make wakeup behave like unpark #97
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wakeup IPIs will now set a token much like Thread::unpark does. Previously there was a race condition: 1. AP 0 starts to halt and calls Scheduler::halt 2. AP 1 wants to schedule a new AP, so it pick 0. It sends an IPI to AP 0. 3. AP 0 executes the wakeup IPI. 4. AP 0 executes `hlt`. To prevent this from happening, we now remember that AP was woken up and run it one more time when it executes `hlt` the first time after being woken up.
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wakeup IPIs will now set a token much like Thread::unpark does.
Previously there was a race condition:
hlt.To prevent this from happening, we now remember that AP was woken up and run it one more time when it executes
hltthe first time after being woken up.