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The term '''thread''' does not have a generally accepted firm/strict definition, but it generally means an [[instruction]] [[execute|execution]] locus which is less powerful (in terms of its capabilities) than a [[process]]; e.g. a thread will generally not have its own [[address space]].
The term '''thread''' does not have a generally accepted firm/strict definition, but it generally means an [[instruction]] [[execute|execution]] locus which is less powerful (in terms of its capabilities) than a [[process]]; e.g. a thread will generally not have its own [[address space]].


Threads are usually instantiated within a process, and share its [[memory]], [[input/output|I/O]] channels, etc. They are often, but not always, supported by the [[kernel]] of an [[operating system]]; e.g. the system's [[scheduler]] may be prepared to run threads. If not, a [[library]] included in the process may manage them.
Threads are usually instantiated within a process, and share its [[memory]], [[input/output|I/O]] channels, etc. All the threads in a particular process exhibit [[fate-sharing]]: if the process is terminated, all the threads within it necessarily are also lost.
 
Threads are often, but not always, supported by the [[kernel]] of an [[operating system]]; e.g. the system's [[scheduler]] may be prepared to run threads. If not, a [[library]] included in the process may manage them.


In [[multi-processor]] systems where the kernel supports threads, it may be allowed for multiple threads in a single process to execute concurrently.
In [[multi-processor]] systems where the kernel supports threads, it may be allowed for multiple threads in a single process to execute concurrently.


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Revision as of 12:58, 31 October 2018

The term thread does not have a generally accepted firm/strict definition, but it generally means an instruction execution locus which is less powerful (in terms of its capabilities) than a process; e.g. a thread will generally not have its own address space.

Threads are usually instantiated within a process, and share its memory, I/O channels, etc. All the threads in a particular process exhibit fate-sharing: if the process is terminated, all the threads within it necessarily are also lost.

Threads are often, but not always, supported by the kernel of an operating system; e.g. the system's scheduler may be prepared to run threads. If not, a library included in the process may manage them.

In multi-processor systems where the kernel supports threads, it may be allowed for multiple threads in a single process to execute concurrently.