In Isabelle2020, when isabelle jedit is started without a session
context, e.g. `isabelle jedit -l ASpec`, theory imports with path
references cause the isabelle process to hang.
Since sessions now declare directories, Isabelle can find those files
without path reference and we therefore remove all such path references
from import statements. With this, `jedit` and `build` should work with
and without explicit session context as before.
Signed-off-by: Gerwin Klein <gerwin.klein@data61.csiro.au>
Colloquially known as "invert-fastpath".
Update verification efforts on ARM for the following seL4 changes:
- scheduling decisions done in possibleSwitchTo are moved to the
scheduler
- possibleSwitchTo only checks whether the candidate is valid for a
fast switch, not its priority, accepting possible candidates
immmediately as a switch-to scheduler action
- the scheduler checks the candidate against the current thread and
against the bitmaps before making a decision
- attemptSwitchTo and switchIfRequiredTo are gone
- scheduler is now more complicated, and numerous proofs related to it
are rewritten from scratch
- fast path now checks ready queues via the scheduler bitmaps
- L2 scheduler bitmap order reversed for better cache locality
Many iterations between the kernel and verification teams were needed
to get this right.
This was broken a long while back because arch_switch_to_idle_thread
might sometimes be skipped in the implementation if the idle thread
was previously scheduled. Putting the same behaviour in the most
abstract (unit) specification is pretty easy, and it's not clear why
it wasn't done earlier.
Gerwin Klein
Rafal Kolanski
Thomas Sewell
Daniel Matichuk
Gerwin Klein