Test.thy
changeset 36 af38526275f8
child 37 c820ac0f3088
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Test.thy	Fri May 23 15:19:32 2014 +0100
@@ -0,0 +1,370 @@
+theory Test 
+imports Precedence_ord
+begin
+
+type_synonym thread = nat -- {* Type for thread identifiers. *}
+type_synonym priority = nat  -- {* Type for priorities. *}
+type_synonym cs = nat -- {* Type for critical sections (or critical resources). *}
+
+datatype event = 
+  Create thread priority 
+| Exit thread 
+| P thread cs 
+| V thread cs 
+| Set thread priority 
+
+type_synonym state = "event list"
+
+fun threads :: "state \<Rightarrow> thread set"
+  where 
+  "threads [] = {}" 
+| "threads (Create th prio#s) = {th} \<union> threads s" 
+| "threads (Exit th # s) = (threads s) - {th}" 
+| "threads (_#s) = threads s" 
+
+fun priority :: "thread \<Rightarrow> state \<Rightarrow> priority"
+  where
+  "priority th [] = 0" 
+| "priority th (Create th' prio#s) = (if th' = th then prio else priority th s)" 
+| "priority th (Set th' prio#s) = (if th' = th then prio else priority th s)" 
+| "priority th (_#s) = priority th s"
+
+fun last_set :: "thread \<Rightarrow> state \<Rightarrow> nat"
+  where
+  "last_set th [] = 0" 
+| "last_set th ((Create th' prio)#s) = (if (th = th') then length s else last_set th s)" 
+| "last_set th ((Set th' prio)#s) = (if (th = th') then length s else last_set th s)" 
+| "last_set th (_#s) = last_set th s"
+
+definition preced :: "thread \<Rightarrow> state \<Rightarrow> precedence"
+  where "preced th s \<equiv> Prc (priority th s) (last_set th s)"
+
+definition
+  "holds wq th cs \<equiv> th \<in> set (wq cs) \<and> th = hd (wq cs)"
+
+definition
+  "waits wq th cs \<equiv> th \<in> set (wq cs) \<and> th \<noteq> hd (wq cs)"
+
+datatype node = 
+  Th "thread" 
+| Cs "cs" 
+
+definition
+  "RAG wq \<equiv> {(Th th, Cs cs) | th cs. waits wq th cs} \<union> {(Cs cs, Th th) | cs th. holds wq th cs}"
+
+definition
+  "dependants wq th \<equiv> {th' . (Th th', Th th) \<in> (RAG wq)^+}"
+
+record schedule_state = 
+  wq_fun :: "cs \<Rightarrow> thread list" 
+  cprec_fun :: "thread \<Rightarrow> precedence" 
+
+definition cpreced :: "(cs \<Rightarrow> thread list) \<Rightarrow> state \<Rightarrow> thread \<Rightarrow> precedence"
+  where 
+  "cpreced wq s th \<equiv> Max ({preced th s} \<union> {preced th' s | th'. th' \<in> dependants wq th})"
+
+abbreviation
+  "all_unlocked \<equiv> \<lambda>_::cs. ([]::thread list)"
+
+abbreviation 
+  "initial_cprec \<equiv> \<lambda>_::thread. Prc 0 0"
+ 
+abbreviation
+  "release qs \<equiv> case qs of
+             [] => [] 
+          |  (_#qs) => (SOME q. distinct q \<and> set q = set qs)"
+
+fun schs :: "state \<Rightarrow> schedule_state"
+  where 
+  "schs [] = (| wq_fun = \<lambda> cs. [],  cprec_fun = (\<lambda>_. Prc 0 0) |)" 
+| "schs (Create th prio # s) = 
+       (let wq = wq_fun (schs s) in
+          (|wq_fun = wq, cprec_fun = cpreced wq (Create th prio # s)|))"
+|  "schs (Exit th # s) = 
+       (let wq = wq_fun (schs s) in
+          (|wq_fun = wq, cprec_fun = cpreced wq (Exit th # s)|))"
+|  "schs (Set th prio # s) = 
