[tor-commits] [tor/master] Use SIMPLEQ, not smartlist_t, for channel cell queues.
andrea at torproject.org
andrea at torproject.org
Tue Oct 30 22:57:38 UTC 2012
commit 7c9954a02abd16e5c74c2a5dea9ed0f65af230be
Author: Nick Mathewson <nickm at torproject.org>
Date: Fri Oct 12 17:58:01 2012 -0400
Use SIMPLEQ, not smartlist_t, for channel cell queues.
This lets us use fewer memory allocations, and avoid O(n^2) iterations
---
src/or/channel.c | 158 ++++++++++++++++++++----------------------------------
src/or/channel.h | 9 +++-
2 files changed, 66 insertions(+), 101 deletions(-)
diff --git a/src/or/channel.c b/src/or/channel.c
index 6527288..b594d05 100644
--- a/src/or/channel.c
+++ b/src/or/channel.c
@@ -31,6 +31,7 @@
typedef struct cell_queue_entry_s cell_queue_entry_t;
struct cell_queue_entry_s {
+ SIMPLEQ_ENTRY(cell_queue_entry_s) next;
enum {
CELL_QUEUE_FIXED,
CELL_QUEUE_VAR,
@@ -768,6 +769,10 @@ channel_init(channel_t *chan)
/* Init next_circ_id */
chan->next_circ_id = crypto_rand_int(1 << 15);
+ /* Initialize queues. */
+ SIMPLEQ_INIT(&chan->incoming_queue);
+ SIMPLEQ_INIT(&chan->outgoing_queue);
+
/* Timestamp it */
channel_timestamp_created(chan);
}
@@ -861,6 +866,7 @@ channel_listener_free(channel_listener_t *chan_l)
static void
channel_force_free(channel_t *chan)
{
+ cell_queue_entry_t *cell, *cell_tmp;
tor_assert(chan);
/* Call a free method if there is one */
@@ -869,26 +875,16 @@ channel_force_free(channel_t *chan)
channel_clear_remote_end(chan);
/* We might still have a cell queue; kill it */
- if (chan->incoming_queue) {
- SMARTLIST_FOREACH_BEGIN(chan->incoming_queue,
- cell_queue_entry_t *, q) {
- cell_queue_entry_free(q, 0);
- } SMARTLIST_FOREACH_END(q);
-
- smartlist_free(chan->incoming_queue);
- chan->incoming_queue = NULL;
+ SIMPLEQ_FOREACH_SAFE(cell, &chan->incoming_queue, next, cell_tmp) {
+ cell_queue_entry_free(cell, 0);
}
+ SIMPLEQ_INIT(&chan->incoming_queue);
/* Outgoing cell queue is similar, but we can have to free packed cells */
- if (chan->outgoing_queue) {
- SMARTLIST_FOREACH_BEGIN(chan->outgoing_queue,
- cell_queue_entry_t *, q) {
- cell_queue_entry_free(q, 0);
- } SMARTLIST_FOREACH_END(q);
-
- smartlist_free(chan->outgoing_queue);
- chan->outgoing_queue = NULL;
+ SIMPLEQ_FOREACH_SAFE(cell, &chan->outgoing_queue, next, cell_tmp) {
+ cell_queue_entry_free(cell, 0);
}
+ SIMPLEQ_INIT(&chan->outgoing_queue);
tor_free(chan);
}
@@ -1046,8 +1042,7 @@ channel_set_cell_handlers(channel_t *chan,
chan->var_cell_handler = var_cell_handler;
/* Re-run the queue if we have one and there's any reason to */
- if (chan->incoming_queue &&
- (smartlist_len(chan->incoming_queue) > 0) &&
+ if (! SIMPLEQ_EMPTY(&chan->incoming_queue) &&
try_again &&
(chan->cell_handler ||
chan->var_cell_handler)) channel_process_cells(chan);
@@ -1669,9 +1664,8 @@ channel_write_cell_queue_entry(channel_t *chan, cell_queue_entry_t *q)
}
/* Can we send it right out? If so, try */
- if (!(chan->outgoing_queue &&
- (smartlist_len(chan->outgoing_queue) > 0)) &&
- chan->state == CHANNEL_STATE_OPEN) {
+ if (SIMPLEQ_EMPTY(&chan->outgoing_queue) &&
+ chan->state == CHANNEL_STATE_OPEN) {
/* Pick the right write function for this cell type and save the result */
switch (q->type) {
case CELL_QUEUE_FIXED:
@@ -1707,14 +1701,12 @@ channel_write_cell_queue_entry(channel_t *chan, cell_queue_entry_t *q)
if (!sent) {
/* Not sent, queue it */
- if (!(chan->outgoing_queue))
- chan->outgoing_queue = smartlist_new();
/*
* We have to copy the queue entry passed in, since the caller probably
* used the stack.
