J-Sim (The J-Sim Simulation Library)

---------------------------- The J-Sim Simulation Library ---------------------------- J-Sim is an object-oriented library for discrete-time process-oriented simulation. Its main application area is queueing network simulation, however, the range of its use can be very wide -- almost any system where object states change in discrete time intervals can be modeled using J-Sim. J-Sim is a Simula-like simulation environment written in Java. For the programmer, it provides the same possibilities as the Simula language does. The basic building blocks of every J-Sim simulation are processes and queues. Processes are active, while queues and other elements of the simulation are passive. The simulation is executed in a step-by-step manner. During a step, just one process is given an chance to run. J-Sim is built up upon some very well known principles inherited from the Simula language, such as: * life of processes, described as a sequence of actions; * simulation time, shared by all processes within a simulation world; * process state manipulation routines (hold(), passivate(), ...), controlling simulation progress; * queue facilities HEAD and LINK, used for easy manipulation with queues and elements contained within them. In addition to the standard features that a Simula user might expect, some extra features are provided: * simulation of Dijkstra semaphores -- processes may get blocked and unblocked on them; * simulation of message passing -- blocking and non-blocking send and receive operations; symmetric, asymetric, and indirect communication is supported; * independent random number generators (exponential, Gaussian, boolean, and uniform distribution) that can be initialized by user-defined seed and therefore guarantee repeatability of experiments; * console mode and two GUI modes (batch and interactive); J-Sim comes already compiled and packaged into a JAR file so no building activities are necessary after download. See file Install.TXT for installation instructions. J-Sim is written completely in Java and therefore 100% portable. All you need is a Java runtime environment running on your computer. J-Sim has been tested on Solaris 8, OS/2 Warp 4, eComStation 1.1, Windows NT 4, Windows XP, and Linux (Not all J-Sim versions on all operating systems). Please note that starting with J-Sim 0.6.0, you need Java 1.5 or newer. There are older versions available for Java 1.4 and even Java 1.1. Source code is available as a standard part of the distribution. J-Sim is released under The Academic Free Licence v. 2.1, a licence certified by the Open Source Initiative (OSI). See enclosed file Licence.TXT for more details or go to http://www.opensource.org/licenses/afl-2.1.php.