#define NO_MB // Poison value for freed memory #define POISON 1 // Memory with correct data #define WINE 0 #define SLAB_SIZE 2 #define read_poison (data_read_first[0] == POISON || data_read_second[0] == POISON) #define RCU_GP_CTR_BIT (1 << 7) #define RCU_GP_CTR_NEST_MASK (RCU_GP_CTR_BIT - 1) //disabled #define REMOTE_BARRIERS #define ARCH_ALPHA //#define ARCH_INTEL //#define ARCH_POWERPC /* * mem.spin: Promela code to validate memory barriers with OOO memory * and out-of-order instruction scheduling. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Copyright (c) 2009 Mathieu Desnoyers */ /* Promela validation variables. */ /* specific defines "included" here */ /* DEFINES file "included" here */ #define NR_READERS 1 #define NR_WRITERS 1 #define NR_PROCS 2 #define get_pid() (_pid) #define get_readerid() (get_pid()) /* * Produced process control and data flow. Updated after each instruction to * show which variables are ready. Using one-hot bit encoding per variable to * save state space. Used as triggers to execute the instructions having those * variables as input. Leaving bits active to inhibit instruction execution. * Scheme used to make instruction disabling and automatic dependency fall-back * automatic. */ #define CONSUME_TOKENS(state, bits, notbits) \ ((!(state & (notbits))) && (state & (bits)) == (bits)) #define PRODUCE_TOKENS(state, bits) \ state = state | (bits); #define CLEAR_TOKENS(state, bits) \ state = state & ~(bits) /* * Types of dependency : * * Data dependency * * - True dependency, Read-after-Write (RAW) * * This type of dependency happens when a statement depends on the result of a * previous statement. This applies to any statement which needs to read a * variable written by a preceding statement. * * - False dependency, Write-after-Read (WAR) * * Typically, variable renaming can ensure that this dependency goes away. * However, if the statements must read and then write from/to the same variable * in the OOO memory model, renaming may be impossible, and therefore this * causes a WAR dependency. * * - Output dependency, Write-after-Write (WAW) * * Two writes to the same variable in subsequent statements. Variable renaming * can ensure this is not needed, but can be required when writing multiple * times to the same OOO mem model variable. * * Control dependency * * Execution of a given instruction depends on a previous instruction evaluating * in a way that allows its execution. E.g. : branches. * * Useful considerations for joining dependencies after branch * * - Pre-dominance * * "We say box i dominates box j if every path (leading from input to output * through the diagram) which passes through box j must also pass through box * i. Thus box i dominates box j if box j is subordinate to box i in the * program." * * http://www.hipersoft.rice.edu/grads/publications/dom14.pdf * Other classic algorithm to calculate dominance : Lengauer-Tarjan (in gcc) * * - Post-dominance * * Just as pre-dominance, but with arcs of the data flow inverted, and input vs * output exchanged. Therefore, i post-dominating j ensures that every path * passing by j will pass by i before reaching the output. * * Prefetch and speculative execution * * If an instruction depends on the result of a previous branch, but it does not * have side-effects, it can be executed before the branch result is known. * however, it must be restarted if a core-synchronizing instruction is issued. * Note that instructions which depend on the speculative instruction result * but that have side-effects must depend on the branch completion in addition * to the speculatively executed instruction. * * Other considerations * * Note about "volatile" keyword dependency : The compiler will order volatile * accesses so they appear in the right order on a given CPU. They can be * reordered by the CPU instruction scheduling. This therefore cannot be * considered as a depencency. * * References : * * Cooper, Keith D.; & Torczon, Linda. (2005). Engineering a Compiler. Morgan * Kaufmann. ISBN 1-55860-698-X. * Kennedy, Ken; & Allen, Randy. (2001). Optimizing Compilers for Modern * Architectures: A Dependence-based