bfc761fdba
an unified way for all the lock primitives to express lock assertions. Currenty, lockmgrs and rmlocks don't have assertions, so just panic in that case. This will be a base for more callout improvements. Ok'ed by: jhb, jeff
838 lines
21 KiB
C
838 lines
21 KiB
C
/*-
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* Copyright (c) 1998 Berkeley Software Design, Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Berkeley Software Design Inc's name may not be used to endorse or
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* promote products derived from this software without specific prior
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* written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from BSDI $Id: mutex_witness.c,v 1.1.2.20 2000/04/27 03:10:27 cp Exp $
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* and BSDI $Id: synch_machdep.c,v 2.3.2.39 2000/04/27 03:10:25 cp Exp $
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*/
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/*
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* Machine independent bits of mutex implementation.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_adaptive_mutexes.h"
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#include "opt_ddb.h"
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#include "opt_global.h"
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#include "opt_sched.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/bus.h>
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#include <sys/conf.h>
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#include <sys/kdb.h>
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#include <sys/kernel.h>
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#include <sys/ktr.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/resourcevar.h>
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#include <sys/sched.h>
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#include <sys/sbuf.h>
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#include <sys/sysctl.h>
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#include <sys/turnstile.h>
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#include <sys/vmmeter.h>
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#include <sys/lock_profile.h>
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#include <machine/atomic.h>
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#include <machine/bus.h>
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#include <machine/cpu.h>
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#include <ddb/ddb.h>
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#include <fs/devfs/devfs_int.h>
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#include <vm/vm.h>
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#include <vm/vm_extern.h>
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#if defined(SMP) && !defined(NO_ADAPTIVE_MUTEXES)
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#define ADAPTIVE_MUTEXES
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#endif
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/*
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* Internal utility macros.
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*/
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#define mtx_unowned(m) ((m)->mtx_lock == MTX_UNOWNED)
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#define mtx_destroyed(m) ((m)->mtx_lock == MTX_DESTROYED)
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#define mtx_owner(m) ((struct thread *)((m)->mtx_lock & ~MTX_FLAGMASK))
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static void assert_mtx(struct lock_object *lock, int what);
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#ifdef DDB
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static void db_show_mtx(struct lock_object *lock);
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#endif
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static void lock_mtx(struct lock_object *lock, int how);
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static void lock_spin(struct lock_object *lock, int how);
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static int unlock_mtx(struct lock_object *lock);
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static int unlock_spin(struct lock_object *lock);
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/*
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* Lock classes for sleep and spin mutexes.
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*/
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struct lock_class lock_class_mtx_sleep = {
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.lc_name = "sleep mutex",
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.lc_flags = LC_SLEEPLOCK | LC_RECURSABLE,
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.lc_assert = assert_mtx,
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#ifdef DDB
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.lc_ddb_show = db_show_mtx,
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#endif
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.lc_lock = lock_mtx,
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.lc_unlock = unlock_mtx,
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};
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struct lock_class lock_class_mtx_spin = {
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.lc_name = "spin mutex",
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.lc_flags = LC_SPINLOCK | LC_RECURSABLE,
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.lc_assert = assert_mtx,
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#ifdef DDB
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.lc_ddb_show = db_show_mtx,
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#endif
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.lc_lock = lock_spin,
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.lc_unlock = unlock_spin,
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};
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/*
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* System-wide mutexes
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*/
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struct mtx blocked_lock;
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struct mtx Giant;
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#ifdef LOCK_PROFILING
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static inline void lock_profile_init(void)
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{
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int i;
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/* Initialize the mutex profiling locks */
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for (i = 0; i < LPROF_LOCK_SIZE; i++) {
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mtx_init(&lprof_locks[i], "mprof lock",
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NULL, MTX_SPIN|MTX_QUIET|MTX_NOPROFILE);
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}
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}
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#else
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static inline void lock_profile_init(void) {;}
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#endif
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void
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assert_mtx(struct lock_object *lock, int what)
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{
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mtx_assert((struct mtx *)lock, what);
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}
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void
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lock_mtx(struct lock_object *lock, int how)
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{
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mtx_lock((struct mtx *)lock);
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}
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void
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lock_spin(struct lock_object *lock, int how)
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{
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panic("spin locks can only use msleep_spin");
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}
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int
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unlock_mtx(struct lock_object *lock)
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{
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struct mtx *m;
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m = (struct mtx *)lock;
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mtx_assert(m, MA_OWNED | MA_NOTRECURSED);
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mtx_unlock(m);
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return (0);
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}
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int
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unlock_spin(struct lock_object *lock)
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{
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panic("spin locks can only use msleep_spin");
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}
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/*
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* Function versions of the inlined __mtx_* macros. These are used by
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* modules and can also be called from assembly language if needed.