*/
tmp = cell_queue_entry_dup(q);
- smartlist_add(chan->outgoing_queue, tmp);
+ SIMPLEQ_INSERT_TAIL(&chan->outgoing_queue, tmp, next);
/* Try to process the queue? */
if (chan->state == CHANNEL_STATE_OPEN) channel_flush_cells(chan);
}
@@ -1900,19 +1892,15 @@ channel_change_state(channel_t *chan, channel_state_t to_state)
channel_do_open_actions(chan);
/* Check for queued cells to process */
- if (chan->incoming_queue &&
- smartlist_len(chan->incoming_queue) > 0)
+ if (! SIMPLEQ_EMPTY(&chan->incoming_queue))
channel_process_cells(chan);
- if (chan->outgoing_queue &&
- smartlist_len(chan->outgoing_queue) > 0)
+ if (! SIMPLEQ_EMPTY(&chan->outgoing_queue))
channel_flush_cells(chan);
} else if (to_state == CHANNEL_STATE_CLOSED ||
to_state == CHANNEL_STATE_ERROR) {
/* Assert that all queues are empty */
- tor_assert(!(chan->incoming_queue) ||
- smartlist_len(chan->incoming_queue) == 0);
- tor_assert(!(chan->outgoing_queue) ||
- smartlist_len(chan->outgoing_queue) == 0);
+ tor_assert(SIMPLEQ_EMPTY(&chan->incoming_queue));
+ tor_assert(SIMPLEQ_EMPTY(&chan->outgoing_queue));
}
}
@@ -2086,16 +2074,9 @@ channel_flush_some_cells_from_outgoing_queue(channel_t *chan,
/* If we aren't in CHANNEL_STATE_OPEN, nothing goes through */
if (chan->state == CHANNEL_STATE_OPEN) {
while ((unlimited || num_cells > flushed) &&
- (chan->outgoing_queue &&
- (smartlist_len(chan->outgoing_queue) > 0))) {
- /*
- * Ewww, smartlist_del_keeporder() is O(n) in list length; maybe a
- * a linked list would make more sense for the queue.
- */
-
- /* Get the head of the queue */
- q = smartlist_get(chan->outgoing_queue, 0);
- if (q) {
+ NULL != (q = SIMPLEQ_FIRST(&chan->outgoing_queue))) {
+
+ if (1) {
/*
* Okay, we have a good queue entry, try to give it to the lower
* layer.
@@ -2180,26 +2161,17 @@ channel_flush_some_cells_from_outgoing_queue(channel_t *chan,
cell_queue_entry_free(q, 0);
q = NULL;
}
- } else {
- /* This shouldn't happen; log and throw it away */
- log_info(LD_CHANNEL,
- "Saw a NULL entry in the outgoing cell queue on channel %p "
- "(global ID " U64_FORMAT "); this is definitely a bug.",
- chan, U64_PRINTF_ARG(chan->global_identifier));
- /* q is already NULL, so we know to delete that queue entry */
- }
- /* if q got NULLed out, we used it and should remove the queue entry */
- if (!q) smartlist_del_keeporder(chan->outgoing_queue, 0);
- /* No cell removed from list, so we can't go on any further */
- else break;
+ /* if q got NULLed out, we used it and should remove the queue entry */
+ if (!q) SIMPLEQ_REMOVE_HEAD(&chan->outgoing_queue, next);
+ /* No cell removed from list, so we can't go on any further */
+ else break;
+ }
}
}
/* Did we drain the queue? */
- if (!(chan->outgoing_queue) ||
- smartlist_len(chan->outgoing_queue) == 0) {
- /* Timestamp it */
+ if (SIMPLEQ_EMPTY(&chan->outgoing_queue)) {
channel_timestamp_drained(chan);
}
@@ -2233,8 +2205,8 @@ channel_more_to_flush(channel_t *chan)
tor_assert(chan);
/* Check if we have any queued */
- if (chan->incoming_queue &&
- smartlist_len(chan->incoming_queue) > 0) return 1;
+ if (! SIMPLEQ_EMPTY(&chan->incoming_queue))
+ return 1;
/* Check if any circuits would like to queue some */
if (circuitmux_num_cells(chan->cmux) > 0) return 1;
@@ -2427,8 +2399,7 @@ channel_listener_queue_incoming(channel_listener_t *listener,
void
channel_process_cells(channel_t *chan)
{
- smartlist_t *queue;
- int putback = 0;
+ cell_queue_entry_t *q;
tor_assert(chan);
tor_assert(chan->state == CHANNEL_STATE_CLOSING ||
chan->state == CHANNEL_STATE_MAINT ||
@@ -2442,24 +2413,21 @@ channel_process_cells(channel_t *chan)
if (!(chan->cell_handler ||
chan->var_cell_handler)) return;
/* Nothing we can do if we have no cells */
- if (!(chan->incoming_queue)) return;
+ if (SIMPLEQ_EMPTY(&chan->incoming_queue)) return;
- queue = chan->incoming_queue;
- chan->incoming_queue = NULL;
/*
* Process cells until we're done or find one we have no current handler
* for.