Approach. Morgan Kaufmann. ISBN * 1-55860-286-0. * Muchnick, Steven S. (1997). Advanced Compiler Design and Implementation. * Morgan Kaufmann. ISBN 1-55860-320-4. */ /* * Note about loops and nested calls * * To keep this model simple, loops expressed in the framework will behave as if * there was a core synchronizing instruction between loops. To see the effect * of loop unrolling, manually unrolling loops is required. Note that if loops * end or start with a core synchronizing instruction, the model is appropriate. * Nested calls are not supported. */ /* * Only Alpha has out-of-order cache bank loads. Other architectures (intel, * powerpc, arm) ensure that dependent reads won't be reordered. c.f. * http://www.linuxjournal.com/article/8212) */ #ifdef ARCH_ALPHA #define HAVE_OOO_CACHE_READ #endif /* * Each process have its own data in cache. Caches are randomly updated. * smp_wmb and smp_rmb forces cache updates (write and read), smp_mb forces * both. */ typedef per_proc_byte { byte val[NR_PROCS]; }; typedef per_proc_bit { bit val[NR_PROCS]; }; /* Bitfield has a maximum of 8 procs */ typedef per_proc_bitfield { byte bitfield; }; #define DECLARE_CACHED_VAR(type, x) \ type mem_##x; #define DECLARE_PROC_CACHED_VAR(type, x)\ type cached_##x; \ bit cache_dirty_##x; #define INIT_CACHED_VAR(x, v) \ mem_##x = v; #define INIT_PROC_CACHED_VAR(x, v) \ cache_dirty_##x = 0; \ cached_##x = v; #define IS_CACHE_DIRTY(x, id) (cache_dirty_##x) #define READ_CACHED_VAR(x) (cached_##x) #define WRITE_CACHED_VAR(x, v) \ atomic { \ cached_##x = v; \ cache_dirty_##x = 1; \ } #define CACHE_WRITE_TO_MEM(x, id) \ if \ :: IS_CACHE_DIRTY(x, id) -> \ mem_##x = cached_##x; \ cache_dirty_##x = 0; \ :: else -> \ skip \ fi; #define CACHE_READ_FROM_MEM(x, id) \ if \ :: !IS_CACHE_DIRTY(x, id) -> \ cached_##x = mem_##x; \ :: else -> \ skip \ fi; /* * May update other caches if cache is dirty, or not. */ #define RANDOM_CACHE_WRITE_TO_MEM(x, id)\ if \ :: 1 -> CACHE_WRITE_TO_MEM(x, id); \ :: 1 -> skip \ fi; #define RANDOM_CACHE_READ_FROM_MEM(x, id)\ if \ :: 1 -> CACHE_READ_FROM_MEM(x, id); \ :: 1 -> skip \ fi; /* Must consume all prior read tokens. All subsequent reads depend on it. */ inline smp_rmb(i) { atomic { CACHE_READ_FROM_MEM(urcu_gp_ctr, get_pid()); i = 0; do :: i < NR_READERS -> CACHE_READ_FROM_MEM(urcu_active_readers[i], get_pid()); i++ :: i >= NR_READERS -> break od; 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; } } /* Must consume all prior write tokens. All subsequent writes depend on it. */ inline smp_wmb(i) { atomic { CACHE_WRITE_TO_MEM(urcu_gp_ctr, get_pid()); i = 0; do :: i < NR_READERS -> CACHE_WRITE_TO_MEM(urcu_active_readers[i], get_pid()); i++ :: i >= NR_READERS -> break od; 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; } } /* Synchronization point. Must consume all prior read and write tokens. All * subsequent reads and writes depend on it. */ inline smp_mb(i) { atomic { smp_wmb(i); smp_rmb(i); } } #ifdef REMOTE_BARRIERS bit reader_barrier[NR_READERS]; /* * We cannot leave the barriers dependencies in place in REMOTE_BARRIERS mode * because they would add unexisting core synchronization and would therefore * create an incomplete model. * Therefore, we model the read-side memory barriers by completely disabling the * memory barriers and their dependencies from the read-side. One at a time * (different verification runs), we make a different instruction listen for * signals. */ #define smp_mb_reader(i, j) /* * Service 0, 1 or many barrier requests. */ inline smp_mb_recv(i, j) { do :: (reader_barrier[get_readerid()] == 1) -> /* * We choose to ignore cycles caused by writer busy-looping, * waiting for the reader, sending barrier requests, and the * reader always services them without continuing execution. */ progress_ignoring_mb1: smp_mb(i); reader_barrier[get_readerid()] = 0; :: 1 -> /* * We choose to ignore writer's non-progress caused by the * reader ignoring the writer's mb() requests. */ progress_ignoring_mb2: break; od; } #define PROGRESS_LABEL(progressid) progress_writer_progid_##progressid: #define smp_mb_send(i, j, progressid) \ { \ smp_mb(i); \ 