X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=include%2Furcu%2Fstatic%2Furcu-signal.h;h=07768b340a768a30584bdf643ff14c61097a8203;hb=c5b26a3e57e3ece89c4a2e27b40e41a5b884289f;hp=385e6f5d5559c5ca6ca7c70858f15425ddd2f732;hpb=4477a87021ffbfbfdb2a2084d05a084171343d36;p=urcu.git diff --git a/include/urcu/static/urcu-signal.h b/include/urcu/static/urcu-signal.h index 385e6f5..07768b3 100644 --- a/include/urcu/static/urcu-signal.h +++ b/include/urcu/static/urcu-signal.h @@ -1,31 +1,17 @@ +// SPDX-FileCopyrightText: 2009 Mathieu Desnoyers +// SPDX-FileCopyrightText: 2009 Paul E. McKenney, IBM Corporation. +// +// SPDX-License-Identifier: LGPL-2.1-or-later + #ifndef _URCU_SIGNAL_STATIC_H #define _URCU_SIGNAL_STATIC_H /* - * urcu-signal-static.h - * * Userspace RCU header. * * TO BE INCLUDED ONLY IN CODE THAT IS TO BE RECOMPILED ON EACH LIBURCU * RELEASE. 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. */ @@ -34,6 +20,7 @@ #include #include +#include #include #include #include @@ -42,8 +29,8 @@ #include #include #include -#include #include +#include #ifdef __cplusplus extern "C" { @@ -57,35 +44,22 @@ extern "C" { * 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 - extern struct urcu_gp urcu_signal_gp; extern DECLARE_URCU_TLS(struct urcu_reader, urcu_signal_reader); /* * Helper for _rcu_read_lock(). The format of urcu_signal_gp.ctr (as well as - * the per-thread rcu_reader.ctr) has the upper bits containing a count of - * _rcu_read_lock() nesting, and a lower-order bit that contains either zero - * or URCU_GP_CTR_PHASE. The cmm_barrier() ensures that the accesses in + * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of + * _rcu_read_lock() nesting, and a single high-order URCU_BP_GP_CTR_PHASE bit + * that contains either zero or one. The cmm_barrier() ensures that the accesses in * _rcu_read_lock() happen before the subsequent read-side critical section. */ static inline void _urcu_signal_read_lock_update(unsigned long tmp) { if (caa_likely(!(tmp & URCU_GP_CTR_NEST_MASK))) { _CMM_STORE_SHARED(URCU_TLS(urcu_signal_reader).ctr, _CMM_LOAD_SHARED(urcu_signal_gp.ctr)); - cmm_barrier(); + cmm_smp_mb(); } else _CMM_STORE_SHARED(URCU_TLS(urcu_signal_reader).ctr, tmp + URCU_GP_COUNT); } @@ -104,10 +78,10 @@ static inline void _urcu_signal_read_lock(void) { unsigned long tmp; - urcu_assert(URCU_TLS(urcu_signal_reader).registered); + urcu_assert_debug(URCU_TLS(urcu_signal_reader).registered); cmm_barrier(); tmp = URCU_TLS(urcu_signal_reader).ctr; - urcu_assert((tmp & URCU_GP_CTR_NEST_MASK) != URCU_GP_CTR_NEST_MASK); + urcu_assert_debug((tmp & URCU_GP_CTR_NEST_MASK) != URCU_GP_CTR_NEST_MASK); _urcu_signal_read_lock_update(tmp); } @@ -121,17 +95,18 @@ static inline void _urcu_signal_read_lock(void) */ static inline void _urcu_signal_read_unlock_update_and_wakeup(unsigned long tmp) { + unsigned long *ctr = &URCU_TLS(urcu_signal_reader).ctr; + if (caa_likely((tmp & URCU_GP_CTR_NEST_MASK) == URCU_GP_COUNT)) { - cmm_barrier(); - _CMM_STORE_SHARED(URCU_TLS(urcu_signal_reader).ctr, tmp - URCU_GP_COUNT); - cmm_barrier(); + uatomic_store(ctr, tmp - URCU_GP_COUNT, CMM_SEQ_CST); urcu_common_wake_up_gp(&urcu_signal_gp); - } else - _CMM_STORE_SHARED(URCU_TLS(urcu_signal_reader).ctr, tmp - URCU_GP_COUNT); + } else { + uatomic_store(ctr, tmp - URCU_GP_COUNT, CMM_RELAXED); + } } /* - * Exit an RCU read-side crtical section. Both this function and its + * Exit an RCU read-side critical section. Both this function and its * helper are smaller than 10 lines of code, and are intended to be * usable by non-LGPL code, as called out in LGPL. */ @@ -139,9 +114,9 @@ static inline void _urcu_signal_read_unlock(void) { unsigned long tmp; - urcu_assert(URCU_TLS(urcu_signal_reader).registered); + urcu_assert_debug(URCU_TLS(urcu_signal_reader).registered); tmp = URCU_TLS(urcu_signal_reader).ctr; - urcu_assert(tmp & URCU_GP_CTR_NEST_MASK); + urcu_assert_debug(tmp & URCU_GP_CTR_NEST_MASK); _urcu_signal_read_unlock_update_and_wakeup(tmp); cmm_barrier(); /* Ensure the compiler does not reorder us with mutex */ }