[tor-commits] [tor/master] Implement circuitmux_make_circuit_inactive(), circuitmux_make_circuit_active() and linked list helper functions in circuitmux.c
andrea at torproject.org
andrea at torproject.org
Thu Oct 11 02:05:23 UTC 2012
commit 38fa3b7e4489dafdb74ebef96f5a684c1f29eb1e
Author: Andrea Shepard <andrea at torproject.org>
Date: Wed Sep 26 15:04:29 2012 -0700
Implement circuitmux_make_circuit_inactive(), circuitmux_make_circuit_active() and linked list helper functions in circuitmux.c
---
src/or/circuitmux.c | 239 ++++++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 227 insertions(+), 12 deletions(-)
diff --git a/src/or/circuitmux.c b/src/or/circuitmux.c
index 61fd30d..77bb568 100644
--- a/src/or/circuitmux.c
+++ b/src/or/circuitmux.c
@@ -85,7 +85,7 @@ struct circuitmux_s {
* free up on this connection's outbuf. Every time we pull cells from
* a circuit, we advance this pointer to the next circuit in the ring.
*/
- struct circuit_t *active_circuits;
+ struct circuit_t *active_circuits_head, *active_circuits_tail;
/*
* Priority queue of cell_ewma_t for circuits with queued cells waiting
@@ -140,10 +140,50 @@ static INLINE unsigned int
chanid_circid_entry_hash(chanid_circid_muxinfo_t *a);
static chanid_circid_muxinfo_t *
circuitmux_find_map_entry(circuitmux_t *cmux, circuit_t *circ);
+static void
+circuitmux_make_circuit_active(circuitmux_t *cmux, circuit_t *circ,
+ cell_direction_t direction);
+static void
+circuitmux_make_circuit_inactive(circuitmux_t *cmux, circuit_t *circ,
+ cell_direction_t direction);
+static INLINE circuit_t **
+circuitmux_next_active_circ_p(circuitmux_t *cmux, circuit_t *circ);
+static INLINE circuit_t **
+circuitmux_prev_active_circ_p(circuitmux_t *cmux, circuit_t *circ);
/* Function definitions */
/**
+ * Linked list helpers
+ */
+
+static INLINE circuit_t **
+circuitmux_next_active_circ_p(circuitmux_t *cmux, circuit_t *circ)
+{
+ tor_assert(cmux);
+ tor_assert(circ);
+
+ if (circ->n_mux == cmux) return &(circ->next_active_on_n_chan);
+ else {
+ tor_assert(TO_OR_CIRCUIT(circ)->p_mux == cmux);
+ return &(TO_OR_CIRCUIT(circ)->next_active_on_p_chan);
+ }
+}
+
+static INLINE circuit_t **
+circuitmux_prev_active_circ_p(circuitmux_t *cmux, circuit_t *circ)
+{
+ tor_assert(cmux);
+ tor_assert(circ);
+
+ if (circ->n_mux == cmux) return &(circ->prev_active_on_n_chan);
+ else {
+ tor_assert(TO_OR_CIRCUIT(circ)->p_mux == cmux);
+ return &(TO_OR_CIRCUIT(circ)->prev_active_on_p_chan);
+ }
+}
+
+/**
* Helper for chanid_circid_cell_count_map_t hash table: compare the channel
* ID and circuit ID for a and b, and return less than, equal to, or greater
* than zero appropriately.
@@ -225,12 +265,16 @@ circuitmux_detach_all_circuits(circuitmux_t *cmux)
if (to_remove->muxinfo.direction == CELL_DIRECTION_OUT) {
/* Clear n_mux */
circ->n_mux = NULL;
+ /* Update active_circuits et al. */
+ circuitmux_make_circuit_inactive(cmux, circ, CELL_DIRECTION_OUT);
} else if (circ->magic == OR_CIRCUIT_MAGIC) {
/*
* It has a sensible p_chan and direction == CELL_DIRECTION_IN,
* so clear p_mux.
