diff options
| author | Thomas Schwinge <thomas@schwinge.name> | 2010-12-13 20:22:52 +0100 |
|---|---|---|
| committer | Thomas Schwinge <thomas@schwinge.name> | 2010-12-13 20:22:52 +0100 |
| commit | 4eea3efc13acccfb613571f604f17e0ec68e5bed (patch) | |
| tree | 9c72a7790d6eb1602614971853131e3cc3f68174 /microkernel/mach/thread.mdwn | |
| parent | cfccdc1bdbee7fb25ef0aa9639a3ffec926bf690 (diff) | |
``Some'' Mach documentation.
Parts have been rescued from
4b382d8daa5a9e2d54e78c18beeff76bc54dc16b:Mach/MachConcepts.mdwn.
Diffstat (limited to 'microkernel/mach/thread.mdwn')
| -rw-r--r-- | microkernel/mach/thread.mdwn | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/microkernel/mach/thread.mdwn b/microkernel/mach/thread.mdwn new file mode 100644 index 00000000..e27bb117 --- /dev/null +++ b/microkernel/mach/thread.mdwn @@ -0,0 +1,37 @@ +[[!meta copyright="Copyright © 2002, 2003, 2010 Free Software Foundation, +Inc."]] + +[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable +id="license" text="Permission is granted to copy, distribute and/or modify this +document under the terms of the GNU Free Documentation License, Version 1.2 or +any later version published by the Free Software Foundation; with no Invariant +Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license +is included in the section entitled [[GNU Free Documentation +License|/fdl]]."]]"""]] + +A Mach *thread* belongs to exactly one [[task]], and is the means of execution. +The task supplies the resources. + +Mach threads are implemented inside the [[kernel]], as opposed to other +systems' user-level thread packages. + +A thread (theoretically) runs concurrently with all the other threads of a +system. If the system provides several processors, they can be used for +simultaneously running either several threads of the same task, or several +threads of different tasks. <!-- This is called SMP; the processors use +*shared memory*. --> [[!tag open_issue_documentation]] <!-- This needs a new +page, also covering Mach's `processor_set`s, and non-SMP, but still +multiprocessor systems. --> (But this is currently not support in [[GNU +Mach|gnumach]].) + +It is easy for the kernel to switch execution from one thread to another one +inside the same task: essentially, it only involves exchanging a few processor +registers' state. + +Threads have scheduling parameters and maintain various statistics about +themselves. + +On GNU/Hurd, APIs for Mach threads and thereabouts are provided by the +[[hurd/libthreads]] (cthreads), and [[libpthread]] (POSIX Threads) packages. + +A task backing a thread is the basis for a [[UNIX process|unix/process]]. |