Programming Languages and Operating Systems 

Abstract: This paper describes a graphical programming language based on the concept of pure data flow sequencing of computations. Programs in this language are constructed through function definition and composition, and are based on the primitive notions of iteration, recursion, conditional expression, data replication, aggregation and selection, and the usual arithmetic and logical operations. Various useful programming devices such as the DO loop and, surprisingly, the memory cell are defined in terms of these primitives. Programs in this language are determinate in operation unless indeterminism is explicitly introduced. The utility of this language for designing and implementing operating systems is discussed.

Abstract: As multi-core processors are becoming common, vendors are starting to explore trade offs between the die size and the number of cores on a die, leading to heterogeneity among cores on a single chip. For efficient utilization of these processors, application threads must be assigned to cores such that the resource needs of a thread closely matches resource availability at the assigned core. Current methods of thread-to-core assignment often require an application's execution trace to determine its runtime properties. These traces are obtained by running the application on some representative input. A problem is that developing these representative input sets is time consuming, and requires expertise that the user of a general-purpose processor may not have. We propose an approach for automatic thread-to-core assignment for heterogeneous multicore processors to address this problem. The key insight behind our approach is simple - if two phases of a program are similar, then the data obtained by dynamic monitoring of one phase can be used to make scheduling decisions about other similar phases. The technical underpinnings of our approach include: a preliminary static analysis-based approach for determining similarity among program sections, and a thread-to-core assignment algorithm that utilizes the statically generated information as well as execution information obtained from monitoring a small fraction of the program to make scheduling decisions.

Abstract: System-level development has been dominated by programming languages like C/C++ for decades. These languages are inherently unsafe, error-prone, and a major reason for vulnerabilities. High-level programming languages with a secure memory model and strong type system are able to improve the quality of the system software. In this paper, we explore the programming language Rust for kernel development and present RustyHermit, which is a unikernel completely written in Rust without any C/C++. We show that the support for RustyHermit can be transparently integratable in the Rust toolchain and common Rust applications are build-able on top of RustyHermit. Previously, we developed the C-based unikernel HermitCore with a similar design to RustyHermit and we are able to compare both kernels. We show that the performance of both kernels is similar and only ~3.27 % of RustyHermit relies on unsafe code, that cannot be checked by the compiler in detail.

Abstract: Safe is a clean-slate design for a secure host architecture. It integrates advances in programming languages, operating systems, and hardware and incorporates formal methods at every step. Though the project is still at an early stage, we have assembled a set of basic architectural choices that we believe will yield a high-assurance system. We sketch the current state of the design and discuss several of these choices.