Remove TestingEnableTbEmptyEvent

This option was used for shadow testing previously, but is no longer
used for anything.  It interferes with refactoring our token buckets.

changes/ticket25760

@@ -0,0 +1,5 @@
+  o Removed features:
+    - The TestingEnableTbEmptyEvent option has been removed.  It was used
+      in testing simulations to measure how often connection buckets were
+      emptied, in order to improve our scheduling, but it has not
+      been actively used in years. Closes ticket 25760.

doc/tor.1.txt

@@ -2896,7 +2896,6 @@ The following options are used for running a testing Tor network.
        TestingDirConnectionMaxStall 30 seconds
        TestingEnableConnBwEvent 1
        TestingEnableCellStatsEvent 1
-       TestingEnableTbEmptyEvent 1
 
 [[TestingV3AuthInitialVotingInterval]] **TestingV3AuthInitialVotingInterval** __N__ **minutes**|**hours**::
     Like V3AuthVotingInterval, but for initial voting interval before the first
@@ -3034,11 +3033,6 @@ The following options are used for running a testing Tor network.
     events.  Changing this requires that **TestingTorNetwork** is set.
     (Default: 0)
 
-[[TestingEnableTbEmptyEvent]] **TestingEnableTbEmptyEvent** **0**|**1**::
-    If this option is set, then Tor controllers may register for TB_EMPTY
-    events.  Changing this requires that **TestingTorNetwork** is set.
-    (Default: 0)
-
 [[TestingMinExitFlagThreshold]] **TestingMinExitFlagThreshold**  __N__ **KBytes**|**MBytes**|**GBytes**|**TBytes**|**KBits**|**MBits**|**GBits**|**TBits**::
     Sets a lower-bound for assigning an exit flag when running as an
     authority on a testing network. Overrides the usual default lower bound

src/or/config.c

@@ -334,7 +334,7 @@ static config_var_t option_vars_[] = {
   V(DownloadExtraInfo,           BOOL,     "0"),
   V(TestingEnableConnBwEvent,    BOOL,     "0"),
   V(TestingEnableCellStatsEvent, BOOL,     "0"),
-  V(TestingEnableTbEmptyEvent,   BOOL,     "0"),
+  OBSOLETE("TestingEnableTbEmptyEvent"),
   V(EnforceDistinctSubnets,      BOOL,     "1"),
   V(EntryNodes,                  ROUTERSET,   NULL),
   V(EntryStatistics,             BOOL,     "0"),
@@ -704,7 +704,6 @@ static const config_var_t testing_tor_network_defaults[] = {
   V(TestingDirConnectionMaxStall, INTERVAL, "30 seconds"),
   V(TestingEnableConnBwEvent,    BOOL,     "1"),
   V(TestingEnableCellStatsEvent, BOOL,     "1"),
-  V(TestingEnableTbEmptyEvent,   BOOL,     "1"),
   VAR("___UsingTestNetworkDefaults", BOOL, UsingTestNetworkDefaults_, "1"),
   V(RendPostPeriod,              INTERVAL, "2 minutes"),
 
@@ -4499,12 +4498,6 @@ options_validate(or_options_t *old_options, or_options_t *options,
            "Tor networks!");
   }
 
-  if (options->TestingEnableTbEmptyEvent &&
-      !options->TestingTorNetwork && !options->UsingTestNetworkDefaults_) {
-    REJECT("TestingEnableTbEmptyEvent may only be changed in testing "
-           "Tor networks!");
-  }
-
   if (options->TestingTorNetwork) {
     log_warn(LD_CONFIG, "TestingTorNetwork is set. This will make your node "
                         "almost unusable in the public Tor network, and is "

src/or/connection.c

@@ -3019,57 +3019,6 @@ record_num_bytes_transferred_impl(connection_t *conn,
     rep_hist_note_exit_bytes(conn->port, num_written, num_read);
 }
 
