[or-cvs] [tor/master 02/38] Teach read_event/write_event manipulators about bufferevents.
nickm at torproject.org
nickm at torproject.org
Mon Sep 27 20:50:58 UTC 2010
Author: Nick Mathewson <nickm at torproject.org>
Date: Fri, 31 Jul 2009 11:11:45 -0400
Subject: Teach read_event/write_event manipulators about bufferevents.
Commit: 57e7b54b7b4102de0c5776a1268367c18090033b
Add an --enable-bufferevents config switch.
---
configure.in | 16 ++++++++++++-
src/common/compat_libevent.h | 3 ++
src/or/buffers.c | 1 +
src/or/connection.c | 8 ++++++
src/or/main.c | 51 +++++++++++++++++++++++++++++++++++++++++-
src/or/main.h | 1 +
src/or/or.h | 19 +++++++++++++++
src/or/relay.c | 2 +-
8 files changed, 98 insertions(+), 3 deletions(-)
diff --git a/configure.in b/configure.in
index 080e562..d67abd4 100644
--- a/configure.in
+++ b/configure.in
@@ -118,6 +118,9 @@ if test "$enable_local_appdata" = "yes"; then
[Defined if we default to host local appdata paths on Windows])
fi
+AC_ARG_ENABLE(bufferevents,
+ AS_HELP_STRING(--enable-bufferevents, use Libevent's buffered IO.))
+
AC_PROG_CC
AC_PROG_CPP
AC_PROG_MAKE_SET
@@ -302,7 +305,7 @@ AC_CHECK_MEMBERS([struct event.min_heap_idx], , ,
[#include <event.h>
])
-AC_CHECK_HEADERS(event2/event.h event2/dns.h)
+AC_CHECK_HEADERS(event2/event.h event2/dns.h event2/bufferevent_ssl.h)
LIBS="$save_LIBS"
LDFLAGS="$save_LDFLAGS"
@@ -323,6 +326,17 @@ fi
AC_SUBST(TOR_LIBEVENT_LIBS)
+dnl This isn't the best test for Libevent 2.0.3-alpha. Once it's released,
+dnl we can do much better.
+if test "$enable_bufferevents" = "yes" && test "$ac_cv_header_event2_bufferevent_ssl_h" != "yes" ; then
+ AC_MSG_ERROR([You've asked for bufferevent support, but you're using a version of Libevent without SSL support. This won't work. We need Libevent 2.0.3-alpha or later. If it isn't released yet, use Libevent from SVN, and talk to Nick.])
+fi
+
+AM_CONDITIONAL(USE_BUFFEREVENTS, test "$enable_bufferevents" = "yes")
+if test "$enable_bufferevents" = "yes"; then
+ AC_DEFINE(USE_BUFFEREVENTS, 1, [Defined if we're going to use Libevent's buffered IO API])
+fi
+
dnl ------------------------------------------------------
dnl Where do you live, openssl? And how do we call you?