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*/
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void
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_mtx_lock_flags(struct mtx *m, int opts, const char *file, int line)
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{
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MPASS(curthread != NULL);
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KASSERT(m->mtx_lock != MTX_DESTROYED,
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("mtx_lock() of destroyed mutex @ %s:%d", file, line));
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KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
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("mtx_lock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
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file, line));
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WITNESS_CHECKORDER(&m->lock_object, opts | LOP_NEWORDER | LOP_EXCLUSIVE,
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file, line);
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_get_sleep_lock(m, curthread, opts, file, line);
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LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file,
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line);
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WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line);
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curthread->td_locks++;
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}
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void
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_mtx_unlock_flags(struct mtx *m, int opts, const char *file, int line)
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{
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MPASS(curthread != NULL);
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KASSERT(m->mtx_lock != MTX_DESTROYED,
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("mtx_unlock() of destroyed mutex @ %s:%d", file, line));
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KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
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("mtx_unlock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
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file, line));
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curthread->td_locks--;
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WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line);
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LOCK_LOG_LOCK("UNLOCK", &m->lock_object, opts, m->mtx_recurse, file,
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line);
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mtx_assert(m, MA_OWNED);
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if (m->mtx_recurse == 0)
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lock_profile_release_lock(&m->lock_object);
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_rel_sleep_lock(m, curthread, opts, file, line);
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}
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void
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_mtx_lock_spin_flags(struct mtx *m, int opts, const char *file, int line)
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{
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MPASS(curthread != NULL);
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KASSERT(m->mtx_lock != MTX_DESTROYED,
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("mtx_lock_spin() of destroyed mutex @ %s:%d", file, line));
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KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin,
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("mtx_lock_spin() of sleep mutex %s @ %s:%d",
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m->lock_object.lo_name, file, line));
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WITNESS_CHECKORDER(&m->lock_object, opts | LOP_NEWORDER | LOP_EXCLUSIVE,
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file, line);
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_get_spin_lock(m, curthread, opts, file, line);
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LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file,
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line);
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WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line);
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}
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void
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_mtx_unlock_spin_flags(struct mtx *m, int opts, const char *file, int line)
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{
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MPASS(curthread != NULL);
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KASSERT(m->mtx_lock != MTX_DESTROYED,
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("mtx_unlock_spin() of destroyed mutex @ %s:%d", file, line));
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KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin,
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("mtx_unlock_spin() of sleep mutex %s @ %s:%d",
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m->lock_object.lo_name, file, line));
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WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line);
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LOCK_LOG_LOCK("UNLOCK", &m->lock_object, opts, m->mtx_recurse, file,
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line);
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mtx_assert(m, MA_OWNED);
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_rel_spin_lock(m);
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}
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/*
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* The important part of mtx_trylock{,_flags}()
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* Tries to acquire lock `m.' If this function is called on a mutex that
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* is already owned, it will recursively acquire the lock.
