From a25c5d699454a9af02556cdb329b521ba0867872 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Mon, 26 Mar 2007 14:08:35 +0000
Subject: r12654@Kushana: nickm | 2007-03-25 19:03:44 -0400 Add
documentation for cell queue functions; make destroy cells result in cell
queues getting cleared before the destroy gets sent.
svn:r9907
---
src/or/or.h | 50 +++++++++++++++++++++++++++++++++++---------------
1 file changed, 35 insertions(+), 15 deletions(-)
(limited to 'src/or/or.h')
diff --git a/src/or/or.h b/src/or/or.h
index 416ffb0b4..590c25540 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -685,11 +685,12 @@ struct cell_t {
char payload[CELL_PAYLOAD_SIZE]; /**< Cell body. */
};
-/** DOCDOC */
+/** A queue of cells on a circuit, waiting to be added to the
+ * or_connection_t's outbuf. */
typedef struct cell_queue_t {
- cell_t *head;
- cell_t *tail;
- int n;
+ cell_t *head; /**< The first cell, or NULL if the queue is empty */
+ cell_t *tail; /**< The last cell, or NULL if the queue is empty */
+ int n; /**< The number of cells in the queue */
} cell_queue_t;
/** Beginning of a RELAY cell payload. */
@@ -754,14 +755,17 @@ typedef struct connection_t {
* connections. Set once we've set the stream end,
* and check in connection_about_to_close_connection().
*/
- unsigned int edge_blocked_on_circ:1; /**< DOCDOC */
+ /** Edge connections only: true if we've blocked writing until the
+ * circuit has fewer queued cells. */
+ unsigned int edge_blocked_on_circ:1;
/** Used for OR conns that shouldn't get any new circs attached to them. */
unsigned int or_is_obsolete:1;
/** For AP connections only. If 1, and we fail to reach the chosen exit,
* stop requiring it. */
unsigned int chosen_exit_optional:1;
- int s; /**< Our socket; -1 if this connection is closed. */
+ int s; /**< Our socket; -1 if this connection is closed, or has no
+ * sockets. */
int conn_array_index; /**< Index into the global connection array. */
struct event *read_event; /**< Libevent event structure. */
struct event *write_event; /**< Libevent event structure. */
@@ -816,7 +820,11 @@ typedef struct or_connection_t {
* bandwidthburst. (OPEN ORs only) */
int n_circuits; /**< How many circuits use this connection as p_conn or
* n_conn ? */
- struct circuit_t *active_circuits; /**< DOCDOC */
+
+ /** Double-linked ring of circuits with queued cells waiting for room to
+ * 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 or_connection_t *next_with_same_id; /**< Next connection with same
* identity digest as this one. */
@@ -1366,7 +1374,7 @@ typedef struct circuit_t {
uint32_t magic; /**< For memory and type debugging: must equal
* ORIGIN_CIRCUIT_MAGIC or OR_CIRCUIT_MAGIC. */
- /** DOCDOC */
+ /** Queue of cells waiting to be transmitted on n_conn. */
cell_queue_t n_conn_cells;
/** The OR connection that is next in this circuit. */
or_connection_t *n_conn;
@@ -1379,8 +1387,11 @@ typedef struct circuit_t {
/** The IPv4 address of the OR that is next in this circuit. */
uint32_t n_addr;
- /** DOCDOC */
+ /** True iff we are waiting for n_conn_cells to become less full before
+ * allowing p_streams to add any more cells. (Origin circuit only.) */
unsigned int streams_blocked_on_n_conn : 1;
+ /** True iff we are waiting for p_conn_cells to become less full before
+ * allowing n_streams to add any more cells. (OR circuit only.) */
unsigned int streams_blocked_on_p_conn : 1;
/** How many relay data cells can we package (read from edge streams)
@@ -1412,9 +1423,13 @@ typedef struct circuit_t {
const char *marked_for_close_file; /**< For debugging: in which file was this
* circuit marked for close? */
- struct circuit_t *next_active_on_n_conn; /**< DOCDOC */
- struct circuit_t *prev_active_on_n_conn; /**< DOCDOC */
- struct circuit_t *next; /**< Next circuit in linked list. */
+ /** Next circuit in the doubly-linked ring of circuits waiting to add
+ * cells to n_conn. NULL if we have no cells pending. */
+ struct circuit_t *next_active_on_n_conn;
+ /** Previous circuit in the doubly-linked ring of circuits waiting to add
+ * cells to n_conn. NULL if we have no cells pending. */
+ struct circuit_t *prev_active_on_n_conn;
+ struct circuit_t *next; /**< Next circuit in linked list of all circuits. */
} circuit_t;
/** An origin_circuit_t holds data necessary to build and use a circuit.
@@ -1468,12 +1483,16 @@ typedef struct origin_circuit_t {
typedef struct or_circuit_t {
circuit_t _base;
- struct circuit_t *next_active_on_p_conn; /**< DOCDOC */
- struct circuit_t *prev_active_on_p_conn; /**< DOCDOC */
+ /** Next circuit in the doubly-linked ring of circuits waiting to add
+ * cells to p_conn. NULL if we have no cells pending. */
+ struct circuit_t *next_active_on_p_conn;
+ /** Previous circuit in the doubly-linked ring of circuits waiting to add
+ * cells to p_conn. NULL if we have no cells pending. */
+ struct circuit_t *prev_active_on_p_conn;
/** The circuit_id used in the previous (backward) hop of this circuit. */
circid_t p_circ_id;
- /** DOCDOC */
+ /** Queue of cells waiting to be transmitted on p_conn. */
cell_queue_t p_conn_cells;
/** The OR connection that is previous in this circuit. */
or_connection_t *p_conn;
@@ -2648,6 +2667,7 @@ int connection_or_flush_from_first_active_circuit(or_connection_t *conn,
void assert_active_circuits_ok(or_connection_t *orconn);
void make_circuit_inactive_on_conn(circuit_t *circ, or_connection_t *conn);
void make_circuit_active_on_conn(circuit_t *circ, or_connection_t *conn);
+void circuit_clear_cell_queue(circuit_t *circ, or_connection_t *orconn);
/********************************* rephist.c ***************************/
--
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