X-Git-Url: http://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu-static.h;fp=urcu-static.h;h=0000000000000000000000000000000000000000;hp=18e4826a5a31789c7cb408832421cbddb7d83c22;hb=af7c2dbeac32c663b64ad05e4eca70e18784463b;hpb=acfd099eae9026369f558e73b2a7e35860962d9d diff --git a/urcu-static.h b/urcu-static.h deleted file mode 100644 index 18e4826..0000000 --- a/urcu-static.h +++ /dev/null @@ -1,305 +0,0 @@ -#ifndef _URCU_STATIC_H -#define _URCU_STATIC_H - -/* - * urcu-static.h - * - * Userspace RCU header. - * - * 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 Paul E. McKenney, IBM Corporation. - * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * This library 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 - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - * - * IBM's contributions to this file may be relicensed under LGPLv2 or later. - */ - -#include -#include -#include -#include - -#include -#include -#include -#include -#include -#include - -#ifdef __cplusplus -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 - * be only linked with the Userspace RCU library. This comes with a small - * performance degradation on the read-side due to the added function calls. - * This is required to permit relinking with newer versions of the library. - */ - -/* - * 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 - -/* - * If a reader is really non-cooperative and refuses to commit its - * rcu_active_readers count to memory (there is no barrier in the reader - * per-se), kick it after a few loops waiting for it. - */ -#define KICK_READER_LOOPS 10000 - -/* - * Active attempts to check for reader Q.S. before calling futex(). - */ -#define RCU_QS_ACTIVE_ATTEMPTS 100 - -#ifdef DEBUG_RCU -#define rcu_assert(args...) assert(args) -#else -#define rcu_assert(args...) -#endif - -#ifdef DEBUG_YIELD -#include -#include -#include -#include - -#define YIELD_READ (1 << 0) -#define YIELD_WRITE (1 << 1) - -/* - * Updates with RCU_SIGNAL are much slower. Account this in the delay. - */ -#ifdef RCU_SIGNAL -/* maximum sleep delay, in us */ -#define MAX_SLEEP 30000 -#else -#define MAX_SLEEP 50 -#endif - -extern unsigned int yield_active; -extern unsigned int __thread rand_yield; - -static inline void debug_yield_read(void) -{ - if (yield_active & YIELD_READ) - if (rand_r(&rand_yield) & 0x1) - usleep(rand_r(&rand_yield) % MAX_SLEEP); -} - -static inline void debug_yield_write(void) -{ - if (yield_active & YIELD_WRITE) - if (rand_r(&rand_yield) & 0x1) - usleep(rand_r(&rand_yield) % MAX_SLEEP); -} - -static inline void debug_yield_init(void) -{ - rand_yield = time(NULL) ^ pthread_self(); -} -#else -static inline void debug_yield_read(void) -{ -} - -static inline void debug_yield_write(void) -{ -} - -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 smp_mb_slave(int group) -{ - cmm_smp_mb(); -} -#endif - -#ifdef RCU_SIGNAL -static inline void smp_mb_slave(int group) -{ - cmm_barrier(); -} -#endif - -/* - * The trick here is that RCU_GP_CTR_PHASE must be a multiple of 8 so we can use - * a full 8-bits, 16-bits or 32-bits bitmask for the lower order bits. - */ -#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(unsigned long) << 2)) -#define RCU_GP_CTR_NEST_MASK (RCU_GP_CTR_PHASE - 1) - -/* - * Global quiescent period counter with low-order bits unused. - * Using a int rather than a char to eliminate false register dependencies - * causing stalls on some architectures. - */ -extern unsigned long rcu_gp_ctr; - -struct rcu_reader { - /* Data used by both reader and synchronize_rcu() */ - unsigned long ctr; - char need_mb; - /* Data used for registry */ - struct cds_list_head node __attribute__((aligned(CAA_CACHE_LINE_SIZE))); - pthread_t tid; -}; - -extern struct rcu_reader __thread rcu_reader; - -extern int gp_futex; - -/* - * Wake-up waiting synchronize_rcu(). Called from many concurrent threads. - */ -static inline void wake_up_gp(void) -{ - if (unlikely(uatomic_read(&gp_futex) == -1)) { - uatomic_set(&gp_futex, 0); - futex_async(&gp_futex, FUTEX_WAKE, 1, - NULL, NULL, 0); - } -} - -static inline int rcu_gp_ongoing(unsigned long *ctr) -{ - unsigned long v; - - /* - * Make sure both tests below are done on the same version of *value - * to insure consistency. - */ - 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) -{ - 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))) { - _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 smp_mb_master(). - */ - smp_mb_slave(RCU_MB_GROUP); - } else { - _CMM_STORE_SHARED(rcu_reader.ctr, tmp + RCU_GP_COUNT); - } -} - -static inline void _rcu_read_unlock(void) -{ - unsigned long tmp; - - tmp = rcu_reader.ctr; - /* - * Finish using rcu before decrementing the pointer. - * See smp_mb_master(). - */ - if (likely((tmp & RCU_GP_CTR_NEST_MASK) == 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 */ - smp_mb_slave(RCU_MB_GROUP); - wake_up_gp(); - } else { - _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 -} -#endif - -#endif /* _URCU_STATIC_H */