commit 8b4e5b7ee902fb7fa07767410a18433d752c7aef Author: Nick Mathewson <nickm@torproject.org> Date: Fri Oct 2 17:55:25 2015 +0200 Experimentally decouple the main body of circuit_mark_for_close --- changes/decouple_circuit_mark | 6 ++++ src/or/circuitlist.c | 77 ++++++++++++++++++++++++++++++----------- src/or/or.h | 8 +++++ 3 files changed, 71 insertions(+), 20 deletions(-) diff --git a/changes/decouple_circuit_mark b/changes/decouple_circuit_mark new file mode 100644 index 0000000..4b7ed77 --- /dev/null +++ b/changes/decouple_circuit_mark @@ -0,0 +1,6 @@ + o Code simplification and refactoring: + - Extract the more complicated parts of circuit_mark_for_close into + a new function run periodically before connections are freed. + This change removes more than half of the functions currently + in the "blob". + Closes ticket #17218. diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c index 716024d..324f9f3 100644 --- a/src/or/circuitlist.c +++ b/src/or/circuitlist.c @@ -44,11 +44,16 @@ static smartlist_t *global_circuitlist = NULL; /** A list of all the circuits in CIRCUIT_STATE_CHAN_WAIT. */ static smartlist_t *circuits_pending_chans = NULL; +/** A list of all the circuits that have been marked with circuit_mark_for_close + * and which are waiting for circuit_about_to_free(). */ +static smartlist_t *circuits_pending_close = NULL; + static void circuit_free_cpath_node(crypt_path_t *victim); static void cpath_ref_decref(crypt_path_reference_t *cpath_ref); //static void circuit_set_rend_token(or_circuit_t *circ, int is_rend_circ, // const uint8_t *token); static void circuit_clear_rend_token(or_circuit_t *circ); +static void circuit_about_to_free(circuit_t *circ); /********* END VARIABLES ************/ @@ -451,16 +456,27 @@ circuit_count_pending_on_channel(channel_t *chan) void circuit_close_all_marked(void) { + if (circuits_pending_close == NULL) + return; + smartlist_t *lst = circuit_get_global_list(); - SMARTLIST_FOREACH_BEGIN(lst, circuit_t *, circ) { - /* Fix up index if SMARTLIST_DEL_CURRENT just moved this one. */ - circ->global_circuitlist_idx = circ_sl_idx; - if (circ->marked_for_close) { - circ->global_circuitlist_idx = -1; - circuit_free(circ); - SMARTLIST_DEL_CURRENT(lst, circ); + SMARTLIST_FOREACH_BEGIN(circuits_pending_close, circuit_t *, circ) { + tor_assert(circ->marked_for_close); + + /* Remove it from the circuit list. */ + int idx = circ->global_circuitlist_idx; + smartlist_del(lst, idx); + if (idx < smartlist_len(lst)) { + circuit_t *replacement = smartlist_get(lst, idx); + replacement->global_circuitlist_idx = idx; } + circ->global_circuitlist_idx = -1; + + circuit_about_to_free(circ); + circuit_free(circ); } SMARTLIST_FOREACH_END(circ); + + smartlist_clear(circuits_pending_close); } /** Return the head of the global linked list of circuits. */ @@ -1703,6 +1719,39 @@ circuit_mark_for_close_, (circuit_t *circ, int reason, int line, reason = END_CIRC_REASON_NONE; } + circ->marked_for_close = line; + circ->marked_for_close_file = file; + circ->marked_for_close_reason = reason; + circ->marked_for_close_orig_reason = orig_reason; + + if (!CIRCUIT_IS_ORIGIN(circ)) { + or_circuit_t *or_circ = TO_OR_CIRCUIT(circ); + if (or_circ->rend_splice) { + if (!or_circ->rend_splice->base_.marked_for_close) { + /* do this after marking this circuit, to avoid infinite recursion. */ + circuit_mark_for_close(TO_CIRCUIT(or_circ->rend_splice), reason); + } + or_circ->rend_splice = NULL; + } + } + + if (circuits_pending_close == NULL) + circuits_pending_close = smartlist_new(); + + smartlist_add(circuits_pending_close, circ); +} + +/** Called immediately before freeing a marked circuit <b>circ</b>. + * Disconnects the circuit from other data structures, launches events + * as appropriate, and performs other housekeeping. + */ +static void +circuit_about_to_free(circuit_t *circ) +{ + + int reason = circ->marked_for_close_reason; + int orig_reason = circ->marked_for_close_orig_reason; + if (circ->state == CIRCUIT_STATE_ONIONSKIN_PENDING) { onion_pending_remove(TO_OR_CIRCUIT(circ)); } @@ -1726,6 +1775,7 @@ circuit_mark_for_close_, (circuit_t *circ, int reason, int line, (circ->state == CIRCUIT_STATE_OPEN)?CIRC_EVENT_CLOSED:CIRC_EVENT_FAILED, orig_reason); } + if (circ->purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) { origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ); int timed_out = (reason == END_CIRC_REASON_TIMEOUT); @@ -1811,19 +1861,6 @@ circuit_mark_for_close_, (circuit_t *circ, int reason, int line, ocirc->p_streams = NULL; } - circ->marked_for_close = line; - circ->marked_for_close_file = file; - - if (!CIRCUIT_IS_ORIGIN(circ)) { - or_circuit_t *or_circ = TO_OR_CIRCUIT(circ); - if (or_circ->rend_splice) { - if (!or_circ->rend_splice->base_.marked_for_close) { - /* do this after marking this circuit, to avoid infinite recursion. */ - circuit_mark_for_close(TO_CIRCUIT(or_circ->rend_splice), reason); - } - or_circ->rend_splice = NULL; - } - } } /** Given a marked circuit <b>circ</b>, aggressively free its cell queues to diff --git a/src/or/or.h b/src/or/or.h index a80cd55..746e462 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -2892,6 +2892,14 @@ typedef struct circuit_t { * where this circuit was marked.) */ const char *marked_for_close_file; /**< For debugging: in which file was this * circuit marked for close? */ + /** For what reason (See END_CIRC_REASON...) is this circuit being closed? + * This field is set in circuit_mark_for_close and used later in + * circuit_about_to_free. */ + uint16_t marked_for_close_reason; + /** As marked_for_close_reason, but reflects the underlying reason for + * closing this circuit. + */ + uint16_t marked_for_close_orig_reason; /** Unique ID for measuring tunneled network status requests. */ uint64_t dirreq_id;