-/** Helper: convert given <b>tvnow</b> time value to milliseconds since
- * midnight. */
-static uint32_t
-msec_since_midnight(const struct timeval *tvnow)
-{
-  return (uint32_t)(((tvnow->tv_sec % 86400L) * 1000L) +
-         ((uint32_t)tvnow->tv_usec / (uint32_t)1000L));
-}
-
-/** Helper: return the time in milliseconds since <b>last_empty_time</b>
- * when a bucket ran empty that previously had <b>tokens_before</b> tokens
- * now has <b>tokens_after</b> tokens after refilling at timestamp
- * <b>tvnow</b>, capped at <b>milliseconds_elapsed</b> milliseconds since
- * last refilling that bucket.  Return 0 if the bucket has not been empty
- * since the last refill or has not been refilled. */
-uint32_t
-bucket_millis_empty(int tokens_before, uint32_t last_empty_time,
-                    int tokens_after, int milliseconds_elapsed,
-                    const struct timeval *tvnow)
-{
-  uint32_t result = 0, refilled;
-  if (tokens_before <= 0 && tokens_after > tokens_before) {
-    refilled = msec_since_midnight(tvnow);
-    result = (uint32_t)((refilled + 86400L * 1000L - last_empty_time) %
-             (86400L * 1000L));
-    if (result > (uint32_t)milliseconds_elapsed)
-      result = (uint32_t)milliseconds_elapsed;
-  }
-  return result;
-}
-
-/** Check if a bucket which had <b>tokens_before</b> tokens and which got
- * <b>tokens_removed</b> tokens removed at timestamp <b>tvnow</b> has run
- * out of tokens, and if so, note the milliseconds since midnight in
- * <b>timestamp_var</b> for the next TB_EMPTY event. */
-void
-connection_buckets_note_empty_ts(uint32_t *timestamp_var,
-                                 int tokens_before, size_t tokens_removed,
-                                 const struct timeval *tvnow)
-{
-  if (tokens_before > 0 && (uint32_t)tokens_before <= tokens_removed)
-    *timestamp_var = msec_since_midnight(tvnow);
-}
-
-/** Last time at which the global or relay buckets were emptied in msec
- * since midnight. */
-static uint32_t global_relayed_read_emptied = 0,
-                global_relayed_write_emptied = 0,
-                global_read_emptied = 0,
-                global_write_emptied = 0;
-
 /** We just read <b>num_read</b> and wrote <b>num_written</b> bytes
  * onto <b>conn</b>. Decrement buckets appropriately. */
 static void
@@ -3094,30 +3043,6 @@ connection_buckets_decrement(connection_t *conn, time_t now,
   if (!connection_is_rate_limited(conn))
     return; /* local IPs are free */
 
-  /* If one or more of our token buckets ran dry just now, note the
-   * timestamp for TB_EMPTY events. */
-  if (get_options()->TestingEnableTbEmptyEvent) {
-    struct timeval tvnow;
-    tor_gettimeofday_cached(&tvnow);
-    if (connection_counts_as_relayed_traffic(conn, now)) {
-      connection_buckets_note_empty_ts(&global_relayed_read_emptied,
-                         global_relayed_read_bucket, num_read, &tvnow);
-      connection_buckets_note_empty_ts(&global_relayed_write_emptied,
-                         global_relayed_write_bucket, num_written, &tvnow);
-    }
-    connection_buckets_note_empty_ts(&global_read_emptied,
-                       global_read_bucket, num_read, &tvnow);
-    connection_buckets_note_empty_ts(&global_write_emptied,
-                       global_write_bucket, num_written, &tvnow);
-    if (connection_speaks_cells(conn) && conn->state == OR_CONN_STATE_OPEN) {
-      or_connection_t *or_conn = TO_OR_CONN(conn);
-      connection_buckets_note_empty_ts(&or_conn->read_emptied_time,
-                         or_conn->read_bucket, num_read, &tvnow);
-      connection_buckets_note_empty_ts(&or_conn->write_emptied_time,
-                         or_conn->write_bucket, num_written, &tvnow);
-    }
-  }
-
   if (connection_counts_as_relayed_traffic(conn, now)) {
     global_relayed_read_bucket -= (int)num_read;
     global_relayed_write_bucket -= (int)num_written;
@@ -3238,12 +3163,6 @@ connection_bucket_refill(int milliseconds_elapsed, time_t now)
   smartlist_t *conns = get_connection_array();
   int bandwidthrate, bandwidthburst, relayrate, relayburst;
 
-  int prev_global_read = global_read_bucket;
-  int prev_global_write = global_write_bucket;
-  int prev_relay_read = global_relayed_read_bucket;
-  int prev_relay_write = global_relayed_write_bucket;
-  struct timeval tvnow; /*< Only used if TB_EMPTY events are enabled. */
-
   bandwidthrate = (int)options->BandwidthRate;
   bandwidthburst = (int)options->BandwidthBurst;
 
@@ -3278,32 +3197,6 @@ connection_bucket_refill(int milliseconds_elapsed, time_t now)
                                   milliseconds_elapsed,
                                   "global_relayed_write_bucket");
 