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. \ */ \ do \ :: (reader_barrier[i] == 1) -> \ PROGRESS_LABEL(progressid) \ skip; \ :: (reader_barrier[i] == 0) -> break; \ od; \ i++; \ :: i >= NR_READERS -> \ break \ od; \ smp_mb(i); \ } #else #define smp_mb_send(i, j, progressid) smp_mb(i) #define smp_mb_reader(i, j) smp_mb(i) #define smp_mb_recv(i, j) #endif /* Keep in sync manually with smp_rmb, smp_wmb, ooo_mem and init() */ DECLARE_CACHED_VAR(byte, urcu_gp_ctr); /* Note ! currently only one reader */ DECLARE_CACHED_VAR(byte, urcu_active_readers[NR_READERS]); /* RCU data */ DECLARE_CACHED_VAR(bit, rcu_data[SLAB_SIZE]); /* RCU pointer */ #if (SLAB_SIZE == 2) DECLARE_CACHED_VAR(bit, rcu_ptr); bit ptr_read_first[NR_READERS]; bit ptr_read_second[NR_READERS]; #else DECLARE_CACHED_VAR(byte, rcu_ptr); byte ptr_read_first[NR_READERS]; byte ptr_read_second[NR_READERS]; #endif bit data_read_first[NR_READERS]; bit data_read_second[NR_READERS]; bit init_done = 0; inline wait_init_done() { do :: init_done == 0 -> skip; :: else -> break; od; } inline ooo_mem(i) { atomic { RANDOM_CACHE_WRITE_TO_MEM(urcu_gp_ctr, get_pid()); i = 0; do :: i < NR_READERS -> RANDOM_CACHE_WRITE_TO_MEM(urcu_active_readers[i], get_pid()); i++ :: i >= NR_READERS -> break od; 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; #ifdef HAVE_OOO_CACHE_READ RANDOM_CACHE_READ_FROM_MEM(urcu_gp_ctr, get_pid()); i = 0; do :: i < NR_READERS -> RANDOM_CACHE_READ_FROM_MEM(urcu_active_readers[i], get_pid()); i++ :: i >= NR_READERS -> break od; 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; #else smp_rmb(i); #endif /* HAVE_OOO_CACHE_READ */ } } /* * Bit encoding, urcu_reader : */ int _proc_urcu_reader; #define proc_urcu_reader _proc_urcu_reader /* Body of PROCEDURE_READ_LOCK */ #define READ_PROD_A_READ (1 << 0) #define READ_PROD_B_IF_TRUE (1 << 1) #define READ_PROD_B_IF_FALSE (1 << 2) #define READ_PROD_C_IF_TRUE_READ (1 << 3) #define PROCEDURE_READ_LOCK(base, consumetoken, consumetoken2, producetoken) \ :: CONSUME_TOKENS(proc_urcu_reader, (consumetoken | consumetoken2), READ_PROD_A_READ << base) -> \ ooo_mem(i); \ tmp = READ_CACHED_VAR(urcu_active_readers[get_readerid()]); \ PRODUCE_TOKENS(proc_urcu_reader, READ_PROD_A_READ << base); \ :: CONSUME_TOKENS(proc_urcu_reader, \ READ_PROD_A_READ << base, /* RAW, pre-dominant */ \ (READ_PROD_B_IF_TRUE | READ_PROD_B_IF_FALSE) << base) -> \ if \ :: (!(tmp & RCU_GP_CTR_NEST_MASK)) -> \ PRODUCE_TOKENS(proc_urcu_reader, READ_PROD_B_IF_TRUE << base); \ :: else -> \ PRODUCE_TOKENS(proc_urcu_reader, READ_PROD_B_IF_FALSE << base); \ fi; \ /* IF TRUE */ \ :: CONSUME_TOKENS(proc_urcu_reader, consumetoken, /* prefetch */ \ READ_PROD_C_IF_TRUE_READ << base) -> \ ooo_mem(i); \ tmp2 = READ_CACHED_VAR(urcu_gp_ctr); \ PRODUCE_TOKENS(proc_urcu_reader, READ_PROD_C_IF_TRUE_READ << base); \ :: CONSUME_TOKENS(proc_urcu_reader, \ (READ_PROD_B_IF_TRUE \ | READ_PROD_C_IF_TRUE_READ /* pre-dominant */ \ | READ_PROD_A_READ) << base, /* WAR */ \ producetoken) -> \ ooo_mem(i); \ WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], tmp2); \ PRODUCE_TOKENS(proc_urcu_reader, producetoken); \ /* IF_MERGE implies \ * post-dominance */ \ /* ELSE */ \ :: CONSUME_TOKENS(proc_urcu_reader, \ (READ_PROD_B_IF_FALSE /* pre-dominant */ \ | READ_PROD_A_READ) << base, /* WAR */ \ producetoken) -> \ ooo_mem(i); \ WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], \ tmp + 1); \ PRODUCE_TOKENS(proc_urcu_reader, producetoken); \ /* IF_MERGE implies \ * post-dominance */ \ /* ENDIF */ \ skip /* Body of PROCEDURE_READ_LOCK */ #define READ_PROC_READ_UNLOCK (1 << 0) #define PROCEDURE_READ_UNLOCK(base, consumetoken, producetoken) \ :: CONSUME_TOKENS(proc_urcu_reader, \ consumetoken, \ READ_PROC_READ_UNLOCK << base) -> \ ooo_mem(i); \ tmp = READ_CACHED_VAR(urcu_active_readers[get_readerid()]); \ PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_READ_UNLOCK << base); \ :: CONSUME_TOKENS(proc_urcu_reader, \ consumetoken \ | (READ_PROC_READ_UNLOCK << base), /* WAR */ \ producetoken) -> \ ooo_mem(i); \ WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], tmp - 1); \ PRODUCE_TOKENS(proc_urcu_reader, producetoken); \ skip #define