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, 1 deletions

diff --git a/src/or/circuituse.c b/src/or/circuituse.c
index 00340fd689..3a1d154178 100644
--- a/src/or/circuituse.c
+++ b/src/or/circuituse.c
@@ -1123,7 +1123,7 @@ circuit_build_needed_circs(time_t now)
    * don't require an exit circuit, review in #13814.
    * This allows HSs to function in a consensus without exits. */
   if (router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN)
-    connection_ap_attach_pending();
+    connection_ap_rescan_and_attach_pending();
 
   /* make sure any hidden services have enough intro points
    * HS intro point streams only require an internal circuit */