diff -r 0fd478e14e87 -r f1b39d77db00 PrioG.thy~ --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/PrioG.thy~ Thu Dec 03 14:34:29 2015 +0800 @@ -0,0 +1,2920 @@ +theory PrioG +imports PrioGDef +begin + +lemma runing_ready: + shows "runing s \ readys s" + unfolding runing_def readys_def + by auto + +lemma readys_threads: + shows "readys s \ threads s" + unfolding readys_def + by auto + +lemma wq_v_neq: + "cs \ cs' \ wq (V thread cs#s) cs' = wq s cs'" + by (auto simp:wq_def Let_def cp_def split:list.splits) + +lemma wq_distinct: "vt s \ distinct (wq s cs)" +proof(erule_tac vt.induct, simp add:wq_def) + fix s e + assume h1: "step s e" + and h2: "distinct (wq s cs)" + thus "distinct (wq (e # s) cs)" + proof(induct rule:step.induct, auto simp: wq_def Let_def split:list.splits) + fix thread s + assume h1: "(Cs cs, Th thread) \ (RAG s)\<^sup>+" + and h2: "thread \ set (wq_fun (schs s) cs)" + and h3: "thread \ runing s" + show "False" + proof - + from h3 have "\ cs. thread \ set (wq_fun (schs s) cs) \ + thread = hd ((wq_fun (schs s) cs))" + by (simp add:runing_def readys_def s_waiting_def wq_def) + from this [OF h2] have "thread = hd (wq_fun (schs s) cs)" . + with h2 + have "(Cs cs, Th thread) \ (RAG s)" + by (simp add:s_RAG_def s_holding_def wq_def cs_holding_def) + with h1 show False by auto + qed + next + fix thread s a list + assume dst: "distinct list" + show "distinct (SOME q. distinct q \ set q = set list)" + proof(rule someI2) + from dst show "distinct list \ set list = set list" by auto + next + fix q assume "distinct q \ set q = set list" + thus "distinct q" by auto + qed + qed +qed + +text {* + The following lemma shows that only the @{text "P"} + operation can add new thread into waiting queues. + Such kind of lemmas are very obvious, but need to be checked formally. + This is a kind of confirmation that our modelling is correct. +*} + +lemma block_pre: + fixes thread cs s + assumes vt_e: "vt (e#s)" + and s_ni: "thread \ set (wq s cs)" + and s_i: "thread \ set (wq (e#s) cs)" + shows "e = P thread cs" +proof - + show ?thesis + proof(cases e) + case (P th cs) + with assms + show ?thesis + by (auto simp:wq_def Let_def split:if_splits) + next + case (Create th prio) + with assms show ?thesis + by (auto simp:wq_def Let_def split:if_splits) + next + case (Exit th) + with assms show ?thesis + by (auto simp:wq_def Let_def split:if_splits) + next + case (Set th prio) + with assms show ?thesis + by (auto simp:wq_def Let_def split:if_splits) + next + case (V th cs) + with assms show ?thesis + apply (auto simp:wq_def Let_def split:if_splits) + proof - + fix q qs + assume h1: "thread \ set (wq_fun (schs s) cs)" + and h2: "q # qs = wq_fun (schs s) cs" + and h3: "thread \ set (SOME q. distinct q \ set q = set qs)" + and vt: "vt (V th cs # s)" + from h1 and h2[symmetric] have "thread \ set (q # qs)" by simp + moreover have "thread \ set qs" + proof - + have "set (SOME q. distinct q \ set q = set qs) = set qs" + proof(rule someI2) + from wq_distinct [OF step_back_vt[OF vt], of cs] + and h2[symmetric, folded wq_def] + show "distinct qs \ set qs = set qs" by auto + next + fix x assume "distinct x \ set x = set qs" + thus "set x = set qs" by auto + qed + with h3 show ?thesis by simp + qed + ultimately show "False" by auto + qed + qed +qed + +text {* + The following lemmas is also obvious and shallow. It says + that only running thread can request for a critical resource + and that the requested resource must be one which is + not current held by the thread. +*} + +lemma p_pre: "\vt ((P thread cs)#s)\ \ + thread \ runing s \ (Cs cs, Th thread) \ (RAG s)^+" +apply (ind_cases "vt ((P thread cs)#s)") +apply (ind_cases "step s (P thread cs)") +by auto + +lemma abs1: + fixes e es + assumes ein: "e \ set es" + and neq: "hd es \ hd (es @ [x])" + shows "False" +proof - + from ein have "es \ []" by auto + then obtain e ess where "es = e # ess" by (cases es, auto) + with neq show ?thesis by auto +qed + +lemma q_head: "Q (hd es) \ hd es = hd [th\es . Q th]" + by (cases es, auto) + +inductive_cases evt_cons: "vt (a#s)" + +lemma abs2: + assumes vt: "vt (e#s)" + and inq: "thread \ set (wq s cs)" + and nh: "thread = hd (wq s cs)" + and qt: "thread \ hd (wq (e#s) cs)" + and inq': "thread \ set (wq (e#s) cs)" + shows "False" +proof - + from assms show "False" + apply (cases e) + apply ((simp split:if_splits add:Let_def wq_def)[1])+ + apply (insert abs1, fast)[1] + apply (auto simp:wq_def simp:Let_def split:if_splits list.splits) + proof - + fix th qs + assume vt: "vt (V th cs # s)" + and th_in: "thread \ set (SOME q. distinct q \ set q = set qs)" + and eq_wq: "wq_fun (schs s) cs = thread # qs" + show "False" + proof - + from wq_distinct[OF step_back_vt[OF vt], of cs] + and eq_wq[folded wq_def] have "distinct (thread#qs)" by simp + moreover have "thread \ set qs" + proof - + have "set (SOME q. distinct q \ set q = set qs) = set qs" + proof(rule someI2) + from wq_distinct [OF step_back_vt[OF vt], of cs] + and eq_wq [folded wq_def] + show "distinct qs \ set qs = set qs" by auto + next + fix x assume "distinct x \ set x = set qs" + thus "set x = set qs" by auto + qed + with th_in show ?thesis by auto + qed + ultimately show ?thesis by auto + qed + qed +qed + +lemma vt_moment: "\ t. \vt s\ \ vt (moment t s)" +proof(induct s, simp) + fix a s t + assume h: "\t.\vt s\ \ vt (moment t s)" + and vt_a: "vt (a # s)" + show "vt (moment t (a # s))" + proof(cases "t \ length (a#s)") + case True + from True have "moment t (a#s) = a#s" by simp + with vt_a show ?thesis by simp + next + case False + hence le_t1: "t \ length s" by simp + from vt_a have "vt s" + by (erule_tac evt_cons, simp) + from h [OF this] have "vt (moment t s)" . + moreover have "moment t (a#s) = moment t s" + proof - + from moment_app [OF le_t1, of "[a]"] + show ?thesis by simp + qed + ultimately show ?thesis by auto + qed +qed + +(* Wrong: + lemma \thread \ set (wq_fun cs1 s); thread \ set (wq_fun cs2 s)\ \ cs1 = cs2" +*) + +text {* (* ??? *) + The nature of the work is like this: since it starts from a very simple and basic + model, even intuitively very `basic` and `obvious` properties need to derived from scratch. + For instance, the fact + that one thread can not be blocked by two critical resources at the same time + is obvious, because only running threads can make new requests, if one is waiting for + a critical resource and get blocked, it can not make another resource request and get + blocked the second time (because it is not running). + + To derive this fact, one needs to prove by contraction and + reason about time (or @{text "moement"}). The reasoning is based on a generic theorem + named @{text "p_split"}, which is about status changing along the time axis. It says if + a condition @{text "Q"} is @{text "True"} at a state @{text "s"}, + but it was @{text "False"} at the very beginning, then there must exits a moment @{text "t"} + in the history of @{text "s"} (notice that @{text "s"} itself is essentially the history + of events leading to it), such that @{text "Q"} switched + from being @{text "False"} to @{text "True"} and kept being @{text "True"} + till the last moment of @{text "s"}. + + Suppose a thread @{text "th"} is blocked + on @{text "cs1"} and @{text "cs2"} in some state @{text "s"}, + since no thread is blocked at the very beginning, by applying + @{text "p_split"} to these two blocking facts, there exist + two moments @{text "t1"} and @{text "t2"} in @{text "s"}, such that + @{text "th"} got blocked on @{text "cs1"} and @{text "cs2"} + and kept on blocked on them respectively ever since. + + Without lose of generality, we assume @{text "t1"} is earlier than @{text "t2"}. + However, since @{text "th"} was blocked ever since memonent @{text "t1"}, so it was still + in blocked state at moment @{text "t2"} and could not + make any request and get blocked the second time: Contradiction. +*} + +lemma waiting_unique_pre: + fixes cs1 cs2 s thread + assumes vt: "vt s" + and h11: "thread \ set (wq s cs1)" + and h12: "thread \ hd (wq s cs1)" + assumes h21: "thread \ set (wq s cs2)" + and h22: "thread \ hd (wq s cs2)" + and neq12: "cs1 \ cs2" + shows "False" +proof - + let "?Q cs s" = "thread \ set (wq s cs) \ thread \ hd (wq s cs)" + from h11 and h12 have q1: "?Q cs1 s" by simp + from h21 and h22 have q2: "?Q cs2 s" by simp + have nq1: "\ ?Q cs1 []" by (simp add:wq_def) + have nq2: "\ ?Q cs2 []" by (simp add:wq_def) + from p_split [of "?Q cs1", OF q1 nq1] + obtain t1 where lt1: "t1 < length s" + and np1: "\(thread \ set (wq (moment t1 s) cs1) \ + thread \ hd (wq (moment t1 s) cs1))" + and nn1: "(\i'>t1. thread \ set (wq (moment i' s) cs1) \ + thread \ hd (wq (moment i' s) cs1))" by auto + from p_split [of "?Q cs2", OF q2 nq2] + obtain t2 where lt2: "t2 < length s" + and np2: "\(thread \ set (wq (moment t2 s) cs2) \ + thread \ hd (wq (moment t2 s) cs2))" + and nn2: "(\i'>t2. thread \ set (wq (moment i' s) cs2) \ + thread \ hd (wq (moment i' s) cs2))" by auto + show ?thesis + proof - + { + assume lt12: "t1 < t2" + let ?t3 = "Suc t2" + from lt2 have le_t3: "?t3 \ length s" by auto + from moment_plus [OF this] + obtain e where eq_m: "moment ?t3 s = e#moment t2 s" by auto + have "t2 < ?t3" by simp + from nn2 [rule_format, OF this] and eq_m + have h1: "thread \ set (wq (e#moment t2 s) cs2)" and + h2: "thread \ hd (wq (e#moment t2 s) cs2)" by auto + have vt_e: "vt (e#moment t2 s)" + proof - + from vt_moment [OF vt] + have "vt (moment ?t3 s)" . + with eq_m show ?thesis by simp + qed + have ?thesis + proof(cases "thread \ set (wq (moment t2 s) cs2)") + case True + from True and np2 have eq_th: "thread = hd (wq (moment t2 s) cs2)" + by auto + thm abs2 + from abs2 [OF vt_e True eq_th h2 h1] + show ?thesis by auto + next + case False + from block_pre [OF vt_e False h1] + have "e = P thread cs2" . + with vt_e have "vt ((P thread cs2)# moment t2 s)" by simp + from p_pre [OF this] have "thread \ runing (moment t2 s)" by simp + with runing_ready have "thread \ readys (moment t2 s)" by auto + with nn1 [rule_format, OF lt12] + show ?thesis by (simp add:readys_def wq_def s_waiting_def, auto) + qed + } moreover { + assume lt12: "t2 < t1" + let ?t3 = "Suc t1" + from lt1 have le_t3: "?t3 \ length s" by auto + from moment_plus [OF this] + obtain e where eq_m: "moment ?t3 s = e#moment t1 s" by auto + have lt_t3: "t1 < ?t3" by simp + from nn1 [rule_format, OF this] and eq_m + have h1: "thread \ set (wq (e#moment t1 s) cs1)" and + h2: "thread \ hd (wq (e#moment t1 s) cs1)" by auto + have vt_e: "vt (e#moment t1 s)" + proof - + from vt_moment [OF vt] + have "vt (moment ?t3 s)" . + with eq_m show ?thesis by simp + qed + have ?thesis + proof(cases "thread \ set (wq (moment t1 s) cs1)") + case True + from True and np1 have eq_th: "thread = hd (wq (moment t1 s) cs1)" + by auto + from abs2 [OF vt_e True eq_th h2 h1] + show ?thesis by auto + next + case False + from block_pre [OF vt_e False h1] + have "e = P thread cs1" . + with vt_e have "vt ((P thread cs1)# moment t1 s)" by simp + from p_pre [OF this] have "thread \ runing (moment t1 s)" by simp + with runing_ready have "thread \ readys (moment t1 s)" by auto + with nn2 [rule_format, OF lt12] + show ?thesis by (simp add:readys_def wq_def s_waiting_def, auto) + qed + } moreover { + assume eqt12: "t1 = t2" + let ?t3 = "Suc t1" + from lt1 have le_t3: "?t3 \ length s" by auto + from moment_plus [OF this] + obtain e where eq_m: "moment ?t3 s = e#moment t1 s" by auto + have lt_t3: "t1 < ?t3" by simp + from nn1 [rule_format, OF this] and eq_m + have h1: "thread \ set (wq (e#moment t1 s) cs1)" and + h2: "thread \ hd (wq (e#moment t1 s) cs1)" by auto + have vt_e: "vt (e#moment t1 s)" + proof - + from vt_moment [OF vt] + have "vt (moment ?t3 s)" . + with eq_m show ?thesis by simp + qed + have ?thesis + proof(cases "thread \ set (wq (moment t1 s) cs1)") + case True + from True and np1 have eq_th: "thread = hd (wq (moment t1 s) cs1)" + by auto + from abs2 [OF vt_e True eq_th h2 h1] + show ?thesis by auto + next + case False + from block_pre [OF vt_e False h1] + have eq_e1: "e = P thread cs1" . + have lt_t3: "t1 < ?t3" by simp + with eqt12 have "t2 < ?t3" by simp + from nn2 [rule_format, OF this] and eq_m and eqt12 + have h1: "thread \ set (wq (e#moment t2 s) cs2)" and + h2: "thread \ hd (wq (e#moment t2 s) cs2)" by auto + show ?thesis + proof(cases "thread \ set (wq (moment t2 s) cs2)") + case True + from True and np2 have eq_th: "thread = hd (wq (moment t2 s) cs2)" + by auto + from vt_e and eqt12 have "vt (e#moment t2 s)" by simp + from abs2 [OF this True eq_th h2 h1] + show ?thesis . + next + case False + have vt_e: "vt (e#moment t2 s)" + proof - + from vt_moment [OF vt] eqt12 + have "vt (moment (Suc t2) s)" by auto + with eq_m eqt12 show ?thesis by simp + qed + from block_pre [OF vt_e False h1] + have "e = P thread cs2" . + with eq_e1 neq12 show ?thesis by auto + qed + qed + } ultimately show ?thesis by arith + qed +qed + +text {* + This lemma is a simple corrolary of @{text "waiting_unique_pre"}. +*} + +lemma waiting_unique: + fixes s cs1 cs2 + assumes "vt s" + and "waiting s th cs1" + and "waiting s th cs2" + shows "cs1 = cs2" +using waiting_unique_pre assms +unfolding wq_def s_waiting_def +by auto + +(* not used *) +text {* + Every thread can only be blocked on one critical resource, + symmetrically, every critical resource can only be held by one thread. + This fact is much more easier according to our definition. +*} +lemma held_unique: + fixes s::"state" + assumes "holding s th1 cs" + and "holding s th2 cs" + shows "th1 = th2" +using assms +unfolding s_holding_def +by auto + + +lemma last_set_lt: "th \ threads s \ last_set th s < length s" + apply (induct s, auto) + by (case_tac a, auto split:if_splits) + +lemma last_set_unique: + "\last_set th1 s = last_set th2 s; th1 \ threads s; th2 \ threads s\ + \ th1 = th2" + apply (induct s, auto) + by (case_tac a, auto split:if_splits dest:last_set_lt) + +lemma preced_unique : + assumes pcd_eq: "preced th1 s = preced th2 s" + and th_in1: "th1 \ threads s" + and th_in2: " th2 \ threads s" + shows "th1 = th2" +proof - + from pcd_eq have "last_set th1 s = last_set th2 s" by (simp add:preced_def) + from last_set_unique [OF this th_in1 th_in2] + show ?thesis . +qed + +lemma preced_linorder: + assumes neq_12: "th1 \ th2" + and th_in1: "th1 \ threads s" + and th_in2: " th2 \ threads s" + shows "preced th1 s < preced th2 s \ preced th1 s > preced th2 s" +proof - + from preced_unique [OF _ th_in1 th_in2] and neq_12 + have "preced th1 s \ preced th2 s" by auto + thus ?thesis by auto +qed + +(* An aux lemma used later *) +lemma unique_minus: + fixes x y z r + assumes unique: "\ a b c. \(a, b) \ r; (a, c) \ r\ \ b = c" + and xy: "(x, y) \ r" + and xz: "(x, z) \ r^+" + and neq: "y \ z" + shows "(y, z) \ r^+" +proof - + from xz and neq show ?thesis + proof(induct) + case (base ya) + have "(x, ya) \ r" by fact + from unique [OF xy this] have "y = ya" . + with base show ?case by auto + next + case (step ya z) + show ?case + proof(cases "y = ya") + case True + from step True show ?thesis by simp + next + case False + from step False + show ?thesis by auto + qed + qed +qed + +lemma unique_base: + fixes r x y z + assumes unique: "\ a b c. \(a, b) \ r; (a, c) \ r\ \ b = c" + and xy: "(x, y) \ r" + and xz: "(x, z) \ r^+" + and neq_yz: "y \ z" + shows "(y, z) \ r^+" +proof - + from xz neq_yz show ?thesis + proof(induct) + case (base ya) + from xy unique base show ?case by auto + next + case (step ya z) + show ?case + proof(cases "y = ya") + case True + from True step show ?thesis by auto + next + case False + from False step + have "(y, ya) \ r\<^sup>+" by auto + with step show ?thesis by auto + qed + qed +qed + +lemma unique_chain: + fixes r x y z + assumes unique: "\ a b c. \(a, b) \ r; (a, c) \ r\ \ b = c" + and xy: "(x, y) \ r^+" + and xz: "(x, z) \ r^+" + and neq_yz: "y \ z" + shows "(y, z) \ r^+ \ (z, y) \ r^+" +proof - + from xy xz neq_yz show ?thesis + proof(induct) + case (base y) + have h1: "(x, y) \ r" and h2: "(x, z) \ r\<^sup>+" and h3: "y \ z" using base by auto + from unique_base [OF _ h1 h2 h3] and unique show ?case by auto + next + case (step y za) + show ?case + proof(cases "y = z") + case True + from True step show ?thesis by auto + next + case False + from False step have "(y, z) \ r\<^sup>+ \ (z, y) \ r\<^sup>+" by auto + thus ?thesis + proof + assume "(z, y) \ r\<^sup>+" + with step have "(z, za) \ r\<^sup>+" by auto + thus ?thesis by auto + next + assume h: "(y, z) \ r\<^sup>+" + from step have yza: "(y, za) \ r" by simp + from step have "za \ z" by simp + from unique_minus [OF _ yza h this] and unique + have "(za, z) \ r\<^sup>+" by auto + thus ?thesis by auto + qed + qed + qed +qed + +text {* + The following three lemmas show that @{text "RAG"} does not change + by the happening of @{text "Set"}, @{text "Create"} and @{text "Exit"} + events, respectively. +*} + +lemma RAG_set_unchanged: "(RAG (Set th prio # s)) = RAG s" +apply (unfold s_RAG_def s_waiting_def wq_def) +by (simp add:Let_def) + +lemma RAG_create_unchanged: "(RAG (Create th prio # s)) = RAG s" +apply (unfold s_RAG_def s_waiting_def wq_def) +by (simp add:Let_def) + +lemma RAG_exit_unchanged: "(RAG (Exit th # s)) = RAG s" +apply (unfold s_RAG_def s_waiting_def wq_def) +by (simp add:Let_def) + + +text {* + The following lemmas are used in the proof of + lemma @{text "step_RAG_v"}, which characterizes how the @{text "RAG"} is changed + by @{text "V"}-events. + However, since our model is very concise, such seemingly obvious lemmas need to be derived from scratch, + starting from the model definitions. +*} +lemma step_v_hold_inv[elim_format]: + "\c t. \vt (V th cs # s); + \ holding (wq s) t c; holding (wq (V th cs # s)) t c\ \ + next_th s th cs t \ c = cs" +proof - + fix c t + assume vt: "vt (V th cs # s)" + and nhd: "\ holding (wq s) t c" + and hd: "holding (wq (V th cs # s)) t c" + show "next_th s th cs t \ c = cs" + proof(cases "c = cs") + case False + with nhd hd show ?thesis + by (unfold cs_holding_def wq_def, auto simp:Let_def) + next + case True + with step_back_step [OF vt] + have "step s (V th c)" by simp + hence "next_th s th cs t" + proof(cases) + assume "holding s th c" + with nhd hd show ?thesis + apply (unfold s_holding_def cs_holding_def wq_def next_th_def, + auto simp:Let_def split:list.splits if_splits) + proof - + assume " hd (SOME q. distinct q \ q = []) \ set (SOME q. distinct q \ q = [])" + moreover have "\ = set []" + proof(rule someI2) + show "distinct [] \ [] = []" by auto + next + fix x assume "distinct x \ x = []" + thus "set x = set []" by auto + qed + ultimately show False by auto + next + assume " hd (SOME q. distinct q \ q = []) \ set (SOME q. distinct q \ q = [])" + moreover have "\ = set []" + proof(rule someI2) + show "distinct [] \ [] = []" by auto + next + fix x assume "distinct x \ x = []" + thus "set x = set []" by auto + qed + ultimately show False by auto + qed + qed + with True show ?thesis by auto + qed +qed + +text {* + The following @{text "step_v_wait_inv"} is also an obvious lemma, which, however, needs to be + derived from scratch, which confirms the correctness of the definition of @{text "next_th"}. +*} +lemma step_v_wait_inv[elim_format]: + "\t c. \vt (V th cs # s); \ waiting (wq (V th cs # s)) t c; waiting (wq s) t c + \ + \ (next_th s th cs t \ cs = c)" +proof - + fix t c + assume vt: "vt (V th cs # s)" + and nw: "\ waiting (wq (V th cs # s)) t c" + and wt: "waiting (wq s) t c" + show "next_th s th cs t \ cs = c" + proof(cases "cs = c") + case False + with nw wt show ?thesis + by (auto simp:cs_waiting_def wq_def Let_def) + next + case True + from nw[folded True] wt[folded True] + have "next_th s th cs t" + apply (unfold next_th_def, auto simp:cs_waiting_def wq_def Let_def split:list.splits) + proof - + fix a list + assume t_in: "t \ set list" + and t_ni: "t \ set (SOME q. distinct q \ set q = set list)" + and eq_wq: "wq_fun (schs s) cs = a # list" + have " set (SOME q. distinct q \ set q = set list) = set list" + proof(rule someI2) + from wq_distinct[OF step_back_vt[OF vt], of cs] and eq_wq[folded wq_def] + show "distinct list \ set list = set list" by auto + next + show "\x. distinct x \ set x = set list \ set x = set list" + by auto + qed + with t_ni and t_in show "a = th" by auto + next + fix a list + assume t_in: "t \ set list" + and t_ni: "t \ set (SOME q. distinct q \ set q = set list)" + and eq_wq: "wq_fun (schs s) cs = a # list" + have " set (SOME q. distinct q \ set q = set list) = set list" + proof(rule someI2) + from wq_distinct[OF step_back_vt[OF vt], of cs] and eq_wq[folded wq_def] + show "distinct list \ set list = set list" by auto + next + show "\x. distinct x \ set x = set list \ set x = set list" + by auto + qed + with t_ni and t_in show "t = hd (SOME q. distinct q \ set q = set list)" by auto + next + fix a list + assume eq_wq: "wq_fun (schs s) cs = a # list" + from step_back_step[OF vt] + show "a = th" + proof(cases) + assume "holding s th cs" + with eq_wq show ?thesis + by (unfold s_holding_def wq_def, auto) + qed + qed + with True show ?thesis by simp + qed +qed + +lemma step_v_not_wait[consumes 3]: + "\vt (V th cs # s); next_th s th cs t; waiting (wq (V th cs # s)) t cs\ \ False" + by (unfold next_th_def cs_waiting_def wq_def, auto simp:Let_def) + +lemma step_v_release: + "\vt (V th cs # s); holding (wq (V th cs # s)) th cs\ \ False" +proof - + assume vt: "vt (V th cs # s)" + and hd: "holding (wq (V th cs # s)) th cs" + from step_back_step [OF vt] and hd + show "False" + proof(cases) + assume "holding (wq (V th cs # s)) th cs" and "holding s th cs" + thus ?thesis + apply (unfold s_holding_def wq_def cs_holding_def) + apply (auto simp:Let_def split:list.splits) + proof - + fix list + assume eq_wq[folded wq_def]: + "wq_fun (schs s) cs = hd (SOME q. distinct q \ set q = set list) # list" + and hd_in: "hd (SOME q. distinct q \ set q = set list) + \ set (SOME q. distinct q \ set q = set list)" + have "set (SOME q. distinct q \ set q = set list) = set list" + proof(rule someI2) + from wq_distinct[OF step_back_vt[OF vt], of cs] and eq_wq + show "distinct list \ set list = set list" by auto + next + show "\x. distinct x \ set x = set list \ set x = set list" + by auto + qed + moreover have "distinct (hd (SOME q. distinct q \ set q = set list) # list)" + proof - + from wq_distinct[OF step_back_vt[OF vt], of cs] and eq_wq + show ?thesis by auto + qed + moreover note eq_wq and hd_in + ultimately show "False" by auto + qed + qed +qed + +lemma step_v_get_hold: + "\th'. \vt (V th cs # s); \ holding (wq (V th cs # s)) th' cs; next_th s th cs th'\ \ False" + apply (unfold cs_holding_def next_th_def wq_def, + auto simp:Let_def) +proof - + fix rest + assume vt: "vt (V th cs # s)" + and eq_wq[folded wq_def]: " wq_fun (schs s) cs = th # rest" + and nrest: "rest \ []" + and ni: "hd (SOME q. distinct q \ set q = set rest) + \ set (SOME q. distinct q \ set q = set rest)" + have "(SOME q. distinct q \ set q = set rest) \ []" + proof(rule someI2) + from wq_distinct[OF step_back_vt[OF vt], of cs] and eq_wq + show "distinct rest \ set rest = set rest" by auto + next + fix x assume "distinct x \ set x = set rest" + hence "set x = set rest" by auto + with nrest + show "x \ []" by (case_tac x, auto) + qed + with ni show "False" by auto +qed + +lemma step_v_release_inv[elim_format]: +"\c t. \vt (V th cs # s); \ holding (wq (V th cs # s)) t c; holding (wq s) t c\ \ + c = cs \ t = th" + apply (unfold cs_holding_def wq_def, auto simp:Let_def split:if_splits list.splits) + proof - + fix a list + assume vt: "vt (V th cs # s)" and eq_wq: "wq_fun (schs s) cs = a # list" + from step_back_step [OF vt] show "a = th" + proof(cases) + assume "holding s th cs" with eq_wq + show ?thesis + by (unfold s_holding_def wq_def, auto) + qed + next + fix a list + assume vt: "vt (V th cs # s)" and eq_wq: "wq_fun (schs s) cs = a # list" + from step_back_step [OF vt] show "a = th" + proof(cases) + assume "holding s th cs" with eq_wq + show ?thesis + by (unfold s_holding_def wq_def, auto) + qed + qed + +lemma step_v_waiting_mono: + "\t c. \vt (V th cs # s); waiting (wq (V th cs # s)) t c\ \ waiting (wq s) t c" +proof - + fix t c + let ?s' = "(V th cs # s)" + assume vt: "vt ?s'" + and wt: "waiting (wq ?s') t c" + show "waiting (wq s) t c" + proof(cases "c = cs") + case False + assume neq_cs: "c \ cs" + hence "waiting (wq ?s') t c = waiting (wq s) t c" + by (unfold cs_waiting_def wq_def, auto simp:Let_def) + with wt show ?thesis by simp + next + case True + with wt show ?thesis + apply (unfold cs_waiting_def wq_def, auto simp:Let_def split:list.splits) + proof - + fix a list + assume not_in: "t \ set list" + and is_in: "t \ set (SOME q. distinct q \ set q = set list)" + and eq_wq: "wq_fun (schs s) cs = a # list" + have "set (SOME q. distinct q \ set q = set list) = set list" + proof(rule someI2) + from wq_distinct [OF step_back_vt[OF vt], of cs] + and eq_wq[folded wq_def] + show "distinct list \ set list = set list" by auto + next + fix x assume "distinct x \ set x = set list" + thus "set x = set list" by auto + qed + with not_in is_in show "t = a" by auto + next + fix list + assume is_waiting: "waiting (wq (V th cs # s)) t cs" + and eq_wq: "wq_fun (schs s) cs = t # list" + hence "t \ set list" + apply (unfold wq_def, auto simp:Let_def cs_waiting_def) + proof - + assume " t \ set (SOME q. distinct q \ set q = set list)" + moreover have "\ = set list" + proof(rule someI2) + from wq_distinct [OF step_back_vt[OF vt], of cs] + and eq_wq[folded wq_def] + show "distinct list \ set list = set list" by auto + next + fix x assume "distinct x \ set x = set list" + thus "set x = set list" by auto + qed + ultimately show "t \ set list" by simp + qed + with eq_wq and wq_distinct [OF step_back_vt[OF vt], of cs, unfolded wq_def] + show False by auto + qed + qed +qed + +text {* (* ??? *) + The following @{text "step_RAG_v"} lemma charaterizes how @{text "RAG"} is changed + with the happening of @{text "V"}-events: +*} +lemma step_RAG_v: +fixes th::thread +assumes vt: + "vt (V th cs#s)" +shows " + RAG (V th cs # s) = + RAG s - {(Cs cs, Th th)} - + {(Th th', Cs cs) |th'. next_th s th cs th'} \ + {(Cs cs, Th th') |th'. next_th s th cs th'}" + apply (insert vt, unfold s_RAG_def) + apply (auto split:if_splits list.splits simp:Let_def) + apply (auto elim: step_v_waiting_mono step_v_hold_inv + step_v_release step_v_wait_inv + step_v_get_hold step_v_release_inv) + apply (erule_tac step_v_not_wait, auto) + done + +text {* + The following @{text "step_RAG_p"} lemma charaterizes how @{text "RAG"} is changed + with the happening of @{text "P"}-events: +*} +lemma step_RAG_p: + "vt (P th cs#s) \ + RAG (P th cs # s) = (if (wq s cs = []) then RAG s \ {(Cs cs, Th th)} + else RAG s \ {(Th th, Cs cs)})" + apply(simp only: s_RAG_def wq_def) + apply (auto split:list.splits prod.splits simp:Let_def wq_def cs_waiting_def cs_holding_def) + apply(case_tac "csa = cs", auto) + apply(fold wq_def) + apply(drule_tac step_back_step) + apply(ind_cases " step s (P (hd (wq s cs)) cs)") + apply(simp add:s_RAG_def wq_def cs_holding_def) + apply(auto) + done + + +lemma RAG_target_th: "(Th th, x) \ RAG (s::state) \ \ cs. x = Cs cs" + by (unfold s_RAG_def, auto) + +text {* + The following lemma shows that @{text "RAG"} is acyclic. + The overall structure is by induction on the formation of @{text "vt s"} + and then case analysis on event @{text "e"}, where the non-trivial cases + for those for @{text "V"} and @{text "P"} events. +*} +lemma acyclic_RAG: + fixes s + assumes vt: "vt s" + shows "acyclic (RAG s)" +using assms +proof(induct) + case (vt_cons s e) + assume ih: "acyclic (RAG s)" + and stp: "step s e" + and vt: "vt s" + show ?case + proof(cases e) + case (Create th prio) + with ih + show ?thesis by (simp add:RAG_create_unchanged) + next + case (Exit th) + with ih show ?thesis by (simp add:RAG_exit_unchanged) + next + case (V th cs) + from V vt stp have vtt: "vt (V th cs#s)" by auto + from step_RAG_v [OF this] + have eq_de: + "RAG (e # s) = + RAG s - {(Cs cs, Th th)} - {(Th th', Cs cs) |th'. next_th s th cs th'} \ + {(Cs cs, Th th') |th'. next_th s th cs th'}" + (is "?L = (?A - ?B - ?C) \ ?D") by (simp add:V) + from ih have ac: "acyclic (?A - ?B - ?C)" by (auto elim:acyclic_subset) + from step_back_step [OF vtt] + have "step s (V th cs)" . + thus ?thesis + proof(cases) + assume "holding s th cs" + hence th_in: "th \ set (wq s cs)" and + eq_hd: "th = hd (wq s cs)" unfolding s_holding_def wq_def by auto + then obtain rest where + eq_wq: "wq s cs = th#rest" + by (cases "wq s cs", auto) + show ?thesis + proof(cases "rest = []") + case False + let ?th' = "hd (SOME q. distinct q \ set q = set rest)" + from eq_wq False have eq_D: "?D = {(Cs cs, Th ?th')}" + by (unfold next_th_def, auto) + let ?E = "(?A - ?B - ?C)" + have "(Th ?th', Cs cs) \ ?E\<^sup>*" + proof + assume "(Th ?th', Cs cs) \ ?E\<^sup>*" + hence " (Th ?th', Cs cs) \ ?E\<^sup>+" by (simp add: rtrancl_eq_or_trancl) + from tranclD [OF this] + obtain x where th'_e: "(Th ?th', x) \ ?E" by blast + hence th_d: "(Th ?th', x) \ ?A" by simp + from RAG_target_th [OF this] + obtain cs' where eq_x: "x = Cs cs'" by auto + with th_d have "(Th ?th', Cs cs') \ ?A" by simp + hence wt_th': "waiting s ?th' cs'" + unfolding s_RAG_def s_waiting_def cs_waiting_def wq_def by simp + hence "cs' = cs" + proof(rule waiting_unique [OF vt]) + from eq_wq wq_distinct[OF vt, of cs] + show "waiting s ?th' cs" + apply (unfold s_waiting_def wq_def, auto) + proof - + assume hd_in: "hd (SOME q. distinct q \ set q = set rest) \ set rest" + and eq_wq: "wq_fun (schs s) cs = th # rest" + have "(SOME q. distinct q \ set q = set rest) \ []" + proof(rule someI2) + from wq_distinct[OF vt, of cs] and eq_wq + show "distinct rest \ set rest = set rest" unfolding wq_def by auto + next + fix x assume "distinct x \ set x = set rest" + with False show "x \ []" by auto + qed + hence "hd (SOME q. distinct q \ set q = set rest) \ + set (SOME q. distinct q \ set q = set rest)" by auto + moreover have "\ = set rest" + proof(rule someI2) + from wq_distinct[OF vt, of cs] and eq_wq + show "distinct rest \ set rest = set rest" unfolding wq_def by auto + next + show "\x. distinct x \ set x = set rest \ set x = set rest" by auto + qed + moreover note hd_in + ultimately show "hd (SOME q. distinct q \ set q = set rest) = th" by auto + next + assume hd_in: "hd (SOME q. distinct q \ set q = set rest) \ set rest" + and eq_wq: "wq s cs = hd (SOME q. distinct q \ set q = set rest) # rest" + have "(SOME q. distinct q \ set q = set rest) \ []" + proof(rule someI2) + from wq_distinct[OF vt, of cs] and eq_wq + show "distinct rest \ set rest = set rest" by auto + next + fix x assume "distinct x \ set x = set rest" + with False show "x \ []" by auto + qed + hence "hd (SOME q. distinct q \ set q = set rest) \ + set (SOME q. distinct q \ set q = set rest)" by auto + moreover have "\ = set rest" + proof(rule someI2) + from wq_distinct[OF vt, of cs] and eq_wq + show "distinct rest \ set rest = set rest" by auto + next + show "\x. distinct x \ set x = set rest \ set x = set rest" by auto + qed + moreover note hd_in + ultimately show False by auto + qed + qed + with th'_e eq_x have "(Th ?th', Cs cs) \ ?E" by simp + with False + show "False" by (auto simp: next_th_def eq_wq) + qed + with acyclic_insert[symmetric] and ac + and eq_de eq_D show ?thesis by auto + next + case True + with eq_wq + have eq_D: "?D = {}" + by (unfold next_th_def, auto) + with eq_de ac + show ?thesis by auto + qed + qed + next + case (P th cs) + from P vt stp have vtt: "vt (P th cs#s)" by auto + from step_RAG_p [OF this] P + have "RAG (e # s) = + (if wq s cs = [] then RAG s \ {(Cs cs, Th th)} else + RAG s \ {(Th th, Cs cs)})" (is "?L = ?R") + by simp + moreover have "acyclic ?R" + proof(cases "wq s cs = []") + case True + hence eq_r: "?R = RAG s \ {(Cs cs, Th th)}" by simp + have "(Th th, Cs cs) \ (RAG s)\<^sup>*" + proof + assume "(Th th, Cs cs) \ (RAG s)\<^sup>*" + hence "(Th th, Cs cs) \ (RAG s)\<^sup>+" by (simp add: rtrancl_eq_or_trancl) + from tranclD2 [OF this] + obtain x where "(x, Cs cs) \ RAG s" by auto + with True show False by (auto simp:s_RAG_def cs_waiting_def) + qed + with acyclic_insert ih eq_r show ?thesis by auto + next + case False + hence eq_r: "?R = RAG s \ {(Th th, Cs cs)}" by simp + have "(Cs cs, Th th) \ (RAG s)\<^sup>*" + proof + assume "(Cs cs, Th th) \ (RAG s)\<^sup>*" + hence "(Cs cs, Th th) \ (RAG s)\<^sup>+" by (simp add: rtrancl_eq_or_trancl) + moreover from step_back_step [OF vtt] have "step s (P th cs)" . + ultimately show False + proof - + show " \(Cs cs, Th th) \ (RAG s)\<^sup>+; step s (P th cs)\ \ False" + by (ind_cases "step s (P th cs)", simp) + qed + qed + with acyclic_insert ih eq_r show ?thesis by auto + qed + ultimately show ?thesis by simp + next + case (Set thread prio) + with ih + thm RAG_set_unchanged + show ?thesis by (simp add:RAG_set_unchanged) + qed + next + case vt_nil + show "acyclic (RAG ([]::state))" + by (auto simp: s_RAG_def cs_waiting_def + cs_holding_def wq_def acyclic_def) +qed + + +lemma finite_RAG: + fixes s + assumes vt: "vt s" + shows "finite (RAG s)" +proof - + from vt show ?thesis + proof(induct) + case (vt_cons s e) + assume ih: "finite (RAG s)" + and stp: "step s e" + and vt: "vt s" + show ?case + proof(cases e) + case (Create th prio) + with ih + show ?thesis by (simp add:RAG_create_unchanged) + next + case (Exit th) + with ih show ?thesis by (simp add:RAG_exit_unchanged) + next + case (V th cs) + from V vt stp have vtt: "vt (V th cs#s)" by auto + from step_RAG_v [OF this] + have eq_de: "RAG (e # s) = + RAG s - {(Cs cs, Th th)} - {(Th th', Cs cs) |th'. next_th s th cs th'} \ + {(Cs cs, Th th') |th'. next_th s th cs th'} +" + (is "?L = (?A - ?B - ?C) \ ?D") by (simp add:V) + moreover from ih have ac: "finite (?A - ?B - ?C)" by simp + moreover have "finite ?D" + proof - + have "?D = {} \ (\ a. ?D = {a})" + by (unfold next_th_def, auto) + thus ?thesis + proof + assume h: "?D = {}" + show ?thesis by (unfold h, simp) + next + assume "\ a. ?D = {a}" + thus ?thesis + by (metis finite.simps) + qed + qed + ultimately show ?thesis by simp + next + case (P th cs) + from P vt stp have vtt: "vt (P th cs#s)" by auto + from step_RAG_p [OF this] P + have "RAG (e # s) = + (if wq s cs = [] then RAG s \ {(Cs cs, Th th)} else + RAG s \ {(Th th, Cs cs)})" (is "?L = ?R") + by simp + moreover have "finite ?R" + proof(cases "wq s cs = []") + case True + hence eq_r: "?R = RAG s \ {(Cs cs, Th th)}" by simp + with True and ih show ?thesis by auto + next + case False + hence "?R = RAG s \ {(Th th, Cs cs)}" by simp + with False and ih show ?thesis by auto + qed + ultimately show ?thesis by auto + next + case (Set thread prio) + with ih + show ?thesis by (simp add:RAG_set_unchanged) + qed + next + case vt_nil + show "finite (RAG ([]::state))" + by (auto simp: s_RAG_def cs_waiting_def + cs_holding_def wq_def acyclic_def) + qed +qed + +text {* Several useful lemmas *} + +lemma wf_dep_converse: + fixes s + assumes vt: "vt s" + shows "wf ((RAG s)^-1)" +proof(rule finite_acyclic_wf_converse) + from finite_RAG [OF vt] + show "finite (RAG s)" . +next + from acyclic_RAG[OF vt] + show "acyclic (RAG s)" . +qed + +lemma hd_np_in: "x \ set l \ hd l \ set l" +by (induct l, auto) + +lemma th_chasing: "(Th th, Cs cs) \ RAG (s::state) \ \ th'. (Cs cs, Th th') \ RAG s" + by (auto simp:s_RAG_def s_holding_def cs_holding_def cs_waiting_def wq_def dest:hd_np_in) + +lemma wq_threads: + fixes s cs + assumes vt: "vt s" + and h: "th \ set (wq s cs)" + shows "th \ threads s" +proof - + from vt and h show ?thesis + proof(induct arbitrary: th cs) + case (vt_cons s e) + assume ih: "\th cs. th \ set (wq s cs) \ th \ threads s" + and stp: "step s e" + and vt: "vt s" + and h: "th \ set (wq (e # s) cs)" + show ?case + proof(cases e) + case (Create th' prio) + with ih h show ?thesis + by (auto simp:wq_def Let_def) + next + case (Exit th') + with stp ih h show ?thesis + apply (auto simp:wq_def Let_def) + apply (ind_cases "step s (Exit th')") + apply (auto simp:runing_def readys_def s_holding_def s_waiting_def holdents_def + s_RAG_def s_holding_def cs_holding_def) + done + next + case (V th' cs') + show ?thesis + proof(cases "cs' = cs") + case False + with h + show ?thesis + apply(unfold wq_def V, auto simp:Let_def V split:prod.splits, fold wq_def) + by (drule_tac ih, simp) + next + case True + from h + show ?thesis + proof(unfold V wq_def) + assume th_in: "th \ set (wq_fun (schs (V th' cs' # s)) cs)" (is "th \ set ?l") + show "th \ threads (V th' cs' # s)" + proof(cases "cs = cs'") + case False + hence "?l = wq_fun (schs s) cs" by (simp add:Let_def) + with th_in have " th \ set (wq s cs)" + by (fold wq_def, simp) + from ih [OF this] show ?thesis by simp + next + case True + show ?thesis + proof(cases "wq_fun (schs s) cs'") + case Nil + with h V show ?thesis + apply (auto simp:wq_def Let_def split:if_splits) + by (fold wq_def, drule_tac ih, simp) + next + case (Cons a rest) + assume eq_wq: "wq_fun (schs s) cs' = a # rest" + with h V show ?thesis + apply (auto simp:Let_def wq_def split:if_splits) + proof - + assume th_in: "th \ set (SOME q. distinct q \ set q = set rest)" + have "set (SOME q. distinct q \ set q = set rest) = set rest" + proof(rule someI2) + from wq_distinct[OF vt, of cs'] and eq_wq[folded wq_def] + show "distinct rest \ set rest = set rest" by auto + next + show "\x. distinct x \ set x = set rest \ set x = set rest" + by auto + qed + with eq_wq th_in have "th \ set (wq_fun (schs s) cs')" by auto + from ih[OF this[folded wq_def]] show "th \ threads s" . + next + assume th_in: "th \ set (wq_fun (schs s) cs)" + from ih[OF this[folded wq_def]] + show "th \ threads s" . + qed + qed + qed + qed + qed + next + case (P th' cs') + from h stp + show ?thesis + apply (unfold P wq_def) + apply (auto simp:Let_def split:if_splits, fold wq_def) + apply (auto intro:ih) + apply(ind_cases "step s (P th' cs')") + by (unfold runing_def readys_def, auto) + next + case (Set thread prio) + with ih h show ?thesis + by (auto simp:wq_def Let_def) + qed + next + case vt_nil + thus ?case by (auto simp:wq_def) + qed +qed + +lemma range_in: "\vt s; (Th th) \ Range (RAG (s::state))\ \ th \ threads s" + apply(unfold s_RAG_def cs_waiting_def cs_holding_def) + by (auto intro:wq_threads) + +lemma readys_v_eq: + fixes th thread cs rest + assumes vt: "vt s" + and neq_th: "th \ thread" + and eq_wq: "wq s cs = thread#rest" + and not_in: "th \ set rest" + shows "(th \ readys (V thread cs#s)) = (th \ readys s)" +proof - + from assms show ?thesis + apply (auto simp:readys_def) + apply(simp add:s_waiting_def[folded wq_def]) + apply (erule_tac x = csa in allE) + apply (simp add:s_waiting_def wq_def Let_def split:if_splits) + apply (case_tac "csa = cs", simp) + apply (erule_tac x = cs in allE) + apply(auto simp add: s_waiting_def[folded wq_def] Let_def split: list.splits) + apply(auto simp add: wq_def) + apply (auto simp:s_waiting_def wq_def Let_def split:list.splits) + proof - + assume th_nin: "th \ set rest" + and th_in: "th \ set (SOME q. distinct q \ set q = set rest)" + and eq_wq: "wq_fun (schs s) cs = thread # rest" + have "set (SOME q. distinct q \ set q = set rest) = set rest" + proof(rule someI2) + from wq_distinct[OF vt, of cs, unfolded wq_def] and eq_wq[unfolded wq_def] + show "distinct rest \ set rest = set rest" by auto + next + show "\x. distinct x \ set x = set rest \ set x = set rest" by auto + qed + with th_nin th_in show False by auto + qed +qed + +text {* \noindent + The following lemmas shows that: starting from any node in @{text "RAG"}, + by chasing out-going edges, it is always possible to reach a node representing a ready + thread. In this lemma, it is the @{text "th'"}. +*} + +lemma chain_building: + assumes vt: "vt s" + shows "node \ Domain (RAG s) \ (\ th'. th' \ readys s \ (node, Th th') \ (RAG s)^+)" +proof - + from wf_dep_converse [OF vt] + have h: "wf ((RAG s)\)" . + show ?thesis + proof(induct rule:wf_induct [OF h]) + fix x + assume ih [rule_format]: + "\y. (y, x) \ (RAG s)\ \ + y \ Domain (RAG s) \ (\th'. th' \ readys s \ (y, Th th') \ (RAG s)\<^sup>+)" + show "x \ Domain (RAG s) \ (\th'. th' \ readys s \ (x, Th th') \ (RAG s)\<^sup>+)" + proof + assume x_d: "x \ Domain (RAG s)" + show "\th'. th' \ readys s \ (x, Th th') \ (RAG s)\<^sup>+" + proof(cases x) + case (Th th) + from x_d Th obtain cs where x_in: "(Th th, Cs cs) \ RAG s" by (auto simp:s_RAG_def) + with Th have x_in_r: "(Cs cs, x) \ (RAG s)^-1" by simp + from th_chasing [OF x_in] obtain th' where "(Cs cs, Th th') \ RAG s" by blast + hence "Cs cs \ Domain (RAG s)" by auto + from ih [OF x_in_r this] obtain th' + where th'_ready: " th' \ readys s" and cs_in: "(Cs cs, Th th') \ (RAG s)\<^sup>+" by auto + have "(x, Th th') \ (RAG s)\<^sup>+" using Th x_in cs_in by auto + with th'_ready show ?thesis by auto + next + case (Cs cs) + from x_d Cs obtain th' where th'_d: "(Th th', x) \ (RAG s)^-1" by (auto simp:s_RAG_def) + show ?thesis + proof(cases "th' \ readys s") + case True + from True and th'_d show ?thesis by auto + next + case False + from th'_d and range_in [OF vt] have "th' \ threads s" by auto + with False have "Th th' \ Domain (RAG s)" + by (auto simp:readys_def wq_def s_waiting_def s_RAG_def cs_waiting_def Domain_def) + from ih [OF th'_d this] + obtain th'' where + th''_r: "th'' \ readys s" and + th''_in: "(Th th', Th th'') \ (RAG s)\<^sup>+" by auto + from th'_d and th''_in + have "(x, Th th'') \ (RAG s)\<^sup>+" by auto + with th''_r show ?thesis by auto + qed + qed + qed + qed +qed + +text {* \noindent + The following is just an instance of @{text "chain_building"}. +*} +lemma th_chain_to_ready: + fixes s th + assumes vt: "vt s" + and th_in: "th \ threads s" + shows "th \ readys s \ (\ th'. th' \ readys s \ (Th th, Th th') \ (RAG s)^+)" +proof(cases "th \ readys s") + case True + thus ?thesis by auto +next + case False + from False and th_in have "Th th \ Domain (RAG s)" + by (auto simp:readys_def s_waiting_def s_RAG_def wq_def cs_waiting_def Domain_def) + from chain_building [rule_format, OF vt this] + show ?thesis by auto +qed + +lemma waiting_eq: "waiting s th cs = waiting (wq s) th cs" + by (unfold s_waiting_def cs_waiting_def wq_def, auto) + +lemma holding_eq: "holding (s::state) th cs = holding (wq s) th cs" + by (unfold s_holding_def wq_def cs_holding_def, simp) + +lemma holding_unique: "\holding (s::state) th1 cs; holding s th2 cs\ \ th1 = th2" + by (unfold s_holding_def cs_holding_def, auto) + +lemma unique_RAG: "\vt s; (n, n1) \ RAG s; (n, n2) \ RAG s\ \ n1 = n2" + apply(unfold s_RAG_def, auto, fold waiting_eq holding_eq) + by(auto elim:waiting_unique holding_unique) + +lemma trancl_split: "(a, b) \ r^+ \ \ c. (a, c) \ r" +by (induct rule:trancl_induct, auto) + +lemma dchain_unique: + assumes vt: "vt s" + and th1_d: "(n, Th th1) \ (RAG s)^+" + and th1_r: "th1 \ readys s" + and th2_d: "(n, Th th2) \ (RAG s)^+" + and th2_r: "th2 \ readys s" + shows "th1 = th2" +proof - + { assume neq: "th1 \ th2" + hence "Th th1 \ Th th2" by simp + from unique_chain [OF _ th1_d th2_d this] and unique_RAG [OF vt] + have "(Th th1, Th th2) \ (RAG s)\<^sup>+ \ (Th th2, Th th1) \ (RAG s)\<^sup>+" by auto + hence "False" + proof + assume "(Th th1, Th th2) \ (RAG s)\<^sup>+" + from trancl_split [OF this] + obtain n where dd: "(Th th1, n) \ RAG s" by auto + then obtain cs where eq_n: "n = Cs cs" + by (auto simp:s_RAG_def s_holding_def cs_holding_def cs_waiting_def wq_def dest:hd_np_in) + from dd eq_n have "th1 \ readys s" + by (auto simp:readys_def s_RAG_def wq_def s_waiting_def cs_waiting_def) + with th1_r show ?thesis by auto + next + assume "(Th th2, Th th1) \ (RAG s)\<^sup>+" + from trancl_split [OF this] + obtain n where dd: "(Th th2, n) \ RAG s" by auto + then obtain cs where eq_n: "n = Cs cs" + by (auto simp:s_RAG_def s_holding_def cs_holding_def cs_waiting_def wq_def dest:hd_np_in) + from dd eq_n have "th2 \ readys s" + by (auto simp:readys_def wq_def s_RAG_def s_waiting_def cs_waiting_def) + with th2_r show ?thesis by auto + qed + } thus ?thesis by auto +qed + + +lemma step_holdents_p_add: + fixes th cs s + assumes vt: "vt (P th cs#s)" + and "wq s cs = []" + shows "holdents (P th cs#s) th = holdents s th \ {cs}" +proof - + from assms show ?thesis + unfolding holdents_test step_RAG_p[OF vt] by (auto) +qed + +lemma step_holdents_p_eq: + fixes th cs s + assumes vt: "vt (P th cs#s)" + and "wq s cs \ []" + shows "holdents (P th cs#s) th = holdents s th" +proof - + from assms show ?thesis + unfolding holdents_test step_RAG_p[OF vt] by auto +qed + + +lemma finite_holding: + fixes s th cs + assumes vt: "vt s" + shows "finite (holdents s th)" +proof - + let ?F = "\ (x, y). the_cs x" + from finite_RAG [OF vt] + have "finite (RAG s)" . + hence "finite (?F `(RAG s))" by simp + moreover have "{cs . (Cs cs, Th th) \ RAG s} \ \" + proof - + { have h: "\ a A f. a \ A \ f a \ f ` A" by auto + fix x assume "(Cs x, Th th) \ RAG s" + hence "?F (Cs x, Th th) \ ?F `(RAG s)" by (rule h) + moreover have "?F (Cs x, Th th) = x" by simp + ultimately have "x \ (\(x, y). the_cs x) ` RAG s" by simp + } thus ?thesis by auto + qed + ultimately show ?thesis by (unfold holdents_test, auto intro:finite_subset) +qed + +lemma cntCS_v_dec: + fixes s thread cs + assumes vtv: "vt (V thread cs#s)" + shows "(cntCS (V thread cs#s) thread + 1) = cntCS s thread" +proof - + from step_back_step[OF vtv] + have cs_in: "cs \ holdents s thread" + apply (cases, unfold holdents_test s_RAG_def, simp) + by (unfold cs_holding_def s_holding_def wq_def, auto) + moreover have cs_not_in: + "(holdents (V thread cs#s) thread) = holdents s thread - {cs}" + apply (insert