coarse grained interfaces are discussed as well. Powered by TCPDF (www.tcpdf.org)
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