From 97a98f6cd767b3a68279890488c7b451788f84f4 Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Tue, 14 Nov 2017 12:57:01 +0100 Subject: RWLOCK(9): Add reader/writer lock implementation --- rtemsbsd/include/machine/rtems-bsd-rwlock.h | 60 ++++ rtemsbsd/include/machine/rtems-bsd-rwlockimpl.h | 429 ++++++++++++++++++++++++ rtemsbsd/rtems/rtems-kernel-rwlock.c | 113 +++++-- rtemsbsd/rtems/rtems-kernel-rwlockimpl.c | 177 ++++++++++ 4 files changed, 749 insertions(+), 30 deletions(-) create mode 100644 rtemsbsd/include/machine/rtems-bsd-rwlock.h create mode 100644 rtemsbsd/include/machine/rtems-bsd-rwlockimpl.h create mode 100644 rtemsbsd/rtems/rtems-kernel-rwlockimpl.c (limited to 'rtemsbsd') diff --git a/rtemsbsd/include/machine/rtems-bsd-rwlock.h b/rtemsbsd/include/machine/rtems-bsd-rwlock.h new file mode 100644 index 00000000..51b41604 --- /dev/null +++ b/rtemsbsd/include/machine/rtems-bsd-rwlock.h @@ -0,0 +1,60 @@ +/** + * @file + * + * @ingroup rtems_bsd_machine + * + * @brief TODO. + */ + +/* + * Copyright (c) 2017 embedded brains GmbH. All rights reserved. + * + * embedded brains GmbH + * Dornierstr. 4 + * 82178 Puchheim + * Germany + * + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef _RTEMS_BSD_MACHINE_RTEMS_BSD_RWLOCK_H_ +#define _RTEMS_BSD_MACHINE_RTEMS_BSD_RWLOCK_H_ + +#include + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +typedef struct { + Thread_queue_Control writer_queue; + Thread_queue_Control reader_queue; + int readers; + int nest_level; +} rtems_bsd_rwlock; + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* _RTEMS_BSD_MACHINE_RTEMS_BSD_RWLOCK_H_ */ diff --git a/rtemsbsd/include/machine/rtems-bsd-rwlockimpl.h b/rtemsbsd/include/machine/rtems-bsd-rwlockimpl.h new file mode 100644 index 00000000..663e7000 --- /dev/null +++ b/rtemsbsd/include/machine/rtems-bsd-rwlockimpl.h @@ -0,0 +1,429 @@ +/** + * @file + * + * @ingroup rtems_bsd_machine + * + * @brief Implementation of a reader/writer lock with priority inheritance for + * exclusive owners (writer). + */ + +/* + * Copyright (c) 2017 embedded brains GmbH. All rights reserved. + * + * embedded brains GmbH + * Dornierstr. 4 + * 82178 Puchheim + * Germany + * + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef _RTEMS_BSD_MACHINE_RTEMS_BSD_RWLOCKIMPL_H_ +#define _RTEMS_BSD_MACHINE_RTEMS_BSD_RWLOCKIMPL_H_ + +#include +#include + +#include +#include + +#include + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +typedef struct { + Thread_queue_Context writer; + Thread_queue_Context reader; +} rtems_bsd_rwlock_context; + +static inline void +rtems_bsd_rwlock_context_init(rtems_bsd_rwlock_context *context) +{ + + _Thread_queue_Context_initialize(&context->writer); +} + +static inline void +rtems_bsd_rwlock_init(struct lock_object *lock, rtems_bsd_rwlock *rw, + struct lock_class *class, const char *name, const char *type, int flags) +{ + _Thread_queue_Initialize(&rw->writer_queue, name); + _Thread_queue_Initialize(&rw->reader_queue, name); + rw->readers = 0; + rw->nest_level = 0; + lock_init(lock, class, name, type, flags); +} + +void rtems_bsd_rwlock_wlock_more(const struct lock_object *lock, + rtems_bsd_rwlock *rw, Thread_Control *executing, + rtems_bsd_rwlock_context *context); + +void rtems_bsd_rwlock_wunlock_more(rtems_bsd_rwlock *rw, + Thread_Control *wowner, rtems_bsd_rwlock_context *context); + +void rtems_bsd_rwlock_rlock_more(rtems_bsd_rwlock *rw, + rtems_bsd_rwlock_context *context); + +void rtems_bsd_rwlock_runlock_more(rtems_bsd_rwlock *rw, + rtems_bsd_rwlock_context *context); + +void rtems_bsd_rwlock_ready_waiting_readers(rtems_bsd_rwlock *rw, + rtems_bsd_rwlock_context *context); + +#define rtems_bsd_rwlock_isr_disable(isr_level, context) \ +do { \ + _ISR_Local_disable(isr_level); \ + _ISR_lock_ISR_disable_profile( \ + &(context)->writer.Lock_context.Lock_context) \ +} while (0) + +static inline void +rtems_bsd_rwlock_acquire_critical(rtems_bsd_rwlock *rw, + rtems_bsd_rwlock_context *context) +{ + + _Thread_queue_Queue_acquire_critical(&rw->writer_queue.Queue, + &rw->writer_queue.Lock_stats, + &context->writer.Lock_context.Lock_context); +#if defined(RTEMS_SMP) && defined(RTEMS_DEBUG) + rw->writer_queue.owner = _SMP_lock_Who_am_I(); +#endif +} + +static inline void +rtems_bsd_rwlock_release(rtems_bsd_rwlock *rw, ISR_Level isr_level, + rtems_bsd_rwlock_context *context) +{ + +#if defined(RTEMS_SMP) && defined(RTEMS_DEBUG) + _Assert( _Thread_queue_Is_lock_owner( &rw->writer_queue ) ); + rw->writer_queue.owner = SMP_LOCK_NO_OWNER; +#endif + _Thread_queue_Queue_release_critical(&rw->writer_queue.Queue, + &context->writer.Lock_context.Lock_context); + _ISR_Local_enable(isr_level); +} + +static inline void +rtems_bsd_rwlock_set_isr_level(rtems_bsd_rwlock_context *context, + ISR_Level isr_level) +{ + + _ISR_lock_Context_set_level(&context->writer.Lock_context.Lock_context, + isr_level); +} + +static inline Thread_Control * +rtems_bsd_rwlock_wowner(const rtems_bsd_rwlock *rw) +{ + + return (rw->writer_queue.Queue.owner); +} + +static inline void +rtems_bsd_rwlock_set_wowner(rtems_bsd_rwlock *rw, Thread_Control *wowner) +{ + + rw->writer_queue.Queue.owner = wowner; +} + +static inline void +rtems_bsd_rwlock_wlock(struct lock_object *lock, rtems_bsd_rwlock *rw) +{ + ISR_Level isr_level; + rtems_bsd_rwlock_context context; + Thread_Control *executing; + + rtems_bsd_rwlock_context_init(&context); + rtems_bsd_rwlock_isr_disable(isr_level, &context); + executing = _Thread_Executing; + rtems_bsd_rwlock_acquire_critical(rw, &context); + + if (__predict_true(rtems_bsd_rwlock_wowner(rw) == NULL && + rw->readers == 0)) { + rtems_bsd_rwlock_set_wowner(rw, executing); + _Thread_Resource_count_increment(executing); + rtems_bsd_rwlock_release(rw, isr_level, &context); + } else { + rtems_bsd_rwlock_set_isr_level(&context, isr_level); + rtems_bsd_rwlock_wlock_more(lock, rw, executing, + &context); + } +} + +static inline int +rtems_bsd_rwlock_try_wlock(struct lock_object *lock, rtems_bsd_rwlock *rw) +{ + int success; + ISR_Level isr_level; + rtems_bsd_rwlock_context context; + Thread_Control *executing; + + rtems_bsd_rwlock_context_init(&context); + rtems_bsd_rwlock_isr_disable(isr_level, &context); + executing = _Thread_Executing; + rtems_bsd_rwlock_acquire_critical(rw, &context); + + if (rw->readers == 0) { + Thread_Control *wowner; + + wowner = rtems_bsd_rwlock_wowner(rw); + + if (wowner == NULL) { + rtems_bsd_rwlock_set_wowner(rw, executing); + _Thread_Resource_count_increment(executing); + success = 1; + } else if (wowner == executing) { + BSD_ASSERT(lock->lo_flags & LO_RECURSABLE); + ++rw->nest_level; + success = 1; + } else { + success = 0; + } + } else { + success = 0; + } + + rtems_bsd_rwlock_release(rw, isr_level, &context); + + return (success); +} + +static inline void +rtems_bsd_rwlock_wunlock(rtems_bsd_rwlock *rw) +{ + ISR_Level isr_level; + rtems_bsd_rwlock_context context; + Thread_Control *wowner; + int nest_level; + + rtems_bsd_rwlock_context_init(&context); + rtems_bsd_rwlock_isr_disable(isr_level, &context); + rtems_bsd_rwlock_acquire_critical(rw, &context); + + nest_level = rw->nest_level; + wowner = rtems_bsd_rwlock_wowner(rw); + + BSD_ASSERT(wowner == _Thread_Executing); + + if (__predict_true(nest_level == 0)) { + rtems_bsd_rwlock_set_wowner(rw, NULL); + _Thread_Resource_count_decrement(wowner); + + if (__predict_true( + _Thread_queue_Is_empty(&rw->writer_queue.Queue) && + _Thread_queue_Is_empty(&rw->reader_queue.Queue))) { + rtems_bsd_rwlock_release(rw, isr_level, &context); + } else { + rtems_bsd_rwlock_set_isr_level(&context, + isr_level); + rtems_bsd_rwlock_wunlock_more(rw, wowner, + &context); + } + } else { + rw->nest_level = nest_level - 1; + rtems_bsd_rwlock_release(rw, isr_level, &context); + } +} + +static inline int +rtems_bsd_rwlock_wowned(const rtems_bsd_rwlock *rw) +{ + + return (rtems_bsd_rwlock_wowner(rw) == _Thread_Get_executing()); +} + +static inline int +rtems_bsd_rwlock_recursed(const rtems_bsd_rwlock *rw) +{ + + return (rw->nest_level != 0); +} + +static inline void +rtems_bsd_rwlock_rlock(struct lock_object *lock, rtems_bsd_rwlock *rw) +{ + ISR_Level isr_level; + rtems_bsd_rwlock_context context; + + rtems_bsd_rwlock_context_init(&context); + rtems_bsd_rwlock_isr_disable(isr_level, &context); + rtems_bsd_rwlock_acquire_critical(rw, &context); + + if (__predict_true(rtems_bsd_rwlock_wowner(rw) == NULL && + _Thread_queue_Is_empty(&rw->writer_queue.Queue))) { + ++rw->readers; + _Thread_Resource_count_increment(_Thread_Executing); + rtems_bsd_rwlock_release(rw, isr_level, &context); + } else { + rtems_bsd_rwlock_set_isr_level(&context, isr_level); + rtems_bsd_rwlock_rlock_more(rw, &context); + } +} + +static inline int +rtems_bsd_rwlock_try_rlock(struct lock_object *lock, rtems_bsd_rwlock *rw) +{ + int success; + ISR_Level isr_level; + rtems_bsd_rwlock_context context; + + rtems_bsd_rwlock_context_init(&context); + rtems_bsd_rwlock_isr_disable(isr_level, &context); + rtems_bsd_rwlock_acquire_critical(rw, &context); + + if (__predict_true(rtems_bsd_rwlock_wowner(rw) == NULL && + _Thread_queue_Is_empty(&rw->writer_queue.Queue))) { + ++rw->readers; + _Thread_Resource_count_increment(_Thread_Executing); + success = 1; + } else { + success = 0; + } + + rtems_bsd_rwlock_release(rw, isr_level, &context); + + return (success); +} + +static inline void +rtems_bsd_rwlock_runlock(rtems_bsd_rwlock *rw) +{ + ISR_Level isr_level; + rtems_bsd_rwlock_context context; + int readers; + + rtems_bsd_rwlock_context_init(&context); + rtems_bsd_rwlock_isr_disable(isr_level, &context); + rtems_bsd_rwlock_acquire_critical(rw, &context); + + readers = rw->readers; + _Thread_Resource_count_decrement(_Thread_Executing); + + if (__predict_true(readers == 1)) { + rw->readers = 0; + + if (__predict_true( + _Thread_queue_Is_empty(&rw->writer_queue.Queue) && + _Thread_queue_Is_empty(&rw->reader_queue.Queue))) { + rtems_bsd_rwlock_release(rw, isr_level, + &context); + } else { + rtems_bsd_rwlock_set_isr_level(&context, + isr_level); + rtems_bsd_rwlock_runlock_more(rw, &context); + } + } else { + rw->readers = readers - 1; + rtems_bsd_rwlock_release(rw, isr_level, &context); + } +} + +static inline int +rtems_bsd_rwlock_try_upgrade(rtems_bsd_rwlock *rw) +{ + int success; + ISR_Level isr_level; + rtems_bsd_rwlock_context context; + Thread_Control *executing; + Thread_Control *wowner; + + rtems_bsd_rwlock_context_init(&context); + rtems_bsd_rwlock_isr_disable(isr_level, &context); + executing = _Thread_Executing; + rtems_bsd_rwlock_acquire_critical(rw, &context); + + wowner = rtems_bsd_rwlock_wowner(rw); + BSD_ASSERT(wowner == NULL); + + if (rw->readers == 1) { + rw->readers = 0; + rtems_bsd_rwlock_set_wowner(rw, executing); + /* FIXME: priority inheritance */ + success = 1; + } else { + success = 0; + } + + rtems_bsd_rwlock_release(rw, isr_level, &context); + + return (success); +} + +static inline void +rtems_bsd_rwlock_downgrade(rtems_bsd_rwlock *rw) +{ + ISR_Level isr_level; + rtems_bsd_rwlock_context context; + Thread_Control *wowner; + + rtems_bsd_rwlock_context_init(&context); + rtems_bsd_rwlock_isr_disable(isr_level, &context); + rtems_bsd_rwlock_acquire_critical(rw, &context); + + wowner = rtems_bsd_rwlock_wowner(rw); + + BSD_ASSERT(wowner == _Thread_Executing); + BSD_ASSERT(rw->nest_level == 0); + + rtems_bsd_rwlock_set_wowner(rw, NULL); + rw->readers = 1; + + if (__predict_true(_Thread_queue_Is_empty(&rw->reader_queue.Queue))) { + rtems_bsd_rwlock_release(rw, isr_level, &context); + } else { + rtems_bsd_rwlock_set_isr_level(&context, isr_level); + rtems_bsd_rwlock_ready_waiting_readers(rw, &context); + } +} + +static inline const char * +rtems_bsd_rwlock_name(const rtems_bsd_rwlock *rw) +{ + + return (rw->writer_queue.Queue.name); +} + +static inline void +rtems_bsd_rwlock_destroy(struct lock_object *lock, rtems_bsd_rwlock *rw) +{ + BSD_ASSERT(_Thread_queue_Is_empty(&rw->writer_queue.Queue)); + BSD_ASSERT(_Thread_queue_Is_empty(&rw->reader_queue.Queue)); + + if (rtems_bsd_rwlock_wowned(rw)) { + rw->nest_level = 0; + rtems_bsd_rwlock_wunlock(rw); + } + + _Thread_queue_Destroy(&rw->writer_queue); + _Thread_queue_Destroy(&rw->reader_queue); + lock_destroy(lock); +} + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* _RTEMS_BSD_MACHINE_RTEMS_BSD_RWLOCKIMPL_H_ */ diff --git a/rtemsbsd/rtems/rtems-kernel-rwlock.c b/rtemsbsd/rtems/rtems-kernel-rwlock.c index 80918f70..c2002e0e 100644 --- a/rtemsbsd/rtems/rtems-kernel-rwlock.c +++ b/rtemsbsd/rtems/rtems-kernel-rwlock.c @@ -15,7 +15,7 @@ * USA * * - * Copyright (c) 2013-2015 embedded brains GmbH. All rights reserved. + * Copyright (c) 2013, 2017 embedded brains GmbH. All rights reserved. * * embedded brains GmbH * Dornierstr. 4 @@ -23,6 +23,9 @@ * Germany * * + * Copyright (c) 2006 John Baldwin + * All rights reserved. + * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: @@ -46,7 +49,7 @@ */ #include -#include +#include #include #include @@ -70,9 +73,9 @@ struct lock_class lock_class_rw = { .lc_unlock = unlock_rw, }; -#define rw_wowner(rw) rtems_bsd_mutex_owner(&(rw)->mutex) +#define rw_wowner(rw) rtems_bsd_rwlock_wowner(&(rw)->rwlock) -#define rw_recursed(rw) rtems_bsd_mutex_recursed(&(rw)->mutex) +#define