*/
TO_OR_CIRCUIT(circ)->p_mux = NULL;
+ /* Update active_circuits et al. */
+ circuitmux_make_circuit_inactive(cmux, circ, CELL_DIRECTION_IN);
} else {
/* Complain and move on */
log_warn(LD_CIRC,
@@ -239,8 +283,6 @@ circuitmux_detach_all_circuits(circuitmux_t *cmux)
to_remove->circ_id,
U64_PRINTF_ARG(to_remove->chan_id));
}
-
- /* TODO update active_circuits / active_circuit_pqueue */
} else {
/* Complain and move on */
log_warn(LD_CIRC,
@@ -432,7 +474,6 @@ circuitmux_num_cells_for_circuit(circuitmux_t *cmux, circuit_t *circ)
return n_cells;
}
-
/**
* Query total number of available cells on a circuitmux
*/
@@ -548,14 +589,14 @@ circuitmux_attach_circuit(circuitmux_t *cmux, circuit_t *circ,
*/
if (hashent->muxinfo.cell_count > 0 && cell_count == 0) {
--(cmux->n_active_circuits);
+ circuitmux_make_circuit_inactive(cmux, circ, direction);
} else if (hashent->muxinfo.cell_count == 0 && cell_count > 0) {
++(cmux->n_active_circuits);
+ circuitmux_make_circuit_active(cmux, circ, direction);
}
cmux->n_cells -= hashent->muxinfo.cell_count;
cmux->n_cells += cell_count;
hashent->muxinfo.cell_count = cell_count;
-
- /* TODO update active_circuits / active_circuit_pqueue */
} else {
/*
* New circuit; add an entry and update the circuit/active circuit
@@ -601,8 +642,6 @@ circuitmux_attach_circuit(circuitmux_t *cmux, circuit_t *circ,
circuitmux_make_circuit_active(cmux, circ, direction);
}
cmux->n_cells += cell_count;
-
- /* TODO update active_circuits / active_circuit_pqueue */
}
}
@@ -651,9 +690,11 @@ circuitmux_detach_circuit(circuitmux_t *cmux, circuit_t *circ)
if (hashent) {
/* Update counters */
--(cmux->n_circuits);
- if (hashent->muxinfo.cell_count > 0) --(cmux->n_active_circuits);
+ if (hashent->muxinfo.cell_count > 0) {
+ --(cmux->n_active_circuits);
+ circuitmux_make_circuit_inactive(cmux, circ, last_searched_direction);
+ }
cmux->n_cells -= hashent->muxinfo.cell_count;
- /* TODO update active_circuits / active_circuit_pqueue */
/* Consistency check: the direction must match the direction searched */
tor_assert(last_searched_direction == hashent->muxinfo.direction);
@@ -667,6 +708,180 @@ circuitmux_detach_circuit(circuitmux_t *cmux, circuit_t *circ)
}
/**
+ * Make a circuit active; update active list and policy-specific info, but
+ * we don't mess with the counters or hash table here.
+ */
+
+static void
+circuitmux_make_circuit_active(circuitmux_t *cmux, circuit_t *circ,
+ cell_direction_t direction)
+{
+ circuit_t **next_active = NULL, **prev_active = NULL, **next_prev = NULL;
+ circuitmux_t *circuit_cmux = NULL;
+ channel_t *chan = NULL;
+ circid_t circ_id;
+ int already_active;
+
+ tor_assert(cmux);
+ tor_assert(circ);
+ tor_assert(direction == CELL_DIRECTION_OUT ||
+ direction == CELL_DIRECTION_IN);
+
+ /* Get the right set of active list links for this direction */
+ if (direction == CELL_DIRECTION_OUT) {
+ next_active = &(circ->next_active_on_n_chan);
+ prev_active = &(circ->prev_active_on_n_chan);
+ circuit_cmux = circ->n_mux;
+ chan = circ->n_chan;
+ circ_id = circ->n_circ_id;
+ } else {
+ next_active = &(TO_OR_CIRCUIT(circ)->next_active_on_p_chan);
+ prev_active = &(TO_OR_CIRCUIT(circ)->prev_active_on_p_chan);
+ circuit_cmux = TO_OR_CIRCUIT(circ)->p_mux;
+ chan = TO_OR_CIRCUIT(circ)->p_chan;
+ circ_id = TO_OR_CIRCUIT(circ)->p_circ_id;
+ }
+
+ /* Assert that it is attached to this mux and a channel */
+ tor_assert(cmux == circuit_cmux);
+ tor_assert(chan != NULL);
+
+ /*
+ * Check if the circuit really was inactive; if it's active, at least one
+ * of the next_active and prev_active pointers will not be NULL, or this
+ * circuit will be either the head or tail of the list for this cmux.
+ */
+ already_active = (*prev_active != NULL || *next_active != NULL ||
+ cmux->active_circuits_head == circ ||
+ cmux->active_circuits_tail == circ);
+
+ /* If we're already active, log a warning and finish */
+ if (already_active) {
+ log_warn(LD_CIRC,
+ "Circuit %d on channel " U64_FORMAT " was already active",
+ circ_id, U64_PRINTF_ARG(chan->global_identifier));
+ return;
+ }
+
+ /*
+ * This is going at the head of the list; if the old head is not NULL,
+ * then its prev pointer should point to this.
+ */
+ *next_active = cmux->active_circuits_head; /* Next is old head */
+ *prev_active = NULL; /* Prev is NULL (this will be the head) */
+ if (cmux->active_circuits_head) {
+ /* The list had an old head; update its prev pointer */
+ next_prev =
+ circuitmux_prev_active_circ_p(cmux, cmux->active_circuits_head);
+ tor_assert(next_prev);
+ *next_prev = circ;
+ } else {
+ /* The list was empty; this becomes the tail as well */
+ cmux->active_circuits_tail = circ;
+ }
+ /* This becomes the new head of the list */
+ cmux->active_circuits_head = circ;
+
+ /* TODO policy-specific notifications */
+}
+
+/**
+ * Make a circuit inactive; update active list and policy-specific info, but
+ * we don't mess with the counters or hash table here.
