REORG: quic: add comment on rare thread concurrence during CID alloc
The comment is here to warn about a possible thread concurrence issue
when treating INITIAL packets from the same client. The macro unlikely
is added to further highlight this scarce occurence.
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 19c6958..d36eb46 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -3771,18 +3771,22 @@
}
HA_RWLOCK_WRUNLOCK(QUIC_LOCK, &l->rx.cids_lock);
- if (n == &qc->odcid_node) {
+ /* If the insertion failed, it means that another
+ * thread has already allocated a QUIC connection for
+ * the same CID. Liberate our allocated connection.
+ */
+ if (unlikely(n != &qc->odcid_node)) {
+ quic_conn_free(qc);
+ qc = ebmb_entry(n, struct quic_conn, odcid_node);
+ pkt->qc = qc;
+ }
+ else {
/* Enqueue this packet. */
pkt->qc = qc;
MT_LIST_APPEND(&l->rx.pkts, &pkt->rx_list);
/* Try to accept a new connection. */
listener_accept(l);
}
- else {
- quic_conn_free(qc);
- qc = ebmb_entry(n, struct quic_conn, odcid_node);
- pkt->qc = qc;
- }
/* This is the DCID node sent in this packet by the client. */
node = &qc->odcid_node;