X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=formal-model%2Furcu-controldataflow%2Furcu.spin;h=b3290589324e50904d045b54deeb0c95970c946f;hb=6af482a9e24a5ee17eef220b25a050be5df8aa39;hp=484205a1dd999a9fd6c97f214e964b9aa2a884ff;hpb=19d8de31dc92430df89d90e8ba76212b764afd44;p=urcu.git diff --git a/formal-model/urcu-controldataflow/urcu.spin b/formal-model/urcu-controldataflow/urcu.spin index 484205a..b329058 100644 --- a/formal-model/urcu-controldataflow/urcu.spin +++ b/formal-model/urcu-controldataflow/urcu.spin @@ -213,7 +213,14 @@ inline smp_rmb(i, j) i++ :: i >= NR_READERS -> break od; - CACHE_READ_FROM_MEM(generation_ptr, get_pid()); + CACHE_READ_FROM_MEM(rcu_ptr, get_pid()); + i = 0; + do + :: i < SLAB_SIZE -> + CACHE_READ_FROM_MEM(rcu_data[i], get_pid()); + i++ + :: i >= SLAB_SIZE -> break + od; } } @@ -229,7 +236,14 @@ inline smp_wmb(i, j) i++ :: i >= NR_READERS -> break od; - CACHE_WRITE_TO_MEM(generation_ptr, get_pid()); + CACHE_WRITE_TO_MEM(rcu_ptr, get_pid()); + i = 0; + do + :: i < SLAB_SIZE -> + CACHE_WRITE_TO_MEM(rcu_data[i], get_pid()); + i++ + :: i >= SLAB_SIZE -> break + od; } } @@ -243,7 +257,6 @@ inline smp_mb(i, j) } } - #ifdef REMOTE_BARRIERS bit reader_barrier[NR_READERS]; @@ -269,55 +282,80 @@ inline smp_mb_recv(i, j) :: (reader_barrier[get_readerid()] == 1) -> smp_mb(i, j); reader_barrier[get_readerid()] = 0; - :: 1 -> skip; - :: 1 -> break; + :: 1 -> + /* + * Busy-looping waiting for other barrier requests is not considered as + * non-progress. + */ +#ifdef READER_PROGRESS +progress_reader2: +#endif +#ifdef WRITER_PROGRESS +//progress_writer_from_reader1: +#endif + skip; + :: 1 -> + /* We choose to ignore writer's non-progress caused from the + * reader ignoring the writer's mb() requests */ +#ifdef WRITER_PROGRESS +//progress_writer_from_reader2: +#endif + break; od; } -inline smp_mb_send(i, j) -{ - smp_mb(i, j); - i = 0; - do - :: i < NR_READERS -> - reader_barrier[i] = 1; - do - :: (reader_barrier[i] == 1) -> skip; - :: (reader_barrier[i] == 0) -> break; - od; - i++; - :: i >= NR_READERS -> - break - od; - smp_mb(i, j); +#ifdef WRITER_PROGRESS +#define PROGRESS_LABEL(progressid) progress_writer_progid_##progressid: +#else +#define PROGRESS_LABEL(progressid) +#endif + +#define smp_mb_send(i, j, progressid) \ +{ \ + smp_mb(i, j); \ + i = 0; \ + do \ + :: i < NR_READERS -> \ + reader_barrier[i] = 1; \ + /* \ + * Busy-looping waiting for reader barrier handling is of little\ + * interest, given the reader has the ability to totally ignore \ + * barrier requests. \ + */ \ +PROGRESS_LABEL(progressid) \ + do \ + :: (reader_barrier[i] == 1) -> skip; \ + :: (reader_barrier[i] == 0) -> break; \ + od; \ + i++; \ + :: i >= NR_READERS -> \ + break \ + od; \ + smp_mb(i, j); \ } #else -#define smp_mb_send smp_mb +#define smp_mb_send(i, j, progressid) smp_mb(i, j) #define