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Operating System
Notes Figure 4.13: Diagram of Process with Multi-thread
OPERATING SYSTEM
PROCESS#1 PROCESS#2 PROCESS#3
REGISTERS THREAD 1A REGISTERS THREAD 2A REGISTERS THREAD 3A
THREAD 1B THREAD 2B THREAD 3B
THREAD 1C THREAD 2C THREAD 3C
PROCESS #1 PROCESS #2 PROCESS #3
MAIN MEMORY
4.13 Benefits of Threads
Following are some reasons why threads are used in designing operating systems:
1. A process with multiple threads make a great server for example printer server.
2. Because threads can share common data, they do not need to use inter-process
communication.
3. Because of the very nature, threads can take advantage of multi-processors.
4. Threads need a stack and storage for registers therefore, threads are cheap to create.
5. Threads do not need new address space, global data, program code or operating system
resources.
4.14 Summary
Process management is an operating system’s way of dealing with running multiple
processes at once.
A multi-tasking operating system may just switch between processes to give the
appearance of many processes executing concurrently or simultaneously, though in fact
only one process can be executing at any one time on a single-core CPU (unless using
multi-threading or other similar technology).
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