wq_distinct[OF step_back_vt[OF vtv], of cs]) + apply (unfold holdents_test, unfold step_RAG_v[OF vtv], + auto simp:next_th_def) + proof - + fix rest + assume dst: "distinct (rest::thread list)" + and ne: "rest \ []" + and hd_ni: "hd (SOME q. distinct q \ set q = set rest) \ set rest" + moreover have "set (SOME q. distinct q \ set q = set rest) = set rest" + proof(rule someI2) + from dst show "distinct rest \ set rest = set rest" by auto + next + show "\x. distinct x \ set x = set rest \ set x = set rest" by auto + qed + ultimately have "hd (SOME q. distinct q \ set q = set rest) \ + set (SOME q. distinct q \ set q = set rest)" by simp + moreover have "(SOME q. distinct q \ set q = set rest) \ []" + proof(rule someI2) + from dst show "distinct rest \ set rest = set rest" by auto + next + fix x assume " distinct x \ set x = set rest" with ne + show "x \ []" by auto + qed + ultimately + show "(Cs cs, Th (hd (SOME q. distinct q \ set q = set rest))) \ RAG s" + by auto + next + fix rest + assume dst: "distinct (rest::thread list)" + and ne: "rest \ []" + and hd_ni: "hd (SOME q. distinct q \ set q = set rest) \ set rest" + moreover have "set (SOME q. distinct q \ set q = set rest) = set rest" + proof(rule someI2) + from dst show "distinct rest \ set rest = set rest" by auto + next + show "\x. distinct x \ set x = set rest \ set x = set rest" by auto + qed + ultimately have "hd (SOME q. distinct q \ set q = set rest) \ + set (SOME q. distinct q \ set q = set rest)" by simp + moreover have "(SOME q. distinct q \ set q = set rest) \ []" + proof(rule someI2) + from dst show "distinct rest \ set rest = set rest" by auto + next + fix x assume " distinct x \ set x = set rest" with ne + show "x \ []" by auto + qed + ultimately show "False" by auto + qed + ultimately + have "holdents s thread = insert cs (holdents (V thread cs#s) thread)" + by auto + moreover have "card \ = + Suc (card ((holdents (V thread cs#s) thread) - {cs}))" + proof(rule card_insert) + from finite_holding [OF vtv] + show " finite (holdents (V thread cs # s) thread)" . + qed + moreover from cs_not_in + have "cs \ (holdents (V thread cs#s) thread)" by auto + ultimately show ?thesis by (simp add:cntCS_def) +qed + +text {* (* ??? *) \noindent + The relationship between @{text "cntP"}, @{text "cntV"} and @{text "cntCS"} + of one particular thread. +*} + +lemma cnp_cnv_cncs: + fixes s th + assumes vt: "vt s" + shows "cntP s th = cntV s th + (if (th \ readys s \ th \ threads s) + then cntCS s th else cntCS s th + 1)" +proof - + from vt show ?thesis + proof(induct arbitrary:th) + case (vt_cons s e) + assume vt: "vt s" + and ih: "\th. cntP s th = cntV s th + + (if (th \ readys s \ th \ threads s) then cntCS s th else cntCS s th + 1)" + and stp: "step s e" + from stp show ?case + proof(cases) + case (thread_create thread prio) + assume eq_e: "e = Create thread prio" + and not_in: "thread \ threads s" + show ?thesis + proof - + { fix cs + assume "thread \ set (wq s cs)" + from wq_threads [OF vt this] have "thread \ threads s" . + with not_in have "False" by simp + } with eq_e have eq_readys: "readys (e#s) = readys s \ {thread}" + by (auto simp:readys_def threads.simps s_waiting_def + wq_def cs_waiting_def Let_def) + from eq_e have eq_cnp: "cntP (e#s) th = cntP s th" by (simp add:cntP_def count_def) + from eq_e have eq_cnv: "cntV (e#s) th = cntV s th" by (simp add:cntV_def count_def) + have eq_cncs: "cntCS (e#s) th = cntCS s th" + unfolding cntCS_def holdents_test + by (simp add:RAG_create_unchanged eq_e) + { assume "th \ thread" + with eq_readys eq_e + have "(th \ readys (e # s) \ th \ threads (e # s)) = + (th \ readys (s) \ th \ threads (s))" + by (simp add:threads.simps) + with eq_cnp eq_cnv eq_cncs ih not_in + have ?thesis by simp + } moreover { + assume eq_th: "th = thread" + with not_in ih have " cntP s th = cntV s th + cntCS s th" by simp + moreover from eq_th and eq_readys have "th \ readys (e#s)" by simp + moreover note eq_cnp eq_cnv eq_cncs + ultimately have ?thesis by auto + } ultimately show ?thesis by blast + qed + next + case (thread_exit thread) + assume eq_e: "e = Exit thread" + and is_runing: "thread \ runing s" + and no_hold: "holdents s thread = {}" + from eq_e have eq_cnp: "cntP (e#s) th = cntP s th" by (simp add:cntP_def count_def) + from eq_e have eq_cnv: "cntV (e#s) th = cntV s th" by (simp add:cntV_def count_def) + have eq_cncs: "cntCS (e#s) th = cntCS s th" + unfolding cntCS_def holdents_test + by (simp add:RAG_exit_unchanged eq_e) + { assume "th \ thread" + with eq_e + have "(th \ readys (e # s) \ th \ threads (e # s)) = + (th \ readys (s) \ th \ threads (s))" + apply (simp add:threads.simps readys_def) + apply (subst s_waiting_def) + apply (simp add:Let_def) + apply (subst s_waiting_def, simp) + done + with eq_cnp eq_cnv eq_cncs ih + have ?thesis by simp + } moreover { + assume eq_th: "th = thread" + with ih is_runing have " cntP s th = cntV s th + cntCS s th" + by (simp add:runing_def) + moreover from eq_th eq_e have "th \ threads (e#s)" + by simp + moreover note eq_cnp eq_cnv eq_cncs + ultimately have ?thesis by auto + } ultimately show ?thesis by blast + next + case (thread_P thread cs) + assume eq_e: "e = P thread cs" + and is_runing: "thread \ runing s" + and no_dep: "(Cs cs, Th thread) \ (RAG s)\<^sup>+" + from thread_P vt stp ih have vtp: "vt (P thread cs#s)" by auto + show ?thesis + proof - + { have hh: "\ A B C. (B = C) \ (A \ B) = (A \ C)" by blast + assume neq_th: "th \ thread" + with eq_e + have eq_readys: "(th \ readys (e#s)) = (th \ readys (s))" + apply (simp add:readys_def s_waiting_def wq_def Let_def) + apply (rule_tac hh) + apply (intro iffI allI, clarify) + apply (erule_tac x = csa in allE, auto) + apply (subgoal_tac "wq_fun (schs s) cs \ []", auto) + apply (erule_tac x = cs in allE, auto) + by (case_tac "(wq_fun (schs s) cs)", auto) + moreover from neq_th eq_e have "cntCS (e # s) th = cntCS s th" + apply (simp add:cntCS_def holdents_test) + by (unfold step_RAG_p [OF vtp], auto) + moreover from eq_e neq_th have "cntP (e # s) th = cntP s th" + by (simp add:cntP_def count_def) + moreover from eq_e neq_th have "cntV (e#s) th = cntV s th" + by (simp add:cntV_def count_def) + moreover from eq_e neq_th have "threads (e#s) = threads s" by simp + moreover note ih [of th] + ultimately have ?thesis by simp + } moreover { + assume eq_th: "th = thread" + have ?thesis + proof - + from eq_e eq_th have eq_cnp: "cntP (e # s) th = 1 + (cntP s th)" + by (simp add:cntP_def count_def) + from eq_e eq_th have eq_cnv: "cntV (e#s) th = cntV s th" + by (simp add:cntV_def count_def) + show ?thesis + proof (cases "wq s cs = []") + case True + with is_runing + have "th \ readys (e#s)" + apply (unfold eq_e wq_def, unfold readys_def s_RAG_def) + apply (simp add: wq_def[symmetric] runing_def eq_th s_waiting_def) + by (auto simp:readys_def wq_def Let_def s_waiting_def wq_def) + moreover have "cntCS (e # s) th = 1 + cntCS s th" + proof - + have "card {csa. csa = cs \ (Cs csa, Th thread) \ RAG s} = + Suc (card {cs. (Cs cs, Th thread) \ RAG s})" (is "card ?L = Suc (card ?R)") + proof - + have "?L = insert cs ?R" by auto + moreover have "card \ = Suc (card (?R - {cs}))" + proof(rule card_insert) + from finite_holding [OF vt, of thread] + show " finite {cs. (Cs cs, Th thread) \ RAG s}" + by (unfold holdents_test, simp) + qed + moreover have "?R - {cs} = ?R" + proof - + have "cs \ ?R" + proof + assume "cs \ {cs. (Cs cs, Th thread) \ RAG s}" + with no_dep show False by auto + qed + thus ?thesis by auto + qed + ultimately show ?thesis by auto + qed + thus ?thesis + apply (unfold eq_e eq_th cntCS_def) + apply (simp add: holdents_test) + by (unfold step_RAG_p [OF vtp], auto simp:True) + qed + moreover from is_runing have "th \ readys s" + by (simp add:runing_def eq_th) + moreover note eq_cnp eq_cnv ih [of th] + ultimately show ?thesis by auto + next + case False + have eq_wq: "wq (e#s) cs = wq s cs @ [th]" + by (unfold eq_th eq_e wq_def, auto simp:Let_def) + have "th \ readys (e#s)" + proof + assume "th \ readys (e#s)" + hence "\cs. \ waiting (e # s) th cs" by (simp add:readys_def) + from this[rule_format, of cs] have " \ waiting (e # s) th cs" . + hence "th \ set (wq (e#s) cs) \ th = hd (wq (e#s) cs)" + by (simp add:s_waiting_def wq_def) + moreover from eq_wq have "th \ set (wq (e#s) cs)" by auto + ultimately have "th = hd (wq (e#s) cs)" by blast + with eq_wq have "th = hd (wq s cs @ [th])" by simp + hence "th = hd (wq s cs)" using False by auto + with False eq_wq wq_distinct [OF vtp, of cs] + show False by (fold eq_e, auto) + qed + moreover from is_runing have "th \ threads (e#s)" + by (unfold eq_e, auto simp:runing_def readys_def eq_th) + moreover have "cntCS (e # s) th = cntCS s th" + apply (unfold cntCS_def holdents_test eq_e step_RAG_p[OF vtp]) + by (auto simp:False) + moreover note eq_cnp eq_cnv ih[of th] + moreover from is_runing have "th \ readys s" + by (simp add:runing_def eq_th) + ultimately show ?thesis by auto + qed + qed + } ultimately show ?thesis by blast + qed + next + case (thread_V thread cs) + from assms vt stp ih thread_V have vtv: "vt (V thread cs # s)" by auto + assume eq_e: "e = V thread cs" + and is_runing: "thread \ runing s" + and hold: "holding s thread cs" + from hold obtain rest + where eq_wq: "wq s cs = thread # rest" + by (case_tac "wq s cs", auto simp: wq_def s_holding_def) + have eq_threads: "threads (e#s) = threads s" by (simp add: eq_e) + have eq_set: "set (SOME q. distinct q \ set q = set rest) = set rest" + proof(rule someI2) + from wq_distinct[OF step_back_vt[OF vtv], of cs] and eq_wq + show "distinct rest \ set rest = set rest" by auto + next + show "\x. distinct x \ set x = set rest \ set x = set rest" + by auto + qed + show ?thesis + proof - + { assume eq_th: "th = thread" + from eq_th have eq_cnp: "cntP (e # s) th = cntP s th" + by (unfold eq_e, simp add:cntP_def count_def) + moreover from eq_th have eq_cnv: "cntV (e#s) th = 1 + cntV s th" + by (unfold eq_e, simp add:cntV_def count_def) + moreover from cntCS_v_dec [OF vtv] + have "cntCS (e # s) thread + 1 = cntCS s thread" + by (simp add:eq_e) + moreover from is_runing have rd_before: "thread \ readys s" + by (unfold runing_def, simp) + moreover have "thread \ readys (e # s)" + proof - + from is_runing + have "thread \ threads (e#s)" + by (unfold eq_e, auto simp:runing_def readys_def) + moreover have "\ cs1. \ waiting (e#s) thread cs1" + proof + fix cs1 + { assume eq_cs: "cs1 = cs" + have "\ waiting (e # s) thread cs1" + proof - + from eq_wq + have "thread \ set (wq (e#s) cs1)" + apply(unfold eq_e wq_def eq_cs s_holding_def) + apply (auto simp:Let_def) + proof - + assume "thread \ set (SOME q. distinct q \ set q = set rest)" + with eq_set have "thread \ set rest" by simp + with wq_distinct[OF step_back_vt[OF vtv], of cs] + and eq_wq show False by auto + qed + thus ?thesis by (simp add:wq_def s_waiting_def) + qed + } moreover { + assume neq_cs: "cs1 \ cs" + have "\ waiting (e # s) thread cs1" + proof - + from wq_v_neq [OF neq_cs[symmetric]] + have "wq (V thread cs # s) cs1 = wq s cs1" . + moreover have "\ waiting s thread cs1" + proof - + from runing_ready and is_runing + have "thread \ readys s" by auto + thus ?thesis by (simp add:readys_def) + qed + ultimately show ?thesis + by (auto simp:wq_def s_waiting_def eq_e) + qed + } ultimately show "\ waiting (e # s) thread cs1" by blast + qed + ultimately show ?thesis by (simp add:readys_def) + qed + moreover note eq_th ih + ultimately have ?thesis by auto + } moreover { + assume neq_th: "th \ thread" + from neq_th eq_e have eq_cnp: "cntP (e # s) th = cntP s th" + by (simp add:cntP_def count_def) + from neq_th eq_e have eq_cnv: "cntV (e # s) th = cntV s th" + by (simp add:cntV_def count_def) + have ?thesis + proof(cases "th \ set rest") + case False + have "(th \ readys (e # s)) = (th \ readys s)" + apply (insert step_back_vt[OF vtv]) + by (unfold eq_e, rule readys_v_eq [OF _ neq_th eq_wq False], auto) + moreover have "cntCS (e#s) th = cntCS s th" + apply (insert neq_th, unfold eq_e cntCS_def holdents_test step_RAG_v[OF vtv], auto) + proof - + have "{csa. (Cs csa, Th th) \ RAG s \ csa = cs \ next_th s thread cs th} = + {cs. (Cs cs, Th th) \ RAG s}" + proof - + from False eq_wq + have " next_th s thread cs th \ (Cs cs, Th th) \ RAG s" + apply (unfold next_th_def, auto) + proof - + assume ne: "rest \ []" + and ni: "hd (SOME q. distinct q \ set q = set rest) \ set rest" + and eq_wq: "wq s cs = thread # rest" + from eq_set ni have "hd (SOME q. distinct q \ set q = set rest) \ + set (SOME q. distinct q \ set q = set rest) + " by simp + moreover have "(SOME q. distinct q \ set q = set rest) \ []" + proof(rule someI2) + from wq_distinct[OF step_back_vt[OF vtv], of cs] and eq_wq + show "distinct rest \ set rest = set rest" by auto + next + fix x assume "distinct x \ set x = set rest" + with ne show "x \ []" by auto + qed + ultimately show + "(Cs cs, Th (hd (SOME q. distinct q \ set q = set rest))) \ RAG s" + by auto + qed + thus ?thesis by auto + qed + thus "card {csa. (Cs csa, Th th) \ RAG s \ csa = cs \ next_th s thread cs th} = + card {cs. (Cs cs, Th th) \ RAG s}" by simp + qed + moreover note ih eq_cnp eq_cnv eq_threads + ultimately show ?thesis by auto + next + case True + assume th_in: "th \ set rest" + show ?thesis + proof(cases "next_th s thread cs th") + case False + with eq_wq and th_in have + neq_hd: "th \ hd (SOME q. distinct q \ set q = set rest)" (is "th \ hd ?rest") + by (auto simp:next_th_def) + have "(th \ readys (e # s)) = (th \ readys s)" + proof - + from eq_wq and th_in + have "\ th \ readys s" + apply (auto simp:readys_def s_waiting_def) + apply (rule_tac x = cs in exI, auto) + by (insert wq_distinct[OF step_back_vt[OF vtv], of cs], auto simp add: wq_def) + moreover + from eq_wq and th_in and neq_hd + have "\ (th \ readys (e # s))" + apply (auto simp:readys_def s_waiting_def eq_e wq_def Let_def split:list.splits) + by (rule_tac x = cs in exI, auto simp:eq_set) + ultimately show ?thesis by auto + qed + moreover have "cntCS (e#s) th = cntCS s th" + proof - + from eq_wq and th_in and neq_hd + have "(holdents (e # s) th) = (holdents s th)" + apply (unfold eq_e step_RAG_v[OF vtv], + auto simp:next_th_def eq_set s_RAG_def holdents_test wq_def + Let_def cs_holding_def) + by (insert wq_distinct[OF step_back_vt[OF vtv], of cs], auto simp:wq_def) + thus ?thesis by (simp add:cntCS_def) + qed + moreover note ih eq_cnp eq_cnv eq_threads + ultimately show ?thesis by auto + next + case True + let ?rest = " (SOME q. distinct q \ set q = set rest)" + let ?t = "hd ?rest" + from True eq_wq th_in neq_th + have "th \ readys (e # s)" + apply (auto simp:eq_e readys_def s_waiting_def wq_def + Let_def next_th_def) + proof - + assume eq_wq: "wq_fun (schs s) cs = thread # rest" + and t_in: "?t \ set rest" + show "?t \ threads s" + proof(rule wq_threads[OF step_back_vt[OF vtv]]) + from eq_wq and t_in + show "?t \ set (wq s cs)" by (auto simp:wq_def) + qed + next + fix csa + assume eq_wq: "wq_fun (schs s) cs = thread # rest" + and t_in: "?t \ set rest" + and neq_cs: "csa \ cs" + and t_in': "?t \ set (wq_fun (schs s) csa)" + show "?t = hd (wq_fun (schs s) csa)" + proof - + { assume neq_hd': "?t \ hd (wq_fun (schs s) csa)" + from wq_distinct[OF step_back_vt[OF vtv], of cs] and + eq_wq[folded wq_def] and t_in eq_wq + have "?t \ thread" by auto + with eq_wq and t_in + have w1: "waiting s ?t cs" + by (auto simp:s_waiting_def wq_def) + from t_in' neq_hd' + have w2: "waiting s ?t csa" + by (auto simp:s_waiting_def wq_def) + from waiting_unique[OF step_back_vt[OF vtv] w1 w2] + and neq_cs have "False" by auto + } thus ?thesis by auto + qed + qed + moreover have "cntP s th = cntV s th + cntCS s th + 1" + proof - + have "th \ readys s" + proof - + from True eq_wq neq_th th_in + show ?thesis + apply (unfold readys_def s_waiting_def, auto) + by (rule_tac x = cs in exI, auto simp add: wq_def) + qed + moreover have "th \ threads s" + proof - + from th_in eq_wq + have "th \ set (wq s cs)" by simp + from wq_threads [OF step_back_vt[OF vtv] this] + show ?thesis . + qed + ultimately show ?thesis using ih by auto + qed + moreover from True neq_th have "cntCS (e # s) th = 1 + cntCS s th" + apply (unfold cntCS_def holdents_test eq_e step_RAG_v[OF vtv], auto) + proof - + show "card {csa. (Cs csa, Th th) \ RAG s \ csa = cs} = + Suc (card {cs. (Cs cs, Th th) \ RAG s})" + (is "card ?A = Suc (card ?B)") + proof - + have "?A = insert cs ?B" by auto + hence "card ?A = card (insert cs ?B)" by simp + also have "\ = Suc (card ?B)" + proof(rule card_insert_disjoint) + have "?B \ ((\ (x, y). the_cs x) ` RAG s)" + apply (auto simp:image_def) + by (rule_tac x = "(Cs x, Th th)" in bexI, auto) + with finite_RAG[OF step_back_vt[OF vtv]] + show "finite {cs. (Cs cs, Th th) \ RAG s}" by (auto intro:finite_subset) + next + show "cs \ {cs. (Cs cs, Th th) \ RAG s}" + proof + assume "cs \ {cs. (Cs cs, Th th) \ RAG s}" + hence "(Cs cs, Th th) \ RAG s" by simp + with True neq_th eq_wq show False + by (auto simp:next_th_def s_RAG_def cs_holding_def) + qed + qed + finally show ?thesis . + qed + qed + moreover note eq_cnp eq_cnv + ultimately show ?thesis by simp + qed + qed + } ultimately show ?thesis by blast + qed + next + case (thread_set thread prio) + assume eq_e: "e = Set thread prio" + and is_runing: "thread \ runing s" + show ?thesis + proof - + from eq_e have eq_cnp: "cntP (e#s) th = cntP s th" by (simp add:cntP_def count_def) + from eq_e have eq_cnv: "cntV (e#s) th = cntV s th" by (simp add:cntV_def count_def) + have eq_cncs: "cntCS (e#s) th = cntCS s th" + unfolding cntCS_def holdents_test + by (simp add:RAG_set_unchanged eq_e) + from eq_e have eq_readys: "readys (e#s) = readys s" + by (simp add:readys_def cs_waiting_def s_waiting_def wq_def, + auto simp:Let_def) + { assume "th \ thread" + with eq_readys eq_e + have "(th \ readys (e # s) \ th \ threads (e # s)) = + (th \ readys (s) \ th \ threads (s))" + by (simp add:threads.simps) + with eq_cnp eq_cnv eq_cncs ih is_runing + have ?thesis by simp + } moreover { + assume eq_th: "th = thread" + with is_runing ih have " cntP s th = cntV s th + cntCS s th" + by (unfold runing_def, auto) + moreover from eq_th and eq_readys is_runing have "th \ readys (e#s)" + by (simp add:runing_def) + moreover note eq_cnp eq_cnv eq_cncs + ultimately have ?thesis by auto + } ultimately show ?thesis by blast + qed + qed + next + case vt_nil + show ?case + by (unfold cntP_def cntV_def cntCS_def, + auto simp:count_def holdents_test s_RAG_def wq_def cs_holding_def) + qed +qed + +lemma not_thread_cncs: + fixes th s + assumes vt: "vt s" + and not_in: "th \ threads s" + shows "cntCS s th = 0" +proof - + from vt not_in show ?thesis + proof(induct arbitrary:th) + case (vt_cons s e th) + assume vt: "vt s" + and ih: "\th. th \ threads s \ cntCS s th = 0" + and stp: "step s e" + and not_in: "th \ threads (e # s)" + from stp show ?case + proof(cases) + case (thread_create thread prio) + assume eq_e: "e = Create thread prio" + and not_in': "thread \ threads s" + have "cntCS (e # s) th = cntCS s th" + apply (unfold eq_e cntCS_def holdents_test) + by (simp add:RAG_create_unchanged) + moreover have "th \ threads s" + proof - + from not_in eq_e show ?thesis by simp + qed + moreover note ih ultimately show ?thesis by auto + next + case (thread_exit thread) + assume eq_e: "e = Exit thread" + and nh: "holdents s thread = {}" + have eq_cns: "cntCS (e # s) th = cntCS s th" + apply (unfold eq_e cntCS_def holdents_test) + by (simp add:RAG_exit_unchanged) + show ?thesis + proof(cases "th = thread") + case True + have "cntCS s th = 0" by (unfold cntCS_def, auto simp:nh True) + with eq_cns show ?thesis by simp + next + case False + with not_in and eq_e + have "th \ threads s" by simp + from ih[OF this] and eq_cns show ?thesis by simp + qed + next + case (thread_P thread cs) + assume eq_e: "e = P thread cs" + and is_runing: "thread \ runing s" + from assms thread_P ih vt stp thread_P have vtp: "vt (P thread cs#s)" by auto + have neq_th: "th \ thread" + proof - + from not_in eq_e have "th \ threads s" by simp + moreover from is_runing have "thread \ threads s" + by (simp add:runing_def readys_def) + ultimately show ?thesis by auto + qed + hence "cntCS (e # s) th = cntCS s th " + apply (unfold cntCS_def holdents_test eq_e) + by (unfold step_RAG_p[OF vtp], auto) + moreover have "cntCS s th = 0" + proof(rule ih) + from not_in eq_e show "th \ threads s" by simp + qed + ultimately show ?thesis by simp + next + case (thread_V thread cs) + assume eq_e: "e = V thread cs" + and is_runing: "thread \ runing s" + and hold: "holding s thread cs" + have neq_th: "th \ thread" + proof - + from not_in eq_e have "th \ threads s" by simp + moreover from is_runing have "thread \ threads s" + by (simp add:runing_def readys_def) + ultimately show ?thesis by auto + qed + from assms thread_V vt stp ih have vtv: "vt (V thread cs#s)" by auto + from hold obtain rest + where eq_wq: "wq s cs = thread # rest" + by (case_tac "wq s cs", auto simp: wq_def s_holding_def) + from not_in eq_e eq_wq + have "\ next_th s thread cs th" + apply (auto simp:next_th_def) + proof - + assume ne: "rest \ []" + and ni: "hd (SOME q. distinct q \ set q = set rest) \ threads s" (is "?t \ threads s") + have "?t \ set rest" + proof(rule someI2) + from wq_distinct[OF step_back_vt[OF vtv], of cs] and eq_wq + show "distinct rest \ set rest = set rest" by auto + next + fix x assume "distinct x \ set x = set rest" with ne + show "hd x \ set rest" by (cases x, auto) + qed + with eq_wq have "?t \ set (wq s cs)" by simp + from wq_threads[OF step_back_vt[OF vtv], OF this] and ni + show False by auto + qed + moreover note neq_th eq_wq + ultimately have "cntCS (e # s) th = cntCS s th" + by (unfold eq_e cntCS_def holdents_test step_RAG_v[OF vtv], auto) + moreover have "cntCS s th = 0" + proof(rule ih) + from not_in eq_e show "th \ threads s" by simp + qed + ultimately show ?thesis by simp + next + case (thread_set thread prio) + print_facts + assume eq_e: "e = Set thread prio" + and is_runing: "thread \ runing s" + from not_in and eq_e have "th \ threads s" by auto + from ih [OF this] and eq_e + show ?thesis + apply (unfold eq_e cntCS_def holdents_test) + by (simp add:RAG_set_unchanged) + qed + next + case vt_nil + show ?case + by (unfold cntCS_def, + auto simp:count_def holdents_test s_RAG_def wq_def cs_holding_def) + qed +qed + +lemma eq_waiting: "waiting (wq (s::state)) th cs = waiting s th cs" + by (auto simp:s_waiting_def cs_waiting_def wq_def) + +lemma dm_RAG_threads: + fixes th s + assumes vt: "vt s" + and in_dom: "(Th th) \ Domain (RAG s)" + shows "th \ threads s" +proof - + from in_dom obtain n where "(Th th, n) \ RAG s" by auto + moreover from RAG_target_th[OF this] obtain cs where "n = Cs cs" by auto + ultimately have "(Th th, Cs cs) \ RAG s" by simp + hence "th \ set (wq s cs)" + by (unfold