diff --git a/src/common/compat_libevent.h b/src/common/compat_libevent.h
index fdf5e0a..a4011e3 100644
--- a/src/common/compat_libevent.h
+++ b/src/common/compat_libevent.h
@@ -8,6 +8,9 @@
struct event;
struct event_base;
+#ifdef USE_BUFFEREVENTS
+struct bufferevent;
+#endif
#ifdef HAVE_EVENT2_EVENT_H
#include <event2/util.h>
diff --git a/src/or/buffers.c b/src/or/buffers.c
index 5ba8819..a1b5a3a 100644
--- a/src/or/buffers.c
+++ b/src/or/buffers.c
@@ -541,6 +541,7 @@ buf_free(buf_t *buf)
{
if (!buf)
return;
+
buf_clear(buf);
buf->magic = 0xdeadbeef;
tor_free(buf);
diff --git a/src/or/connection.c b/src/or/connection.c
index 91ce74b..6e3f8e6 100644
--- a/src/or/connection.c
+++ b/src/or/connection.c
@@ -36,6 +36,10 @@
#include "router.h"
#include "routerparse.h"
+#ifdef USE_BUFFEREVENTS
+#include <event2/bufferevent.h>
+#endif
+
static connection_t *connection_create_listener(
struct sockaddr *listensockaddr,
socklen_t listensocklen, int type,
@@ -424,6 +428,10 @@ _connection_free(connection_t *conn)
tor_free(conn->read_event); /* Probably already freed by connection_free. */
tor_free(conn->write_event); /* Probably already freed by connection_free. */
+ IF_HAS_BUFFEREVENT(conn, {
+ bufferevent_free(conn->bufev);
+ conn->bufev = NULL;
+ });
if (conn->type == CONN_TYPE_DIR) {
dir_connection_t *dir_conn = TO_DIR_CONN(conn);
diff --git a/src/or/main.c b/src/or/main.c
index 477a274..a9dfecb 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -56,6 +56,10 @@
#include <event.h>
#endif
+#ifdef USE_BUFFEREVENTS
+#include <event2/bufferevent.h>
+#endif
+
void evdns_shutdown(int);
/********* PROTOTYPES **********/
@@ -168,7 +172,7 @@ connection_add(connection_t *conn)
conn->conn_array_index = smartlist_len(connection_array);
smartlist_add(connection_array, conn);
- if (conn->s >= 0 || conn->linked) {
+ if (!HAS_BUFFEREVENT(conn) && (conn->s >= 0 || conn->linked)) {
conn->read_event = tor_event_new(tor_libevent_get_base(),
conn->s, EV_READ|EV_PERSIST, conn_read_callback, conn);
conn->write_event = tor_event_new(tor_libevent_get_base(),
@@ -196,6 +200,12 @@ connection_unregister_events(connection_t *conn)
log_warn(LD_BUG, "Error removing write event for %d", conn->s);
tor_free(conn->write_event);
}
+#ifdef USE_BUFFEREVENTS
+ if (conn->bufev) {
+ bufferevent_free(conn->bufev);
+ conn->bufev = NULL;
+ }
+#endif
if (conn->dns_server_port) {
dnsserv_close_listener(conn);
}
@@ -310,6 +320,15 @@ get_connection_array(void)
void
connection_watch_events(connection_t *conn, watchable_events_t events)
{
+ IF_HAS_BUFFEREVENT(conn, {
+ short ev = ((short)events) & (EV_READ|EV_WRITE);
+ short old_ev = bufferevent_get_enabled(conn->bufev);
+ if ((ev & ~old_ev) != 0)
+ bufferevent_enable(conn->bufev, ev);
+ if ((old_ev & ~ev) != 0)
+ bufferevent_disable(conn->bufev, old_ev & ~ev);
+ return;
+ });
if (events & READ_EVENT)
connection_start_reading(conn);
else
@@ -327,6 +346,9 @@ connection_is_reading(connection_t *conn)
{
tor_assert(conn);
+ IF_HAS_BUFFEREVENT(conn,
+ return (bufferevent_get_enabled(conn->bufev) & EV_READ) != 0;
+ );
return conn->reading_from_linked_conn ||
(conn->read_event && event_pending(conn->read_event, EV_READ, NULL));
}
@@ -336,6 +358,12 @@ void
connection_stop_reading(connection_t *conn)
{
tor_assert(conn);
+
+ IF_HAS_BUFFEREVENT(conn, {
+ bufferevent_disable(conn->bufev, EV_READ);
+ return;
+ });
+
tor_assert(conn->read_event);