-  /* If buckets were empty before and have now been refilled, tell any
-   * interested controllers. */
-  if (get_options()->TestingEnableTbEmptyEvent) {
-    uint32_t global_read_empty_time, global_write_empty_time,
-             relay_read_empty_time, relay_write_empty_time;
-    tor_gettimeofday_cached(&tvnow);
-    global_read_empty_time = bucket_millis_empty(prev_global_read,
-                             global_read_emptied, global_read_bucket,
-                             milliseconds_elapsed, &tvnow);
-    global_write_empty_time = bucket_millis_empty(prev_global_write,
-                              global_write_emptied, global_write_bucket,
-                              milliseconds_elapsed, &tvnow);
-    control_event_tb_empty("GLOBAL", global_read_empty_time,
-                           global_write_empty_time, milliseconds_elapsed);
-    relay_read_empty_time = bucket_millis_empty(prev_relay_read,
-                            global_relayed_read_emptied,
-                            global_relayed_read_bucket,
-                            milliseconds_elapsed, &tvnow);
-    relay_write_empty_time = bucket_millis_empty(prev_relay_write,
-                             global_relayed_write_emptied,
-                             global_relayed_write_bucket,
-                             milliseconds_elapsed, &tvnow);
-    control_event_tb_empty("RELAY", relay_read_empty_time,
-                           relay_write_empty_time, milliseconds_elapsed);
-  }
-
   /* refill the per-connection buckets */
   SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
     if (connection_speaks_cells(conn)) {
@@ -3311,9 +3204,6 @@ connection_bucket_refill(int milliseconds_elapsed, time_t now)
       int orbandwidthrate = or_conn->bandwidthrate;
       int orbandwidthburst = or_conn->bandwidthburst;
 
-      int prev_conn_read = or_conn->read_bucket;
-      int prev_conn_write = or_conn->write_bucket;
-
       if (connection_bucket_should_increase(or_conn->read_bucket, or_conn)) {
         connection_bucket_refill_helper(&or_conn->read_bucket,
                                         orbandwidthrate,
@@ -3328,27 +3218,6 @@ connection_bucket_refill(int milliseconds_elapsed, time_t now)
                                         milliseconds_elapsed,
                                         "or_conn->write_bucket");
       }
-
-      /* If buckets were empty before and have now been refilled, tell any
-       * interested controllers. */
-      if (get_options()->TestingEnableTbEmptyEvent) {
-        char *bucket;
-        uint32_t conn_read_empty_time, conn_write_empty_time;
-        tor_asprintf(&bucket, "ORCONN ID="U64_FORMAT,
-                     U64_PRINTF_ARG(or_conn->base_.global_identifier));
-        conn_read_empty_time = bucket_millis_empty(prev_conn_read,
-                               or_conn->read_emptied_time,
-                               or_conn->read_bucket,
-                               milliseconds_elapsed, &tvnow);
-        conn_write_empty_time = bucket_millis_empty(prev_conn_write,
-                                or_conn->write_emptied_time,
-                                or_conn->write_bucket,
-                                milliseconds_elapsed, &tvnow);
-        control_event_tb_empty(bucket, conn_read_empty_time,
-                               conn_write_empty_time,
-                               milliseconds_elapsed);
-        tor_free(bucket);
-      }
     }
 
     if (conn->read_blocked_on_bw == 1 /* marked to turn reading back on now */

src/or/connection.h

@@ -272,13 +272,6 @@ void connection_check_oos(int n_socks, int failed);
 STATIC void connection_free_minimal(connection_t *conn);
 
 /* Used only by connection.c and test*.c */
-uint32_t bucket_millis_empty(int tokens_before, uint32_t last_empty_time,
-                             int tokens_after, int milliseconds_elapsed,
-                             const struct timeval *tvnow);
-void connection_buckets_note_empty_ts(uint32_t *timestamp_var,
-                                      int tokens_before,
-                                      size_t tokens_removed,
-                                      const struct timeval *tvnow);
 MOCK_DECL(STATIC int,connection_connect_sockaddr,
                                             (connection_t *conn,
                                              const struct sockaddr *sa,

src/or/control.c

@@ -1214,7 +1214,6 @@ static const struct control_event_t control_event_table[] = {
   { EVENT_CONF_CHANGED, "CONF_CHANGED"},
   { EVENT_CONN_BW, "CONN_BW" },
   { EVENT_CELL_STATS, "CELL_STATS" },
-  { EVENT_TB_EMPTY, "TB_EMPTY" },
   { EVENT_CIRC_BANDWIDTH_USED, "CIRC_BW" },
   { EVENT_TRANSPORT_LAUNCHED, "TRANSPORT_LAUNCHED" },
   { EVENT_HS_DESC, "HS_DESC" },
@@ -6077,28 +6076,6 @@ control_event_circuit_cell_stats(void)
   return 0;
 }
 