s_RAG_def, auto simp:cs_waiting_def) + from wq_threads [OF vt this] show ?thesis . +qed + +lemma cp_eq_cpreced: "cp s th = cpreced (wq s) s th" +unfolding cp_def wq_def +apply(induct s rule: schs.induct) +thm cpreced_initial +apply(simp add: Let_def cpreced_initial) +apply(simp add: Let_def) +apply(simp add: Let_def) +apply(simp add: Let_def) +apply(subst (2) schs.simps) +apply(simp add: Let_def) +apply(subst (2) schs.simps) +apply(simp add: Let_def) +done + +(* FIXME: NOT NEEDED *) +lemma runing_unique: + fixes th1 th2 s + assumes vt: "vt s" + and runing_1: "th1 \ runing s" + and runing_2: "th2 \ runing s" + shows "th1 = th2" +proof - + from runing_1 and runing_2 have "cp s th1 = cp s th2" + unfolding runing_def + apply(simp) + done + hence eq_max: "Max ((\th. preced th s) ` ({th1} \ dependants (wq s) th1)) = + Max ((\th. preced th s) ` ({th2} \ dependants (wq s) th2))" + (is "Max (?f ` ?A) = Max (?f ` ?B)") + thm cp_def image_Collect + unfolding cp_eq_cpreced + unfolding cpreced_def . + obtain th1' where th1_in: "th1' \ ?A" and eq_f_th1: "?f th1' = Max (?f ` ?A)" + thm Max_in + proof - + have h1: "finite (?f ` ?A)" + proof - + have "finite ?A" + proof - + have "finite (dependants (wq s) th1)" + proof- + have "finite {th'. (Th th', Th th1) \ (RAG (wq s))\<^sup>+}" + proof - + let ?F = "\ (x, y). the_th x" + have "{th'. (Th th', Th th1) \ (RAG (wq s))\<^sup>+} \ ?F ` ((RAG (wq s))\<^sup>+)" + apply (auto simp:image_def) + by (rule_tac x = "(Th x, Th th1)" in bexI, auto) + moreover have "finite \" + proof - + from finite_RAG[OF vt] have "finite (RAG s)" . + hence "finite ((RAG (wq s))\<^sup>+)" + apply (unfold finite_trancl) + by (auto simp: s_RAG_def cs_RAG_def wq_def) + thus ?thesis by auto + qed + ultimately show ?thesis by (auto intro:finite_subset) + qed + thus ?thesis by (simp add:cs_dependants_def) + qed + thus ?thesis by simp + qed + thus ?thesis by auto + qed + moreover have h2: "(?f ` ?A) \ {}" + proof - + have "?A \ {}" by simp + thus ?thesis by simp + qed + thm Max_in + from Max_in [OF h1 h2] + have "Max (?f ` ?A) \ (?f ` ?A)" . + thus ?thesis + thm cpreced_def + unfolding cpreced_def[symmetric] + unfolding cp_eq_cpreced[symmetric] + unfolding cpreced_def + using that[intro] by (auto) + qed + obtain th2' where th2_in: "th2' \ ?B" and eq_f_th2: "?f th2' = Max (?f ` ?B)" + proof - + have h1: "finite (?f ` ?B)" + proof - + have "finite ?B" + proof - + have "finite (dependants (wq s) th2)" + proof- + have "finite {th'. (Th th', Th th2) \ (RAG (wq s))\<^sup>+}" + proof - + let ?F = "\ (x, y). the_th x" + have "{th'. (Th th', Th th2) \ (RAG (wq s))\<^sup>+} \ ?F ` ((RAG (wq s))\<^sup>+)" + apply (auto simp:image_def) + by (rule_tac x = "(Th x, Th th2)" in bexI, auto) + moreover have "finite \" + proof - + from finite_RAG[OF vt] have "finite (RAG s)" . + hence "finite ((RAG (wq s))\<^sup>+)" + apply (unfold finite_trancl) + by (auto simp: s_RAG_def cs_RAG_def wq_def) + thus ?thesis by auto + qed + ultimately show ?thesis by (auto intro:finite_subset) + qed + thus ?thesis by (simp add:cs_dependants_def) + qed + thus ?thesis by simp + qed + thus ?thesis by auto + qed + moreover have h2: "(?f ` ?B) \ {}" + proof - + have "?B \ {}" by simp + thus ?thesis by simp + qed + from Max_in [OF h1 h2] + have "Max (?f ` ?B) \ (?f ` ?B)" . + thus ?thesis by (auto intro:that) + qed + from eq_f_th1 eq_f_th2 eq_max + have eq_preced: "preced th1' s = preced th2' s" by auto + hence eq_th12: "th1' = th2'" + proof (rule preced_unique) + from th1_in have "th1' = th1 \ (th1' \ dependants (wq s) th1)" by simp + thus "th1' \ threads s" + proof + assume "th1' \ dependants (wq s) th1" + hence "(Th th1') \ Domain ((RAG s)^+)" + apply (unfold cs_dependants_def cs_RAG_def s_RAG_def) + by (auto simp:Domain_def) + hence "(Th th1') \ Domain (RAG s)" by (simp add:trancl_domain) + from dm_RAG_threads[OF vt this] show ?thesis . + next + assume "th1' = th1" + with runing_1 show ?thesis + by (unfold runing_def readys_def, auto) + qed + next + from th2_in have "th2' = th2 \ (th2' \ dependants (wq s) th2)" by simp + thus "th2' \ threads s" + proof + assume "th2' \ dependants (wq s) th2" + hence "(Th th2') \ Domain ((RAG s)^+)" + apply (unfold cs_dependants_def cs_RAG_def s_RAG_def) + by (auto simp:Domain_def) + hence "(Th th2') \ Domain (RAG s)" by (simp add:trancl_domain) + from dm_RAG_threads[OF vt this] show ?thesis . + next + assume "th2' = th2" + with runing_2 show ?thesis + by (unfold runing_def readys_def, auto) + qed + qed + from th1_in have "th1' = th1 \ th1' \ dependants (wq s) th1" by simp + thus ?thesis + proof + assume eq_th': "th1' = th1" + from th2_in have "th2' = th2 \ th2' \ dependants (wq s) th2" by simp + thus ?thesis + proof + assume "th2' = th2" thus ?thesis using eq_th' eq_th12 by simp + next + assume "th2' \ dependants (wq s) th2" + with eq_th12 eq_th' have "th1 \ dependants (wq s) th2" by simp + hence "(Th th1, Th th2) \ (RAG s)^+" + by (unfold cs_dependants_def s_RAG_def cs_RAG_def, simp) + hence "Th th1 \ Domain ((RAG s)^+)" + apply (unfold cs_dependants_def cs_RAG_def s_RAG_def) + by (auto simp:Domain_def) + hence "Th th1 \ Domain (RAG s)" by (simp add:trancl_domain) + then obtain n where d: "(Th th1, n) \ RAG s" by (auto simp:Domain_def) + from RAG_target_th [OF this] + obtain cs' where "n = Cs cs'" by auto + with d have "(Th th1, Cs cs') \ RAG s" by simp + with runing_1 have "False" + apply (unfold runing_def readys_def s_RAG_def) + by (auto simp:eq_waiting) + thus ?thesis by simp + qed + next + assume th1'_in: "th1' \ dependants (wq s) th1" + from th2_in have "th2' = th2 \ th2' \ dependants (wq s) th2" by simp + thus ?thesis + proof + assume "th2' = th2" + with th1'_in eq_th12 have "th2 \ dependants (wq s) th1" by simp + hence "(Th th2, Th th1) \ (RAG s)^+" + by (unfold cs_dependants_def s_RAG_def cs_RAG_def, simp) + hence "Th th2 \ Domain ((RAG s)^+)" + apply (unfold cs_dependants_def cs_RAG_def s_RAG_def) + by (auto simp:Domain_def) + hence "Th th2 \ Domain (RAG s)" by (simp add:trancl_domain) + then obtain n where d: "(Th th2, n) \ RAG s" by (auto simp:Domain_def) + from RAG_target_th [OF this] + obtain cs' where "n = Cs cs'" by auto + with d have "(Th th2, Cs cs') \ RAG s" by simp + with runing_2 have "False" + apply (unfold runing_def readys_def s_RAG_def) + by (auto simp:eq_waiting) + thus ?thesis by simp + next + assume "th2' \ dependants (wq s) th2" + with eq_th12 have "th1' \ dependants (wq s) th2" by simp + hence h1: "(Th th1', Th th2) \ (RAG s)^+" + by (unfold cs_dependants_def s_RAG_def cs_RAG_def, simp) + from th1'_in have h2: "(Th th1', Th th1) \ (RAG s)^+" + by (unfold cs_dependants_def s_RAG_def cs_RAG_def, simp) + show ?thesis + proof(rule dchain_unique[OF vt h1 _ h2, symmetric]) + from runing_1 show "th1 \ readys s" by (simp add:runing_def) + from runing_2 show "th2 \ readys s" by (simp add:runing_def) + qed + qed + qed +qed + + +lemma "vt s \ card (runing s) \ 1" +apply(subgoal_tac "finite (runing s)") +prefer 2 +apply (metis finite_nat_set_iff_bounded lessI runing_unique) +apply(rule ccontr) +apply(simp) +apply(case_tac "Suc (Suc 0) \ card (runing s)") +apply(subst (asm) card_le_Suc_iff) +apply(simp) +apply(auto)[1] +apply (metis insertCI runing_unique) +apply(auto) +done + +lemma create_pre: + assumes stp: "step s e" + and not_in: "th \ threads s" + and is_in: "th \ threads (e#s)" + obtains prio where "e = Create th prio" +proof - + from assms + show ?thesis + proof(cases) + case (thread_create thread prio) + with is_in not_in have "e = Create th prio" by simp + from that[OF this] show ?thesis . + next + case (thread_exit thread) + with assms show ?thesis by (auto intro!:that) + next + case (thread_P thread) + with assms show ?thesis by (auto intro!:that) + next + case (thread_V thread) + with assms show ?thesis by (auto intro!:that) + next + case (thread_set thread) + with assms show ?thesis by (auto intro!:that) + qed +qed + +lemma length_down_to_in: + assumes le_ij: "i \ j" + and le_js: "j \ length s" + shows "length (down_to j i s) = j - i" +proof - + have "length (down_to j i s) = length (from_to i j (rev s))" + by (unfold down_to_def, auto) + also have "\ = j - i" + proof(rule length_from_to_in[OF le_ij]) + from le_js show "j \ length (rev s)" by simp + qed + finally show ?thesis . +qed + + +lemma moment_head: + assumes le_it: "Suc i \ length t" + obtains e where "moment (Suc i) t = e#moment i t" +proof - + have "i \ Suc i" by simp + from length_down_to_in [OF this le_it] + have "length (down_to (Suc i) i t) = 1" by auto + then obtain e where "down_to (Suc i) i t = [e]" + apply (cases "(down_to (Suc i) i t)") by auto + moreover have "down_to (Suc i) 0 t = down_to (Suc i) i t @ down_to i 0 t" + by (rule down_to_conc[symmetric], auto) + ultimately have eq_me: "moment (Suc i) t = e#(moment i t)" + by (auto simp:down_to_moment) + from that [OF this] show ?thesis . +qed + +lemma cnp_cnv_eq: + fixes th s + assumes "vt s" + and "th \ threads s" + shows "cntP s th = cntV s th" + by (simp add: assms(1) assms(2) cnp_cnv_cncs not_thread_cncs) + +lemma eq_RAG: + "RAG (wq s) = RAG s" +by (unfold cs_RAG_def s_RAG_def, auto) + +lemma count_eq_dependants: + assumes vt: "vt s" + and eq_pv: "cntP s th = cntV s th" + shows "dependants (wq s) th = {}" +proof - + from cnp_cnv_cncs[OF vt] and eq_pv + have "cntCS s th = 0" + by (auto split:if_splits) + moreover have "finite {cs. (Cs cs, Th th) \ RAG s}" + proof - + from finite_holding[OF vt, of th] show ?thesis + by (simp add:holdents_test) + qed + ultimately have h: "{cs. (Cs cs, Th th) \ RAG s} = {}" + by (unfold cntCS_def holdents_test cs_dependants_def, auto) + show ?thesis + proof(unfold cs_dependants_def) + { assume "{th'. (Th th', Th th) \ (RAG (wq s))\<^sup>+} \ {}" + then obtain th' where "(Th th', Th th) \ (RAG (wq s))\<^sup>+" by auto + hence "False" + proof(cases) + assume "(Th th', Th th) \ RAG (wq s)" + thus "False" by (auto simp:cs_RAG_def) + next + fix c + assume "(c, Th th) \ RAG (wq s)" + with h and eq_RAG show "False" + by (cases c, auto simp:cs_RAG_def) + qed + } thus "{th'. (Th th', Th th) \ (RAG (wq s))\<^sup>+} = {}" by auto + qed +qed + +lemma dependants_threads: + fixes s th + assumes vt: "vt s" + shows "dependants (wq s) th \ threads s" +proof + { fix th th' + assume h: "th \ {th'a. (Th th'a, Th th') \ (RAG (wq s))\<^sup>+}" + have "Th th \ Domain (RAG s)" + proof - + from h obtain th' where "(Th th, Th th') \ (RAG (wq s))\<^sup>+" by auto + hence "(Th th) \ Domain ( (RAG (wq s))\<^sup>+)" by (auto simp:Domain_def) + with trancl_domain have "(Th th) \ Domain (RAG (wq s))" by simp + thus ?thesis using eq_RAG by simp + qed + from dm_RAG_threads[OF vt this] + have "th \ threads s" . + } note hh = this + fix th1 + assume "th1 \ dependants (wq s) th" + hence "th1 \ {th'a. (Th th'a, Th th) \ (RAG (wq s))\<^sup>+}" + by (unfold cs_dependants_def, simp) + from hh [OF this] show "th1 \ threads s" . +qed + +lemma finite_threads: + assumes vt: "vt s" + shows "finite (threads s)" +using vt +by (induct) (auto elim: step.cases) + +lemma Max_f_mono: + assumes seq: "A \ B" + and np: "A \ {}" + and fnt: "finite B" + shows "Max (f ` A) \ Max (f ` B)" +proof(rule Max_mono) + from seq show "f ` A \ f ` B" by auto +next + from np show "f ` A \ {}" by auto +next + from fnt and seq show "finite (f ` B)" by auto +qed + +lemma cp_le: + assumes vt: "vt s" + and th_in: "th \ threads s" + shows "cp s th \ Max ((\ th. (preced th s)) ` threads