rw_recursed(rw) rtems_bsd_rwlock_recursed(&(rw)->rwlock) void assert_rw(const struct lock_object *lock, int what) @@ -84,16 +87,29 @@ assert_rw(const struct lock_object *lock, int what) void lock_rw(struct lock_object *lock, uintptr_t how) { + struct rwlock *rw; - rw_wlock((struct rwlock *)lock); + rw = (struct rwlock *)lock; + if (how) + rw_rlock(rw); + else + rw_wlock(rw); } uintptr_t unlock_rw(struct lock_object *lock) { - - rw_unlock((struct rwlock *)lock); - return (0); + struct rwlock *rw; + + rw = (struct rwlock *)lock; + rw_assert(rw, RA_LOCKED | LA_NOTRECURSED); + if (rw->rwlock.readers > 0) { + rw_runlock(rw); + return (1); + } else { + rw_wunlock(rw); + return (0); + } } void @@ -105,7 +121,7 @@ rw_init_flags(struct rwlock *rw, const char *name, int opts) if (opts & RW_RECURSE) flags |= LO_RECURSABLE; - rtems_bsd_mutex_init(&rw->lock_object, &rw->mutex, &lock_class_rw, + rtems_bsd_rwlock_init(&rw->lock_object, &rw->rwlock, &lock_class_rw, name, NULL, flags); } @@ -113,77 +129,87 @@ void rw_destroy(struct rwlock *rw) { - rtems_bsd_mutex_destroy(&rw->lock_object, &rw->mutex); + rtems_bsd_rwlock_destroy(&rw->lock_object, &rw->rwlock); } void rw_sysinit(void *arg) { - struct rw_args *args = arg; + struct rw_args *args = arg; - rw_init(args->ra_rw, args->ra_desc); + rw_init((struct rwlock *)args->ra_rw, args->ra_desc); } void rw_sysinit_flags(void *arg) { - struct rw_args_flags *args = arg; + struct rw_args_flags *args = arg; - rw_init_flags(args->ra_rw, args->ra_desc, args->ra_flags); + rw_init_flags((struct rwlock *)args->ra_rw, args->ra_desc, + args->ra_flags); } int rw_wowned(struct rwlock *rw) { - return (rtems_bsd_mutex_owned(&rw->mutex)); + + return (rtems_bsd_rwlock_wowned(&rw->rwlock)); } void _rw_wlock(struct rwlock *rw, const char *file, int line) { - rtems_bsd_mutex_lock(&rw->lock_object, &rw->mutex); + + rtems_bsd_rwlock_wlock(&rw->lock_object, &rw->rwlock); } int _rw_try_wlock(struct rwlock *rw, const char *file, int line) { - return (rtems_bsd_mutex_trylock(&rw->lock_object, &rw->mutex)); + + return (rtems_bsd_rwlock_try_wlock(&rw->lock_object, &rw->rwlock)); } void _rw_wunlock(struct rwlock *rw, const char *file, int line) { - rtems_bsd_mutex_unlock(&rw->mutex); + + rtems_bsd_rwlock_wunlock(&rw->rwlock); } void _rw_rlock(struct rwlock *rw, const char *file, int line) { - rtems_bsd_mutex_lock(&rw->lock_object, &rw->mutex); + + rtems_bsd_rwlock_rlock(&rw->lock_object, &rw->rwlock); } int _rw_try_rlock(struct rwlock *rw, const char *file, int line) { - return (rtems_bsd_mutex_trylock(&rw->lock_object, &rw->mutex)); + + return (rtems_bsd_rwlock_try_rlock(&rw->lock_object, &rw->rwlock)); } void _rw_runlock(struct rwlock *rw, const char *file, int line) { - rtems_bsd_mutex_unlock(&rw->mutex); + + rtems_bsd_rwlock_runlock(&rw->rwlock); } int _rw_try_upgrade(struct rwlock *rw, const char *file, int line) { - return (1); + + return (rtems_bsd_rwlock_try_upgrade(&rw->rwlock)); } void _rw_downgrade(struct rwlock *rw, const char *file, int line) { - /* Nothing to do */ + + rtems_bsd_rwlock_downgrade(&rw->rwlock); } #ifdef INVARIANT_SUPPORT @@ -195,7 +221,7 @@ _rw_downgrade(struct rwlock *rw, const char *file, int line) void _rw_assert(const struct rwlock *rw, int what, const char *file, int line) { - const char *name = rtems_bsd_mutex_name(&rw->mutex); + const char *name = rtems_bsd_rwlock_name(&rw->rwlock); switch (what) { case RA_LOCKED: @@ -204,6 +230,33 @@ _rw_assert(const struct rwlock *rw, int what, const char *file, int line) case RA_RLOCKED: case RA_RLOCKED | RA_RECURSED: case RA_RLOCKED | RA_NOTRECURSED: +#ifdef WITNESS + witness_assert(&rw->lock_object, what, file, line); +#else + /* + * If some other thread has a write lock or we have one + * and are asserting a read lock, fail. Also, if no one + * has a lock at all, fail. + */ + if ((rw->rwlock.readers == 0 && rw_wowner(rw) == NULL) || + (rw->rwlock.readers == 0 && (what & RA_RLOCKED || + rw_wowner(rw) != _Thread_Get_executing()))) + panic("Lock %s not %slocked @ %s:%d\n", + name, (what & RA_RLOCKED) ? + "read " : "", file, line); + + if (rw->rwlock.readers == 0 && !(what & RA_RLOCKED)) { + if (rw_recursed(rw)) { + if (what & RA_NOTRECURSED) + panic("Lock %s recursed @ %s:%d\n", + name, file, + line); + } else if (what & RA_RECURSED) + panic("Lock %s not recursed @ %s:%d\n", + name, file, line); + } +#endif + break; case RA_WLOCKED: case RA_WLOCKED | RA_RECURSED: case RA_WLOCKED | RA_NOTRECURSED: @@ -212,11 +265,11 @@ _rw_assert(const struct rwlock *rw, int what, const char *file, int line) name, file, line); if (rw_recursed(rw)) { if (what & RA_NOTRECURSED) - panic("Lock %s recursed @ %s:%d\n", name, file, - line); + panic("Lock %s recursed @ %s:%d\n", + name, file, line); } else if (what & RA_RECURSED) - panic("Lock %s not recursed @ %s:%d\n", name, file, - line); + panic("Lock %s not recursed @ %s:%d\n", + name, file, line); break; case RA_UNLOCKED: #ifdef WITNESS @@ -227,8 +280,8 @@ _rw_assert(const struct rwlock *rw, int what, const char *file, int line) * to see if we hold a read lock or not. */ if (rw_wowner(rw) == _Thread_Get_executing()) - panic("Lock %s exclusively locked @ %s:%d\n", name, - file, line); + panic("Lock %s exclusively locked @ %s:%d\n", + name, file, line); #endif break; default: diff --git a/rtemsbsd/rtems/rtems-kernel-rwlockimpl.c b/rtemsbsd/rtems/rtems-kernel-rwlockimpl.c new file mode 100644 index 00000000..2434e51d --- /dev/null +++ b/rtemsbsd/rtems/rtems-kernel-rwlockimpl.c @@ -0,0 +1,177 @@ +/** + * @file + * + * @ingroup rtems_bsd_rtems + * + * @brief TODO. + */ + +/* + * Copyright (c) 2017 embedded brains GmbH. All rights reserved. + * + * embedded brains GmbH + * Dornierstr. 4 + * 82178 Puchheim + * Germany + * + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include +#include + +#include + +void +rtems_bsd_rwlock_wlock_more(const struct lock_object *lock, + rtems_bsd_rwlock *rw, Thread_Control *executing, + rtems_bsd_rwlock_context *context) +{ + Thread_Control *wowner; + + wowner = rtems_bsd_rwlock_wowner(rw); + + if (wowner == executing) { + BSD_ASSERT(lock->lo_flags & LO_RECURSABLE); + ++rw->nest_level; + + _Thread_queue_Release(&rw->writer_queue, &context->writer); + } else { + _Thread_queue_Context_set_thread_state(&context->writer, + STATES_WAITING_FOR_RWLOCK); + _Thread_queue_Context_set_enqueue_do_nothing_extra( + &context->writer); + _Thread_queue_Context_set_deadlock_callout(&context->writer, + _Thread_queue_Deadlock_fatal); + _Thread_queue_Enqueue(&rw->writer_queue.Queue, + &_Thread_queue_Operations_priority, executing, + &context->writer); + } +} + +static