*/
- SMARTLIST_FOREACH_BEGIN(queue, cell_queue_entry_t *, q) {
+ while (NULL != (q = SIMPLEQ_FIRST(&chan->incoming_queue))) {
tor_assert(q);
tor_assert(q->type == CELL_QUEUE_FIXED ||
q->type == CELL_QUEUE_VAR);
- if (putback) {
- smartlist_add(chan->incoming_queue, q);
- } else if (q->type == CELL_QUEUE_FIXED &&
+ if (q->type == CELL_QUEUE_FIXED &&
chan->cell_handler) {
/* Handle a fixed-length cell */
+ SIMPLEQ_REMOVE_HEAD(&chan->incoming_queue, next);
tor_assert(q->u.fixed.cell);
log_debug(LD_CHANNEL,
"Processing incoming cell_t %p for channel %p (global ID "
@@ -2471,6 +2439,7 @@ channel_process_cells(channel_t *chan)
} else if (q->type == CELL_QUEUE_VAR &&
chan->var_cell_handler) {
/* Handle a variable-length cell */
+ SIMPLEQ_REMOVE_HEAD(&chan->incoming_queue, next);
tor_assert(q->u.var.var_cell);
log_debug(LD_CHANNEL,
"Processing incoming var_cell_t %p for channel %p (global ID "
@@ -2481,15 +2450,10 @@ channel_process_cells(channel_t *chan)
tor_free(q);
} else {
/* Can't handle this one */
- if (!chan->incoming_queue)
- chan->incoming_queue = smartlist_new();
- smartlist_add(chan->incoming_queue, q);
- putback = 1;
+ break;
}
- } SMARTLIST_FOREACH_END(q);
+ }
- /* If the list is empty, free it */
- smartlist_free(queue);
}
/**
@@ -2511,15 +2475,9 @@ channel_queue_cell(channel_t *chan, cell_t *cell)
/* Do we need to queue it, or can we just call the handler right away? */
if (!(chan->cell_handler)) need_to_queue = 1;
- if (chan->incoming_queue &&
- (smartlist_len(chan->incoming_queue) > 0))
+ if (! SIMPLEQ_EMPTY(&chan->incoming_queue))
need_to_queue = 1;
- /* If we need to queue and have no queue, create one */
- if (need_to_queue && !(chan->incoming_queue)) {
- chan->incoming_queue = smartlist_new();
- }
-
/* Timestamp for receiving */
channel_timestamp_recv(chan);
@@ -2537,14 +2495,13 @@ channel_queue_cell(channel_t *chan, cell_t *cell)
chan->cell_handler(chan, cell);
} else {
/* Otherwise queue it and then process the queue if possible. */
- tor_assert(chan->incoming_queue);
q = cell_queue_entry_new_fixed(cell);
log_debug(LD_CHANNEL,
"Queueing incoming cell_t %p for channel %p "
"(global ID " U64_FORMAT ")",
cell, chan,
U64_PRINTF_ARG(chan->global_identifier));
- smartlist_add(chan->incoming_queue, q);
+ SIMPLEQ_INSERT_TAIL(&chan->incoming_queue, q, next);
if (chan->cell_handler ||
chan->var_cell_handler) {
channel_process_cells(chan);
@@ -2571,15 +2528,9 @@ channel_queue_var_cell(channel_t *chan, var_cell_t *var_cell)
/* Do we need to queue it, or can we just call the handler right away? */
if (!(chan->var_cell_handler)) need_to_queue = 1;
- if (chan->incoming_queue &&
- (smartlist_len(chan->incoming_queue) > 0))
+ if (! SIMPLEQ_EMPTY(&chan->incoming_queue))
need_to_queue = 1;
- /* If we need to queue and have no queue, create one */
- if (need_to_queue && !(chan->incoming_queue)) {
- chan->incoming_queue = smartlist_new();
- }
-
/* Timestamp for receiving */
channel_timestamp_recv(chan);
@@ -2597,14 +2548,13 @@ channel_queue_var_cell(channel_t *chan, var_cell_t *var_cell)
