diff options
Diffstat (limited to 'sys/kern/kern_sx.c')
| -rw-r--r-- | sys/kern/kern_sx.c | 73 |
1 files changed, 63 insertions, 10 deletions
diff --git a/sys/kern/kern_sx.c b/sys/kern/kern_sx.c index a1c576f..0f39097 100644 --- a/sys/kern/kern_sx.c +++ b/sys/kern/kern_sx.c @@ -46,43 +46,68 @@ #include <sys/systm.h> #include <sys/ktr.h> #include <sys/condvar.h> +#include <sys/lock.h> #include <sys/mutex.h> #include <sys/sx.h> +/* + * XXX: We don't implement the LO_RECURSED flag for this lock yet. + * We could do this by walking p_sleeplocks if we really wanted to. + */ +struct lock_class lock_class_sx = { + "sx", + LC_SLEEPLOCK | LC_SLEEPABLE | LC_RECURSABLE +}; + void sx_init(struct sx *sx, const char *description) { - - mtx_init(&sx->sx_lock, description, MTX_DEF); + struct lock_object *lock; + + bzero(sx, sizeof(*sx)); + lock = &sx->sx_object; + lock->lo_class = &lock_class_sx; + lock->lo_name = description; + lock->lo_flags = LO_WITNESS | LO_SLEEPABLE; + mtx_init(&sx->sx_lock, "sx backing lock", + MTX_DEF | MTX_NOWITNESS | MTX_QUIET); sx->sx_cnt = 0; cv_init(&sx->sx_shrd_cv, description); sx->sx_shrd_wcnt = 0; cv_init(&sx->sx_excl_cv, description); - sx->sx_descr = description; sx->sx_excl_wcnt = 0; sx->sx_xholder = NULL; + + LOCK_LOG_INIT(lock, 0); + + WITNESS_INIT(lock); } void sx_destroy(struct sx *sx) { + LOCK_LOG_DESTROY(&sx->sx_object, 0); + KASSERT((sx->sx_cnt == 0 && sx->sx_shrd_wcnt == 0 && sx->sx_excl_wcnt == - 0), ("%s (%s): holders or waiters\n", __FUNCTION__, sx->sx_descr)); + 0), ("%s (%s): holders or waiters\n", __FUNCTION__, + sx->sx_object.lo_name)); mtx_destroy(&sx->sx_lock); cv_destroy(&sx->sx_shrd_cv); cv_destroy(&sx->sx_excl_cv); + + WITNESS_DESTROY(&sx->sx_object); } void -sx_slock(struct sx *sx) +_sx_slock(struct sx *sx, const char *file, int line) { mtx_lock(&sx->sx_lock); KASSERT(sx->sx_xholder != curproc, ("%s (%s): trying to get slock while xlock is held\n", __FUNCTION__, - sx->sx_descr)); + sx->sx_object.lo_name)); /* * Loop in case we lose the race for lock acquisition. @@ -96,11 +121,17 @@ sx_slock(struct sx *sx) /* Acquire a shared lock. */ sx->sx_cnt++; +#ifdef WITNESS + sx->sx_object.lo_flags |= LO_LOCKED; +#endif + LOCK_LOG_LOCK("SLOCK", &sx->sx_object, 0, 0, file, line); + WITNESS_LOCK(&sx->sx_object, 0, file, line); + mtx_unlock(&sx->sx_lock); } void -sx_xlock(struct sx *sx) +_sx_xlock(struct sx *sx, const char *file, int line) { mtx_lock(&sx->sx_lock); @@ -113,7 +144,8 @@ sx_xlock(struct sx *sx) * INVARIANTS. */ KASSERT(sx->sx_xholder != curproc, - ("%s (%s): xlock already held", __FUNCTION__, sx->sx_descr)); + ("%s (%s): xlock already held @ %s:%d", __FUNCTION__, + sx->sx_object.lo_name, file, line)); /* Loop in case we lose the race for lock acquisition. */ while (sx->sx_cnt != 0) { @@ -128,16 +160,28 @@ sx_xlock(struct sx *sx) sx->sx_cnt--; sx->sx_xholder = curproc; +#ifdef WITNESS + sx->sx_object.lo_flags |= LO_LOCKED; +#endif + LOCK_LOG_LOCK("XLOCK", &sx->sx_object, 0, 0, file, line); + WITNESS_LOCK(&sx->sx_object, 0, file, line); + mtx_unlock(&sx->sx_lock); } void -sx_sunlock(struct sx *sx) +_sx_sunlock(struct sx *sx, const char *file, int line) { mtx_lock(&sx->sx_lock); _SX_ASSERT_SLOCKED(sx); +#ifdef WITNESS + if (sx->sx_cnt == 0) + sx->sx_object.lo_flags &= ~LO_LOCKED; +#endif + WITNESS_UNLOCK(&sx->sx_object, 0, file, line); + /* Release. */ sx->sx_cnt--; @@ -153,17 +197,24 @@ sx_sunlock(struct sx *sx) } else if (sx->sx_shrd_wcnt > 0) cv_broadcast(&sx->sx_shrd_cv); + LOCK_LOG_LOCK("SUNLOCK", &sx->sx_object, 0, 0, file, line); + mtx_unlock(&sx->sx_lock); } void -sx_xunlock(struct sx *sx) +_sx_xunlock(struct sx *sx, const char *file, int line) { mtx_lock(&sx->sx_lock); _SX_ASSERT_XLOCKED(sx); MPASS(sx->sx_cnt == -1); +#ifdef WITNESS + sx->sx_object.lo_flags &= ~LO_LOCKED; +#endif + WITNESS_UNLOCK(&sx->sx_object, 0, file, line); + /* Release. */ sx->sx_cnt++; sx->sx_xholder = NULL; @@ -176,5 +227,7 @@ sx_xunlock(struct sx *sx) else if (sx->sx_excl_wcnt > 0) cv_signal(&sx->sx_excl_cv); + LOCK_LOG_LOCK("XUNLOCK", &sx->sx_object, 0, 0, file, line); + mtx_unlock(&sx->sx_lock); } |
