66 lines
1.9 KiB
Plaintext
66 lines
1.9 KiB
Plaintext
(*
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* Copyright 2020, Data61, CSIRO (ABN 41 687 119 230)
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*
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* SPDX-License-Identifier: GPL-2.0-only
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*)
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theory Schedule_D
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imports KHeap_D
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begin
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(*
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* Collect the set of runnable threads in the system.
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*)
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definition
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all_active_tcbs :: "cdl_state \<Rightarrow> cdl_object_id set"
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where
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"all_active_tcbs state \<equiv> {x \<in> dom (cdl_objects state).
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\<exists> a. (cdl_objects state) x = Some (Tcb a)
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\<and> ( ((cdl_tcb_caps a) tcb_pending_op_slot) = (Some RunningCap) \<or> ((cdl_tcb_caps a) tcb_pending_op_slot) = (Some RestartCap))}"
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definition
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active_tcbs_in_domain :: "word8 \<Rightarrow> cdl_state \<Rightarrow> cdl_object_id set"
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where
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"active_tcbs_in_domain domain state = {x \<in> dom (cdl_objects state).
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\<exists> a. (cdl_objects state) x = Some (Tcb a)
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\<and> ( ((cdl_tcb_caps a) tcb_pending_op_slot) = (Some RunningCap) \<or> ((cdl_tcb_caps a) tcb_pending_op_slot) = (Some RestartCap))
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\<and> cdl_tcb_domain a = domain }"
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(*
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* Switch to a new thread.
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*)
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definition
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switch_to_thread :: "cdl_object_id option \<Rightarrow> unit k_monad"
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where
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"switch_to_thread target \<equiv>
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modify (\<lambda> t. t\<lparr> cdl_current_thread := target \<rparr>)"
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definition
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change_current_domain :: "unit k_monad"
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where
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"change_current_domain = do
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next_domain \<leftarrow> select UNIV;
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modify (\<lambda>s. s\<lparr> cdl_current_domain := next_domain \<rparr>)
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od"
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(*
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* Scheduling is fully nondeterministic at this level.
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*)
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definition
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schedule :: "unit k_monad"
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where
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"schedule \<equiv> do
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change_current_domain;
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next_domain \<leftarrow> gets cdl_current_domain;
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threads \<leftarrow> gets (active_tcbs_in_domain next_domain);
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next_thread \<leftarrow> select threads;
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switch_to_thread (Some next_thread)
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od \<sqinter> do
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change_current_domain;
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switch_to_thread None
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od"
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end
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