Thread_Control * +rtems_bsd_rwlock_flush_reader_filter(Thread_Control *reader, + Thread_queue_Queue *queue, Thread_queue_Context *queue_context) +{ + rtems_bsd_rwlock *rw; + + rw = RTEMS_CONTAINER_OF(queue, rtems_bsd_rwlock, reader_queue.Queue); + ++rw->readers; + _Thread_Resource_count_increment(reader); + return (reader); +} + +static void +rtems_bsd_rwlock_flush_reader_post_release(Thread_queue_Queue *queue, + Thread_queue_Context *queue_context) +{ + rtems_bsd_rwlock *rw; + rtems_bsd_rwlock_context *context; + + rw = RTEMS_CONTAINER_OF(queue, rtems_bsd_rwlock, reader_queue.Queue); + context = RTEMS_CONTAINER_OF(queue_context, rtems_bsd_rwlock_context, + reader); + _Thread_queue_Release(&rw->writer_queue, &context->writer); +} + +void +rtems_bsd_rwlock_wunlock_more(rtems_bsd_rwlock *rw, Thread_Control *wowner, + rtems_bsd_rwlock_context *context) +{ + + if (!_Thread_queue_Is_empty(&rw->reader_queue.Queue)) { + BSD_ASSERT(rw->readers == 0); + rtems_bsd_rwlock_ready_waiting_readers(rw, context); + } else { + BSD_ASSERT(!_Thread_queue_Is_empty(&rw->writer_queue.Queue)); + _Thread_queue_Surrender(&rw->writer_queue.Queue, + rw->writer_queue.Queue.heads, wowner, &context->writer, + &_Thread_queue_Operations_priority); + } +} + +static void +rtems_bsd_rwlock_reader_enqueue(Thread_queue_Queue *queue, + Thread_Control *executing, Per_CPU_Control *cpu_self, + Thread_queue_Context *queue_context +) +{ + rtems_bsd_rwlock *rw; + rtems_bsd_rwlock_context *context; + + rw = RTEMS_CONTAINER_OF(queue, rtems_bsd_rwlock, reader_queue.Queue); + context = RTEMS_CONTAINER_OF(queue_context, rtems_bsd_rwlock_context, + reader); + _Thread_queue_Release(&rw->writer_queue, &context->writer); +} + +void +rtems_bsd_rwlock_rlock_more(rtems_bsd_rwlock *rw, + rtems_bsd_rwlock_context *context) +{ + Thread_Control *executing; + + executing = _Thread_Executing; + + _Thread_queue_Context_initialize(&context->reader); + _Thread_queue_Context_set_thread_state(&context->reader, + STATES_WAITING_FOR_RWLOCK); + _Thread_queue_Context_set_enqueue_callout( + &context->reader, rtems_bsd_rwlock_reader_enqueue); + _Thread_queue_Context_set_deadlock_callout(&context->reader, + _Thread_queue_Deadlock_fatal); + _Thread_queue_Acquire(&rw->reader_queue, &context->reader); + _Thread_queue_Enqueue(&rw->reader_queue.Queue, + &_Thread_queue_Operations_FIFO, executing, &context->reader); +} + +void +rtems_bsd_rwlock_runlock_more(rtems_bsd_rwlock *rw, + rtems_bsd_rwlock_context *context) +{ + + if (!_Thread_queue_Is_empty(&rw->writer_queue.Queue)) { + BSD_ASSERT(rw->readers == 0); + + _Thread_queue_Surrender(&rw->writer_queue.Queue, + rw->writer_queue.Queue.heads, NULL, &context->writer, + &_Thread_queue_Operations_priority); + } else { + BSD_ASSERT(!_Thread_queue_Is_empty(&rw->reader_queue.Queue)); + rtems_bsd_rwlock_ready_waiting_readers(rw, context); + } +} + +void +rtems_bsd_rwlock_ready_waiting_readers(rtems_bsd_rwlock *rw, + rtems_bsd_rwlock_context *context) +{ + + _Thread_queue_Context_initialize(&context->reader); + _Thread_queue_Acquire(&rw->reader_queue, &context->reader); + _Thread_queue_Flush_critical(&rw->reader_queue.Queue, + &_Thread_queue_Operations_FIFO, + rtems_bsd_rwlock_flush_reader_filter, + rtems_bsd_rwlock_flush_reader_post_release, + &context->reader); +} -- cgit v1.2.3