smp_mb_reader smp_mb #define smp_mb_recv(i, j) #endif -/* Keep in sync manually with smp_rmb, wmp_wmb, ooo_mem and init() */ +/* Keep in sync manually with smp_rmb, smp_wmb, ooo_mem and init() */ DECLARE_CACHED_VAR(byte, urcu_gp_ctr); /* Note ! currently only two readers */ DECLARE_CACHED_VAR(byte, urcu_active_readers[NR_READERS]); -/* pointer generation */ -DECLARE_CACHED_VAR(byte, generation_ptr); - -byte last_free_gen = 0; -bit free_done = 0; -byte read_generation[NR_READERS]; -bit data_access[NR_READERS]; +/* RCU pointer */ +DECLARE_CACHED_VAR(byte, rcu_ptr); +/* RCU data */ +DECLARE_CACHED_VAR(byte, rcu_data[2]); -bit write_lock = 0; +byte ptr_read[NR_READERS]; +byte data_read[NR_READERS]; bit init_done = 0; -bit sighand_exec = 0; - inline wait_init_done() { do @@ -338,7 +376,14 @@ inline ooo_mem(i) i++ :: i >= NR_READERS -> break od; - RANDOM_CACHE_WRITE_TO_MEM(generation_ptr, get_pid()); + RANDOM_CACHE_WRITE_TO_MEM(rcu_ptr, get_pid()); + i = 0; + do + :: i < SLAB_SIZE -> + RANDOM_CACHE_WRITE_TO_MEM(rcu_data[i], get_pid()); + i++ + :: i >= SLAB_SIZE -> break + od; RANDOM_CACHE_READ_FROM_MEM(urcu_gp_ctr, get_pid()); i = 0; do @@ -348,7 +393,14 @@ inline ooo_mem(i) i++ :: i >= NR_READERS -> break od; - RANDOM_CACHE_READ_FROM_MEM(generation_ptr, get_pid()); + RANDOM_CACHE_READ_FROM_MEM(rcu_ptr, get_pid()); + i = 0; + do + :: i < SLAB_SIZE -> + RANDOM_CACHE_READ_FROM_MEM(rcu_data[i], get_pid()); + i++ + :: i >= SLAB_SIZE -> break + od; } } @@ -592,7 +644,7 @@ non_atomic3_end: goto non_atomic3_skip; non_atomic3: - smp_mb_recv(i, j); + smp_mb_recv(i, j); goto non_atomic3_end; non_atomic3_skip: @@ -615,17 +667,19 @@ non_atomic3_skip: READ_PROC_FIRST_MB, /* mb() orders reads */ READ_PROC_READ_GEN) -> ooo_mem(i); - read_generation[get_readerid()] = - READ_CACHED_VAR(generation_ptr); + ptr_read[get_readerid()] = + READ_CACHED_VAR(rcu_ptr); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_READ_GEN); :: CONSUME_TOKENS(proc_urcu_reader, READ_PROC_FIRST_MB /* mb() orders reads */ | READ_PROC_READ_GEN, READ_PROC_ACCESS_GEN) -> - ooo_mem(i); - goto non_atomic; -non_atomic_end: + /* smp_read_barrier_depends */ + goto rmb1; +rmb1_end: + data_read[get_readerid()] = + READ_CACHED_VAR(rcu_data[ptr_read[get_readerid()]]); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_ACCESS_GEN); @@ -692,8 +746,7 @@ non_atomic_end: | READ_PROC_THIRD_MB, /* mb() orders reads */ READ_PROC_READ_GEN_UNROLL) -> ooo_mem(i); - read_generation[get_readerid()] = - READ_CACHED_VAR(generation_ptr); + ptr_read[get_readerid()] = READ_CACHED_VAR(rcu_ptr); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_READ_GEN_UNROLL); :: CONSUME_TOKENS(proc_urcu_reader, @@ -702,9 +755,11 @@ non_atomic_end: | READ_PROC_SECOND_MB /* mb() orders reads */ | READ_PROC_THIRD_MB, /* mb() orders reads */ READ_PROC_ACCESS_GEN_UNROLL) -> - ooo_mem(i); - goto non_atomic2; -non_atomic2_end: + /* smp_read_barrier_depends */ + goto rmb2; +rmb2_end: + data_read[get_readerid()] = + READ_CACHED_VAR(rcu_data[ptr_read[get_readerid()]]); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_ACCESS_GEN_UNROLL); :: CONSUME_TOKENS(proc_urcu_reader, @@ -752,14 +807,20 @@ non_atomic2_end: * to spill its execution on other loop's execution. */ goto end; -non_atomic: - data_access[get_readerid()] = 1; - data_access[get_readerid()] = 0; - goto non_atomic_end; -non_atomic2: - data_access[get_readerid()] = 1; - data_access[get_readerid()] = 0; - goto non_atomic2_end; +rmb1: +#ifndef NO_RMB + smp_rmb(i, j); +#else + ooo_mem(); +#endif + goto rmb1_end; +rmb2: +#ifndef NO_RMB + smp_rmb(i, j); +#else + ooo_mem(); +#endif + goto rmb2_end; end: skip; } @@ -836,40 +897,48 @@ int _proc_urcu_writer; #define WRITE_PROC_ALL_TOKENS_CLEAR ((1 << 11) - 1) +/* + * Mutexes are implied around writer execution. A single writer at a time. + */ active proctype urcu_writer() { byte i, j; byte tmp, tmp2, tmpa; - byte old_gen; + byte cur_data = 0, old_data, loop_nr = 0; + byte cur_gp_val = 0; /* + * Keep a local trace of the current parity so + * we don't add non-existing dependencies on the global + * GP update. Needed to test single flip case. + */ wait_init_done(); assert(get_pid() < NR_PROCS); do - :: (READ_CACHED_VAR(generation_ptr) < 5) -> + :: (loop_nr < 3) -> #ifdef WRITER_PROGRESS progress_writer1: #endif + loop_nr = loop_nr + 1; + + /* TODO : add instruction scheduling to this code path to test + * missing wmb effect. */ + /* smp_wmb() ensures order of the following instructions */ + /* malloc */ + cur_data = (cur_data + 1) % SLAB_SIZE; ooo_mem(i); - atomic { - old_gen = READ_CACHED_VAR(generation_ptr); - WRITE_CACHED_VAR(generation_ptr, old_gen + 1); - } + WRITE_CACHED_VAR(rcu_data[cur_data], WINE); +#ifndef NO_WMB + smp_wmb(i, j); +#else + ooo_mem(i); +#endif + old_data = READ_CACHED_VAR(rcu_ptr); + ooo_mem(i); + WRITE_CACHED_VAR(rcu_ptr, cur_data); /* rcu_assign_pointer() */ ooo_mem(i); - do - :: 1 -> - atomic { - if - :: write_lock == 0 -> - write_lock = 1; - break; - :: else -> - skip; - fi; - } - od; PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROD_NONE); @@ -882,13 +951,18 @@ progress_writer1: PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_READ_GP); PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WRITE_GP); PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WAIT); + /* For single flip, we need to know the current parity */ + cur_gp_val = cur_gp_val ^ RCU_GP_CTR_BIT; #endif - do + do :: 1 -> + atomic { + if :: CONSUME_TOKENS(proc_urcu_writer, WRITE_PROD_NONE, WRITE_PROC_FIRST_MB) -> - smp_mb_send(i, j); + goto smp_mb_send1; +smp_mb_send1_end: PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_MB); /* first