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*/
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int
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_mtx_trylock(struct mtx *m, int opts, const char *file, int line)
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{
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int rval, contested = 0;
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uint64_t waittime = 0;
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MPASS(curthread != NULL);
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KASSERT(m->mtx_lock != MTX_DESTROYED,
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("mtx_trylock() of destroyed mutex @ %s:%d", file, line));
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KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
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("mtx_trylock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
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file, line));
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if (mtx_owned(m) && (m->lock_object.lo_flags & LO_RECURSABLE) != 0) {
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m->mtx_recurse++;
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atomic_set_ptr(&m->mtx_lock, MTX_RECURSED);
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rval = 1;
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} else
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rval = _obtain_lock(m, (uintptr_t)curthread);
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LOCK_LOG_TRY("LOCK", &m->lock_object, opts, rval, file, line);
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if (rval) {
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WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE | LOP_TRYLOCK,
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file, line);
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curthread->td_locks++;
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if (m->mtx_recurse == 0)
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lock_profile_obtain_lock_success(&m->lock_object, contested,
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waittime, file, line);
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}
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return (rval);
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}
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/*
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* _mtx_lock_sleep: the tougher part of acquiring an MTX_DEF lock.
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*
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* We call this if the lock is either contested (i.e. we need to go to
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* sleep waiting for it), or if we need to recurse on it.
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*/
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void
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_mtx_lock_sleep(struct mtx *m, uintptr_t tid, int opts, const char *file,
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int line)
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{
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struct turnstile *ts;
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#ifdef ADAPTIVE_MUTEXES
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volatile struct thread *owner;
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#endif
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#ifdef KTR
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int cont_logged = 0;
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#endif
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int contested = 0;
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uint64_t waittime = 0;
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uintptr_t v;
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if (mtx_owned(m)) {
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KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0,
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("_mtx_lock_sleep: recursed on non-recursive mutex %s @ %s:%d\n",
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m->lock_object.lo_name, file, line));
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m->mtx_recurse++;
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atomic_set_ptr(&m->mtx_lock, MTX_RECURSED);
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if (LOCK_LOG_TEST(&m->lock_object, opts))
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CTR1(KTR_LOCK, "_mtx_lock_sleep: %p recursing", m);
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return;
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}
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lock_profile_obtain_lock_failed(&m->lock_object,
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&contested, &waittime);
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if (LOCK_LOG_TEST(&m->lock_object, opts))
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CTR4(KTR_LOCK,
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"_mtx_lock_sleep: %s contested (lock=%p) at %s:%d",
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m->lock_object.lo_name, (void *)m->mtx_lock, file, line);
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while (!_obtain_lock(m, tid)) {
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ts = turnstile_trywait(&m->lock_object);
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v = m->mtx_lock;
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/*
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* Check if the lock has been released while spinning for
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* the turnstile chain lock.
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*/
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if (v == MTX_UNOWNED) {
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turnstile_cancel(ts);
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cpu_spinwait();
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continue;
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}
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MPASS(v != MTX_CONTESTED);
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/*
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* If the mutex isn't already contested and a failure occurs
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* setting the contested bit, the mutex was either released
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* or the state of the MTX_RECURSED bit changed.
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*/
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if ((v & MTX_CONTESTED) == 0 &&
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!atomic_cmpset_ptr(&m->mtx_lock, v, v | MTX_CONTESTED)) {
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turnstile_cancel(ts);
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cpu_spinwait();
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continue;
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}
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#ifdef ADAPTIVE_MUTEXES
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/*
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* If the current owner of the lock is executing on another
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* CPU, spin instead of blocking.
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*/
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owner = (struct thread *)(v & ~MTX_FLAGMASK);
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#ifdef ADAPTIVE_GIANT
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if (TD_IS_RUNNING(owner))
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#else
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if (m != &Giant && TD_IS_RUNNING(owner))
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#endif
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{
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turnstile_cancel(ts);
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while (mtx_owner(m) == owner && TD_IS_RUNNING(owner)) {
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cpu_spinwait();
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}
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continue;
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}
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#endif /* ADAPTIVE_MUTEXES */
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/*
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* We definitely must sleep for this lock.
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*/
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mtx_assert(m, MA_NOTOWNED);
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#ifdef KTR
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if (!cont_logged) {
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CTR6(KTR_CONTENTION,
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"contention: %p at %s:%d wants %s, taken by %s:%d",
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(void *)tid, file, line, m->lock_object.lo_name,
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WITNESS_FILE(&m->lock_object),
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WITNESS_LINE(&m->lock_object));
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cont_logged = 1;
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}
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#endif
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/*
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* Block on the turnstile.