READ_PROD_NONE (1 << 0) /* PROCEDURE_READ_LOCK base = << 1 : 1 to 5 */ #define READ_LOCK_BASE 1 #define READ_LOCK_OUT (1 << 5) #define READ_PROC_FIRST_MB (1 << 6) /* PROCEDURE_READ_LOCK (NESTED) base : << 7 : 7 to 11 */ #define READ_LOCK_NESTED_BASE 7 #define READ_LOCK_NESTED_OUT (1 << 11) #define READ_PROC_READ_GEN (1 << 12) #define READ_PROC_ACCESS_GEN (1 << 13) /* PROCEDURE_READ_UNLOCK (NESTED) base = << 14 : 14 to 15 */ #define READ_UNLOCK_NESTED_BASE 14 #define READ_UNLOCK_NESTED_OUT (1 << 15) #define READ_PROC_SECOND_MB (1 << 16) /* PROCEDURE_READ_UNLOCK base = << 17 : 17 to 18 */ #define READ_UNLOCK_BASE 17 #define READ_UNLOCK_OUT (1 << 18) /* PROCEDURE_READ_LOCK_UNROLL base = << 19 : 19 to 23 */ #define READ_LOCK_UNROLL_BASE 19 #define READ_LOCK_OUT_UNROLL (1 << 23) #define READ_PROC_THIRD_MB (1 << 24) #define READ_PROC_READ_GEN_UNROLL (1 << 25) #define READ_PROC_ACCESS_GEN_UNROLL (1 << 26) #define READ_PROC_FOURTH_MB (1 << 27) /* PROCEDURE_READ_UNLOCK_UNROLL base = << 28 : 28 to 29 */ #define READ_UNLOCK_UNROLL_BASE 28 #define READ_UNLOCK_OUT_UNROLL (1 << 29) /* Should not include branches */ #define READ_PROC_ALL_TOKENS (READ_PROD_NONE \ | READ_LOCK_OUT \ | READ_PROC_FIRST_MB \ | READ_LOCK_NESTED_OUT \ | READ_PROC_READ_GEN \ | READ_PROC_ACCESS_GEN \ | READ_UNLOCK_NESTED_OUT \ | READ_PROC_SECOND_MB \ | READ_UNLOCK_OUT \ | READ_LOCK_OUT_UNROLL \ | READ_PROC_THIRD_MB \ | READ_PROC_READ_GEN_UNROLL \ | READ_PROC_ACCESS_GEN_UNROLL \ | READ_PROC_FOURTH_MB \ | READ_UNLOCK_OUT_UNROLL) /* Must clear all tokens, including branches */ #define READ_PROC_ALL_TOKENS_CLEAR ((1 << 30) - 1) inline urcu_one_read(i, j, nest_i, tmp, tmp2) { PRODUCE_TOKENS(proc_urcu_reader, READ_PROD_NONE); #ifdef NO_MB PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_FIRST_MB); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_SECOND_MB); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_THIRD_MB); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_FOURTH_MB); #endif #ifdef REMOTE_BARRIERS PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_FIRST_MB); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_SECOND_MB); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_THIRD_MB); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_FOURTH_MB); #endif do :: 1 -> #ifdef REMOTE_BARRIERS /* * Signal-based memory barrier will only execute when the * execution order appears in program order. */ if :: 1 -> atomic { if :: CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE, READ_LOCK_OUT | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_PROC_ACCESS_GEN | READ_UNLOCK_NESTED_OUT | READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL | READ_PROC_READ_GEN_UNROLL | READ_PROC_ACCESS_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT, READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_PROC_ACCESS_GEN | READ_UNLOCK_NESTED_OUT | READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL | READ_PROC_READ_GEN_UNROLL | READ_PROC_ACCESS_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | READ_LOCK_NESTED_OUT, READ_PROC_READ_GEN | READ_PROC_ACCESS_GEN | READ_UNLOCK_NESTED_OUT | READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL | READ_PROC_READ_GEN_UNROLL | READ_PROC_ACCESS_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN, READ_PROC_ACCESS_GEN | READ_UNLOCK_NESTED_OUT | READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL | READ_PROC_READ_GEN_UNROLL | READ_PROC_ACCESS_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_PROC_ACCESS_GEN, READ_UNLOCK_NESTED_OUT | READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL | READ_PROC_READ_GEN_UNROLL | READ_PROC_ACCESS_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_PROC_ACCESS_GEN | READ_UNLOCK_NESTED_OUT, READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL | READ_PROC_READ_GEN_UNROLL | READ_PROC_ACCESS_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_PROC_ACCESS_GEN | READ_UNLOCK_NESTED_OUT | READ_UNLOCK_OUT, READ_LOCK_OUT_UNROLL | READ_PROC_READ_GEN_UNROLL | READ_PROC_ACCESS_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_PROC_ACCESS_GEN | READ_UNLOCK_NESTED_OUT | READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL, READ_PROC_READ_GEN_UNROLL | READ_PROC_ACCESS_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_PROC_ACCESS_GEN | READ_UNLOCK_NESTED_OUT | READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL | READ_PROC_READ_GEN_UNROLL, READ_PROC_ACCESS_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_PROC_ACCESS_GEN | READ_UNLOCK_NESTED_OUT | READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL | READ_PROC_READ_GEN_UNROLL | READ_PROC_ACCESS_GEN_UNROLL, READ_UNLOCK_OUT_UNROLL) || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_PROC_ACCESS_GEN | READ_UNLOCK_NESTED_OUT | READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL | READ_PROC_READ_GEN_UNROLL | READ_PROC_ACCESS_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL, 0) -> goto non_atomic3; non_atomic3_end: skip; fi; } fi; goto non_atomic3_skip; non_atomic3: smp_mb_recv(i, j); goto non_atomic3_end; non_atomic3_skip: #endif /* REMOTE_BARRIERS */ atomic { if PROCEDURE_READ_LOCK(READ_LOCK_BASE, READ_PROD_NONE, 0, READ_LOCK_OUT); :: CONSUME_TOKENS(proc_urcu_reader, READ_LOCK_OUT, /* post-dominant */ READ_PROC_FIRST_MB) -> smp_mb_reader(i, j); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_FIRST_MB); PROCEDURE_READ_LOCK(READ_LOCK_NESTED_BASE, READ_PROC_FIRST_MB, READ_LOCK_OUT, READ_LOCK_NESTED_OUT); :: CONSUME_TOKENS(proc_urcu_reader, READ_PROC_FIRST_MB, /* mb() orders reads */ READ_PROC_READ_GEN) -> ooo_mem(i); ptr_read_first[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) -> /* smp_read_barrier_depends */ goto rmb1; rmb1_end: data_read_first[get_readerid()] = READ_CACHED_VAR(rcu_data[ptr_read_first[get_readerid()]]); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_ACCESS_GEN); /* Note : we remove the nested memory barrier from the read unlock * model, given it is not usually needed. The implementation has the barrier * because the performance impact added by a branch in the common case does not * justify it. */ PROCEDURE_READ_UNLOCK(READ_UNLOCK_NESTED_BASE, READ_PROC_FIRST_MB | READ_LOCK_OUT | READ_LOCK_NESTED_OUT, READ_UNLOCK_NESTED_OUT); :: CONSUME_TOKENS(proc_urcu_reader, READ_PROC_ACCESS_GEN /* mb() orders reads */ | READ_PROC_READ_GEN /* mb() orders reads */ | READ_PROC_FIRST_MB /* mb() ordered */ | READ_LOCK_OUT /* post-dominant */ | READ_LOCK_NESTED_OUT /* post-dominant */ | READ_UNLOCK_NESTED_OUT, READ_PROC_SECOND_MB) -> smp_mb_reader(i, j); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_SECOND_MB); PROCEDURE_READ_UNLOCK(READ_UNLOCK_BASE, READ_PROC_SECOND_MB /* mb() orders reads */ | READ_PROC_FIRST_MB /* mb() orders reads */ | READ_LOCK_NESTED_OUT /* RAW */ | READ_LOCK_OUT /* RAW */ | READ_UNLOCK_NESTED_OUT, /* RAW */ READ_UNLOCK_OUT); /* Unrolling loop : second consecutive lock */ /* reading urcu_active_readers, which have been written by * READ_UNLOCK_OUT : RAW */ PROCEDURE_READ_LOCK(READ_LOCK_UNROLL_BASE, READ_PROC_SECOND_MB /* mb() orders reads */ | READ_PROC_FIRST_MB, /* mb() orders reads */ READ_LOCK_NESTED_OUT /* RAW */ | READ_LOCK_OUT /* RAW */ | READ_UNLOCK_NESTED_OUT /* RAW */ | READ_UNLOCK_OUT, /* RAW */ READ_LOCK_OUT_UNROLL); :: CONSUME_TOKENS(proc_urcu_reader, READ_PROC_FIRST_MB /* mb() ordered */ | READ_PROC_SECOND_MB /* mb() ordered */ | READ_LOCK_OUT_UNROLL /* post-dominant */ | READ_LOCK_NESTED_OUT | READ_LOCK_OUT | READ_UNLOCK_NESTED_OUT | READ_UNLOCK_OUT, READ_PROC_THIRD_MB) -> smp_mb_reader(i, j); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_THIRD_MB); :: CONSUME_TOKENS(proc_urcu_reader, READ_PROC_FIRST_MB /* mb() orders reads */ | READ_PROC_SECOND_MB /* mb() orders reads */ | READ_PROC_THIRD_MB, /* mb() orders reads */ READ_PROC_READ_GEN_UNROLL) -> ooo_mem(i); ptr_read_second[get_readerid()] = READ_CACHED_VAR(rcu_ptr); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_READ_GEN_UNROLL); :: CONSUME_TOKENS(proc_urcu_reader, READ_PROC_READ_GEN_UNROLL | READ_PROC_FIRST_MB /* mb() orders reads */ | READ_PROC_SECOND_MB /* mb() orders reads */ | READ_PROC_THIRD_MB, /* mb() orders reads */ READ_PROC_ACCESS_GEN_UNROLL) -> /* smp_read_barrier_depends */ goto rmb2; rmb2_end: