X-Git-Url: http://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu-static.h;h=18e4826a5a31789c7cb408832421cbddb7d83c22;hp=0708df7c344038682595a39b3eb0fe977200d859;hb=acfd099eae9026369f558e73b2a7e35860962d9d;hpb=78ff941908d1c336106c06649c0892015cc98e18 diff --git a/urcu-static.h b/urcu-static.h index 0708df7..18e4826 100644 --- a/urcu-static.h +++ b/urcu-static.h @@ -9,7 +9,7 @@ * TO BE INCLUDED ONLY IN LGPL-COMPATIBLE CODE. See urcu.h for linking * dynamically with the userspace rcu library. * - * Copyright (c) 2009 Mathieu Desnoyers + * Copyright (c) 2009 Mathieu Desnoyers * Copyright (c) 2009 Paul E. McKenney, IBM Corporation. * * This library is free software; you can redistribute it and/or @@ -45,6 +45,27 @@ extern "C" { #endif +/* Default is RCU_MEMBARRIER */ +#if !defined(RCU_MEMBARRIER) && !defined(RCU_MB) && !defined(RCU_SIGNAL) +#define RCU_MEMBARRIER +#endif + +#ifdef RCU_MEMBARRIER +#include +#include + +/* If the headers do not support SYS_membarrier, statically use RCU_MB */ +#ifdef SYS_membarrier +# define MEMBARRIER_EXPEDITED (1 << 0) +# define MEMBARRIER_DELAYED (1 << 1) +# define MEMBARRIER_QUERY (1 << 16) +# define membarrier(...) syscall(SYS_membarrier, __VA_ARGS__) +#else +# undef RCU_MEMBARRIER +# define RCU_MB +#endif +#endif + /* * This code section can only be included in LGPL 2.1 compatible source code. * See below for the function call wrappers which can be used in code meant to @@ -56,7 +77,12 @@ extern "C" { /* * The signal number used by the RCU library can be overridden with * -DSIGRCU= when compiling the library. + * Provide backward compatibility for liburcu 0.3.x SIGURCU. */ +#ifdef SIGURCU +#define SIGRCU SIGURCU +#endif + #ifndef SIGRCU #define SIGRCU SIGUSR1 #endif @@ -89,14 +115,13 @@ extern "C" { #define YIELD_WRITE (1 << 1) /* - * Updates without RCU_MB are much slower. Account this in - * the delay. + * Updates with RCU_SIGNAL are much slower. Account this in the delay. */ -#ifdef RCU_MB +#ifdef RCU_SIGNAL /* maximum sleep delay, in us */ -#define MAX_SLEEP 50 -#else #define MAX_SLEEP 30000 +#else +#define MAX_SLEEP 50 #endif extern unsigned int yield_active; @@ -135,15 +160,44 @@ static inline void debug_yield_init(void) } #endif +/* + * RCU memory barrier broadcast group. Currently, only broadcast to all process + * threads is supported (group 0). + * + * Slave barriers are only guaranteed to be ordered wrt master barriers. + * + * The pair ordering is detailed as (O: ordered, X: not ordered) : + * slave master + * slave X O + * master O O + */ + +#define MB_GROUP_ALL 0 +#define RCU_MB_GROUP MB_GROUP_ALL + +#ifdef RCU_MEMBARRIER +extern int has_sys_membarrier; + +static inline void smp_mb_slave(int group) +{ + if (likely(has_sys_membarrier)) + cmm_barrier(); + else + cmm_smp_mb(); +} +#endif + #ifdef RCU_MB -static inline void reader_barrier() +static inline void smp_mb_slave(int group) { - smp_mb(); + cmm_smp_mb(); } -#else -static inline void reader_barrier() +#endif + +#ifdef RCU_SIGNAL +static inline void