Document inverted mutex lock/unlock.

All other code in this file does lock/call/unlock, except this one
instance, so we should explain why.

1 files changed, 2 insertions, 0 deletions

diff --git a/toxcore/net_crypto.c b/toxcore/net_crypto.c
index 0390e44e..606561bb 100644
--- a/toxcore/net_crypto.c
+++ b/toxcore/net_crypto.c
@@ -1957,6 +1957,8 @@ static int tcp_data_callback(void *object, int id, const uint8_t *data, uint16_t
         return tcp_handle_cookie_request(c, conn->connection_number_tcp, data, length);
     }
 
+    // This unlocks the mutex that at this point is locked by do_tcp before
+    // calling do_tcp_connections.
     pthread_mutex_unlock(&c->tcp_mutex);
     int ret = handle_packet_connection(c, id, data, length, 0, userdata);
     pthread_mutex_lock(&c->tcp_mutex);