Welcome to CS697B! Special Topics on Concurrent and Distributed Systems Tue Thu 8:30pm to 9:45 :-(

2 Course Topics Object-oriented concurrent systems –Processes and threads –Concurrency principles and techniques –Java threads –Design patterns for threading Object-oriented distributed systems –TCP and UDP –Socket interface –I/O techniques –Design patterns for socket and I/O handling –Remoting middleware including Java RMI, corba

3 Course Work Lectures Homework -> –Reading –Programming exercises –Project Student presentations

4Grading Grading factors –Programming exercises (in Java) (40%) –Deliverables of a course project (40%) –Student presentations (20%) No textbooks! No midterm and final exams!!

Processes in an Operating System

6Processes One of the most important concepts in all operating systems A process is a container (or execution environment) for a program (software) in execution. In terms of operating systems, a software system is a collection of processes.

7 Example Processes

8 Multi-Tasking (Time Sharing) Any modern OS support multi-tasking. –e.g., writing a document with MS Word, while listening music with iTunes and downloading a file. At any moment, a CPU can execute a single program. Pseudo parallelism: an OS periodically assigns one program to another to a CPU –every several tens of milliseconds to several hundreds of milliseconds –A CPU is multiplexed among processes; processes are not executed in a completely parallel manner.

9 Process State As a process runs, it changes its state. New ReadyRunning Terminated Waiting (Blocked) admitted Dispatched to a CPU interrupted I/O or event wait I/O or event completion exit

10 New –A process is being created Ready –Waiting to be assigned to a CPU Running –A program is being executed. Waiting –Waiting for some event to occur (I/O completion or signal reception) Termination –Execution finished. New ReadyRunning Terminated Waiting (Blocked) admitted Dispatched to a CPU interrupted I/O or event wait I/O or event completion exit

11 cat file1 file2 file3 | grep UMB InputStreamReader fp = new InputStreamReader(System.in); fp.read();