We have formally described a substantial subset of the MC68020, a widely used microprocessor built by Motorola, within the mathematical logic of the automated reasoning system Nqthm, a.k.a. the Boyer-Moore Theorem Prover 6]. Using this formal description, we have mechanically checked the correctness of MC68020 object code programs for binary search, Hoare's Quick Sort, twenty-one functions from...

This paper describes a pragmatic but portable fallback approach for creating and dispatching between the machine contexts of multiple threads of execution on Unix systems that lack a dedicated user-space context switching facility. Such a fallback approach for implementing machine contexts is a vital part of a user-space multithreading environment, if it has to achieve maximum portability acros...

The game of Go is very interesting from a machine learning point of view since it has been shown to be PSPACE hard to solve explicitly [9]. A major factor for the complexity is due to being played on a 19x19 board where moves can not be considered using only spacial locality. Heuristics are difficult to make for Go because much of the game is qualitative and it is hard to assign quantitative va...

Mancoosi (Managing the Complexity of the Open Source Infrastructure) is an ongoing research project funded by the European Union for addressing some of the challenges related to the “upgrade problem” of interdependent software components of which Debian packages are prototypical examples. Mancoosi is the natural continuation of the EDOS project which has already contributed tools for distributi...

This paper shows a circuit to emulate the operation of a photovoltaic (PV) cell. The values of equation is based on data sheet in the Standard Condition Measurement (SCM), this model allows emulate PV cell, including effects due to variations of irradiance receiver and temperature of cell. The generic model is the same for all types of PV cells, only can used the same equations including variab...

We present the “big-step” operational semantics of a small programming language NIL (Natural Imperative Language) in definite clauses, thus building on the fixpoint semantics of logic programs. NIL operates on a state which is just a sequence of counters. As basic statements NIL has incrementation, decrementation and test for null. NIL allows for sequential composition and non-deterministic cho...

This document describes the interface of the Pthreads library developed at Florida State University. The implementation is based on the \POSIX 1003.1c Threads Extension" standard by the IEEE. The implementation is currently limited to the Sun SPARC architecture and the SunOS 4.1.x or Solaris 2.x operating systems as well as the Inter x86 architecture under Linux, FreeBSD, SCO and DOS+DJGPP. The...

Schedulers used by modern OSs (e.g., Oracle Solaris 11 and GNU/Linux) balance load by balancing the number of threads in runqueues of different cores. While this approach is effective for a single CPU multicore system, we show that it can lead to a significant load imbalance across CPUs of a multiCPU multicore system. Because different threads of a multithreaded application often exhibit differ...

The introduction of a GNU/Linux-based desktop system in a large company is often problematic, in terms of technical issues but especially for employees' training costs. Mainly, these obstacles are represented by different hardware configurations that might require several ad-hoc activities to adapt a standard release to the specific environment, including company's application profile. On the o...

Defining software reliability is hard enough, let alone ensuring it. However, most all software developers agree on the importance of testing. The often unspoken assumption with testing is that the test programs cover a majority of the source code written. A test covers a line of code if running the test executes the line. Coverage analysis measures how much of the target code is run during a t...