Biblio

Reducing latency in inter-process/inter-thread communication is one of the key challenges in parallel and distributed computing. This is because as the number of threads in an application increases, the communication overhead also increases. Moreover, the presence of background load further increases the latency. Reducing communication latency can have a significant impact on multi-threaded application performance in multi-core environments. In a wide-range of applications that utilize queueing mechanism, inter-process/ inter-thread communication typically involves enqueuing and dequeuing. This paper presents a queueing techniques called eLCRQ, which is a lock-free block-when-necessary multi-producer multi-consumer (MPMC) FIFO queue. It is designed for scenarios where the queue can randomly and frequently become empty during runtime. By combining lock-free performance with blocking resource efficiency, it delivers improved performance. Specifically, it results in a 1.7X reduction in latency and a 2.3X reduction in CPU usage when compared to existing message-passing mechanisms including PIPE and Sockets while running on multi-core Linux based systems. The proposed scheme also provides a 3.4X decrease in CPU usage while maintaining comparable latency when compared to other (MPMC) lock-free queues in low load scenarios. Our work is based on open-source Linux and support libraries.

In order to significantly improve the reliable interaction and fast processing when TT&C(Tracking, Telemetry and Command) Resource Scheduling and Management System (TRSMS) communicate with external systems which are diverse, multiple directional and high concurrent, this paper designs and implements a highly concurrent and secure middleware for TT&C Resource Automatic Scheduling Interface (TRASI). The middleware designs memory pool, data pool, thread pool and task pool to improve the efficiency of concurrent processing, uses the rule dictionary, communication handshake and wait retransmission mechanism to ensure the data interaction security and reliability. This middleware can effectively meet the requirements of TRASI for data exchange with external users and system, significantly improve the data processing speed and efficiency, and promote the information technology and automation level of Aerospace TT&C Network Management Center (TNMC).

In order to significantly improve the reliable interaction and fast processing when TT&C(Tracking, Telemetry and Command) Resource Scheduling and Management System (TRSMS) communicate with external systems which are diverse, multiple directional and high concurrent, this paper designs and implements a highly concurrent and secure middleware for TT&C Resource Automatic Scheduling Interface (TRASI). The middleware designs memory pool, data pool, thread pool and task pool to improve the efficiency of concurrent processing, uses the rule dictionary, communication handshake and wait retransmission mechanism to ensure the data interaction security and reliability. This middleware can effectively meet the requirements of TRASI for data exchange with external users and system, significantly improve the data processing speed and efficiency, and promote the information technology and automation level of Aerospace TT&C Network Management Center (TNMC).

This article is devoted to new asynchronous methods for rendering text information in mobile applications for iOS operating system.

This paper presents an implementation of a Graphical User Interface (GUI) for the OpenThread software. OpenThread is a software package for Thread. Thread is a networking protocol for Internet of Things (IoT) designed for home automation. OpenThread package was released by Nest Labs as an open source implementation of the Thread specification v1.1.1. The OpenThread includes IPv6, 6LoWPAN, IEEE 802.15.4 with MAC security, Mesh Link Establishment, and Mesh Routing. OpenThread includes all Thread supported device types and supports both SOC and NCP implementations. OpenThread runs on Linux and allows the users to use it as a simulator with a command line interface. This research is focused on adding a Graphical User Interface (GUI) to the OpenThread. The GUI package is implemented in TCL/Tk (Tool Control Language). OpenThread with a GUI makes working with OpenThread much easier for researchers and students. The GUI also makes it easier to visualize the Thread network and its operations.

Many state-of-the-art information-flow control (IFC) tools are implemented as Haskell libraries. A distinctive feature of this language is lazy evaluation. In his influencal paper on why functional programming matters, John Hughes proclaims:,,Lazy evaluation is perhaps the most powerful tool for modularization in the functional programmer's repertoire.,,Unfortunately, lazy evaluation makes IFC libraries vulnerable to leaks via the internal timing covert channel. The problem arises due to sharing, the distinguishing feature of lazy evaluation, which ensures that results of evaluated terms are stored for subsequent re-utilization. In this sense, the evaluation of a term in a high context represents a side-effect that eludes the security mechanisms of the libraries. A naïve approach to prevent that consists in forcing the evaluation of terms before entering a high context. However, this is not always possible in lazy languages, where terms often denote infinite data structures. Instead, we propose a new language primitive, lazyDup, which duplicates terms lazily. By using lazyDup to duplicate terms manipulated in high contexts, we make the security library MAC robust against internal timing leaks via lazy evaluation. We show that well-typed programs satisfy progress-sensitive non-interference in our lazy calculus with non-strict references. Our security guarantees are supported by mechanized proofs in the Agda proof assistant.

Hash functions, such as SHA (secure hash algorithm) and MD (message digest) families that are built upon Merkle-Damgard construction, suffer many attacks due to the iterative nature of block-by-block message processing. Chum and Zhang [4] proposed a new hash function construction that takes advantage of the randomize-then-combine technique, which was used in the incremental hash functions, to the iterative hash function. In this paper, we implement such hash construction in three ways distinguished by their corresponding padding methods. We conduct the experiment in parallel multi-threaded programming settings. The results show that the speed of proposed hash function is no worse than SHA1.
 

Byzantine fault tolerance has been intensively studied over the past decade as a way to enhance the intrusion resilience of computer systems. However, state-machine-based Byzantine fault tolerance algorithms require deterministic application processing and sequential execution of totally ordered requests. One way of increasing the practicality of Byzantine fault tolerance is to exploit the application semantics, which we refer to as application-aware Byzantine fault tolerance. Application-aware Byzantine fault tolerance makes it possible to facilitate concurrent processing of requests, to minimize the use of Byzantine agreement, and to identify and control replica nondeterminism. In this paper, we provide an overview of recent works on application-aware Byzantine fault tolerance techniques. We elaborate the need for exploiting application semantics for Byzantine fault tolerance and the benefits of doing so, provide a classification of various approaches to application-aware Byzantine fault tolerance, and outline the mechanisms used in achieving application-aware Byzantine fault tolerance according to our classification.

Byzantine fault tolerance has been intensively studied over the past decade as a way to enhance the intrusion resilience of computer systems. However, state-machine-based Byzantine fault tolerance algorithms require deterministic application processing and sequential execution of totally ordered requests. One way of increasing the practicality of Byzantine fault tolerance is to exploit the application semantics, which we refer to as application-aware Byzantine fault tolerance. Application-aware Byzantine fault tolerance makes it possible to facilitate concurrent processing of requests, to minimize the use of Byzantine agreement, and to identify and control replica nondeterminism. In this paper, we provide an overview of recent works on application-aware Byzantine fault tolerance techniques. We elaborate the need for exploiting application semantics for Byzantine fault tolerance and the benefits of doing so, provide a classification of various approaches to application-aware Byzantine fault tolerance, and outline the mechanisms used in achieving application-aware Byzantine fault tolerance according to our classification.