On 4/04/2016 4:57 PM, 김은영 wrote:
1. What is domain? i read manual but i don't understand well.
I hope that you explain to me in detail about the domain.
Let me try to answer your questions about domains. I'll leave others to
answer questions about the specifics of the thread API.
seL4 implements a two-level scheduling algorithm. You can think of
domains as a way to group different threads together. Domains are
important if you are trying to implement a system where you need to
prevent information leakage between different system components --- i.e.
you have various components that are mutually suspicious and some of
them need to keep secrets from others. Domains exist to prevent certain
kinds of information leaks via the scheduler.
When built, the kernel is configured to support some static number of
scheduling domains, and to schedule domains according to a fixed,
repeating schedule. This allows for fully-deterministic scheduling of
domains, and means that the decision to schedule a particular domain
never depends on secret information. For instance, whether a particular
domain gets scheduled does not depend on whether any of its threads are
actually runnable -- if all threads assigned to the current domain are
blocked (i.e. cannot be scheduled) then the kernel schedules the idle
thread instead to take up the slack time.
If you don't care about enforcing confidentiality between mutually
untrusting components, then you can simply leave the number of domains
at 1 (the default) and have all threads automatically assigned to domain
0 (the only domain in the system). In this case, the scheduler devolves
to the priority-based one that schedules all threads in accordance with
Within a particular domain, threads are scheduled using the kernel's
priority-based scheduling mechanism.
2. What is the maximum number of threads that can be
created in one domain?
There is no maximum
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