X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=urcu-bp-static.h;fp=urcu-bp-static.h;h=0000000000000000000000000000000000000000;hb=af7c2dbeac32c663b64ad05e4eca70e18784463b;hp=14c6cfecac3af01a3bc4680c36381736f37a30f7;hpb=acfd099eae9026369f558e73b2a7e35860962d9d;p=urcu.git diff --git a/urcu-bp-static.h b/urcu-bp-static.h deleted file mode 100644 index 14c6cfe..0000000 --- a/urcu-bp-static.h +++ /dev/null @@ -1,210 +0,0 @@ -#ifndef _URCU_BP_STATIC_H -#define _URCU_BP_STATIC_H - -/* - * urcu-bp-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 - -/* - * 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. - */ - -#ifdef __cplusplus -extern "C" { -#endif - -/* - * Active attempts to check for reader Q.S. before calling sleep(). - */ -#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 without RCU_MB are much slower. Account this in - * the delay. - */ -/* maximum sleep delay, in us */ -#define MAX_SLEEP 50 - -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 - -/* - * 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(long) << 2)) -#define RCU_GP_CTR_NEST_MASK (RCU_GP_CTR_PHASE - 1) - -/* - * Used internally by _rcu_read_lock. - */ -extern void rcu_bp_register(void); - -/* - * 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 long rcu_gp_ctr; - -struct rcu_reader { - /* Data used by both reader and synchronize_rcu() */ - long ctr; - /* Data used for registry */ - struct cds_list_head node __attribute__((aligned(CAA_CACHE_LINE_SIZE))); - pthread_t tid; - int alloc; /* registry entry allocated */ -}; - -/* - * Bulletproof version keeps a pointer to a registry not part of the TLS. - * Adds a pointer dereference on the read-side, but won't require to unregister - * the reader thread. - */ -extern struct rcu_reader __thread *rcu_reader; - -static inline int rcu_old_gp_ongoing(long *value) -{ - long v; - - if (value == NULL) - return 0; - /* - * Make sure both tests below are done on the same version of *value - * to insure consistency. - */ - v = CMM_LOAD_SHARED(*value); - return (v & RCU_GP_CTR_NEST_MASK) && - ((v ^ rcu_gp_ctr) & RCU_GP_CTR_PHASE); -} - -static inline void _rcu_read_lock(void) -{ - long tmp; - - /* Check if registered */ - if (unlikely(!rcu_reader)) - rcu_bp_register(); - - 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. - */ - cmm_smp_mb(); - } else { - _CMM_STORE_SHARED(rcu_reader->ctr, tmp + RCU_GP_COUNT); - } -} - -static inline void _rcu_read_unlock(void) -{ - /* - * Finish using rcu before decrementing the pointer. - */ - cmm_smp_mb(); - _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_BP_STATIC_H */