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Try refactoring channel list to use HT_ and LIST_ stuff directly

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This commit is contained in:
Nick Mathewson 2012-10-12 20:16:43 -04:00
parent 7c9954a02a
commit 2b10e99eb0
2 changed files with 75 additions and 120 deletions
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171
src/or/channel.c
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@ -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) {
/*
@ -584,41 +607,22 @@ channel_remove_from_digest_map(channel_t *chan)
return;
}
#endif
/* Pull it out of its list, wherever that list is */
LIST_REMOVE(chan, next_with_same_id);
memcpy(search.digest, chan->identity_digest, DIGEST_LEN);
ent = HT_FIND(channel_idmap, &channel_identity_map, &search);
/* Look for it in the map */
tmp = digestmap_get(channel_identity_map, chan->identity_digest);
if (tmp) {
if (ent) {
/* Okay, it's here */
/* Look for this channel */
while (tmp && tmp != chan) {
tmp = tmp->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;
if (LIST_EMPTY(&ent->channel_list)) {
HT_REMOVE(channel_idmap, &channel_identity_map, ent);
tor_free(ent);
}
/* 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);
}
}
/* NULL out its next/prev pointers, and we're finished */
chan->next_with_same_id = NULL;
chan->prev_with_same_id = NULL;
log_debug(LD_CHANNEL,
"Removed channel %p (global ID " U64_FORMAT ") from "
@ -626,24 +630,6 @@ channel_remove_from_digest_map(channel_t *chan)
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;
}
} 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;
}
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

4
src/or/channel.h
View File

@ -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