2d96f0b145
struct lock_instance that is stored in the per-process and per-CPU lock lists. Previously, the lock lists just kept a pointer to each lock held. That pointer is now replaced by a lock instance which contains a pointer to the lock object, the file and line of the last acquisition of a lock, and various flags about a lock including its recursion count. - If we sleep while holding a sleepable lock, then mark that lock instance as having slept and ignore any lock order violations that occur while acquiring Giant when we wake up with slept locks. This is ok because of Giant's special nature. - Allow witness to differentiate between shared and exclusive locks and unlocks of a lock. Witness will now detect the case when a lock is acquired first in one mode and then in another. Mutexes are always locked and unlocked exclusively. Witness will also now detect the case where a process attempts to unlock a shared lock while holding an exclusive lock and vice versa. - Fix a bug in the lock list implementation where we used the wrong constant to detect the case where a lock list entry was full.
679 lines
17 KiB
C
679 lines
17 KiB
C
/*-
|
|
* Copyright (c) 1998 Berkeley Software Design, Inc. 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. Berkeley Software Design Inc's name may not be used to endorse or
|
|
* promote products derived from this software without specific prior
|
|
* written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``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 BERKELEY SOFTWARE DESIGN INC 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.
|
|
*
|
|
* from BSDI $Id: mutex_witness.c,v 1.1.2.20 2000/04/27 03:10:27 cp Exp $
|
|
* and BSDI $Id: synch_machdep.c,v 2.3.2.39 2000/04/27 03:10:25 cp Exp $
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
/*
|
|
* Machine independent bits of mutex implementation and implementation of
|
|
* `witness' structure & related debugging routines.
|
|
*/
|
|
|
|
/*
|
|
* Main Entry: witness
|
|
* Pronunciation: 'wit-n&s
|
|
* Function: noun
|
|
* Etymology: Middle English witnesse, from Old English witnes knowledge,
|
|
* testimony, witness, from 2wit
|
|
* Date: before 12th century
|
|
* 1 : attestation of a fact or event : TESTIMONY
|
|
* 2 : one that gives evidence; specifically : one who testifies in
|
|
* a cause or before a judicial tribunal
|
|
* 3 : one asked to be present at a transaction so as to be able to
|
|
* testify to its having taken place
|
|
* 4 : one who has personal knowledge of something
|
|
* 5 a : something serving as evidence or proof : SIGN
|
|
* b : public affirmation by word or example of usually
|
|
* religious faith or conviction <the heroic witness to divine
|
|
* life -- Pilot>
|
|
* 6 capitalized : a member of the Jehovah's Witnesses
|
|
*/
|
|
|
|
#include "opt_ddb.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/bus.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mutex.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/vmmeter.h>
|
|
#include <sys/ktr.h>
|
|
|
|
#include <machine/atomic.h>
|
|
#include <machine/bus.h>
|
|
#include <machine/clock.h>
|
|
#include <machine/cpu.h>
|
|
|
|
#include <ddb/ddb.h>
|
|
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_extern.h>
|
|
|
|
/*
|
|
* Internal utility macros.
|
|
*/
|
|
#define mtx_unowned(m) ((m)->mtx_lock == MTX_UNOWNED)
|
|
|
|
#define mtx_owner(m) (mtx_unowned((m)) ? NULL \
|
|
: (struct proc *)((m)->mtx_lock & MTX_FLAGMASK))
|
|
|
|
#define SET_PRIO(p, pri) (p)->p_pri.pri_level = (pri)
|
|
|
|
/*
|
|
* Lock classes for sleep and spin mutexes.
|
|
*/
|
|
struct lock_class lock_class_mtx_sleep = {
|
|
"sleep mutex",
|
|
LC_SLEEPLOCK | LC_RECURSABLE
|
|
};
|
|
struct lock_class lock_class_mtx_spin = {
|
|
"spin mutex",
|
|
LC_SPINLOCK | LC_RECURSABLE
|
|
};
|
|
|
|
/*
|
|
* Prototypes for non-exported routines.
|
|
*/
|
|
static void propagate_priority(struct proc *);
|
|
|
|
static void
|
|
propagate_priority(struct proc *p)
|
|
{
|
|
int pri = p->p_pri.pri_level;
|
|
struct mtx *m = p->p_blocked;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
for (;;) {
|
|
struct proc *p1;
|
|
|
|
p = mtx_owner(m);
|
|
|
|
if (p == NULL) {
|
|
/*
|
|
* This really isn't quite right. Really
|
|
* ought to bump priority of process that
|
|
* next acquires the mutex.
