chiark / gitweb /
sd-rtnl: use GREEDY_REALLOC for message queues
[elogind.git] / src / libsystemd / sd-rtnl / sd-rtnl.c
index 551e95b592d87eb48a3e34a21cb3ed80f13e29d4..8e709bb66dfb16c3a9c73a7bf47af178b1e9006a 100644 (file)
@@ -31,7 +31,7 @@
 #include "rtnl-util.h"
 
 static int sd_rtnl_new(sd_rtnl **ret) {
-        sd_rtnl *rtnl;
+        _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
 
         assert_return(ret, -EINVAL);
 
@@ -51,13 +51,12 @@ static int sd_rtnl_new(sd_rtnl **ret) {
 
         /* We guarantee that wqueue always has space for at least
          * one entry */
-        rtnl->wqueue = new(sd_rtnl_message*, 1);
-        if (!rtnl->wqueue) {
-                free(rtnl);
+        if (!GREEDY_REALLOC(rtnl->wqueue, rtnl->wqueue_allocated, 1))
                 return -ENOMEM;
-        }
 
         *ret = rtnl;
+        rtnl = NULL;
+
         return 0;
 }
 
@@ -104,6 +103,9 @@ 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);
 
@@ -111,81 +113,39 @@ 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..
-         */
-
-        refs = rtnl->rqueue_size + rtnl->wqueue_size + 1;
+        assert_return(!rtnl_pid_changed(rtnl), NULL);
 
-        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);
 
-                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;
-                        }
-                }
+                for (i = 0; i < rtnl->wqueue_size; i++)
+                        sd_rtnl_message_unref(rtnl->wqueue[i]);
+                free(rtnl->wqueue);
 
-                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);
+                hashmap_free_free(rtnl->reply_callbacks);
+                prioq_free(rtnl->reply_callbacks_prioq);
 
-                        for (i = 0; i < rtnl->rqueue_size; i++)
-                                sd_rtnl_message_unref(rtnl->rqueue[i]);
-                        free(rtnl->rqueue);
+                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);
 
-                        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);
-                        free(rtnl);
-
-                        return NULL;
+                while ((f = rtnl->match_callbacks)) {
+                        LIST_REMOVE(match_callbacks, rtnl->match_callbacks, f);
+                        free(f);
                 }
-        }
 
-        assert_se(REFCNT_GET(rtnl->n_ref) > 0);
-        REFCNT_DEC(rtnl->n_ref);
+                safe_close(rtnl->fd);
+                free(rtnl);
+        }
 
         return NULL;
 }
@@ -227,18 +187,14 @@ int sd_rtnl_send(sd_rtnl *nl,
                         nl->wqueue_size = 1;
                 }
         } else {
-                sd_rtnl_message **q;
-
                 /* append to queue */
                 if (nl->wqueue_size >= RTNL_WQUEUE_MAX)
                         return -ENOBUFS;
 
-                q = realloc(nl->wqueue, sizeof(sd_rtnl_message*) * (nl->wqueue_size + 1));
-                if (!q)
+                if (!GREEDY_REALLOC(nl->wqueue, nl->wqueue_allocated, nl->wqueue_size + 1))
                         return -ENOMEM;
 
-                nl->wqueue = q;
-                q[nl->wqueue_size ++] = sd_rtnl_message_ref(message);
+                nl->wqueue[nl->wqueue_size ++] = sd_rtnl_message_ref(message);
         }
 
         if (serial)