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*/
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turnstile_wait(ts, mtx_owner(m), TS_EXCLUSIVE_QUEUE);
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}
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#ifdef KTR
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if (cont_logged) {
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CTR4(KTR_CONTENTION,
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"contention end: %s acquired by %p at %s:%d",
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m->lock_object.lo_name, (void *)tid, file, line);
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}
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#endif
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lock_profile_obtain_lock_success(&m->lock_object, contested,
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waittime, (file), (line));
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}
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static void
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_mtx_lock_spin_failed(struct mtx *m)
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{
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struct thread *td;
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td = mtx_owner(m);
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/* If the mutex is unlocked, try again. */
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if (td == NULL)
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return;
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printf( "spin lock %p (%s) held by %p (tid %d) too long\n",
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m, m->lock_object.lo_name, td, td->td_tid);
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#ifdef WITNESS
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witness_display_spinlock(&m->lock_object, td);
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#endif
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panic("spin lock held too long");
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}
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#ifdef SMP
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/*
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* _mtx_lock_spin: the tougher part of acquiring an MTX_SPIN lock.
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*
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* This is only called if we need to actually spin for the lock. Recursion
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* is handled inline.
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*/
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void
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_mtx_lock_spin(struct mtx *m, uintptr_t tid, int opts, const char *file,
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int line)
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{
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int i = 0, contested = 0;
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uint64_t waittime = 0;
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if (LOCK_LOG_TEST(&m->lock_object, opts))
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CTR1(KTR_LOCK, "_mtx_lock_spin: %p spinning", m);
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lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime);
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while (!_obtain_lock(m, tid)) {
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/* Give interrupts a chance while we spin. */
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spinlock_exit();
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while (m->mtx_lock != MTX_UNOWNED) {
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if (i++ < 10000000) {
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cpu_spinwait();
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continue;
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}
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if (i < 60000000 || kdb_active || panicstr != NULL)
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DELAY(1);
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else
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_mtx_lock_spin_failed(m);
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cpu_spinwait();
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}
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spinlock_enter();