+       (let wq = wq_fun (schs s) in
+          (|wq_fun = wq, cprec_fun = cpreced wq (Set th prio # s)|))"
+|  "schs (P th cs # s) = 
+       (let wq = wq_fun (schs s) in
+        let new_wq = wq(cs := (wq cs @ [th])) in
+          (|wq_fun = new_wq, cprec_fun = cpreced new_wq (P th cs # s)|))"
+|  "schs (V th cs # s) = 
+       (let wq = wq_fun (schs s) in
+        let new_wq = wq(cs := release (wq cs)) in
+          (|wq_fun = new_wq, cprec_fun = cpreced new_wq (V th cs # s)|))"
+
+definition wq :: "state \<Rightarrow> cs \<Rightarrow> thread list" 
+  where "wq s = wq_fun (schs s)"
+
+definition cp :: "state \<Rightarrow> thread \<Rightarrow> precedence"
+  where "cp s \<equiv> cprec_fun (schs s)"
+
+definition
+  "holds2 s \<equiv> holds (wq_fun (schs s))"
+
+definition
+  "waits2 s \<equiv> waits (wq_fun (schs s))"
+
+definition
+  "RAG2 s \<equiv> RAG (wq_fun (schs s))"
+  
+definition
+  "dependants2 s \<equiv> dependants (wq_fun (schs s))"
+
+definition readys :: "state \<Rightarrow> thread set"
+  where "readys s \<equiv> {th . th \<in> threads s \<and> (\<forall> cs. \<not> waits2 s th cs)}"
+
+definition runing :: "state \<Rightarrow> thread set"
+  where "runing s \<equiv> {th . th \<in> readys s \<and> cp s th = Max ((cp s) ` (readys s))}"
+
+definition holding :: "state \<Rightarrow> thread \<Rightarrow> cs set"
+  where "holding s th \<equiv> {cs . holds2 s th cs}"
+
+lemma holding_RAG: 
+  "holding s th = {cs . (Cs cs, Th th) \<in> RAG2 s}"
+unfolding holding_def
+unfolding holds2_def
+unfolding RAG2_def RAG_def
+unfolding holds_def waits_def
+by auto
+
+inductive step :: "state \<Rightarrow> event \<Rightarrow> bool"
+  where
+  step_Create: "\<lbrakk>th \<notin> threads s\<rbrakk> \<Longrightarrow> step s (Create th prio)" 
+| step_Exit: "\<lbrakk>th \<in> runing s; holding s th = {}\<rbrakk> \<Longrightarrow> step s (Exit th)" 
+| step_P: "\<lbrakk>th \<in> runing s;  (Cs cs, Th th)  \<notin> (RAG2 s)^+\<rbrakk> \<Longrightarrow> step s (P th cs)" 
+| step_V: "\<lbrakk>th \<in> runing s;  holds2 s th cs\<rbrakk> \<Longrightarrow> step s (V th cs)" 
+| step_Set: "\<lbrakk>th \<in> runing s\<rbrakk> \<Longrightarrow> step s (Set th prio)"
+
+inductive vt :: "state \<Rightarrow> bool"
+  where
+  vt_nil[intro]: "vt []" 
+| vt_cons[intro]: "\<lbrakk>vt s; step s e\<rbrakk> \<Longrightarrow> vt (e#s)"
+
+lemma runing_ready: 
+  shows "runing s \<subseteq> readys s"
+  unfolding runing_def readys_def
+  by auto 
+
+lemma readys_threads:
+  shows "readys s \<subseteq> threads s"
+  unfolding readys_def
+  by auto
+
+lemma wq_distinct_step: 
+  assumes "step s e" "distinct (wq s cs)" 
+  shows "distinct (wq (e # s) cs)"
+using assms
+apply(induct)
+apply(auto simp add: wq_def Let_def)
+apply(auto simp add: wq_def Let_def RAG2_def RAG_def holds_def runing_def waits2_def waits_def readys_def)[1]
+apply(auto split: list.split)
+apply(rule someI2)
+apply(auto)
+done
+
+lemma wq_distinct: 
+  assumes "vt s" 
+  shows "distinct (wq s cs)"
+using assms
+apply(induct)
+apply(simp add: wq_def)
+apply(simp add: wq_distinct_step)
+done
+
+lemma RAG_set_unchanged[simp]: 
