Introduction

What is a Thread

A single flow of control with a process ...

Why use Threads

• Exploit Latency
• Exploit Concurrency
  • Parallel Processing
  • Distributed Processing
  • Eamples: Fractal Calculator, Ray tracer
• Event Driven Software
  • Waiting on events (HTTPD, News Servers, Mail Servers)
  • Interactive (Real time games: Netrek)
  • Anything that uses select()

Types of Threads

• User threads
• Kernel Threads
  • Not to be confused with a threaded kernel.
  • clone on Linux
  • rfork on Plan9
  • sproc on IRIX
• Hybrid Threads
  • Solaris LWP and threads.
  • WinNT threads and fibers.