shaba/systemd
1
0
Fork 0
mirror of https://github.com/systemd/systemd.git synced 2025-01-12 13:18:14 +03:00
Code

sd-rtnl: message - don't reference associated rtnl object

Browse Source 
The object is not currently used, so just drop the refenence. If/when we end up
using the object in the future, we must make sure to deal with possible mutual
references between rtnl busses and their queued messages; as is done in sd-bus.
This commit is contained in:
Tom Gundersen 2014-03-23 15:33:24 +01:00
parent bf81e792f3
commit 8c57830308
2 changed files with 31 additions and 75 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
src/libsystemd/sd-rtnl/rtnl-message.c
View File

@ -46,6 +46,11 @@ int message_new(sd_rtnl *rtnl, sd_rtnl_message **ret, size_t initial_size) {
assert_return(ret, -EINVAL);
assert_return(initial_size >= sizeof(struct nlmsghdr), -EINVAL);
/* Note that 'rtnl' is curretly unused, if we start using it internally
we must take care to avoid problems due to mutual references between
busses and their queued messages. See sd-bus.
*/
m = new0(sd_rtnl_message, 1);
if (!m)
return -ENOMEM;
@ -61,9 +66,6 @@ int message_new(sd_rtnl *rtnl, sd_rtnl_message **ret, size_t initial_size) {
m->hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
m->sealed = false;
if (rtnl)
m->rtnl = sd_rtnl_ref(rtnl);
*ret = m;
return 0;
@ -275,7 +277,6 @@ sd_rtnl_message *sd_rtnl_message_unref(sd_rtnl_message *m) {
if (m && REFCNT_DEC(m->n_ref) <= 0) {
unsigned i;
sd_rtnl_unref(m->rtnl);
free(m->hdr);
for (i = 0; i < m->n_containers; i++)

97
src/libsystemd/sd-rtnl/sd-rtnl.c
View File

@ -104,6 +104,9 @@ int sd_rtnl_open(sd_rtnl **ret, uint32_t groups) {
}
sd_rtnl *sd_rtnl_ref(sd_rtnl *rtnl) {
assert_return(rtnl, NULL);
assert_return(!rtnl_pid_changed(rtnl), NULL);
if (rtnl)
assert_se(REFCNT_INC(rtnl->n_ref) >= 2);
@ -111,88 +114,40 @@ sd_rtnl *sd_rtnl_ref(sd_rtnl *rtnl) {
}
sd_rtnl *sd_rtnl_unref(sd_rtnl *rtnl) {
unsigned long refs;
if (!rtnl)
return NULL;
/*
* If our ref-cnt is exactly the number of internally queued messages
* plus the ref-cnt to be dropped, then we know there's no external
* reference to us. Hence, we look through all queued messages and if
* they also have no external references, we're about to drop the last
* ref. Flush the queues so the REFCNT_DEC() below will drop to 0.
* We must be careful not to introduce inter-message references or this
* logic will fall apart..
*/
assert_return(!rtnl_pid_changed(rtnl), NULL);
refs = rtnl->rqueue_size + rtnl->wqueue_size + 1;
if (REFCNT_GET(rtnl->n_ref) <= refs) {
if (REFCNT_DEC(rtnl->n_ref) <= 0) {
struct match_callback *f;
bool q = true;
unsigned i;
for (i = 0; i < rtnl->rqueue_size; i++) {
if (REFCNT_GET(rtnl->rqueue[i]->n_ref) > 1) {
q = false;
break;
} else if (rtnl->rqueue[i]->rtnl != rtnl)
--refs;
for (i = 0; i < rtnl->rqueue_size; i++)
sd_rtnl_message_unref(rtnl->rqueue[i]);
free(rtnl->rqueue);
for (i = 0; i < rtnl->wqueue_size; i++)
sd_rtnl_message_unref(rtnl->wqueue[i]);
free(rtnl->wqueue);
hashmap_free_free(rtnl->reply_callbacks);
prioq_free(rtnl->reply_callbacks_prioq);
sd_event_source_unref(rtnl->io_event_source);
sd_event_source_unref(rtnl->time_event_source);
sd_event_source_unref(rtnl->exit_event_source);
sd_event_unref(rtnl->event);
while ((f = rtnl->match_callbacks)) {
LIST_REMOVE(match_callbacks, rtnl->match_callbacks, f);
free(f);
}
if (q) {
for (i = 0; i < rtnl->wqueue_size; i++) {
if (REFCNT_GET(rtnl->wqueue[i]->n_ref) > 1) {
q = false;
break;
} else if (rtnl->wqueue[i]->rtnl != rtnl)
--refs;
}
}
if (q && REFCNT_GET(rtnl->n_ref) == refs) {
/* Drop our own ref early to avoid recursion from:
* sd_rtnl_message_unref()
* sd_rtnl_unref()
* These must enter sd_rtnl_unref() with a ref-cnt
* smaller than us. */
REFCNT_DEC(rtnl->n_ref);
for (i = 0; i < rtnl->rqueue_size; i++)
sd_rtnl_message_unref(rtnl->rqueue[i]);
free(rtnl->rqueue);
for (i = 0; i < rtnl->wqueue_size; i++)
sd_rtnl_message_unref(rtnl->wqueue[i]);
free(rtnl->wqueue);
assert_se(REFCNT_GET(rtnl->n_ref) == 0);
hashmap_free_free(rtnl->reply_callbacks);
prioq_free(rtnl->reply_callbacks_prioq);
while ((f = rtnl->match_callbacks)) {
LIST_REMOVE(match_callbacks, rtnl->match_callbacks, f);
free(f);
}
safe_close(rtnl->fd);
sd_event_source_unref(rtnl->io_event_source);
sd_event_source_unref(rtnl->time_event_source);
sd_event_source_unref(rtnl->exit_event_source);
sd_event_unref(rtnl->event);
free(rtnl);
return NULL;
}
safe_close(rtnl->fd);
free(rtnl);
}
assert_se(REFCNT_GET(rtnl->n_ref) > 0);
REFCNT_DEC(rtnl->n_ref);
return NULL;
}