-/** Tokens in <b>bucket</b> have been refilled: the read bucket was empty
- * for <b>read_empty_time</b> millis, the write bucket was empty for
- * <b>write_empty_time</b> millis, and buckets were last refilled
- * <b>milliseconds_elapsed</b> millis ago.  Only emit TB_EMPTY event if
- * either read or write bucket have been empty before. */
-int
-control_event_tb_empty(const char *bucket, uint32_t read_empty_time,
-                       uint32_t write_empty_time,
-                       int milliseconds_elapsed)
-{
-  if (get_options()->TestingEnableTbEmptyEvent &&
-      EVENT_IS_INTERESTING(EVENT_TB_EMPTY) &&
-      (read_empty_time > 0 || write_empty_time > 0)) {
-    send_control_event(EVENT_TB_EMPTY,
-                       "650 TB_EMPTY %s READ=%d WRITTEN=%d "
-                       "LAST=%d\r\n",
-                       bucket, read_empty_time, write_empty_time,
-                       milliseconds_elapsed);
-  }
-  return 0;
-}
-
 /* about 5 minutes worth. */
 #define N_BW_EVENTS_TO_CACHE 300
 /* Index into cached_bw_events to next write. */

src/or/control.h

@@ -59,9 +59,6 @@ int control_event_circ_bandwidth_used(void);
 int control_event_conn_bandwidth(connection_t *conn);
 int control_event_conn_bandwidth_used(void);
 int control_event_circuit_cell_stats(void);
-int control_event_tb_empty(const char *bucket, uint32_t read_empty_time,
-                           uint32_t write_empty_time,
-                           int milliseconds_elapsed);
 void control_event_logmsg(int severity, uint32_t domain, const char *msg);
 int control_event_descriptors_changed(smartlist_t *routers);
 int control_event_address_mapped(const char *from, const char *to,
@@ -194,7 +191,7 @@ void control_free_all(void);
 #define EVENT_CONF_CHANGED            0x0019
 #define EVENT_CONN_BW                 0x001A
 #define EVENT_CELL_STATS              0x001B
-#define EVENT_TB_EMPTY                0x001C
+/* UNUSED :                           0x001C */
 #define EVENT_CIRC_BANDWIDTH_USED     0x001D
 #define EVENT_TRANSPORT_LAUNCHED      0x0020
 #define EVENT_HS_DESC                 0x0021

src/or/or.h

@@ -1660,13 +1660,6 @@ typedef struct or_connection_t {
                     * bandwidthburst. (OPEN ORs only) */
   int write_bucket; /**< When this hits 0, stop writing. Like read_bucket. */
 
-  /** Last emptied read token bucket in msec since midnight; only used if
-   * TB_EMPTY events are enabled. */
-  uint32_t read_emptied_time;
-  /** Last emptied write token bucket in msec since midnight; only used if
-   * TB_EMPTY events are enabled. */
-  uint32_t write_emptied_time;
-
   /*
    * Count the number of bytes flushed out on this orconn, and the number of
    * bytes TLS actually sent - used for overhead estimation for scheduling.
@@ -4427,9 +4420,6 @@ typedef struct {
   /** Enable CELL_STATS events.  Only altered on testing networks. */
   int TestingEnableCellStatsEvent;
 
-  /** Enable TB_EMPTY events.  Only altered on testing networks. */
-  int TestingEnableTbEmptyEvent;
-
   /** If true, and we have GeoIP data, and we're a bridge, keep a per-country
    * count of how many client addresses have contacted us so that we can help
    * the bridge authority guess which countries have blocked access to us. */

src/test/test_controller_events.c

@@ -11,79 +11,6 @@
 #include "control.h"
 #include "test.h"
 