chan->var_cell_handler(chan, var_cell);
} else {
/* Otherwise queue it and then process the queue if possible. */
- tor_assert(chan->incoming_queue);
q = cell_queue_entry_new_var(var_cell);
log_debug(LD_CHANNEL,
"Queueing incoming var_cell_t %p for channel %p "
"(global ID " U64_FORMAT ")",
var_cell, chan,
U64_PRINTF_ARG(chan->global_identifier));
- smartlist_add(chan->incoming_queue, q);
+ SIMPLEQ_INSERT_TAIL(&chan->incoming_queue, q, next);
if (chan->cell_handler ||
chan->var_cell_handler) {
channel_process_cells(chan);
@@ -3134,6 +3084,19 @@ channel_listener_describe_transport(channel_listener_t *chan_l)
}
/**
+ * Return the number of entries in <b>queue</b>
+ */
+static int
+chan_cell_queue_len(const chan_cell_queue_t *queue)
+{
+ int r = 0;
+ cell_queue_entry_t *cell;
+ SIMPLEQ_FOREACH(cell, queue, next)
+ ++r;
+ return r;
+}
+
+/**
* Dump channel statistics
*
* Dump statistics for one channel to the log
@@ -3246,10 +3209,8 @@ channel_dump_statistics(channel_t *chan, int severity)
" * Channel " U64_FORMAT " has %d queued incoming cells"
" and %d queued outgoing cells",
U64_PRINTF_ARG(chan->global_identifier),
- (chan->incoming_queue != NULL) ?
- smartlist_len(chan->incoming_queue) : 0,
- (chan->outgoing_queue != NULL) ?
- smartlist_len(chan->outgoing_queue) : 0);
+ chan_cell_queue_len(&chan->incoming_queue),
+ chan_cell_queue_len(&chan->outgoing_queue));
/* Describe circuits */
log(severity, LD_GENERAL,
@@ -3498,8 +3459,7 @@ channel_has_queued_writes(channel_t *chan)
tor_assert(chan);
tor_assert(chan->has_queued_writes);
- if (chan->outgoing_queue &&
- smartlist_len(chan->outgoing_queue) > 0) {
+ if (! SIMPLEQ_EMPTY(&chan->outgoing_queue)) {
has_writes = 1;
} else {
/* Check with the lower layer */
diff --git a/src/or/channel.h b/src/or/channel.h
index cb9835a..ccb8fe8 100644
--- a/src/or/channel.h
+++ b/src/or/channel.h
@@ -10,6 +10,7 @@
#define _TOR_CHANNEL_H
#include "or.h"
+#include "tor_queue.h"
#include "circuitmux.h"
/* Channel handler function pointer typedefs */
@@ -17,6 +18,10 @@ typedef void (*channel_listener_fn_ptr)(channel_listener_t *, channel_t *);
typedef void (*channel_cell_handler_fn_ptr)(channel_t *, cell_t *);
typedef void (*channel_var_cell_handler_fn_ptr)(channel_t *, var_cell_t *);
+struct cell_queue_entry_s;
+SIMPLEQ_HEAD(chan_cell_queue, cell_queue_entry_s) incoming_queue;
+typedef struct chan_cell_queue chan_cell_queue_t;
+
/*
* Channel struct; see the channel_t typedef in or.h. A channel is an
* abstract interface for the OR-to-OR connection, similar to connection_or_t,
@@ -120,10 +125,10 @@ struct channel_s {
channel_t *next_with_same_id, *prev_with_same_id;
/* List of incoming cells to handle */
- smartlist_t *incoming_queue;
+ chan_cell_queue_t incoming_queue;
/* List of queued outgoing cells */
- smartlist_t *outgoing_queue;
+ chan_cell_queue_t outgoing_queue;
/* Circuit mux for circuits sending on this channel */
circuitmux_t *cmux;
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