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1 | This readme refers to the file thr-mach.c. |
2 | ||
3 | Under mach, thread priorities are kinda strange-- any given thread has | |
4 | a MAXIMUM priority and a BASE priority. The BASE priority is the | |
5 | current priority of the thread and the MAXIMUM is the maximum possible | |
6 | priority the thread can assume. The developer can lower, but never | |
7 | raise the maximum priority. | |
8 | ||
9 | The gcc concept of thread priorities is that they run at one of three | |
10 | levels; interactive, background, and low. | |
11 | ||
12 | Under mach, this is translated to: | |
13 | ||
14 | interactive -- set priority to maximum | |
15 | background -- set priority to 2/3 of maximum | |
16 | low -- set priority to 1/3 of maximum | |
17 | ||
18 | This means that it is possible for a thread with the priority of | |
19 | interactive to actually run at a lower priority than another thread | |
20 | with a background, or even low, priority if the developer has modified | |
21 | the maximum priority. | |
22 | ||
23 |