|
|
*/
|
|
MPASS(m->mtx_lock == MTX_CONTESTED);
|
|
return;
|
|
}
|
|
|
|
MPASS(p->p_magic == P_MAGIC);
|
|
KASSERT(p->p_stat != SSLEEP, ("sleeping process owns a mutex"));
|
|
if (p->p_pri.pri_level <= pri)
|
|
return;
|
|
|
|
/*
|
|
* Bump this process' priority.
|
|
*/
|
|
SET_PRIO(p, pri);
|
|
|
|
/*
|
|
* If lock holder is actually running, just bump priority.
|
|
*/
|
|
if (p->p_oncpu != NOCPU) {
|
|
MPASS(p->p_stat == SRUN || p->p_stat == SZOMB || p->p_stat == SSTOP);
|
|
return;
|
|
}
|
|
|
|
#ifndef SMP
|
|
/*
|
|
* For UP, we check to see if p is curproc (this shouldn't
|
|
* ever happen however as it would mean we are in a deadlock.)
|
|
*/
|
|
KASSERT(p != curproc, ("Deadlock detected"));
|
|
#endif
|
|
|
|
/*
|
|
* If on run queue move to new run queue, and
|
|
* quit.
|
|
*/
|
|
if (p->p_stat == SRUN) {
|
|
MPASS(p->p_blocked == NULL);
|
|
remrunqueue(p);
|
|
setrunqueue(p);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If we aren't blocked on a mutex, we should be.
|
|
*/
|
|
KASSERT(p->p_stat == SMTX, (
|
|
"process %d(%s):%d holds %s but isn't blocked on a mutex\n",
|
|
p->p_pid, p->p_comm, p->p_stat,
|
|
m->mtx_object.lo_name));
|
|
|
|
/*
|
|
* Pick up the mutex that p is blocked on.
|
|
*/
|
|
m = p->p_blocked;
|
|
MPASS(m != NULL);
|
|
|
|
/*
|
|
* Check if the proc needs to be moved up on
|
|
* the blocked chain
|
|
*/
|
|
if (p == TAILQ_FIRST(&m->mtx_blocked)) {
|
|
continue;
|
|
}
|
|
|
|
p1 = TAILQ_PREV(p, procqueue, p_procq);
|
|
if (p1->p_pri.pri_level <= pri) {
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Remove proc from blocked chain and determine where
|
|
* it should be moved up to. Since we know that p1 has
|
|
* a lower priority than p, we know that at least one
|
|
* process in the chain has a lower priority and that
|
|
* p1 will thus not be NULL after the loop.
|
|
*/
|
|
TAILQ_REMOVE(&m->mtx_blocked, p, p_procq);
|
|
TAILQ_FOREACH(p1, &m->mtx_blocked, p_procq) {
|
|
MPASS(p1->p_magic == P_MAGIC);
|
|
if (p1->p_pri.pri_level > pri)
|
|
break;
|
|
}
|
|
|
|
MPASS(p1 != NULL);
|
|
TAILQ_INSERT_BEFORE(p1, p, p_procq);
|
|
CTR4(KTR_LOCK,
|
|
"propagate_priority: p %p moved before %p on [%p] %s",
|
|
p, p1, m, m->mtx_object.lo_name);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Function versions of the inlined __mtx_* macros. These are used by
|
|
* modules and can also be called from assembly language if needed.
|
|
*/
|
|
void
|
|
_mtx_lock_flags(struct mtx *m, int opts, const char *file, int line)
|
|
{
|
|
|
|
__mtx_lock_flags(m, opts, file, line);
|
|
}
|
|
|
|
void
|
|
_mtx_unlock_flags(struct mtx *m, int opts, const char *file, int line)
|
|
{
|
|
|
|
__mtx_unlock_flags(m, opts, file, line);
|
|
}
|
|
|
|
void
|
|
_mtx_lock_spin_flags(struct mtx *m, int opts, const char *file, int line)
|
|
{
|
|
|
|
__mtx_lock_spin_flags(m, opts, file, line);
|
|
}
|
|
|
|
void
|
|
_mtx_unlock_spin_flags(struct mtx *m, int opts, const char *file, int line)
|
|
{
|
|
|
|
__mtx_unlock_spin_flags(m, opts, file, line);
|
|
}
|
|
|
|
/*
|
|
* The important part of mtx_trylock{,_flags}()
|
|
* Tries to acquire lock `m.' We do NOT handle recursion here; we assume that
|
|
* if we're called, it's because we know we don't already own this lock.