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}
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if (LOCK_LOG_TEST(&m->lock_object, opts))
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CTR1(KTR_LOCK, "_mtx_lock_spin: %p spin done", m);
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lock_profile_obtain_lock_success(&m->lock_object, contested,
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waittime, (file), (line));
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}
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#endif /* SMP */
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void
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_thread_lock_flags(struct thread *td, int opts, const char *file, int line)
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{
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struct mtx *m;
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uintptr_t tid;
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int i, contested;
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uint64_t waittime;
|
|
|
|
|
|
contested = i = 0;
|
|
waittime = 0;
|
|
tid = (uintptr_t)curthread;
|
|
for (;;) {
|
|
retry:
|
|
spinlock_enter();
|
|
m = td->td_lock;
|
|
WITNESS_CHECKORDER(&m->lock_object,
|
|
opts | LOP_NEWORDER | LOP_EXCLUSIVE, file, line);
|
|
while (!_obtain_lock(m, tid)) {
|
|
if (m->mtx_lock == tid) {
|
|
m->mtx_recurse++;
|
|
break;
|
|
}
|
|
lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime);
|
|
/* Give interrupts a chance while we spin. */
|
|
spinlock_exit();
|
|
while (m->mtx_lock != MTX_UNOWNED) {
|
|
if (i++ < 10000000)
|
|
cpu_spinwait();
|
|
else if (i < 60000000 ||
|
|
kdb_active || panicstr != NULL)
|
|
DELAY(1);
|
|
else
|
|
_mtx_lock_spin_failed(m);
|
|
cpu_spinwait();
|
|
if (m != td->td_lock)
|
|
goto retry;
|
|
}
|
|
spinlock_enter();
|
|
}
|
|
if (m == td->td_lock)
|
|
break;
|
|
_rel_spin_lock(m); /* does spinlock_exit() */
|
|
}
|
|
lock_profile_obtain_lock_success(&m->lock_object, contested,
|
|
waittime, (file), (line));
|
|
WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line);
|
|
}
|
|
|
|
struct mtx *
|
|
thread_lock_block(struct thread *td)
|
|
{
|
|
struct mtx *lock;
|
|
|
|
spinlock_enter();
|
|
THREAD_LOCK_ASSERT(td, MA_OWNED);
|
|
lock = td->td_lock;
|
|
td->td_lock = &blocked_lock;
|
|
mtx_unlock_spin(lock);
|
|
|
|
return (lock);
|
|
}
|
|
|
|
void
|
|
thread_lock_unblock(struct thread *td, struct mtx *new)
|
|
{
|
|
mtx_assert(new, MA_OWNED);
|
|
MPASS(td->td_lock == &blocked_lock);
|
|
atomic_store_rel_ptr((volatile void *)&td->td_lock, (uintptr_t)new);
|
|
spinlock_exit();
|
|
}
|
|
|
|
void
|
|
thread_lock_set(struct thread *td, struct mtx *new)
|
|
{
|
|
struct mtx *lock;
|
|
|
|
mtx_assert(new, MA_OWNED);
|
|
THREAD_LOCK_ASSERT(td, MA_OWNED);
|
|
lock = td->td_lock;
|
|
td->td_lock = new;
|
|
mtx_unlock_spin(lock);
|
|
}
|
|
|
|
/*
|
|
* _mtx_unlock_sleep: the tougher part of releasing an MTX_DEF lock.
|
|
*
|
|
* We are only called here if the lock is recursed or contested (i.e. we
|
|
* need to wake up a blocked thread).
|
|
*/
|
|
void
|
|
_mtx_unlock_sleep(struct mtx *m, int opts, const char *file, int line)
|
|
{
|
|
struct turnstile *ts;
|
|
|
|
if (mtx_recursed(m)) {
|
|
if (--(m->mtx_recurse) == 0)
|
|
atomic_clear_ptr(&m->mtx_lock, MTX_RECURSED);
|
|
if (LOCK_LOG_TEST(&m->lock_object, opts))
|
|
CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p unrecurse", m);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* We have to lock the chain before the turnstile so this turnstile
|
|
* can be removed from the hash list if it is empty.
|
|
*/
|
|
turnstile_chain_lock(&m->lock_object);
|
|
ts = turnstile_lookup(&m->lock_object);
|
|
if (LOCK_LOG_TEST(&m->lock_object, opts))
|
|
CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p contested", m);
|
|
|
|
#ifdef ADAPTIVE_MUTEXES
|
|
if (ts == NULL) {
|
|
_release_lock_quick(m);
|
|
if (LOCK_LOG_TEST(&m->lock_object, opts))
|
|
CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p no sleepers", m);
|
|
turnstile_chain_unlock(&m->lock_object);
|
|
return;
|
|
}
|
|
#else
|
|
MPASS(ts != NULL);
|
|
#endif
|
|
turnstile_broadcast(ts, TS_EXCLUSIVE_QUEUE);
|
|
_release_lock_quick(m);
|
|
/*
|
|
* This turnstile is now no longer associated with the mutex. We can
|
|
* unlock the chain lock so a new turnstile may take it's place.
|
|
*/
|
|
turnstile_unpend(ts, TS_EXCLUSIVE_LOCK);
|
|
turnstile_chain_unlock(&m->lock_object);
|
|
}
|
|
|
|
/*
|
|
* All the unlocking of MTX_SPIN locks is done inline.
|
|
* See the _rel_spin_lock() macro for the details.
