Decouple ..attach_circuit() from most of its callers.

Long ago we used to call connection_ap_handshake_attach_circuit()
only in a few places, since connection_ap_attach_pending() attaches
all the pending connections, and does so regularly.  But this turned
out to have a performance problem: it would introduce a delay to
launching or connecting a stream.

We couldn't just call connection_ap_attach_pending() every time we
make a new connection, since it walks the whole connection list.  So
we started calling connection_ap_attach_pending all over, instead!
But that's kind of ugly and messes up our callgraph.

So instead, we now have connection_ap_attach_pending() use a list
only of the pending connections, so we can call it much more
frequently.  We have a separate function to scan the whole
connection array to see if we missed adding anything, and log a
warning if so.

Closes ticket #17590

1 files changed, 1 insertions, 6 deletions

diff --git a/src/or/rendclient.c b/src/or/rendclient.c
index a39e518e99..3846ef0c32 100644
--- a/src/or/rendclient.c
+++ b/src/or/rendclient.c
@@ -1226,12 +1226,7 @@ rend_client_desc_trynow(const char *query)
       base_conn->timestamp_lastread = now;
       base_conn->timestamp_lastwritten = now;
 
-      if (connection_ap_handshake_attach_circuit(conn) < 0) {
-        /* it will never work */
-        log_warn(LD_REND,"Rendezvous attempt failed. Closing.");
-        if (!base_conn->marked_for_close)
-          connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
-      }
+      connection_ap_mark_as_pending_circuit(conn);
     } else { /* 404, or fetch didn't get that far */
       log_notice(LD_REND,"Closing stream for '%s.onion': hidden service is "
                  "unavailable (try again later).",