flip */ @@ -911,9 +985,15 @@ progress_writer1: ooo_mem(i); /* ONLY WAITING FOR READER 0 */ tmp2 = READ_CACHED_VAR(urcu_active_readers[0]); +#ifndef SINGLE_FLIP + /* In normal execution, we are always starting by + * waiting for the even parity. + */ + cur_gp_val = RCU_GP_CTR_BIT; +#endif if :: (tmp2 & RCU_GP_CTR_NEST_MASK) - && ((tmp2 ^ RCU_GP_CTR_BIT) & RCU_GP_CTR_BIT) -> + && ((tmp2 ^ cur_gp_val) & RCU_GP_CTR_BIT) -> PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_WAIT_LOOP); :: else -> PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_WAIT); @@ -927,7 +1007,8 @@ progress_writer1: | WRITE_PROC_FIRST_MB, /* can be reordered before/after flips */ 0) -> #ifndef GEN_ERROR_WRITER_PROGRESS - smp_mb_send(i, j); + goto smp_mb_send2; +smp_mb_send2_end: #else ooo_mem(i); #endif @@ -942,7 +1023,6 @@ progress_writer1: | WRITE_PROC_FIRST_READ_GP | WRITE_PROC_FIRST_MB, WRITE_PROC_SECOND_READ_GP) -> - //smp_mb_send(i, j); //TEST ooo_mem(i); tmpa = READ_CACHED_VAR(urcu_gp_ctr); PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_READ_GP); @@ -982,7 +1062,8 @@ progress_writer1: | WRITE_PROC_FIRST_MB, /* can be reordered before/after flips */ 0) -> #ifndef GEN_ERROR_WRITER_PROGRESS - smp_mb_send(i, j); + goto smp_mb_send3; +smp_mb_send3_end: #else ooo_mem(i); #endif @@ -999,20 +1080,19 @@ progress_writer1: | WRITE_PROC_SECOND_WRITE_GP | WRITE_PROC_FIRST_MB, WRITE_PROC_SECOND_MB) -> - smp_mb_send(i, j); + goto smp_mb_send4; +smp_mb_send4_end: PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_MB); :: CONSUME_TOKENS(proc_urcu_writer, WRITE_PROC_ALL_TOKENS, 0) -> CLEAR_TOKENS(proc_urcu_writer, WRITE_PROC_ALL_TOKENS_CLEAR); break; + fi; + } od; - write_lock = 0; - /* free-up step, e.g., kfree(). */ - atomic { - last_free_gen = old_gen; - free_done = 1; - } + WRITE_CACHED_VAR(rcu_data[old_data], POISON); + :: else -> break; od; /* @@ -1028,6 +1108,25 @@ progress_writer2: #endif skip; od; + + /* Non-atomic parts of the loop */ + goto end; +smp_mb_send1: + smp_mb_send(i, j, 1); + goto smp_mb_send1_end; +#ifndef GEN_ERROR_WRITER_PROGRESS +smp_mb_send2: + smp_mb_send(i, j, 2); + goto smp_mb_send2_end; +smp_mb_send3: + smp_mb_send(i, j, 3); + goto smp_mb_send3_end; +#endif +smp_mb_send4: + smp_mb_send(i, j, 4); + goto smp_mb_send4_end; +end: + skip; } /* no name clash please */ @@ -1040,17 +1139,25 @@ init { atomic { INIT_CACHED_VAR(urcu_gp_ctr, 1, j); - INIT_CACHED_VAR(generation_ptr, 0, j); + INIT_CACHED_VAR(rcu_ptr, 0, j); i = 0; do :: i < NR_READERS -> INIT_CACHED_VAR(urcu_active_readers[i], 0, j); - read_generation[i] = 1; - data_access[i] = 0; + data_read[i] = 0; i++; :: i >= NR_READERS -> break od; + INIT_CACHED_VAR(rcu_data[0], WINE, j); + i = 1; + do + :: i < SLAB_SIZE -> + INIT_CACHED_VAR(rcu_data[i], POISON, j); + i++ + :: i >= SLAB_SIZE -> break + od; + init_done = 1; } }