|
|
*/
|
|
|
|
/*
|
|
* The backing function for the INVARIANTS-enabled mtx_assert()
|
|
*/
|
|
#ifdef INVARIANT_SUPPORT
|
|
void
|
|
_mtx_assert(struct mtx *m, int what, const char *file, int line)
|
|
{
|
|
|
|
if (panicstr != NULL || dumping)
|
|
return;
|
|
switch (what) {
|
|
case MA_OWNED:
|
|
case MA_OWNED | MA_RECURSED:
|
|
case MA_OWNED | MA_NOTRECURSED:
|
|
if (!mtx_owned(m))
|
|
panic("mutex %s not owned at %s:%d",
|
|
m->lock_object.lo_name, file, line);
|
|
if (mtx_recursed(m)) {
|
|
if ((what & MA_NOTRECURSED) != 0)
|
|
panic("mutex %s recursed at %s:%d",
|
|
m->lock_object.lo_name, file, line);
|
|
} else if ((what & MA_RECURSED) != 0) {
|
|
panic("mutex %s unrecursed at %s:%d",
|
|
m->lock_object.lo_name, file, line);
|
|
}
|
|
break;
|
|
case MA_NOTOWNED:
|
|
if (mtx_owned(m))
|
|
panic("mutex %s owned at %s:%d",
|
|
m->lock_object.lo_name, file, line);
|
|
break;
|
|
default:
|
|
panic("unknown mtx_assert at %s:%d", file, line);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* The MUTEX_DEBUG-enabled mtx_validate()
|
|
*
|
|
* Most of these checks have been moved off into the LO_INITIALIZED flag
|
|
* maintained by the witness code.
|
|
*/
|
|
#ifdef MUTEX_DEBUG
|
|
|
|
void mtx_validate(struct mtx *);
|
|
|
|
void
|
|
mtx_validate(struct mtx *m)
|
|
{
|
|
|
|
/*
|
|
* XXX: When kernacc() does not require Giant we can reenable this check
|
|
*/
|
|
#ifdef notyet
|
|
/*
|
|
* Can't call kernacc() from early init386(), especially when
|
|
* initializing Giant mutex, because some stuff in kernacc()
|
|
* requires Giant itself.
|
|
*/
|
|
if (!cold)
|
|
if (!kernacc((caddr_t)m, sizeof(m),
|
|
VM_PROT_READ | VM_PROT_WRITE))
|
|
panic("Can't read and write to mutex %p", m);
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* General init routine used by the MTX_SYSINIT() macro.
|
|
*/
|
|
void
|
|
mtx_sysinit(void *arg)
|
|
{
|
|
struct mtx_args *margs = arg;
|
|
|
|
mtx_init(margs->ma_mtx, margs->ma_desc, NULL, margs->ma_opts);
|
|
}
|
|
|
|
/*
|
|
* Mutex initialization routine; initialize lock `m' of type contained in
|
|
* `opts' with options contained in `opts' and name `name.' The optional
|
|
* lock type `type' is used as a general lock category name for use with
|
|
* witness.
|
|
*/
|
|
void
|
|
mtx_init(struct mtx *m, const char *name, const char *type, int opts)
|
|
{
|
|
struct lock_class *class;
|
|
int flags;
|
|
|
|
MPASS((opts & ~(MTX_SPIN | MTX_QUIET | MTX_RECURSE |
|
|
MTX_NOWITNESS | MTX_DUPOK | MTX_NOPROFILE)) == 0);
|
|
|
|
#ifdef MUTEX_DEBUG
|
|
/* Diagnostic and error correction */
|
|
mtx_validate(m);
|
|
#endif
|
|
|
|
/* Determine lock class and lock flags. */
|
|
if (opts & MTX_SPIN)
|
|
class = &lock_class_mtx_spin;
|
|
else
|
|
class = &lock_class_mtx_sleep;
|
|
flags = 0;
|
|
if (opts & MTX_QUIET)
|
|
flags |= LO_QUIET;
|
|
if (opts & MTX_RECURSE)
|
|
flags |= LO_RECURSABLE;
|
|
if ((opts & MTX_NOWITNESS) == 0)
|
|
flags |= LO_WITNESS;
|
|
if (opts & MTX_DUPOK)
|
|
flags |= LO_DUPOK;
|
|
if (opts & MTX_NOPROFILE)
|
|
flags |= LO_NOPROFILE;
|
|
|
|
/* Initialize mutex. */
|
|
m->mtx_lock = MTX_UNOWNED;
|
|
m->mtx_recurse = 0;
|
|
|
|
lock_init(&m->lock_object, class, name, type, flags);
|
|
}
|
|
|
|
/*
|
|
* Remove lock `m' from all_mtx queue. We don't allow MTX_QUIET to be
|
|
* passed in as a flag here because if the corresponding mtx_init() was
|
|
* called with MTX_QUIET set, then it will already be set in the mutex's
|
|
* flags.