-static void
-help_test_bucket_note_empty(uint32_t expected_msec_since_midnight,
-                            int tokens_before, size_t tokens_removed,
-                            uint32_t msec_since_epoch)
-{
-  uint32_t timestamp_var = 0;
-  struct timeval tvnow;
-  tvnow.tv_sec = msec_since_epoch / 1000;
-  tvnow.tv_usec = (msec_since_epoch % 1000) * 1000;
-  connection_buckets_note_empty_ts(&timestamp_var, tokens_before,
-                                   tokens_removed, &tvnow);
-  tt_int_op(expected_msec_since_midnight, OP_EQ, timestamp_var);
-
- done:
-  ;
-}
-
-static void
-test_cntev_bucket_note_empty(void *arg)
-{
-  (void)arg;
-
-  /* Two cases with nothing to note, because bucket was empty before;
-   * 86442200 == 1970-01-02 00:00:42.200000 */
-  help_test_bucket_note_empty(0, 0, 0, 86442200);
-  help_test_bucket_note_empty(0, -100, 100, 86442200);
-
-  /* Nothing to note, because bucket has not been emptied. */
-  help_test_bucket_note_empty(0, 101, 100, 86442200);
-
-  /* Bucket was emptied, note 42200 msec since midnight. */
-  help_test_bucket_note_empty(42200, 101, 101, 86442200);
-  help_test_bucket_note_empty(42200, 101, 102, 86442200);
-}
-
-static void
-test_cntev_bucket_millis_empty(void *arg)
-{
-  struct timeval tvnow;
-  (void)arg;
-
-  /* 1970-01-02 00:00:42.200000 */
-  tvnow.tv_sec = 86400 + 42;
-  tvnow.tv_usec = 200000;
-
-  /* Bucket has not been refilled. */
-  tt_int_op(0, OP_EQ, bucket_millis_empty(0, 42120, 0, 100, &tvnow));
-  tt_int_op(0, OP_EQ, bucket_millis_empty(-10, 42120, -10, 100, &tvnow));
-
-  /* Bucket was not empty. */
-  tt_int_op(0, OP_EQ, bucket_millis_empty(10, 42120, 20, 100, &tvnow));
-
-  /* Bucket has been emptied 80 msec ago and has just been refilled. */
-  tt_int_op(80, OP_EQ, bucket_millis_empty(-20, 42120, -10, 100, &tvnow));
-  tt_int_op(80, OP_EQ, bucket_millis_empty(-10, 42120, 0, 100, &tvnow));
-  tt_int_op(80, OP_EQ, bucket_millis_empty(0, 42120, 10, 100, &tvnow));
-
-  /* Bucket has been emptied 180 msec ago, last refill was 100 msec ago
-   * which was insufficient to make it positive, so cap msec at 100. */
-  tt_int_op(100, OP_EQ, bucket_millis_empty(0, 42020, 1, 100, &tvnow));
-
-  /* 1970-01-02 00:00:00:050000 */
-  tvnow.tv_sec = 86400;
-  tvnow.tv_usec = 50000;
-
-  /* Last emptied 30 msec before midnight, tvnow is 50 msec after
-   * midnight, that's 80 msec in total. */
-  tt_int_op(80, OP_EQ, bucket_millis_empty(0, 86400000 - 30, 1, 100, &tvnow));
-
- done:
-  ;
-}
-
 static void
 add_testing_cell_stats_entry(circuit_t *circ, uint8_t command,
                              unsigned int waiting_time,
@@ -395,8 +322,6 @@ test_cntev_event_mask(void *arg)
   { #name, test_cntev_ ## name, flags, 0, NULL }
 
 struct testcase_t controller_event_tests[] = {
-  TEST(bucket_note_empty, TT_FORK),
-  TEST(bucket_millis_empty, TT_FORK),
   TEST(sum_up_cell_stats, TT_FORK),
   TEST(append_cell_stats, TT_FORK),
   TEST(format_cell_stats, TT_FORK),

src/test/test_options.c

@@ -4132,16 +4132,6 @@ test_options_validate__testing_options(void *ignored)
   tt_assert(!msg);
   tor_free(msg);
 
-  free_options_test_data(tdata);
-  tdata = get_options_test_data(TEST_OPTIONS_DEFAULT_VALUES
-                                "TestingEnableTbEmptyEvent 1\n"
-                                );
-  ret = options_validate(tdata->old_opt, tdata->opt, tdata->def_opt, 0, &msg);
-  tt_int_op(ret, OP_EQ, -1);
-  tt_str_op(msg, OP_EQ, "TestingEnableTbEmptyEvent may only be changed "
-            "in testing Tor networks!");
-  tor_free(msg);
-
   free_options_test_data(tdata);
   tdata = get_options_test_data(TEST_OPTIONS_DEFAULT_VALUES
                                 "TestingEnableTbEmptyEvent 1\n"