block/throttle-groups: Make incref/decref public

Throttle groups are not necessarily referenced by BDSs alone; a later
patch will essentially allow BBs to reference them, too. Make the
ref/unref functions public so that reference can be properly accounted
for.

Their interface is slightly adjusted in that they return and take a
ThrottleState pointer, respectively, instead of a ThrottleGroup pointer.
Functionally, they are equivalent, but since ThrottleGroup is not meant
to be used outside of block/throttle-groups.c, ThrottleState is easier
to handle.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Max Reitz 2015-10-19 17:53:23 +02:00 committed by Kevin Wolf
parent 373340b26c
commit 973f2ddf7b
2 changed files with 14 additions and 8 deletions

View file

@ -76,9 +76,9 @@ static QTAILQ_HEAD(, ThrottleGroup) throttle_groups =
* created.
*
* @name: the name of the ThrottleGroup
* @ret: the ThrottleGroup
* @ret: the ThrottleState member of the ThrottleGroup
*/
static ThrottleGroup *throttle_group_incref(const char *name)
ThrottleState *throttle_group_incref(const char *name)
{
ThrottleGroup *tg = NULL;
ThrottleGroup *iter;
@ -108,7 +108,7 @@ static ThrottleGroup *throttle_group_incref(const char *name)
qemu_mutex_unlock(&throttle_groups_lock);
return tg;
return &tg->ts;
}
/* Decrease the reference count of a ThrottleGroup.
@ -116,10 +116,12 @@ static ThrottleGroup *throttle_group_incref(const char *name)
* When the reference count reaches zero the ThrottleGroup is
* destroyed.
*
* @tg: The ThrottleGroup to unref
* @ts: The ThrottleGroup to unref, given by its ThrottleState member
*/
static void throttle_group_unref(ThrottleGroup *tg)
void throttle_group_unref(ThrottleState *ts)
{
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
qemu_mutex_lock(&throttle_groups_lock);
if (--tg->refcount == 0) {
QTAILQ_REMOVE(&throttle_groups, tg, list);
@ -401,7 +403,8 @@ static void write_timer_cb(void *opaque)
void throttle_group_register_bs(BlockDriverState *bs, const char *groupname)
{
int i;
ThrottleGroup *tg = throttle_group_incref(groupname);
ThrottleState *ts = throttle_group_incref(groupname);
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
int clock_type = QEMU_CLOCK_REALTIME;
if (qtest_enabled()) {
@ -409,7 +412,7 @@ void throttle_group_register_bs(BlockDriverState *bs, const char *groupname)
clock_type = QEMU_CLOCK_VIRTUAL;
}
bs->throttle_state = &tg->ts;
bs->throttle_state = ts;
qemu_mutex_lock(&tg->lock);
/* If the ThrottleGroup is new set this BlockDriverState as the token */
@ -461,7 +464,7 @@ void throttle_group_unregister_bs(BlockDriverState *bs)
throttle_timers_destroy(&bs->throttle_timers);
qemu_mutex_unlock(&tg->lock);
throttle_group_unref(tg);
throttle_group_unref(&tg->ts);
bs->throttle_state = NULL;
}

View file

@ -30,6 +30,9 @@
const char *throttle_group_get_name(BlockDriverState *bs);
ThrottleState *throttle_group_incref(const char *name);
void throttle_group_unref(ThrottleState *ts);
void throttle_group_config(BlockDriverState *bs, ThrottleConfig *cfg);
void throttle_group_get_config(BlockDriverState *bs, ThrottleConfig *cfg);