|
|
*/
|
|
void
|
|
mtx_destroy(struct mtx *m)
|
|
{
|
|
|
|
if (!mtx_owned(m))
|
|
MPASS(mtx_unowned(m));
|
|
else {
|
|
MPASS((m->mtx_lock & (MTX_RECURSED|MTX_CONTESTED)) == 0);
|
|
|
|
/* Perform the non-mtx related part of mtx_unlock_spin(). */
|
|
if (LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin)
|
|
spinlock_exit();
|
|
else
|
|
curthread->td_locks--;
|
|
|
|
/* Tell witness this isn't locked to make it happy. */
|
|
WITNESS_UNLOCK(&m->lock_object, LOP_EXCLUSIVE, __FILE__,
|
|
__LINE__);
|
|
}
|
|
|
|
m->mtx_lock = MTX_DESTROYED;
|
|
lock_destroy(&m->lock_object);
|
|
}
|
|
|
|
/*
|
|
* Intialize the mutex code and system mutexes. This is called from the MD
|
|
* startup code prior to mi_startup(). The per-CPU data space needs to be
|
|
* setup before this is called.
|
|
*/
|
|
void
|
|
mutex_init(void)
|
|
{
|
|
|
|
/* Setup turnstiles so that sleep mutexes work. */
|
|
init_turnstiles();
|
|
|
|
/*
|
|
* Initialize mutexes.
|
|
*/
|
|
mtx_init(&Giant, "Giant", NULL, MTX_DEF | MTX_RECURSE);
|
|
mtx_init(&blocked_lock, "blocked lock", NULL, MTX_SPIN);
|
|
blocked_lock.mtx_lock = 0xdeadc0de; /* Always blocked. */
|
|
mtx_init(&proc0.p_mtx, "process lock", NULL, MTX_DEF | MTX_DUPOK);
|
|
mtx_init(&proc0.p_slock, "process slock", NULL, MTX_SPIN | MTX_RECURSE);
|
|
mtx_init(&devmtx, "cdev", NULL, MTX_DEF);
|
|
mtx_lock(&Giant);
|
|
|
|
lock_profile_init();
|
|
}
|
|
|
|
#ifdef DDB
|
|
void
|
|
db_show_mtx(struct lock_object *lock)
|
|
{
|
|
struct thread *td;
|
|
struct mtx *m;
|
|
|
|
m = (struct mtx *)lock;
|
|
|
|
db_printf(" flags: {");
|
|
if (LOCK_CLASS(lock) == &lock_class_mtx_spin)
|
|
db_printf("SPIN");
|
|
else
|
|
db_printf("DEF");
|
|
if (m->lock_object.lo_flags & LO_RECURSABLE)
|
|
db_printf(", RECURSE");
|
|
if (m->lock_object.lo_flags & LO_DUPOK)
|
|
db_printf(", DUPOK");
|
|
db_printf("}\n");
|
|
db_printf(" state: {");
|
|
if (mtx_unowned(m))
|
|
db_printf("UNOWNED");
|
|
else if (mtx_destroyed(m))
|
|
db_printf("DESTROYED");
|
|
else {
|
|
db_printf("OWNED");
|
|
if (m->mtx_lock & MTX_CONTESTED)
|
|
db_printf(", CONTESTED");
|
|
if (m->mtx_lock & MTX_RECURSED)
|
|
db_printf(", RECURSED");
|
|
}
|
|
db_printf("}\n");
|
|
if (!mtx_unowned(m) && !mtx_destroyed(m)) {
|
|
td = mtx_owner(m);
|
|
db_printf(" owner: %p (tid %d, pid %d, \"%s\")\n", td,
|
|
td->td_tid, td->td_proc->p_pid, td->td_name);
|
|
if (mtx_recursed(m))
|
|
db_printf(" recursed: %d\n", m->mtx_recurse);
|
|
}
|
|
}
|
|
#endif
|