if (conn->linked) {
@@ -355,6 +383,12 @@ void
connection_start_reading(connection_t *conn)
{
tor_assert(conn);
+
+ IF_HAS_BUFFEREVENT(conn, {
+ bufferevent_enable(conn->bufev, EV_READ);
+ return;
+ });
+
tor_assert(conn->read_event);
if (conn->linked) {
@@ -376,6 +410,10 @@ connection_is_writing(connection_t *conn)
{
tor_assert(conn);
+ IF_HAS_BUFFEREVENT(conn,
+ return (bufferevent_get_enabled(conn->bufev) & EV_WRITE) != 0;
+ );
+
return conn->writing_to_linked_conn ||
(conn->write_event && event_pending(conn->write_event, EV_WRITE, NULL));
}
@@ -385,6 +423,12 @@ void
connection_stop_writing(connection_t *conn)
{
tor_assert(conn);
+
+ IF_HAS_BUFFEREVENT(conn, {
+ bufferevent_disable(conn->bufev, EV_WRITE);
+ return;
+ });
+
tor_assert(conn->write_event);
if (conn->linked) {
@@ -407,6 +451,11 @@ connection_start_writing(connection_t *conn)
tor_assert(conn);
tor_assert(conn->write_event);
+ IF_HAS_BUFFEREVENT(conn, {
+ bufferevent_enable(conn->bufev, EV_WRITE);
+ return;
+ });
+
if (conn->linked) {
conn->writing_to_linked_conn = 1;
if (conn->linked_conn &&
diff --git a/src/or/main.h b/src/or/main.h
index ef38dc9..6175c28 100644
--- a/src/or/main.h
+++ b/src/or/main.h
@@ -24,6 +24,7 @@ int connection_is_on_closeable_list(connection_t *conn);
smartlist_t *get_connection_array(void);
typedef enum watchable_events {
+ /* Yes, it is intentional that these match Libevent's EV_READ and EV_WRITE */
READ_EVENT=0x02,
WRITE_EVENT=0x04
} watchable_events_t;
diff --git a/src/or/or.h b/src/or/or.h
index 6332de8..a699685 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -959,6 +959,7 @@ typedef struct connection_t {
/** Our socket; -1 if this connection is closed, or has no socket. */
evutil_socket_t s;
int conn_array_index; /**< Index into the global connection array. */
+
struct event *read_event; /**< Libevent event structure. */
struct event *write_event; /**< Libevent event structure. */
buf_t *inbuf; /**< Buffer holding data read over this connection. */
@@ -969,6 +970,11 @@ typedef struct connection_t {
* read? */
time_t timestamp_lastwritten; /**< When was the last time libevent said we
* could write? */
+
+#ifdef USE_BUFFEREVENTS
+ struct bufferevent *bufev; /**< A Libevent buffered IO structure. */
+#endif
+
time_t timestamp_created; /**< When was this connection_t created? */
/* XXXX_IP6 make this IPv6-capable */
@@ -1264,6 +1270,19 @@ static INLINE control_connection_t *TO_CONTROL_CONN(connection_t *c)
return DOWNCAST(control_connection_t, c);
}
+#ifdef USE_BUFFEREVENTS
+#define HAS_BUFFEREVENT(c) (((c)->bufev) != NULL)
+#define IF_HAS_BUFFEREVENT(c, stmt) \
+ do { \
+ if ((conn)->bufev) do { \
+ stmt ; \
+ } while(0); \
+ } while (0)
+#else
+#define HAS_BUFFEREVENT(c) (0)
+#define IF_HAS_BUFFEREVENT(c, stmt) (void)0
+#endif
+
/** What action type does an address policy indicate: accept or reject? */
typedef enum {
ADDR_POLICY_ACCEPT=1,
diff --git a/src/or/relay.c b/src/or/relay.c
index b12cef4..480a291 100644
--- a/src/or/relay.c
+++ b/src/or/relay.c
@@ -2214,7 +2214,7 @@ set_streams_blocked_on_circ(circuit_t *circ, or_connection_t *orconn,
edge->edge_blocked_on_circ = block;
}
- if (!conn->read_event) {
+ if (!conn->read_event && !HAS_BUFFEREVENT(conn)) {
/* This connection is a placeholder for something; probably a DNS
* request. It can't actually stop or start reading.*/
continue;
--
1.7.1
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