+  shows "RAG2 (Set th prio # s) = RAG2 s"
+unfolding RAG2_def
+by (simp add: Let_def)
+
+lemma RAG_create_unchanged[simp]: 
+  "RAG2 (Create th prio # s) = RAG2 s"
+unfolding RAG2_def
+by (simp add: Let_def)
+
+lemma RAG_exit_unchanged[simp]: 
+  shows "RAG2 (Exit th # s) = RAG2 s"
+unfolding RAG2_def
+by (simp add: Let_def)
+
+lemma RAG_p1:
+  assumes "wq s cs = []"
+  shows "RAG2 (P th cs # s) = RAG2 s \<union> {(Cs cs, Th th)}"
+  using assms
+  apply(auto simp add: RAG2_def RAG_def wq_def Let_def waits_def holds_def)
+  apply (metis in_set_insert insert_Nil list.distinct(1))
+  done
+
+lemma RAG_p2:
+  assumes "vt (P th cs#s)" "wq s cs \<noteq> []"
+  shows "RAG2 (P th cs # s) = RAG2 s \<union> {(Th th, Cs cs)}"
+  using assms
+  apply(simp add: RAG2_def Let_def)
+  apply(erule_tac vt.cases)
+  apply(simp)
+  apply(clarify)
+  apply(simp)
+  apply(erule_tac step.cases)
+  apply(simp_all)
+  apply(simp add: wq_def RAG_def RAG2_def)
+  apply(simp add: waits_def holds_def)
+  apply(auto)
+  done
+
+definition next_th:: "state \<Rightarrow> thread \<Rightarrow> cs \<Rightarrow> thread \<Rightarrow> bool"
+  where "next_th s th cs t = 
+    (\<exists> rest. wq s cs = th#rest \<and> rest \<noteq> [] \<and> t = hd (SOME q. distinct q \<and> set q = set rest))"
+
+lemma RAG_v:
+assumes vt:"vt (V th cs#s)"
+shows "
+  RAG2 (V th cs # s) =
+  RAG2 s - {(Cs cs, Th th)} -
+  {(Th th', Cs cs) |th'. next_th s th cs th'} \<union>
+  {(Cs cs, Th th') |th'.  next_th s th cs th'}"
+  apply (insert vt, unfold RAG2_def RAG_def)
+  sorry
+
+lemma waiting_unique:
+  assumes "vt s"
+  and "waits2 s th cs1"
+  and "waits2 s th cs2"
+  shows "cs1 = cs2"
+sorry
+
+lemma singleton_Un:
+  shows "A \<union> {x} = insert x A"
+by simp
+
+
+lemma acyclic_RAG_step: 
+  assumes vt: "vt s"
+  and     stp: "step s e"
+  and     ac: "acyclic (RAG2 s)"
+  shows "acyclic (RAG2 (e # s))"
+using stp vt ac
+proof (induct)
+  case (step_P th s cs)
+  have vt: "vt s" by fact
+  have ac: "acyclic (RAG2 s)" by fact
+  have rn: "th \<in> runing s" by fact
+  have ds: "(Cs cs, Th th) \<notin> (RAG2 s)\<^sup>+" by fact
+  have vtt: "vt (P th cs#s)" using vt rn ds by (metis step.step_P vt_cons)
+  { assume a: "wq s cs = []" -- "case waiting queue is empty"
+    have "(Th th, Cs cs) \<notin> (RAG2 s)\<^sup>*"  
+    proof
+      assume "(Th th, Cs cs) \<in> (RAG2 s)\<^sup>*"
+      then have "(Th th, Cs cs) \<in> (RAG2 s)\<^sup>+" by (simp add: rtrancl_eq_or_trancl)
+      then obtain x where "(x, Cs cs) \<in> RAG2 s" using tranclD2 by metis 
+      with a show False by (auto simp: RAG2_def RAG_def wq_def waits_def)
+    qed
+    with acyclic_insert ac
+    have "acyclic (RAG2 s \<union> {(Cs cs, Th th)})" by simp
+    then have "acyclic (RAG2 (P th cs # s))" using RAG_p1[OF a] by simp
+  }
+  moreover
+  { assume a: "wq s cs \<noteq> []" -- "case waiting queue is not empty"
+    from ds have "(Cs cs, Th th) \<notin> (RAG2 s)\<^sup>*" by (metis node.distinct(1) rtranclD)
+    with acyclic_insert ac 
+    have "acyclic (RAG2 s \<union> {(Th th, Cs cs)})" by auto
+    then have "acyclic (RAG2 (P th cs # s))" using RAG_p2[OF vtt a] by simp
