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author | Joel Sherrill <joel.sherrill@oarcorp.com> | 2012-03-08 07:25:21 -0600 |
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committer | Joel Sherrill <joel.sherrill@oarcorp.com> | 2012-03-08 07:25:21 -0600 |
commit | e2d2bf579b8d9ac67c1fdf0ad419b22860b93b35 (patch) | |
tree | 4f285040086226090aa9f664e011ffd8ced0a03a /freebsd/sys/rwlock.h | |
parent | Add wish list for freebsd-to-rtems.py (diff) | |
download | rtems-libbsd-e2d2bf579b8d9ac67c1fdf0ad419b22860b93b35.tar.bz2 |
Move rtems/freebsd to freebsd and contrib to freebsd/contrib
Diffstat (limited to 'freebsd/sys/rwlock.h')
-rw-r--r-- | freebsd/sys/rwlock.h | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/freebsd/sys/rwlock.h b/freebsd/sys/rwlock.h new file mode 100644 index 00000000..cee67827 --- /dev/null +++ b/freebsd/sys/rwlock.h @@ -0,0 +1,251 @@ +/*- + * 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: + * 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. + * 3. Neither the name of the author nor the names of any co-contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * 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. + * + * $FreeBSD$ + */ + +#ifndef _SYS_RWLOCK_HH_ +#define _SYS_RWLOCK_HH_ + +#include <rtems/freebsd/sys/_lock.h> +#include <rtems/freebsd/sys/_rwlock.h> +#include <rtems/freebsd/sys/lock_profile.h> +#include <rtems/freebsd/sys/lockstat.h> + +#ifdef _KERNEL +#include <rtems/freebsd/sys/pcpu.h> +#include <rtems/freebsd/machine/atomic.h> +#endif + +#ifdef __rtems__ +#define RWLOCK_NOINLINE 1 +#endif /* __rtems__ */ + +/* + * The rw_lock field consists of several fields. The low bit indicates + * if the lock is locked with a read (shared) or write (exclusive) lock. + * A value of 0 indicates a write lock, and a value of 1 indicates a read + * lock. Bit 1 is a boolean indicating if there are any threads waiting + * for a read lock. Bit 2 is a boolean indicating if there are any threads + * waiting for a write lock. The rest of the variable's definition is + * dependent on the value of the first bit. For a write lock, it is a + * pointer to the thread holding the lock, similar to the mtx_lock field of + * mutexes. For read locks, it is a count of read locks that are held. + * + * When the lock is not locked by any thread, it is encoded as a read lock + * with zero waiters. + */ + +#define RW_LOCK_READ 0x01 +#define RW_LOCK_READ_WAITERS 0x02 +#define RW_LOCK_WRITE_WAITERS 0x04 +#define RW_LOCK_WRITE_SPINNER 0x08 +#define RW_LOCK_FLAGMASK \ + (RW_LOCK_READ | RW_LOCK_READ_WAITERS | RW_LOCK_WRITE_WAITERS | \ + RW_LOCK_WRITE_SPINNER) +#define RW_LOCK_WAITERS (RW_LOCK_READ_WAITERS | RW_LOCK_WRITE_WAITERS) + +#define RW_OWNER(x) ((x) & ~RW_LOCK_FLAGMASK) +#define RW_READERS_SHIFT 4 +#define RW_READERS(x) (RW_OWNER((x)) >> RW_READERS_SHIFT) +#define RW_READERS_LOCK(x) ((x) << RW_READERS_SHIFT | RW_LOCK_READ) +#define RW_ONE_READER (1 << RW_READERS_SHIFT) + +#define RW_UNLOCKED RW_READERS_LOCK(0) +#define RW_DESTROYED (RW_LOCK_READ_WAITERS | RW_LOCK_WRITE_WAITERS) + +#ifdef _KERNEL + +#define rw_recurse lock_object.lo_data + +/* Very simple operations on rw_lock. */ + +/* Try to obtain a write lock once. */ +#define _rw_write_lock(rw, tid) \ + atomic_cmpset_acq_ptr(&(rw)->rw_lock, RW_UNLOCKED, (tid)) + +/* Release a write lock quickly if there are no waiters. */ +#define _rw_write_unlock(rw, tid) \ + atomic_cmpset_rel_ptr(&(rw)->rw_lock, (tid), RW_UNLOCKED) + +/* + * Full lock operations that are suitable to be inlined in non-debug + * kernels. If the lock cannot be acquired or released trivially then + * the work is deferred to another function. + */ + +#ifndef __rtems__ +/* Acquire a write lock. */ +#define __rw_wlock(rw, tid, file, line) do { \ + uintptr_t _tid = (uintptr_t)(tid); \ + \ + if (!_rw_write_lock((rw), _tid)) \ + _rw_wlock_hard((rw), _tid, (file), (line)); \ + else \ + LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(LS_RW_WLOCK_ACQUIRE, \ + rw, 0, 0, (file), (line)); \ +} while (0) + +/* Release a write lock. */ +#define __rw_wunlock(rw, tid, file, line) do { \ + uintptr_t _tid = (uintptr_t)(tid); \ + \ + if ((rw)->rw_recurse) \ + (rw)->rw_recurse--; \ + else if (!