Process and Threads

1. Process Control Block

1.1. contains the process elements

1.2. created and managed by the OS

1.3. key tools that allows support for multiple processes

2. Two-State Process Model

2.1. Running

2.2. Not-running

3. Process Creation

3.1. Process spawning

3.2. Parent process

3.3. Child process

4. Swapping

4.1. involves moving part of all of a process from main memory to disk

5. Processes

5.1. a virtual address space that holds the process image

5.2. protected access to :

5.3. processors

5.4. other processes

5.5. files

5.6. I/O resources

5.7. unit of resource allocation

5.8. unit of protection

6. Benefits of Threads

6.1. takes less time to create a new thread than a process

6.2. less time to terminate a thread than a process

6.3. switching between two threads take less time than switching between processes

6.4. threads enhance efficiently in communication between programs

7. Process

7.1. a process in execution

7.2. an instance of running program

7.3. the entity that can be assigned to, and executed on, a processor

7.4. a unit of activity characterized by a single sequential thread of execution, a current state, and an associated set of system resources

8. Process Elements

8.1. identifier

8.2. state

8.3. priority

8.4. program counter

8.5. memory pointers

8.6. context data

8.7. I/O status information

8.8. accounting information

9. Process States

9.1. Traces

9.2. Dispatcher

10. Processes and Threads

10.1. Resouces Ownership

11. Operationg System Control Structures

11.1. Four different types of tables maintained by the OS :

11.2. Memory tables

11.3. IO tables

11.4. File tables

11.5. Process tables