commit a2acb9b9e9f1a6e21625b2d77c2e7df4e35f3599 Author: Nick Mathewson nickm@torproject.org Date: Tue Apr 17 12:20:06 2018 -0400

Refill each token bucket at the last instant before reading/writing.

(This patch does not yet eliminate the global refill callback; fortunately, bucket refilling is idempotent.) --- src/or/connection.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+)

diff --git a/src/or/connection.c b/src/or/connection.c index 062c85c7f..7dc4ecf5c 100644 --- a/src/or/connection.c +++ b/src/or/connection.c @@ -3186,6 +3186,34 @@ connection_bucket_adjust(const or_options_t *options) } }

+/** + * Cached value of the last coarse-timestamp when we refilled the + * global buckets. + */ +static uint32_t last_refilled_global_buckets_ts=0; +/** + * Refill the token buckets for a single connection <b>conn</b>, and the + * global token buckets as appropriate. Requires that <b>now_ts</b> is + * the time in coarse timestamp units. + */ +static void +connection_bucket_refill_single(connection_t *conn, uint32_t now_ts) +{ + /* Note that we only check for equality here: the underlying + * token bucket functions can handle moving backwards in time if they + * need to. */ + if (now_ts != last_refilled_global_buckets_ts) { + token_bucket_rw_refill(&global_bucket, now_ts); + token_bucket_rw_refill(&global_relayed_bucket, now_ts); + last_refilled_global_buckets_ts = now_ts; + } + + if (connection_speaks_cells(conn) && conn->state == OR_CONN_STATE_OPEN) { + or_connection_t *or_conn = TO_OR_CONN(conn); + token_bucket_rw_refill(&or_conn->bucket, now_ts); + } +} + /** Time has passed; increment buckets appropriately and re-enable formerly * blocked connections. */ void @@ -3196,6 +3224,7 @@ connection_bucket_refill_all(time_t now, uint32_t now_ts) /* refill the global buckets */ token_bucket_rw_refill(&global_bucket, now_ts); token_bucket_rw_refill(&global_relayed_bucket, now_ts); + last_refilled_global_buckets_ts = now_ts;

/* refill the per-connection buckets */ SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) { @@ -3256,6 +3285,8 @@ connection_handle_read_impl(connection_t *conn)

conn->timestamp_last_read_allowed = approx_time();

+ connection_bucket_refill_single(conn, monotime_coarse_get_stamp()); + switch (conn->type) { case CONN_TYPE_OR_LISTENER: return connection_handle_listener_read(conn, CONN_TYPE_OR); @@ -3690,6 +3721,8 @@ connection_handle_write_impl(connection_t *conn, int force)

conn->timestamp_last_write_allowed = now;

+ connection_bucket_refill_single(conn, monotime_coarse_get_stamp()); + /* Sometimes, "writable" means "connected". */ if (connection_state_is_connecting(conn)) { if (getsockopt(conn->s, SOL_SOCKET, SO_ERROR, (void*)&e, &len) < 0) {