smp_mb_slave(int group) { - barrier(); + cmm_barrier(); } #endif @@ -153,7 +207,7 @@ static inline void reader_barrier() */ #define RCU_GP_COUNT (1UL << 0) /* Use the amount of bits equal to half of the architecture long size */ -#define RCU_GP_CTR_PHASE (1UL << (sizeof(long) << 2)) +#define RCU_GP_CTR_PHASE (1UL << (sizeof(unsigned long) << 2)) #define RCU_GP_CTR_NEST_MASK (RCU_GP_CTR_PHASE - 1) /* @@ -161,14 +215,14 @@ static inline void reader_barrier() * Using a int rather than a char to eliminate false register dependencies * causing stalls on some architectures. */ -extern long rcu_gp_ctr; +extern unsigned long rcu_gp_ctr; struct rcu_reader { /* Data used by both reader and synchronize_rcu() */ - long ctr; + unsigned long ctr; char need_mb; /* Data used for registry */ - struct list_head head __attribute__((aligned(CACHE_LINE_SIZE))); + struct cds_list_head node __attribute__((aligned(CAA_CACHE_LINE_SIZE))); pthread_t tid; }; @@ -188,63 +242,63 @@ static inline void wake_up_gp(void) } } -static inline int rcu_old_gp_ongoing(long *value) +static inline int rcu_gp_ongoing(unsigned long *ctr) { - long v; + unsigned long v; - if (value == NULL) - return 0; /* * Make sure both tests below are done on the same version of *value * to insure consistency. */ - v = LOAD_SHARED(*value); + v = CMM_LOAD_SHARED(*ctr); return (v & RCU_GP_CTR_NEST_MASK) && ((v ^ rcu_gp_ctr) & RCU_GP_CTR_PHASE); } static inline void _rcu_read_lock(void) { - long tmp; + unsigned long tmp; + cmm_barrier(); /* Ensure the compiler does not reorder us with mutex */ tmp = rcu_reader.ctr; /* * rcu_gp_ctr is * RCU_GP_COUNT | (~RCU_GP_CTR_PHASE or RCU_GP_CTR_PHASE) */ if (likely(!(tmp & RCU_GP_CTR_NEST_MASK))) { - _STORE_SHARED(rcu_reader.ctr, _LOAD_SHARED(rcu_gp_ctr)); + _CMM_STORE_SHARED(rcu_reader.ctr, _CMM_LOAD_SHARED(rcu_gp_ctr)); /* * Set active readers count for outermost nesting level before - * accessing the pointer. See force_mb_all_readers(). + * accessing the pointer. See smp_mb_master(). */ - reader_barrier(); + smp_mb_slave(RCU_MB_GROUP); } else { - _STORE_SHARED(rcu_reader.ctr, tmp + RCU_GP_COUNT); + _CMM_STORE_SHARED(rcu_reader.ctr, tmp + RCU_GP_COUNT); } } static inline void _rcu_read_unlock(void) { - long tmp; + unsigned long tmp; tmp = rcu_reader.ctr; /* * Finish using rcu before decrementing the pointer. - * See force_mb_all_readers(). + * See smp_mb_master(). */ if (likely((tmp & RCU_GP_CTR_NEST_MASK) == RCU_GP_COUNT)) { - reader_barrier(); - _STORE_SHARED(rcu_reader.ctr, rcu_reader.ctr - RCU_GP_COUNT); + smp_mb_slave(RCU_MB_GROUP); + _CMM_STORE_SHARED(rcu_reader.ctr, rcu_reader.ctr - RCU_GP_COUNT); /* write rcu_reader.ctr before read futex */ - reader_barrier(); + smp_mb_slave(RCU_MB_GROUP); wake_up_gp(); } else { - _STORE_SHARED(rcu_reader.ctr, rcu_reader.ctr - RCU_GP_COUNT); + _CMM_STORE_SHARED(rcu_reader.ctr, rcu_reader.ctr - RCU_GP_COUNT); } + cmm_barrier(); /* Ensure the compiler does not reorder us with mutex */ } -#ifdef __cplusplus +#ifdef __cplusplus } #endif