data_read_second[get_readerid()] = READ_CACHED_VAR(rcu_data[ptr_read_second[get_readerid()]]); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_ACCESS_GEN_UNROLL); :: CONSUME_TOKENS(proc_urcu_reader, READ_PROC_READ_GEN_UNROLL /* mb() orders reads */ | READ_PROC_ACCESS_GEN_UNROLL /* mb() orders reads */ | READ_PROC_FIRST_MB /* mb() ordered */ | READ_PROC_SECOND_MB /* mb() ordered */ | READ_PROC_THIRD_MB /* mb() ordered */ | READ_LOCK_OUT_UNROLL /* post-dominant */ | READ_LOCK_NESTED_OUT | READ_LOCK_OUT | READ_UNLOCK_NESTED_OUT | READ_UNLOCK_OUT, READ_PROC_FOURTH_MB) -> smp_mb_reader(i, j); PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_FOURTH_MB); PROCEDURE_READ_UNLOCK(READ_UNLOCK_UNROLL_BASE, READ_PROC_FOURTH_MB /* mb() orders reads */ | READ_PROC_THIRD_MB /* mb() orders reads */ | READ_LOCK_OUT_UNROLL /* RAW */ | READ_PROC_SECOND_MB /* mb() orders reads */ | READ_PROC_FIRST_MB /* mb() orders reads */ | READ_LOCK_NESTED_OUT /* RAW */ | READ_LOCK_OUT /* RAW */ | READ_UNLOCK_NESTED_OUT, /* RAW */ READ_UNLOCK_OUT_UNROLL); :: CONSUME_TOKENS(proc_urcu_reader, READ_PROC_ALL_TOKENS, 0) -> CLEAR_TOKENS(proc_urcu_reader, READ_PROC_ALL_TOKENS_CLEAR); break; fi; } od; /* * Dependency between consecutive loops : * RAW dependency on * WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], tmp2 - 1) * tmp = READ_CACHED_VAR(urcu_active_readers[get_readerid()]); * between loops. * _WHEN THE MB()s are in place_, they add full ordering of the * generation pointer read wrt active reader count read, which ensures * execution will not spill across loop execution. * However, in the event mb()s are removed (execution using signal * handler to promote barrier()() -> smp_mb()), nothing prevents one loop * to spill its execution on other loop's execution. */ goto end; rmb1: #ifndef NO_RMB smp_rmb(i); #else ooo_mem(i); #endif goto rmb1_end; rmb2: #ifndef NO_RMB smp_rmb(i); #else ooo_mem(i); #endif goto rmb2_end; end: skip; } active proctype urcu_reader() { byte i, j, nest_i; byte tmp, tmp2; /* Keep in sync manually with smp_rmb, smp_wmb, ooo_mem and init() */ DECLARE_PROC_CACHED_VAR(byte, urcu_gp_ctr); /* Note ! currently only one reader */ DECLARE_PROC_CACHED_VAR(byte, urcu_active_readers[NR_READERS]); /* RCU data */ DECLARE_PROC_CACHED_VAR(bit, rcu_data[SLAB_SIZE]); /* RCU pointer */ #if (SLAB_SIZE == 2) DECLARE_PROC_CACHED_VAR(bit, rcu_ptr); #else DECLARE_PROC_CACHED_VAR(byte, rcu_ptr); #endif atomic { INIT_PROC_CACHED_VAR(urcu_gp_ctr, 1); INIT_PROC_CACHED_VAR(rcu_ptr, 0); i = 0; do :: i < NR_READERS -> INIT_PROC_CACHED_VAR(urcu_active_readers[i], 0); i++; :: i >= NR_READERS -> break od; INIT_PROC_CACHED_VAR(rcu_data[0], WINE); i = 1; do :: i < SLAB_SIZE -> INIT_PROC_CACHED_VAR(rcu_data[i], POISON); i++ :: i >= SLAB_SIZE -> break od; } wait_init_done(); assert(get_pid() < NR_PROCS); end_reader: do :: 1 -> /* * We do not test reader's progress here, because we are mainly * interested in writer's progress. The reader never blocks * anyway. We have to test for reader/writer's progress * separately, otherwise we could think the writer is doing * progress when it's blocked by an always progressing reader. */ #ifdef READER_PROGRESS progress_reader: #endif urcu_one_read(i, j, nest_i, tmp, tmp2); od; } /* no name clash please */ #undef proc_urcu_reader /* Model the RCU update process. */ /* * Bit encoding, urcu_writer : * Currently only supports one reader. */ int _proc_urcu_writer; #define proc_urcu_writer _proc_urcu_writer #define WRITE_PROD_NONE (1 << 0) #define WRITE_DATA (1 << 1) #define WRITE_PROC_WMB (1 << 2) #define WRITE_XCHG_PTR (1 << 3) #define WRITE_PROC_FIRST_MB (1 << 4) /* first flip */ #define WRITE_PROC_FIRST_READ_GP (1 << 5) #define WRITE_PROC_FIRST_WRITE_GP (1 << 6) #define WRITE_PROC_FIRST_WAIT (1 << 7) #define WRITE_PROC_FIRST_WAIT_LOOP (1 << 8) /* second flip */ #define WRITE_PROC_SECOND_READ_GP (1 << 9) #define WRITE_PROC_SECOND_WRITE_GP (1 << 10) #define WRITE_PROC_SECOND_WAIT (1 << 11) #define WRITE_PROC_SECOND_WAIT_LOOP (1 << 12) #define WRITE_PROC_SECOND_MB (1 << 13) #define WRITE_FREE (1 << 14) #define WRITE_PROC_ALL_TOKENS (WRITE_PROD_NONE \ | WRITE_DATA \ | WRITE_PROC_WMB \ | WRITE_XCHG_PTR \ | WRITE_PROC_FIRST_MB \ | WRITE_PROC_FIRST_READ_GP \ | WRITE_PROC_FIRST_WRITE_GP \ | WRITE_PROC_FIRST_WAIT \ | WRITE_PROC_SECOND_READ_GP \ | WRITE_PROC_SECOND_WRITE_GP \ | WRITE_PROC_SECOND_WAIT \ | WRITE_PROC_SECOND_MB \ | WRITE_FREE) #define WRITE_PROC_ALL_TOKENS_CLEAR ((1 << 15) - 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 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. */ /* Keep in sync manually with smp_rmb, smp_wmb, ooo_mem and init() */ DECLARE_PROC_CACHED_VAR(byte, urcu_gp_ctr); /* Note ! currently only one reader */ DECLARE_PROC_CACHED_VAR(byte, urcu_active_readers[NR_READERS]); /* RCU data */ DECLARE_PROC_CACHED_VAR(bit, rcu_data[SLAB_SIZE]); /* RCU pointer */ #if (SLAB_SIZE == 2) DECLARE_PROC_CACHED_VAR(bit, rcu_ptr); #else DECLARE_PROC_CACHED_VAR(byte, rcu_ptr); #endif atomic { INIT_PROC_CACHED_VAR(urcu_gp_ctr, 1); INIT_PROC_CACHED_VAR(rcu_ptr, 0); i = 0; do :: i < NR_READERS -> INIT_PROC_CACHED_VAR(urcu_active_readers[i], 0); i++; :: i >= NR_READERS -> break od; INIT_PROC_CACHED_VAR(rcu_data[0], WINE); i = 1; do :: i < SLAB_SIZE -> INIT_PROC_CACHED_VAR(rcu_data[i], POISON); i++ :: i >= SLAB_SIZE -> break od; } wait_init_done(); assert(get_pid() < NR_PROCS); do :: (loop_nr < 3) -> #ifdef WRITER_PROGRESS progress_writer1: #endif loop_nr = loop_nr + 1; PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROD_NONE); #ifdef NO_WMB PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_WMB); #endif #ifdef NO_MB PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_MB); PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_MB); #endif #ifdef SINGLE_FLIP 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 :: 1 -> atomic { if :: CONSUME_TOKENS(proc_urcu_writer, WRITE_PROD_NONE, WRITE_DATA) -> ooo_mem(i); cur_data = (cur_data + 1) % SLAB_SIZE; WRITE_CACHED_VAR(rcu_data[cur_data], WINE); PRODUCE_TOKENS(proc_urcu_writer, WRITE_DATA); :: CONSUME_TOKENS(proc_urcu_writer, WRITE_DATA, WRITE_PROC_WMB) -> smp_wmb(i); PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_WMB); :: CONSUME_TOKENS(proc_urcu_writer, WRITE_PROC_WMB, WRITE_XCHG_PTR) -> /* rcu_xchg_pointer() */ atomic { old_data = READ_CACHED_VAR(rcu_ptr); WRITE_CACHED_VAR(rcu_ptr, cur_data); } PRODUCE_TOKENS(proc_urcu_writer, WRITE_XCHG_PTR); :: CONSUME_TOKENS(proc_urcu_writer, WRITE_DATA | WRITE_PROC_WMB | WRITE_XCHG_PTR, WRITE_PROC_FIRST_MB) -> goto smp_mb_send1; smp_mb_send1_end: PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_MB); /* first flip */ :: CONSUME_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_MB, WRITE_PROC_FIRST_READ_GP) -> tmpa = READ_CACHED_VAR(urcu_gp_ctr); PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_READ_GP); :: CONSUME_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_MB | WRITE_PROC_WMB | WRITE_PROC_FIRST_READ_GP, WRITE_PROC_FIRST_WRITE_GP) -> ooo_mem(i); WRITE_CACHED_VAR(urcu_gp_ctr, tmpa ^ RCU_GP_CTR_BIT); PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_WRITE_GP); :: CONSUME_TOKENS(proc_urcu_writer, //WRITE_PROC_FIRST_WRITE_GP | /* TEST ADDING SYNC CORE */ WRITE_PROC_FIRST_MB, /* can be reordered before/after flips */ WRITE_PROC_FIRST_WAIT | WRITE_PROC_FIRST_WAIT_LOOP) -> ooo_mem(i); //smp_mb(i); /* TEST */ /* 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 ^ 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); fi; :: CONSUME_TOKENS(proc_urcu_writer, //WRITE_PROC_FIRST_WRITE_GP /* TEST ADDING SYNC CORE */ WRITE_PROC_FIRST_WRITE_GP | WRITE_PROC_FIRST_READ_GP | WRITE_PROC_FIRST_WAIT_LOOP | WRITE_DATA | WRITE_PROC_WMB | WRITE_XCHG_PTR | WRITE_PROC_FIRST_MB, /* can be reordered before/after flips */ 0) -> #ifndef GEN_ERROR_WRITER_PROGRESS goto smp_mb_send2; smp_mb_send2_end: /* The memory barrier will invalidate the * second read done as prefetching. Note that all * instructions with side-effects depending on * WRITE_PROC_SECOND_READ_GP should also depend on * completion of this busy-waiting loop. */ CLEAR_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_READ_GP); #else ooo_mem(i); #endif /* This instruction loops to WRITE_PROC_FIRST_WAIT */ CLEAR_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_WAIT_LOOP | WRITE_PROC_FIRST_WAIT); /* second