1 / 23

Chapter 5: Threads

Chapter 5: Threads. Overview Multithreading Models Threading Issues Pthreads Solaris 2 Threads Windows 2000 Threads Linux Threads Java Threads. Example: fork(). main() { int pid = 0; printf(“the parent is going to fork<br>”); if (pid = fork() != 0)

Download Presentation

Chapter 5: Threads

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Chapter 5: Threads • Overview • Multithreading Models • Threading Issues • Pthreads • Solaris 2 Threads • Windows 2000 Threads • Linux Threads • Java Threads Operating System Concepts

  2. Example: fork() main() { int pid = 0; printf(“the parent is going to fork\n”); if (pid = fork() != 0) printf(“I am the father of %d\n”, pid); else printf(“I am the child\n”); } Operating System Concepts

  3. Single and Multithreaded Processes Operating System Concepts

  4. Benefits • Responsiveness (e.g. thread as GUI engine) • Resource Sharing (e.g. shared variable) • Economy (e.g. save memory) • Utilization of MP Architectures Operating System Concepts

  5. User Threads • Thread management done by user-levelthreads library • Examples - POSIX Pthreads - Mach C-threads - Solaris threads Operating System Concepts

  6. Example: Solaris 2 Operating System Concepts

  7. Example: Solaris 2 User-level thread kernel thread CPU Operating System Concepts

  8. Kernel Threads • Supported by the Kernel • Examples - Windows 95/98/NT/2000 - Solaris 2 Operating System Concepts

  9. Multithreading Models • Many-to-One • One-to-One • Many-to-Many Operating System Concepts

  10. Many-to-One • Many user-level threads mapped to single kernel thread. • Used on systems that do not support kernel threads. Operating System Concepts

  11. Many-to-One Model Operating System Concepts

  12. One-to-One • Each user-level thread maps to kernel thread. • Examples - Windows 95/98/NT/2000 - OS/2 Operating System Concepts

  13. One-to-one Model Operating System Concepts

  14. Many-to-Many Model • Allows many user level threads to be mapped to many kernel threads. • Allows the operating system to create a sufficient number of kernel threads. • Solaris 2 • Windows NT/2000 with the ThreadFiber package Operating System Concepts

  15. Many-to-Many Model Operating System Concepts

  16. Threading Issues • Semantics of fork() system call duplicate all threads or one • Semantics of exec() system call replace the entire process codes • Thread cancellation cancellation point • Signal handling • Thread pools • Thread specific data Operating System Concepts

  17. Pthreads • a POSIX standard (IEEE 1003.1c) API for thread creation and synchronization. • API specifies behavior of the thread library, implementation is up to development of the library. • Common in UNIX operating systems. Operating System Concepts

  18. Solaris 2 Threads Operating System Concepts

  19. Solaris Process Operating System Concepts

  20. Windows 2000 Threads • Implements the one-to-one mapping. • Each thread contains - a thread id - register set - separate user and kernel stacks - private data storage area Operating System Concepts

  21. Linux Threads • Linux refers to them as tasks rather than threads. • Thread creation is done through clone() system call. • Clone() allows a child task to share the address space of the parent task (process) Operating System Concepts

  22. Java Threads • Java threads may be created by: • Extending Thread class • Implementing the Runnable interface • Java threads are managed by the JVM. Operating System Concepts

  23. Java Thread States Operating System Concepts

More Related