[tor-commits] [tor/master] Try refactoring channel list to use HT_ and LIST_ stuff directly
andrea at torproject.org
andrea at torproject.org
Tue Oct 30 22:57:38 UTC 2012
commit 2b10e99eb093e1e5e699db355e0c54342fa693b5
Author: Nick Mathewson <nickm at torproject.org>
Date: Fri Oct 12 20:16:43 2012 -0400
Try refactoring channel list to use HT_ and LIST_ stuff directly
---
src/or/channel.c | 191 +++++++++++++++++++++---------------------------------
src/or/channel.h | 4 +-
2 files changed, 75 insertions(+), 120 deletions(-)
diff --git a/src/or/channel.c b/src/or/channel.c
index b594d05..7f3c6f5 100644
--- a/src/or/channel.c
+++ b/src/or/channel.c
@@ -81,7 +81,37 @@ static uint64_t n_channels_allocated = 0;
* If more than one channel exists, follow the next_with_same_id pointer
* as a linked list.
*/
-static digestmap_t *channel_identity_map = NULL;
+HT_HEAD(channel_idmap, channel_idmap_entry_s) channel_identity_map =
+ HT_INITIALIZER();
+
+typedef struct channel_idmap_entry_s {
+ HT_ENTRY(channel_idmap_entry_s) node;
+ uint8_t digest[DIGEST_LEN];
+ LIST_HEAD(channel_list_s, channel_s) channel_list;
+} channel_idmap_entry_t;
+
+static INLINE unsigned
+channel_idmap_hash(const channel_idmap_entry_t *ent)
+{
+ const unsigned *a = (const unsigned *)ent->digest;
+#if SIZEOF_INT == 4
+ return a[0] ^ a[1] ^ a[2] ^ a[3] ^ a[4];
+#elif SIZEOF_INT == 8
+ return a[0] ^ a[1];
+#endif
+}
+
+static INLINE int
+channel_idmap_eq(const channel_idmap_entry_t *a,
+ const channel_idmap_entry_t *b)
+{
+ return tor_memeq(a->digest, b->digest, DIGEST_LEN);
+}
+
+HT_PROTOTYPE(channel_idmap, channel_idmap_entry_s, node, channel_idmap_hash,
+ channel_idmap_eq);
+HT_GENERATE(channel_idmap, channel_idmap_entry_s, node, channel_idmap_hash,
+ channel_idmap_eq, 0.5, tor_malloc, tor_realloc, _tor_free);
static cell_queue_entry_t * cell_queue_entry_dup(cell_queue_entry_t *q);
static void cell_queue_entry_free(cell_queue_entry_t *q, int handed_off);
@@ -505,7 +535,7 @@ channel_listener_unregister(channel_listener_t *chan_l)
static void
channel_add_to_digest_map(channel_t *chan)
{
- channel_t *tmp;
+ channel_idmap_entry_t *ent, search;
tor_assert(chan);
@@ -517,23 +547,15 @@ channel_add_to_digest_map(channel_t *chan)
/* Assert that there is a digest */
tor_assert(!tor_digest_is_zero(chan->identity_digest));
- /* Allocate the identity map if we have to */
- if (!channel_identity_map) channel_identity_map = digestmap_new();
-
- /* Insert it */
- tmp = digestmap_set(channel_identity_map,
- chan->identity_digest,
- chan);
- if (tmp) {
- /* There already was one, this goes at the head of the list */
- chan->next_with_same_id = tmp;
- chan->prev_with_same_id = NULL;
- tmp->prev_with_same_id = chan;
- } else {
- /* First with this digest */
- chan->next_with_same_id = NULL;
- chan->prev_with_same_id = NULL;
+ memcpy(search.digest, chan->identity_digest, DIGEST_LEN);
+ ent = HT_FIND(channel_idmap, &channel_identity_map, &search);
+ if (! ent) {
+ ent = tor_malloc(sizeof(channel_idmap_entry_t));
+ memcpy(ent->digest, chan->identity_digest, DIGEST_LEN);
+ LIST_INIT(&ent->channel_list);
+ HT_INSERT(channel_idmap, &channel_identity_map, ent);
}
+ LIST_INSERT_HEAD(&ent->channel_list, chan, next_with_same_id);
log_debug(LD_CHANNEL,
"Added channel %p (global ID " U64_FORMAT ") "
@@ -553,13 +575,14 @@ channel_add_to_digest_map(channel_t *chan)
static void
channel_remove_from_digest_map(channel_t *chan)
{
- channel_t *tmp;
+ channel_idmap_entry_t *ent, search;
tor_assert(chan);
/* Assert that there is a digest */
tor_assert(!tor_digest_is_zero(chan->identity_digest));
+#if 0
/* Make sure we have a map */
if (!channel_identity_map) {
/*
