coroutine-sleep: allow qemu_co_sleep_wake that wakes nothing

All callers of qemu_co_sleep_wake are checking whether they are passing
a NULL argument inside the pointer-to-pointer: do the check in
qemu_co_sleep_wake itself.

As a side effect, qemu_co_sleep_wake can be called more than once and
it will only wake the coroutine once; after the first time, the argument
will be set to NULL via *sleep_state->user_state_pointer.  However, this
would not be safe unless co_sleep_cb keeps using the QemuCoSleepState*
directly, so make it go through the pointer-to-pointer instead.

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20210517100548.28806-4-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Paolo Bonzini 2021-05-17 12:05:45 +02:00 committed by Stefan Hajnoczi
parent fb74a286fe
commit eaee072085
3 changed files with 15 additions and 18 deletions

View file

@ -289,9 +289,7 @@ static void coroutine_fn nbd_client_co_drain_begin(BlockDriverState *bs)
BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
s->drained = true;
if (s->connection_co_sleep_ns_state) {
qemu_co_sleep_wake(s->connection_co_sleep_ns_state);
}
qemu_co_sleep_wake(s->connection_co_sleep_ns_state);
nbd_co_establish_connection_cancel(bs, false);
@ -330,9 +328,7 @@ static void nbd_teardown_connection(BlockDriverState *bs)
s->state = NBD_CLIENT_QUIT;
if (s->connection_co) {
if (s->connection_co_sleep_ns_state) {
qemu_co_sleep_wake(s->connection_co_sleep_ns_state);
}
qemu_co_sleep_wake(s->connection_co_sleep_ns_state);
nbd_co_establish_connection_cancel(bs, true);
}
if (qemu_in_coroutine()) {