+ */
+
+static void
+circuitmux_make_circuit_inactive(circuitmux_t *cmux, circuit_t *circ,
+ cell_direction_t direction)
+{
+ circuit_t **next_active = NULL, **prev_active = NULL;
+ circuit_t **next_prev = NULL, **prev_next = NULL;
+ circuitmux_t *circuit_cmux = NULL;
+ channel_t *chan = NULL;
+ circid_t circ_id;
+ int already_inactive;
+
+ tor_assert(cmux);
+ tor_assert(circ);
+ tor_assert(direction == CELL_DIRECTION_OUT ||
+ direction == CELL_DIRECTION_IN);
+
+ /* Get the right set of active list links for this direction */
+ if (direction == CELL_DIRECTION_OUT) {
+ next_active = &(circ->next_active_on_n_chan);
+ prev_active = &(circ->prev_active_on_n_chan);
+ circuit_cmux = circ->n_mux;
+ chan = circ->n_chan;
+ circ_id = circ->n_circ_id;
+ } else {
+ next_active = &(TO_OR_CIRCUIT(circ)->next_active_on_p_chan);
+ prev_active = &(TO_OR_CIRCUIT(circ)->prev_active_on_p_chan);
+ circuit_cmux = TO_OR_CIRCUIT(circ)->p_mux;
+ chan = TO_OR_CIRCUIT(circ)->p_chan;
+ circ_id = TO_OR_CIRCUIT(circ)->p_circ_id;
+ }
+
+ /* Assert that it is attached to this mux and a channel */
+ tor_assert(cmux == circuit_cmux);
+ tor_assert(chan != NULL);
+
+ /*
+ * Check if the circuit really was active; if it's inactive, the
+ * next_active and prev_active pointers will be NULL and this circuit
+ * will not be the head or tail of the list for this cmux.
+ */
+ already_inactive = (*prev_active == NULL && *next_active == NULL &&
+ cmux->active_circuits_head != circ &&
+ cmux->active_circuits_tail != circ);
+
+ /* If we're already inactive, log a warning and finish */
+ if (already_inactive) {
+ log_warn(LD_CIRC,
+ "Circuit %d on channel " U64_FORMAT " was already inactive",
+ circ_id, U64_PRINTF_ARG(chan->global_identifier));
+ return;
+ }
+
+ /* Remove from the list; first get next_prev and prev_next */
+ if (*next_active) {
+ /*
+ * If there's a next circuit, its previous circuit becomes this
+ * circuit's previous circuit.
+ */
+ next_prev = circuitmux_prev_active_circ_p(cmux, *next_active);
+ } else {
+ /* Else, the tail becomes this circuit's previous circuit */
+ next_prev = &(cmux->active_circuits_tail);
+ }
+
+ /* Got next_prev, now prev_next */
+ if (*prev_active) {
+ /*
+ * If there's a previous circuit, its next circuit becomes this circuit's
+ * next circuit.
+ */
+ prev_next = circuitmux_next_active_circ_p(cmux, *prev_active);
+ } else {
+ /* Else, the head becomes this circuit's next circuit */
+ prev_next = &(cmux->active_circuits_head);
+ }
+
+ /* Assert that we got sensible values for the next/prev pointers */
+ tor_assert(next_prev != NULL);
+ tor_assert(prev_next != NULL);
+
+ /* Update the next/prev pointers - this removes circ from the list */
+ *next_prev = *prev_active;
+ *prev_next = *next_active;
+
+ /* Now null out prev_active/next_active */
+ *prev_active = NULL;
+ *next_active = NULL;
+
+ /* TODO policy-specific notifications */
+}
+
+/**
* Clear the cell counter for a circuit on a circuitmux
*/
@@ -705,11 +920,11 @@ circuitmux_set_num_cells(circuitmux_t *cmux, circuit_t *circ,
*/
if (hashent->muxinfo.cell_count > 0 && n_cells == 0) {
--(cmux->n_active_circuits);
- /* TODO update active_circuits / active_circuit_pqueue */
+ circuitmux_make_circuit_inactive(cmux, circ, hashent->muxinfo.direction);
/* Is the old cell count == 0 and the new cell count > 0 ? */
} else if (hashent->muxinfo.cell_count == 0 && n_cells > 0) {
++(cmux->n_active_circuits);
- /* TODO update active_circuits / active_circuit_pqueue */
+ circuitmux_make_circuit_active(cmux, circ, hashent->muxinfo.direction);
}
/* Update hash entry cell counter */
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