@@ -584,66 +607,29 @@ channel_remove_from_digest_map(channel_t *chan)
return;
}
+#endif
- /* Look for it in the map */
- tmp = digestmap_get(channel_identity_map, chan->identity_digest);
- if (tmp) {
- /* Okay, it's here */
- /* Look for this channel */
- while (tmp && tmp != chan) {
- tmp = tmp->next_with_same_id;
- }
+ /* Pull it out of its list, wherever that list is */
+ LIST_REMOVE(chan, next_with_same_id);
- if (tmp == chan) {
- /* Found it, good */
- if (chan->next_with_same_id) {
- chan->next_with_same_id->prev_with_same_id = chan->prev_with_same_id;
- }
- /* else we're the tail of the list */
- if (chan->prev_with_same_id) {
- /* We're not the head of the list, so we can *just* unlink */
- chan->prev_with_same_id->next_with_same_id = chan->next_with_same_id;
- } else {
- /* We're the head, so we have to point the digest map entry at our
- * next if we have one, or remove it if we're also the tail */
- if (chan->next_with_same_id) {
- digestmap_set(channel_identity_map,
- chan->identity_digest,
- chan->next_with_same_id);
- } else {
- digestmap_remove(channel_identity_map,
- chan->identity_digest);
- }
- }
+ memcpy(search.digest, chan->identity_digest, DIGEST_LEN);
+ ent = HT_FIND(channel_idmap, &channel_identity_map, &search);
- /* NULL out its next/prev pointers, and we're finished */
- chan->next_with_same_id = NULL;
- chan->prev_with_same_id = NULL;
+ /* Look for it in the map */
+ if (ent) {
+ /* Okay, it's here */
- log_debug(LD_CHANNEL,
- "Removed channel %p (global ID " U64_FORMAT ") from "
- "identity map in state %s (%d) with digest %s",
- chan, U64_PRINTF_ARG(chan->global_identifier),
- channel_state_to_string(chan->state), chan->state,
- hex_str(chan->identity_digest, DIGEST_LEN));
- } else {
- /* This is not good */
- log_warn(LD_BUG,
- "Trying to remove channel %p (global ID " U64_FORMAT ") "
- "with digest %s from identity map, but couldn't find it in "
- "the list for that digest",
- chan, U64_PRINTF_ARG(chan->global_identifier),
- hex_str(chan->identity_digest, DIGEST_LEN));
- /* Unlink it and hope for the best */
- if (chan->next_with_same_id) {
- chan->next_with_same_id->prev_with_same_id = chan->prev_with_same_id;
- }
- if (chan->prev_with_same_id) {
- chan->prev_with_same_id->next_with_same_id = chan->next_with_same_id;
- }
- chan->next_with_same_id = NULL;
- chan->prev_with_same_id = NULL;
+ if (LIST_EMPTY(&ent->channel_list)) {
+ HT_REMOVE(channel_idmap, &channel_identity_map, ent);
+ tor_free(ent);
}
+
+ log_debug(LD_CHANNEL,
+ "Removed channel %p (global ID " U64_FORMAT ") from "
+ "identity map in state %s (%d) with digest %s",
+ chan, U64_PRINTF_ARG(chan->global_identifier),
+ channel_state_to_string(chan->state), chan->state,
+ hex_str(chan->identity_digest, DIGEST_LEN));
} else {
/* Shouldn't happen */
log_warn(LD_BUG,
@@ -652,15 +638,6 @@ channel_remove_from_digest_map(channel_t *chan)
"that digest",
chan, U64_PRINTF_ARG(chan->global_identifier),
hex_str(chan->identity_digest, DIGEST_LEN));
- /* Clear out its next/prev pointers */
- if (chan->next_with_same_id) {
- chan->next_with_same_id->prev_with_same_id = chan->prev_with_same_id;
- }
- if (chan->prev_with_same_id) {
- chan->prev_with_same_id->next_with_same_id = chan->next_with_same_id;
- }
- chan->next_with_same_id = NULL;
- chan->prev_with_same_id = NULL;
}
}
@@ -698,20 +675,21 @@ channel_find_by_global_id(uint64_t global_identifier)
*
* This function looks up a channel by the digest of its remote endpoint in
* the channel digest map. It's possible that more than one channel to a
- * given endpoint exists. Use channel_next_with_digest() and
- * channel_prev_with_digest() to walk the list.