|
|
*/
|
|
int
|
|
_mtx_trylock(struct mtx *m, int opts, const char *file, int line)
|
|
{
|
|
int rval;
|
|
|
|
MPASS(curproc != NULL);
|
|
|
|
/*
|
|
* _mtx_trylock does not accept MTX_NOSWITCH option.
|
|
*/
|
|
KASSERT((opts & MTX_NOSWITCH) == 0,
|
|
("mtx_trylock() called with invalid option flag(s) %d", opts));
|
|
|
|
rval = _obtain_lock(m, curproc);
|
|
|
|
LOCK_LOG_TRY("LOCK", &m->mtx_object, opts, rval, file, line);
|
|
if (rval) {
|
|
/*
|
|
* We do not handle recursion in _mtx_trylock; see the
|
|
* note at the top of the routine.
|
|
*/
|
|
KASSERT(!mtx_recursed(m),
|
|
("mtx_trylock() called on a recursed mutex"));
|
|
WITNESS_LOCK(&m->mtx_object, opts | LOP_EXCLUSIVE | LOP_TRYLOCK,
|
|
file, line);
|
|
}
|
|
|
|
return (rval);
|
|
}
|
|
|
|
/*
|
|
* _mtx_lock_sleep: the tougher part of acquiring an MTX_DEF lock.
|
|
*
|
|
* We call this if the lock is either contested (i.e. we need to go to
|
|
* sleep waiting for it), or if we need to recurse on it.
|
|
*/
|
|
void
|
|
_mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line)
|
|
{
|
|
struct proc *p = curproc;
|
|
|
|
if ((m->mtx_lock & MTX_FLAGMASK) == (uintptr_t)p) {
|
|
m->mtx_recurse++;
|
|
atomic_set_ptr(&m->mtx_lock, MTX_RECURSED);
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR1(KTR_LOCK, "_mtx_lock_sleep: %p recursing", m);
|
|
return;
|
|
}
|
|
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR4(KTR_LOCK,
|
|
"_mtx_lock_sleep: %s contested (lock=%p) at %s:%d",
|
|
m->mtx_object.lo_name, (void *)m->mtx_lock, file, line);
|
|
|
|
while (!_obtain_lock(m, p)) {
|
|
uintptr_t v;
|
|
struct proc *p1;
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
/*
|
|
* Check if the lock has been released while spinning for
|
|
* the sched_lock.
|
|
*/
|
|
if ((v = m->mtx_lock) == MTX_UNOWNED) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* The mutex was marked contested on release. This means that
|
|
* there are processes blocked on it.
|
|
*/
|
|
if (v == MTX_CONTESTED) {
|
|
p1 = TAILQ_FIRST(&m->mtx_blocked);
|
|
MPASS(p1 != NULL);
|
|
m->mtx_lock = (uintptr_t)p | MTX_CONTESTED;
|
|
|
|
if (p1->p_pri.pri_level < p->p_pri.pri_level)
|
|
SET_PRIO(p, p1->p_pri.pri_level);
|
|
mtx_unlock_spin(&sched_lock);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If the mutex isn't already contested and a failure occurs
|
|
* setting the contested bit, the mutex was either released
|
|
* or the state of the MTX_RECURSED bit changed.
|
|
*/
|
|
if ((v & MTX_CONTESTED) == 0 &&
|
|
!atomic_cmpset_ptr(&m->mtx_lock, (void *)v,
|
|
(void *)(v | MTX_CONTESTED))) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* We deffinately must sleep for this lock.
|
|
*/
|
|
mtx_assert(m, MA_NOTOWNED);
|
|
|
|
#ifdef notyet
|
|
/*
|
|
* If we're borrowing an interrupted thread's VM context, we
|
|
* must clean up before going to sleep.
|
|
*/
|
|
if (p->p_ithd != NULL) {
|
|
struct ithd *it = p->p_ithd;
|
|
|
|
if (it->it_interrupted) {
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR2(KTR_LOCK,
|
|
"_mtx_lock_sleep: %p interrupted %p",
|
|
it, it->it_interrupted);
|
|
intr_thd_fixup(it);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Put us on the list of threads blocked on this mutex.