+  }
+  ultimately show "acyclic (RAG2 (P th cs # s))" by metis
+next    
+  case (step_V th s cs) 
+  have vt: "vt s" by fact
+  have ac: "acyclic (RAG2 s)" by fact
+  have rn: "th \<in> runing s" by fact
+  have hd: "holds2 s th cs" by fact
+  from hd 
+  have th_in: "th \<in> set (wq s cs)" and
+       eq_hd: "th = hd (wq s cs)" unfolding holds2_def holds_def wq_def by auto
+  then obtain rest where
+    eq_wq: "wq s cs = th # rest" by (cases "wq s cs") (auto)
+  show ?case
+    apply(subst RAG_v)
+    apply(rule vt_cons)
+    apply(rule vt)
+    apply(rule step.step_V)
+    apply(rule rn)
+    apply(rule hd)
+    using eq_wq
+    apply(cases "rest = []")
+    apply(subgoal_tac "{(Cs cs, Th th') |th'. next_th s th cs th'} = {}")
+    apply(simp)
+    apply(rule acyclic_subset)
+    apply(rule ac)
+    apply(auto)[1]
+    apply(auto simp add: next_th_def)[1]
+    -- "case wq more than a singleton"
+    apply(subgoal_tac "{(Cs cs, Th (hd (SOME q. distinct q \<and> set q = set rest)))} = 
+      {(Cs cs, Th th') |th'. next_th s th cs th'}")
+    apply(rotate_tac 2)
+    apply(drule sym)
+    apply(simp only: singleton_Un)
+    apply(simp only: acyclic_insert)
+    apply(rule conjI)
+    apply(rule acyclic_subset)
+    apply(rule ac)
+    apply(auto)[1]
+    apply(rotate_tac 2)
+    apply(thin_tac "?X")
+    defer 
+    apply(simp add: next_th_def)
+    apply(clarify)
+    apply(simp add: rtrancl_eq_or_trancl)
+    apply(drule tranclD)
+    apply(erule exE)
+    apply(drule conjunct1)
+    apply(subgoal_tac "(Th (hd (SOME q. distinct q \<and> set q = set rest)), z) \<in> RAG2 s")
+    prefer 2
+    apply(simp)
+    apply(case_tac z)
+    apply(simp add: RAG2_def RAG_def)
+    apply(clarify)
+    apply(simp)
+    apply(simp add: next_th_def)
+    apply(rule waiting_unique)
+    apply(rule vt)
+    apply(simp add: RAG2_def RAG_def waits2_def waits_def wq_def)
+    apply(rotate_tac 2)
+    apply(thin_tac "?X")
+    apply(subgoal_tac "distinct (wq s cs)")
+    prefer 2
+    apply(rule wq_distinct)
+    apply(rule vt)
+    apply (unfold waits2_def waits_def wq_def, auto)
+    apply(subgoal_tac "(SOME q. distinct q \<and> set q = set rest) \<noteq> []")
+    prefer 2
+    apply (metis (mono_tags) set_empty tfl_some)
+    apply(subgoal_tac "hd (SOME q. distinct q \<and> set q = set rest) \<in> 
+                set (SOME q. distinct q \<and> set q = set rest)") 
+    prefer 2
+    apply(auto)[1]
+    apply(subgoal_tac "set (SOME q. distinct q \<and> set q = set rest) = set rest") 
+    prefer 2
+    apply(rule someI2)
+    apply(auto)[2]
+    apply(auto)[1]
+    apply(subgoal_tac "(SOME q. distinct q \<and> set q = set rest) \<noteq> []")
+    prefer 2
+    apply (metis (mono_tags) set_empty tfl_some)
+    apply(subgoal_tac "hd (SOME q. distinct q \<and> set q = set rest) \<in> 
+                set (SOME q. distinct q \<and> set q = set rest)") 
+    prefer 2
+    apply(auto)[1]
+    apply(subgoal_tac "set (SOME q. distinct q \<and> set q = set rest) = set rest") 
+    prefer 2
+    apply(rule someI2)
+    apply(auto)[2]
+    apply(auto)[1]
+    done
+qed (simp_all)
+
+
+
+
+
+