+ * given endpoint exists. Use channel_next_with_digest() to walk the list.
*/
channel_t *
channel_find_by_remote_digest(const char *identity_digest)
{
channel_t *rv = NULL;
+ channel_idmap_entry_t *ent, search;
tor_assert(identity_digest);
- /* Search for it in the identity map */
- if (channel_identity_map) {
- rv = digestmap_get(channel_identity_map, identity_digest);
+ memcpy(search.digest, identity_digest, DIGEST_LEN);
+ ent = HT_FIND(channel_idmap, &channel_identity_map, &search);
+ if (ent) {
+ rv = LIST_FIRST(&ent->channel_list);
}
return rv;
@@ -729,22 +707,7 @@ channel_next_with_digest(channel_t *chan)
{
tor_assert(chan);
- return chan->next_with_same_id;
-}
-
-/**
- * Get previous channel with digest
- *
- * This function takes a channel and finds the previos channel in the list
- * with the same digest.
- */
-
-channel_t *
-channel_prev_with_digest(channel_t *chan)
-{
- tor_assert(chan);
-
- return chan->prev_with_same_id;
+ return LIST_NEXT(chan, next_with_same_id);
}
/**
@@ -773,6 +736,9 @@ channel_init(channel_t *chan)
SIMPLEQ_INIT(&chan->incoming_queue);
SIMPLEQ_INIT(&chan->outgoing_queue);
+ /* Initialize list entries. */
+ memset(&chan->next_with_same_id, 0, sizeof(chan->next_with_same_id));
+
/* Timestamp it */
channel_timestamp_created(chan);
}
@@ -2846,13 +2812,10 @@ channel_free_all(void)
}
/* Now free channel_identity_map */
- if (channel_identity_map) {
- log_debug(LD_CHANNEL,
- "Freeing channel_identity_map");
- /* Geez, anything still left over just won't die ... let it leak then */
- digestmap_free(channel_identity_map, NULL);
- channel_identity_map = NULL;
- }
+ log_debug(LD_CHANNEL,
+ "Freeing channel_identity_map");
+ /* Geez, anything still left over just won't die ... let it leak then */
+ HT_CLEAR(channel_idmap, &channel_identity_map);
log_debug(LD_CHANNEL,
"Done cleaning up after channels");
@@ -2959,12 +2922,6 @@ channel_get_for_extend(const char *digest,
tor_assert(msg_out);
tor_assert(launch_out);
- if (!channel_identity_map) {
- *msg_out = "Router not connected (nothing is). Connecting.";
- *launch_out = 1;
- return NULL;
- }
-
chan = channel_find_by_remote_digest(digest);
/* Walk the list, unrefing the old one and refing the new at each
diff --git a/src/or/channel.h b/src/or/channel.h
index ccb8fe8..1e7279a 100644
--- a/src/or/channel.h
+++ b/src/or/channel.h
@@ -122,7 +122,7 @@ struct channel_s {
* Linked list of channels with the same identity digest, for the
* digest->channel map
*/
- channel_t *next_with_same_id, *prev_with_same_id;
+ LIST_ENTRY(channel_s) next_with_same_id;
/* List of incoming cells to handle */
chan_cell_queue_t incoming_queue;
@@ -417,9 +417,7 @@ channel_t * channel_find_by_remote_digest(const char *identity_digest);
/** For things returned by channel_find_by_remote_digest(), walk the list.
*/
-
channel_t * channel_next_with_digest(channel_t *chan);
-channel_t * channel_prev_with_digest(channel_t *chan);
/*
* Metadata queries/updates
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