|
|
*/
|
|
if (TAILQ_EMPTY(&m->mtx_blocked)) {
|
|
p1 = (struct proc *)(m->mtx_lock & MTX_FLAGMASK);
|
|
LIST_INSERT_HEAD(&p1->p_contested, m, mtx_contested);
|
|
TAILQ_INSERT_TAIL(&m->mtx_blocked, p, p_procq);
|
|
} else {
|
|
TAILQ_FOREACH(p1, &m->mtx_blocked, p_procq)
|
|
if (p1->p_pri.pri_level > p->p_pri.pri_level)
|
|
break;
|
|
if (p1)
|
|
TAILQ_INSERT_BEFORE(p1, p, p_procq);
|
|
else
|
|
TAILQ_INSERT_TAIL(&m->mtx_blocked, p, p_procq);
|
|
}
|
|
|
|
/*
|
|
* Save who we're blocked on.
|
|
*/
|
|
p->p_blocked = m;
|
|
p->p_mtxname = m->mtx_object.lo_name;
|
|
p->p_stat = SMTX;
|
|
propagate_priority(p);
|
|
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR3(KTR_LOCK,
|
|
"_mtx_lock_sleep: p %p blocked on [%p] %s", p, m,
|
|
m->mtx_object.lo_name);
|
|
|
|
mi_switch();
|
|
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR3(KTR_LOCK,
|
|
"_mtx_lock_sleep: p %p free from blocked on [%p] %s",
|
|
p, m, m->mtx_object.lo_name);
|
|
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* _mtx_lock_spin: the tougher part of acquiring an MTX_SPIN lock.
|
|
*
|
|
* This is only called if we need to actually spin for the lock. Recursion
|
|
* is handled inline.
|
|
*/
|
|
void
|
|
_mtx_lock_spin(struct mtx *m, int opts, critical_t mtx_crit, const char *file,
|
|
int line)
|
|
{
|
|
int i = 0;
|
|
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR1(KTR_LOCK, "_mtx_lock_spin: %p spinning", m);
|
|
|
|
for (;;) {
|
|
if (_obtain_lock(m, curproc))
|
|
break;
|
|
|
|
/* Give interrupts a chance while we spin. */
|
|
critical_exit(mtx_crit);
|
|
while (m->mtx_lock != MTX_UNOWNED) {
|
|
if (i++ < 1000000)
|
|
continue;
|
|
if (i++ < 6000000)
|
|
DELAY(1);
|
|
#ifdef DDB
|
|
else if (!db_active)
|
|
#else
|
|
else
|
|
#endif
|
|
panic("spin lock %s held by %p for > 5 seconds",
|
|
m->mtx_object.lo_name, (void *)m->mtx_lock);
|
|
}
|
|
mtx_crit = critical_enter();
|
|
}
|
|
|
|
m->mtx_savecrit = mtx_crit;
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR1(KTR_LOCK, "_mtx_lock_spin: %p spin done", m);
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* _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 proc *p, *p1;
|
|
struct mtx *m1;
|
|
int pri;
|
|
|
|
p = curproc;
|
|
|
|
if (mtx_recursed(m)) {
|
|
if (--(m->mtx_recurse) == 0)
|
|
atomic_clear_ptr(&m->mtx_lock, MTX_RECURSED);
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p unrecurse", m);
|
|
return;
|
|
}
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p contested", m);
|
|
|
|
p1 = TAILQ_FIRST(&m->mtx_blocked);
|
|
MPASS(p->p_magic == P_MAGIC);
|
|
MPASS(p1->p_magic == P_MAGIC);
|
|
|
|
TAILQ_REMOVE(&m->mtx_blocked, p1, p_procq);
|
|
|
|
if (TAILQ_EMPTY(&m->mtx_blocked)) {
|
|
LIST_REMOVE(m, mtx_contested);
|
|
_release_lock_quick(m);
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p not held", m);
|
|
} else
|
|
atomic_store_rel_ptr(&m->mtx_lock, (void *)MTX_CONTESTED);
|
|
|
|
pri = PRI_MAX;
|
|
LIST_FOREACH(m1, &p->p_contested, mtx_contested) {
|
|
int cp = TAILQ_FIRST(&m1->mtx_blocked)->p_pri.pri_level;
|
|
if (cp < pri)
|
|
pri = cp;
|
|
}
|
|
|
|
if (pri > p->p_pri.pri_native)
|
|
pri = p->p_pri.pri_native;
|
|
SET_PRIO(p, pri);
|
|
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR2(KTR_LOCK, "_mtx_unlock_sleep: %p contested setrunqueue %p",
