diff options
author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2017-11-14 12:57:01 +0100 |
---|---|---|
committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2017-11-16 09:02:24 +0100 |
commit | 97a98f6cd767b3a68279890488c7b451788f84f4 (patch) | |
tree | 279ba49b9f03b0f111ff5df771e9d4f3b3fd4feb /rtemsbsd/rtems | |
parent | LOCKING(9): Remove dead code (DDB) (diff) | |
download | rtems-libbsd-97a98f6cd767b3a68279890488c7b451788f84f4.tar.bz2 |
RWLOCK(9): Add reader/writer lock implementation
Diffstat (limited to 'rtemsbsd/rtems')
-rw-r--r-- | rtemsbsd/rtems/rtems-kernel-rwlock.c | 113 | ||||
-rw-r--r-- | rtemsbsd/rtems/rtems-kernel-rwlockimpl.c | 177 |
2 files changed, 260 insertions, 30 deletions
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 * <kevin.kirspel@optimedical.com> * - * 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 * <rtems@embedded-brains.de> * + * Copyright (c) 2006 John Baldwin <jhb@FreeBSD.org> + * 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 <machine/rtems-bsd-kernel-space.h> -#include <machine/rtems-bsd-muteximpl.h> +#include <machine/rtems-bsd-rwlockimpl.h> #include <sys/param.h> #include <sys/types.h> @@ -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 + * <rtems@embedded-brains.de> + * + * 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 <machine/rtems-bsd-kernel-space.h> +#include <machine/rtems-bsd-rwlockimpl.h> + +#include <rtems/score/schedulerimpl.h> + +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); +} |