_rw_write_unlock((rw), _tid)) \ + _rw_wunlock_hard((rw), _tid, (file), (line)); \ +} while (0) +#endif /* __rtems__ */ + +/* + * Function prototypes. Routines that start with _ are not part of the + * external API and should not be called directly. Wrapper macros should + * be used instead. + */ + +#define rw_init(rw, name) rw_init_flags((rw), (name), 0) +void rw_init_flags(struct rwlock *rw, const char *name, int opts); +void rw_destroy(struct rwlock *rw); +void rw_sysinit(void *arg); +void rw_sysinit_flags(void *arg); +int rw_wowned(struct rwlock *rw); +void _rw_wlock(struct rwlock *rw, const char *file, int line); +int _rw_try_wlock(struct rwlock *rw, const char *file, int line); +void _rw_wunlock(struct rwlock *rw, const char *file, int line); +void _rw_rlock(struct rwlock *rw, const char *file, int line); +int _rw_try_rlock(struct rwlock *rw, const char *file, int line); +void _rw_runlock(struct rwlock *rw, const char *file, int line); +void _rw_wlock_hard(struct rwlock *rw, uintptr_t tid, const char *file, + int line); +void _rw_wunlock_hard(struct rwlock *rw, uintptr_t tid, const char *file, + int line); +int _rw_try_upgrade(struct rwlock *rw, const char *file, int line); +void _rw_downgrade(struct rwlock *rw, const char *file, int line); +#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) +void _rw_assert(struct rwlock *rw, int what, const char *file, int line); +#endif + +/* + * Public interface for lock operations. + */ + +#ifndef LOCK_DEBUG +#error LOCK_DEBUG not defined, include <sys/lock.h> before <sys/rwlock.h> +#endif +#if LOCK_DEBUG > 0 || defined(RWLOCK_NOINLINE) +#define rw_wlock(rw) _rw_wlock((rw), LOCK_FILE, LOCK_LINE) +#define rw_wunlock(rw) _rw_wunlock((rw), LOCK_FILE, LOCK_LINE) +#else +#define rw_wlock(rw) \ + __rw_wlock((rw), curthread, LOCK_FILE, LOCK_LINE) +#define rw_wunlock(rw) \ + __rw_wunlock((rw), curthread, LOCK_FILE, LOCK_LINE) +#endif +#define rw_rlock(rw) _rw_rlock((rw), LOCK_FILE, LOCK_LINE) +#define rw_runlock(rw) _rw_runlock((rw), LOCK_FILE, LOCK_LINE) +#define rw_try_rlock(rw) _rw_try_rlock((rw), LOCK_FILE, LOCK_LINE) +#define rw_try_upgrade(rw) _rw_try_upgrade((rw), LOCK_FILE, LOCK_LINE) +#define rw_try_wlock(rw) _rw_try_wlock((rw), LOCK_FILE, LOCK_LINE) +#define rw_downgrade(rw) _rw_downgrade((rw), LOCK_FILE, LOCK_LINE) +#define rw_unlock(rw) do { \ + if (rw_wowned(rw)) \ + rw_wunlock(rw); \ + else \ + rw_runlock(rw); \ +} while (0) +#define rw_sleep(chan, rw, pri, wmesg, timo) \ + _sleep((chan), &(rw)->lock_object, (pri), (wmesg), (timo)) + +#define rw_initialized(rw) lock_initalized(&(rw)->lock_object) + +struct rw_args { + struct rwlock *ra_rw; + const char *ra_desc; +}; + +struct rw_args_flags { + struct rwlock *ra_rw; + const char *ra_desc; + int ra_flags; +}; + +#define RW_SYSINIT(name, rw, desc) \ + static struct rw_args name##_args = { \ + (rw), \ + (desc), \ + }; \ + SYSINIT(name##_rw_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \ + rw_sysinit, &name##_args); \ + SYSUNINIT(name##_rw_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \ + rw_destroy, (rw)) + + +#define RW_SYSINIT_FLAGS(name, rw, desc, flags) \ + static struct rw_args_flags name##_args = { \ + (rw), \ + (desc), \ + (flags), \ + }; \ + SYSINIT(name##_rw_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \ + rw_sysinit_flags, &name##_args); \ + SYSUNINIT(name##_rw_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \ + rw_destroy, (rw)) + +/* + * Options passed to rw_init_flags(). + */ +#define RW_DUPOK 0x01 +#define RW_NOPROFILE 0x02 +#define RW_NOWITNESS 0x04 +#define RW_QUIET 0x08 +#define RW_RECURSE 0x10 + +/* + * The INVARIANTS-enabled rw_assert() functionality. + * + * The constants need to be defined for INVARIANT_SUPPORT infrastructure + * support as _rw_assert() itself uses them and the latter implies that + * _rw_assert() must build. + */ +#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) +#define RA_LOCKED LA_LOCKED +#define RA_RLOCKED LA_SLOCKED +#define RA_WLOCKED LA_XLOCKED +#define RA_UNLOCKED LA_UNLOCKED +#define RA_RECURSED LA_RECURSED +#define RA_NOTRECURSED LA_NOTRECURSED +#endif + +#ifdef INVARIANTS +#define rw_assert(rw, what) _rw_assert((rw), (what), LOCK_FILE, LOCK_LINE) +#else +#define rw_assert(rw, what) +#endif + +#endif /* _KERNEL */ +#endif /* !_SYS_RWLOCK_HH_ */ |