diff options
Diffstat (limited to 'contrib/ntp/sntp/libevent/bufferevent_pair.c')
| -rw-r--r-- | contrib/ntp/sntp/libevent/bufferevent_pair.c | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/contrib/ntp/sntp/libevent/bufferevent_pair.c b/contrib/ntp/sntp/libevent/bufferevent_pair.c index 4340f23723c0..8154e17be732 100644 --- a/contrib/ntp/sntp/libevent/bufferevent_pair.c +++ b/contrib/ntp/sntp/libevent/bufferevent_pair.c @@ -45,6 +45,8 @@ struct bufferevent_pair { struct bufferevent_private bev; struct bufferevent_pair *partner; + /* For ->destruct() lock checking */ + struct bufferevent_pair *unlinked_partner; }; @@ -265,11 +267,40 @@ be_pair_unlink(struct bufferevent *bev) struct bufferevent_pair *bev_p = upcast(bev); if (bev_p->partner) { + bev_p->unlinked_partner = bev_p->partner; bev_p->partner->partner = NULL; bev_p->partner = NULL; } } +/* Free *shared* lock in the latest be (since we share it between two of them). */ +static void +be_pair_destruct(struct bufferevent *bev) +{ + struct bufferevent_pair *bev_p = upcast(bev); + + /* Transfer ownership of the lock into partner, otherwise we will use + * already free'd lock during freeing second bev, see next example: + * + * bev1->own_lock = 1 + * bev2->own_lock = 0 + * bev2->lock = bev1->lock + * + * bufferevent_free(bev1) # refcnt == 0 -> unlink + * bufferevent_free(bev2) # refcnt == 0 -> unlink + * + * event_base_free() -> finilizers -> EVTHREAD_FREE_LOCK(bev1->lock) + * -> BEV_LOCK(bev2->lock) <-- already freed + * + * Where bev1 == pair[0], bev2 == pair[1]. + */ + if (bev_p->unlinked_partner && bev_p->bev.own_lock) { + bev_p->unlinked_partner->bev.own_lock = 1; + bev_p->bev.own_lock = 0; + } + bev_p->unlinked_partner = NULL; +} + static int be_pair_flush(struct bufferevent *bev, short iotype, enum bufferevent_flush_mode mode) @@ -320,7 +351,7 @@ const struct bufferevent_ops bufferevent_ops_pair = { be_pair_enable, be_pair_disable, be_pair_unlink, - NULL, /* be_pair_destruct, */ + be_pair_destruct, bufferevent_generic_adj_timeouts_, be_pair_flush, NULL, /* ctrl */ |