|
|
m, p1);
|
|
|
|
p1->p_blocked = NULL;
|
|
p1->p_stat = SRUN;
|
|
setrunqueue(p1);
|
|
|
|
if ((opts & MTX_NOSWITCH) == 0 && p1->p_pri.pri_level < pri) {
|
|
#ifdef notyet
|
|
if (p->p_ithd != NULL) {
|
|
struct ithd *it = p->p_ithd;
|
|
|
|
if (it->it_interrupted) {
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR2(KTR_LOCK,
|
|
"_mtx_unlock_sleep: %p interrupted %p",
|
|
it, it->it_interrupted);
|
|
intr_thd_fixup(it);
|
|
}
|
|
}
|
|
#endif
|
|
setrunqueue(p);
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR2(KTR_LOCK,
|
|
"_mtx_unlock_sleep: %p switching out lock=%p", m,
|
|
(void *)m->mtx_lock);
|
|
|
|
mi_switch();
|
|
if (LOCK_LOG_TEST(&m->mtx_object, opts))
|
|
CTR2(KTR_LOCK, "_mtx_unlock_sleep: %p resuming lock=%p",
|
|
m, (void *)m->mtx_lock);
|
|
}
|
|
|
|
mtx_unlock_spin(&sched_lock);
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
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->mtx_object.lo_name, file, line);
|
|
if (mtx_recursed(m)) {
|
|
if ((what & MA_NOTRECURSED) != 0)
|
|
panic("mutex %s recursed at %s:%d",
|
|
m->mtx_object.lo_name, file, line);
|
|
} else if ((what & MA_RECURSED) != 0) {
|
|
panic("mutex %s unrecursed at %s:%d",
|
|
m->mtx_object.lo_name, file, line);
|
|
}
|
|
break;
|
|
case MA_NOTOWNED:
|
|
if (mtx_owned(m))
|
|
panic("mutex %s owned at %s:%d",
|
|
m->mtx_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 __P((struct mtx *));
|
|
|
|
void
|
|
mtx_validate(struct mtx *m)
|
|
{
|
|
|
|
/*
|
|
* XXX - When kernacc() is fixed on the alpha to handle K0_SEG memory properly
|
|
* we can re-enable the kernacc() checks.
|
|
*/
|
|
#ifndef __alpha__
|
|
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
|
|
|
|
/*
|
|
* Mutex initialization routine; initialize lock `m' of type contained in
|
|
* `opts' with options contained in `opts' and description `description.'
|
|
*/
|
|
void
|
|
mtx_init(struct mtx *m, const char *description, int opts)
|
|
{
|
|
struct lock_object *lock;
|
|
|
|
MPASS((opts & ~(MTX_SPIN | MTX_QUIET | MTX_RECURSE |
|
|
MTX_SLEEPABLE | MTX_NOWITNESS)) == 0);
|
|
|
|
#ifdef MUTEX_DEBUG
|
|
/* Diagnostic and error correction */
|
|
mtx_validate(m);
|
|
#endif
|
|
|
|
bzero(m, sizeof(*m));
|
|
lock = &m->mtx_object;
|
|
if (opts & MTX_SPIN)
|
|
lock->lo_class = &lock_class_mtx_spin;
|
|
else
|
|
lock->lo_class = &lock_class_mtx_sleep;
|
|
lock->lo_name = description;
|
|
if (opts & MTX_QUIET)
|
|
lock->lo_flags = LO_QUIET;
|
|
if (opts & MTX_RECURSE)
|
|
lock->lo_flags |= LO_RECURSABLE;
|
|
if (opts & MTX_SLEEPABLE)
|
|
lock->lo_flags |= LO_SLEEPABLE;
|
|
if ((opts & MTX_NOWITNESS) == 0)
|
|
lock->lo_flags |= LO_WITNESS;
|
|
|
|
m->mtx_lock = MTX_UNOWNED;
|
|
TAILQ_INIT(&m->mtx_blocked);
|
|
|
|
LOCK_LOG_INIT(lock, opts);
|
|
|
|
WITNESS_INIT(lock);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
|
|
LOCK_LOG_DESTROY(&m->mtx_object, 0);
|
|
|
|
if (!mtx_owned(m))
|
|
MPASS(mtx_unowned(m));
|
|
else {
|
|
MPASS((m->mtx_lock & (MTX_RECURSED|MTX_CONTESTED)) == 0);
|
|
|
|
/* Tell witness this isn't locked to make it happy. */
|
|
WITNESS_UNLOCK(&m->mtx_object, LOP_EXCLUSIVE | LOP_NOSWITCH,
|
|
__FILE__, __LINE__);
|
|
}
|
|
|
|
WITNESS_DESTROY(&m->mtx_object);
|
|
}
|