flip */ :: CONSUME_TOKENS(proc_urcu_writer, //WRITE_PROC_FIRST_WAIT | //test /* no dependency. Could pre-fetch, no side-effect. */ WRITE_PROC_FIRST_WRITE_GP | WRITE_PROC_FIRST_READ_GP | WRITE_PROC_FIRST_MB, WRITE_PROC_SECOND_READ_GP) -> ooo_mem(i); //smp_mb(i); /* TEST */ tmpa = READ_CACHED_VAR(urcu_gp_ctr); PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_READ_GP); :: CONSUME_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_WAIT /* dependency on first wait, because this * instruction has globally observable * side-effects. */ | WRITE_PROC_FIRST_MB | WRITE_PROC_WMB | WRITE_PROC_FIRST_READ_GP | WRITE_PROC_FIRST_WRITE_GP | WRITE_PROC_SECOND_READ_GP, WRITE_PROC_SECOND_WRITE_GP) -> ooo_mem(i); WRITE_CACHED_VAR(urcu_gp_ctr, tmpa ^ RCU_GP_CTR_BIT); PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WRITE_GP); :: CONSUME_TOKENS(proc_urcu_writer, //WRITE_PROC_FIRST_WRITE_GP | /* TEST ADDING SYNC CORE */ WRITE_PROC_FIRST_WAIT | WRITE_PROC_FIRST_MB, /* can be reordered before/after flips */ WRITE_PROC_SECOND_WAIT | WRITE_PROC_SECOND_WAIT_LOOP) -> ooo_mem(i); //smp_mb(i); /* TEST */ /* ONLY WAITING FOR READER 0 */ tmp2 = READ_CACHED_VAR(urcu_active_readers[0]); if :: (tmp2 & RCU_GP_CTR_NEST_MASK) && ((tmp2 ^ 0) & RCU_GP_CTR_BIT) -> PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WAIT_LOOP); :: else -> PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WAIT); fi; :: CONSUME_TOKENS(proc_urcu_writer, //WRITE_PROC_FIRST_WRITE_GP | /* TEST ADDING SYNC CORE */ WRITE_PROC_SECOND_WRITE_GP | WRITE_PROC_FIRST_WRITE_GP | WRITE_PROC_SECOND_READ_GP | WRITE_PROC_FIRST_READ_GP | WRITE_PROC_SECOND_WAIT_LOOP | WRITE_DATA | WRITE_PROC_WMB | WRITE_XCHG_PTR | WRITE_PROC_FIRST_MB, /* can be reordered before/after flips */ 0) -> #ifndef GEN_ERROR_WRITER_PROGRESS goto smp_mb_send3; smp_mb_send3_end: #else ooo_mem(i); #endif /* This instruction loops to WRITE_PROC_SECOND_WAIT */ CLEAR_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WAIT_LOOP | WRITE_PROC_SECOND_WAIT); :: CONSUME_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_WAIT | WRITE_PROC_SECOND_WAIT | WRITE_PROC_FIRST_READ_GP | WRITE_PROC_SECOND_READ_GP | WRITE_PROC_FIRST_WRITE_GP | WRITE_PROC_SECOND_WRITE_GP | WRITE_DATA | WRITE_PROC_WMB | WRITE_XCHG_PTR | WRITE_PROC_FIRST_MB, WRITE_PROC_SECOND_MB) -> goto smp_mb_send4; smp_mb_send4_end: PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_MB); :: CONSUME_TOKENS(proc_urcu_writer, WRITE_XCHG_PTR | WRITE_PROC_FIRST_WAIT | WRITE_PROC_SECOND_WAIT | WRITE_PROC_WMB /* No dependency on * WRITE_DATA because we * write to a * different location. */ | WRITE_PROC_SECOND_MB | WRITE_PROC_FIRST_MB, WRITE_FREE) -> WRITE_CACHED_VAR(rcu_data[old_data], POISON); PRODUCE_TOKENS(proc_urcu_writer, WRITE_FREE); :: CONSUME_TOKENS(proc_urcu_writer, WRITE_PROC_ALL_TOKENS, 0) -> CLEAR_TOKENS(proc_urcu_writer, WRITE_PROC_ALL_TOKENS_CLEAR); break; fi; } od; /* * Note : Promela model adds implicit serialization of the * WRITE_FREE instruction. Normally, it would be permitted to * spill on the next loop execution. Given the validation we do * checks for the data entry read to be poisoned, it's ok if * we do not check "late arriving" memory poisoning. */ :: else -> break; od; /* * Given the reader loops infinitely, let the writer also busy-loop * with progress here so, with weak fairness, we can test the * writer's progress. */ end_writer: do :: 1 -> #ifdef WRITER_PROGRESS progress_writer2: #endif #ifdef READER_PROGRESS /* * Make sure we don't block the reader's progress. */ smp_mb_send(i, j, 5); #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 */ #undef proc_urcu_writer /* Leave after the readers and writers so the pid count is ok. */ init { byte i, j; atomic { INIT_CACHED_VAR(urcu_gp_ctr, 1); INIT_CACHED_VAR(rcu_ptr, 0); i = 0; do :: i < NR_READERS -> INIT_CACHED_VAR(urcu_active_readers[i], 0); ptr_read_first[i] = 1; ptr_read_second[i] = 1; data_read_first[i] = WINE; data_read_second[i] = WINE; i++; :: i >= NR_READERS -> break od; INIT_CACHED_VAR(rcu_data[0], WINE); i = 1; do :: i < SLAB_SIZE -> INIT_CACHED_VAR(rcu_data[i], POISON); i++ :: i >= SLAB_SIZE -> break od; init_done = 1; } }