s)" +proof(unfold cp_eq_cpreced cpreced_def cs_dependants_def) + show "Max ((\th. preced th s) ` ({th} \ {th'. (Th th', Th th) \ (RAG (wq s))\<^sup>+})) + \ Max ((\th. preced th s) ` threads s)" + (is "Max (?f ` ?A) \ Max (?f ` ?B)") + proof(rule Max_f_mono) + show "{th} \ {th'. (Th th', Th th) \ (RAG (wq s))\<^sup>+} \ {}" by simp + next + from finite_threads [OF vt] + show "finite (threads s)" . + next + from th_in + show "{th} \ {th'. (Th th', Th th) \ (RAG (wq s))\<^sup>+} \ threads s" + apply (auto simp:Domain_def) + apply (rule_tac dm_RAG_threads[OF vt]) + apply (unfold trancl_domain [of "RAG s", symmetric]) + by (unfold cs_RAG_def s_RAG_def, auto simp:Domain_def) + qed +qed + +lemma le_cp: + assumes vt: "vt s" + shows "preced th s \ cp s th" +proof(unfold cp_eq_cpreced preced_def cpreced_def, simp) + show "Prc (priority th s) (last_set th s) + \ Max (insert (Prc (priority th s) (last_set th s)) + ((\th. Prc (priority th s) (last_set th s)) ` dependants (wq s) th))" + (is "?l \ Max (insert ?l ?A)") + proof(cases "?A = {}") + case False + have "finite ?A" (is "finite (?f ` ?B)") + proof - + have "finite ?B" + proof- + have "finite {th'. (Th th', Th th) \ (RAG (wq s))\<^sup>+}" + proof - + let ?F = "\ (x, y). the_th x" + have "{th'. (Th th', Th th) \ (RAG (wq s))\<^sup>+} \ ?F ` ((RAG (wq s))\<^sup>+)" + apply (auto simp:image_def) + by (rule_tac x = "(Th x, Th th)" in bexI, auto) + moreover have "finite \" + proof - + from finite_RAG[OF vt] have "finite (RAG s)" . + hence "finite ((RAG (wq s))\<^sup>+)" + apply (unfold finite_trancl) + by (auto simp: s_RAG_def cs_RAG_def wq_def) + thus ?thesis by auto + qed + ultimately show ?thesis by (auto intro:finite_subset) + qed + thus ?thesis by (simp add:cs_dependants_def) + qed + thus ?thesis by simp + qed + from Max_insert [OF this False, of ?l] show ?thesis by auto + next + case True + thus ?thesis by auto + qed +qed + +lemma max_cp_eq: + assumes vt: "vt s" + shows "Max ((cp s) ` threads s) = Max ((\ th. (preced th s)) ` threads s)" + (is "?l = ?r") +proof(cases "threads s = {}") + case True + thus ?thesis by auto +next + case False + have "?l \ ((cp s) ` threads s)" + proof(rule Max_in) + from finite_threads[OF vt] + show "finite (cp s ` threads s)" by auto + next + from False show "cp s ` threads s \ {}" by auto + qed + then obtain th + where th_in: "th \ threads s" and eq_l: "?l = cp s th" by auto + have "\ \ ?r" by (rule cp_le[OF vt th_in]) + moreover have "?r \ cp s th" (is "Max (?f ` ?A) \ cp s th") + proof - + have "?r \ (?f ` ?A)" + proof(rule Max_in) + from finite_threads[OF vt] + show " finite ((\th. preced th s) ` threads s)" by auto + next + from False show " (\th. preced th s) ` threads s \ {}" by auto + qed + then obtain th' where + th_in': "th' \ ?A " and eq_r: "?r = ?f th'" by auto + from le_cp [OF vt, of th'] eq_r + have "?r \ cp s th'" by auto + moreover have "\ \ cp s th" + proof(fold eq_l) + show " cp s th' \ Max (cp s ` threads s)" + proof(rule Max_ge) + from th_in' show "cp s th' \ cp s ` threads s" + by auto + next + from finite_threads[OF vt] + show "finite (cp s ` threads s)" by auto + qed + qed + ultimately show ?thesis by auto + qed + ultimately show ?thesis using eq_l by auto +qed + +lemma max_cp_readys_threads_pre: + assumes vt: "vt s" + and np: "threads s \ {}" + shows "Max (cp s ` readys s) = Max (cp s ` threads s)" +proof(unfold max_cp_eq[OF vt]) + show "Max (cp s ` readys s) = Max ((\th. preced th s) ` threads s)" + proof - + let ?p = "Max ((\th. preced th s) ` threads s)" + let ?f = "(\th. preced th s)" + have "?p \ ((\th. preced th s) ` threads s)" + proof(rule Max_in) + from finite_threads[OF vt] show "finite (?f ` threads s)" by simp + next + from np show "?f ` threads s \ {}" by simp + qed + then obtain tm where tm_max: "?f tm = ?p" and tm_in: "tm \ threads s" + by (auto simp:Image_def) + from th_chain_to_ready [OF vt tm_in] + have "tm \ readys s \ (\th'. th' \ readys s \ (Th tm, Th th') \ (RAG s)\<^sup>+)" . + thus ?thesis + proof + assume "\th'. th' \ readys s \ (Th tm, Th th') \ (RAG s)\<^sup>+ " + then obtain th' where th'_in: "th' \ readys s" + and tm_chain:"(Th tm, Th th') \ (RAG s)\<^sup>+" by auto + have "cp s th' = ?f tm" + proof(subst cp_eq_cpreced, subst cpreced_def, rule Max_eqI) + from dependants_threads[OF vt] finite_threads[OF vt] + show "finite ((\th. preced th s) ` ({th'} \ dependants (wq s) th'))" + by (auto intro:finite_subset) + next + fix p assume p_in: "p \ (\th. preced th s) ` ({th'} \ dependants (wq s) th')" + from tm_max have " preced tm s = Max ((\th. preced th s) ` threads s)" . + moreover have "p \ \" + proof(rule Max_ge) + from finite_threads[OF vt] + show "finite ((\th. preced th s) ` threads s)" by simp + next + from p_in and th'_in and dependants_threads[OF vt, of th'] + show "p \ (\th. preced th s) ` threads s" + by (auto simp:readys_def) + qed + ultimately show "p \ preced tm s" by auto + next + show "preced tm s \ (\th. preced th s) ` ({th'} \ dependants (wq s) th')" + proof - + from tm_chain + have "tm \ dependants (wq s) th'" + by (unfold cs_dependants_def s_RAG_def cs_RAG_def, auto) + thus ?thesis by auto + qed + qed + with tm_max + have h: "cp s th' = Max ((\th. preced th s) ` threads s)" by simp + show ?thesis + proof (fold h, rule Max_eqI) + fix q + assume "q \ cp s ` readys s" + then obtain th1 where th1_in: "th1 \ readys s" + and eq_q: "q = cp s th1" by auto + show "q \ cp s th'" + apply (unfold h eq_q) + apply (unfold cp_eq_cpreced cpreced_def) + apply (rule Max_mono) + proof - + from dependants_threads [OF vt, of th1] th1_in + show "(\th. preced th s) ` ({th1} \ dependants (wq s) th1) \ + (\th. preced th s) ` threads s" + by (auto simp:readys_def) + next + show "(\th. preced th s) ` ({th1} \ dependants (wq s) th1) \ {}" by simp + next + from finite_threads[OF vt] + show " finite ((\th. preced th s) ` threads s)" by simp + qed + next + from finite_threads[OF vt] + show "finite (cp s ` readys s)" by (auto simp:readys_def) + next + from th'_in + show "cp s th' \ cp s ` readys s" by simp + qed + next + assume tm_ready: "tm \ readys s" + show ?thesis + proof(fold tm_max) + have cp_eq_p: "cp s tm = preced tm s" + proof(unfold cp_eq_cpreced cpreced_def, rule Max_eqI) + fix y + assume hy: "y \ (\th. preced th s) ` ({tm} \ dependants (wq s) tm)" + show "y \ preced tm s" + proof - + { fix y' + assume hy' : "y' \ ((\th. preced th s) ` dependants (wq s) tm)" + have "y' \ preced tm s" + proof(unfold tm_max, rule Max_ge) + from hy' dependants_threads[OF vt, of tm] + show "y' \ (\th. preced th s) ` threads s" by auto + next + from finite_threads[OF vt] + show "finite ((\th. preced th s) ` threads s)" by simp + qed + } with hy show ?thesis by auto + qed + next + from dependants_threads[OF vt, of tm] finite_threads[OF vt] + show "finite ((\th. preced th s) ` ({tm} \ dependants (wq s) tm))" + by (auto intro:finite_subset) + next + show "preced tm s \ (\th. preced th s) ` ({tm} \ dependants (wq s) tm)" + by simp + qed + moreover have "Max (cp s ` readys s) = cp s tm" + proof(rule Max_eqI) + from tm_ready show "cp s tm \ cp s ` readys s" by simp + next + from finite_threads[OF vt] + show "finite (cp s ` readys s)" by (auto simp:readys_def) + next + fix y assume "y \ cp s ` readys s" + then obtain th1 where th1_readys: "th1 \ readys s" + and h: "y = cp s th1" by auto + show "y \ cp s tm" + apply(unfold cp_eq_p h) + apply(unfold cp_eq_cpreced cpreced_def tm_max, rule Max_mono) + proof - + from finite_threads[OF vt] + show "finite ((\th. preced th s) ` threads s)" by simp + next + show "(\th. preced th s) ` ({th1} \ dependants (wq s) th1) \ {}" + by simp + next + from dependants_threads[OF vt, of th1] th1_readys + show "(\th. preced th s) ` ({th1} \ dependants (wq s) th1) + \ (\th. preced th s) ` threads s" + by (auto simp:readys_def) + qed + qed + ultimately show " Max (cp s ` readys s) = preced tm s" by simp + qed + qed + qed +qed + +text {* (* ccc *) \noindent + Since the current precedence of the threads in ready queue will always be boosted, + there must be one inside it has the maximum precedence of the whole system. +*} +lemma max_cp_readys_threads: + assumes vt: "vt s" + shows "Max (cp s ` readys s) = Max (cp s ` threads s)" +proof(cases "threads s = {}") + case True + thus ?thesis + by (auto simp:readys_def) +next + case False + show ?thesis by (rule max_cp_readys_threads_pre[OF vt False]) +qed + + +lemma eq_holding: "holding (wq s) th cs = holding s th cs" + apply (unfold s_holding_def cs_holding_def wq_def, simp) + done + +lemma f_image_eq: + assumes h: "\ a. a \ A \ f a = g a" + shows "f ` A = g ` A" +proof + show "f ` A \ g ` A" + by(rule image_subsetI, auto intro:h) +next + show "g ` A \ f ` A" + by (rule image_subsetI, auto intro:h[symmetric]) +qed + + +definition detached :: "state \ thread \ bool" + where "detached s th \ (\(\ cs. holding s th cs)) \ (\(\cs. waiting s th cs))" + + +lemma detached_test: + shows "detached s th = (Th th \ Field (RAG s))" +apply(simp add: detached_def Field_def) +apply(simp add: s_RAG_def) +apply(simp add: s_holding_abv s_waiting_abv) +apply(simp add: Domain_iff Range_iff) +apply(simp add: wq_def) +apply(auto) +done + +lemma detached_intro: + fixes s th + assumes vt: "vt s" + and eq_pv: "cntP s th = cntV s th" + shows "detached s th" +proof - + from cnp_cnv_cncs[OF vt] + have eq_cnt: "cntP s th = + cntV s th + (if th \ readys s \ th \ threads s then cntCS s th else cntCS s th + 1)" . + hence cncs_zero: "cntCS s th = 0" + by (auto simp:eq_pv split:if_splits) + with eq_cnt + have "th \ readys s \ th \ threads s" by (auto simp:eq_pv) + thus ?thesis + proof + assume "th \ threads s" + with range_in[OF vt] dm_RAG_threads[OF vt] + show ?thesis + by (auto simp add: detached_def s_RAG_def s_waiting_abv s_holding_abv wq_def Domain_iff Range_iff) + next + assume "th \ readys s" + moreover have "Th th \ Range (RAG s)" + proof - + from card_0_eq [OF finite_holding [OF vt]] and cncs_zero + have "holdents s th = {}" + by (simp add:cntCS_def) + thus ?thesis + apply(auto simp:holdents_test) + apply(case_tac a) + apply(auto simp:holdents_test s_RAG_def) + done + qed + ultimately show ?thesis + by (auto simp add: detached_def s_RAG_def s_waiting_abv s_holding_abv wq_def readys_def) + qed +qed + +lemma detached_elim: + fixes s th + assumes vt: "vt s" + and dtc: "detached s th" + shows "cntP s th = cntV s th" +proof - + from cnp_cnv_cncs[OF vt] + have eq_pv: " cntP s th = + cntV s th + (if th \ readys s \ th \ threads s then cntCS s th else cntCS s th + 1)" . + have cncs_z: "cntCS s th = 0" + proof - + from dtc have "holdents s th = {}" + unfolding detached_def holdents_test s_RAG_def + by (simp add: s_waiting_abv wq_def s_holding_abv Domain_iff Range_iff) + thus ?thesis by (auto simp:cntCS_def) + qed + show ?thesis + proof(cases "th \ threads s") + case True + with dtc + have "th \ readys s" + by (unfold readys_def detached_def Field_def Domain_def Range_def, + auto simp:eq_waiting s_RAG_def) + with cncs_z and eq_pv show ?thesis by simp + next + case False + with cncs_z and eq_pv show ?thesis by simp + qed +qed + +lemma detached_eq: + fixes s th + assumes vt: "vt s" + shows "(detached s th) = (cntP s th = cntV s th)" + by (insert vt, auto intro:detached_intro detached_elim) + +text {* + The lemmas in this .thy file are all obvious lemmas, however, they still needs to be derived + from the concise and miniature model of PIP given in PrioGDef.thy. +*} + +end