Commit c612ddee authored by Nick Mathewson's avatar Nick Mathewson 🎨
Browse files

Add a new option to enable/disable IOCP support

parent d6e255ed
......@@ -6,4 +6,7 @@
flag. Using this feature will make our networking code more flexible,
lets us stack layers on each other, and let us use more efficient
zero-copy transports where available.
- As an experimental feature, when using the "bufferevents" buffered
IO backend, Tor can try to use Windows's IOCP networking API. This
is off by default. To turn it on, add "DisableIOCP 0" to your torrc.
......@@ -397,6 +397,11 @@ Other options can be specified either on the command-line (--option
networkstatus. This is an advanced option; you generally shouldn't have
to mess with it. (Default: not set.)
**DisableIOCP** **0**|**1**::
If Tor was built to use the Libevent's "bufferevents" networking code
and you're running on Windows, setting this option to 1 will tell Libevent
not to use the Windows IOCP networking API. (Default: 1)
CLIENT OPTIONS
--------------
......
......@@ -159,7 +159,7 @@ struct event_base *the_event_base = NULL;
/** Initialize the Libevent library and set up the event base. */
void
tor_libevent_initialize(void)
tor_libevent_initialize(tor_libevent_cfg *torcfg)
{
tor_assert(the_event_base == NULL);
......@@ -171,7 +171,21 @@ tor_libevent_initialize(void)
#endif
#ifdef HAVE_EVENT2_EVENT_H
the_event_base = event_base_new();
{
struct event_config *cfg = event_config_new();
#if defined(MS_WINDOWS) && defined(USE_BUFFEREVENTS)
if (! torcfg->disable_iocp)
event_config_set_flag(cfg, EVENT_BASE_FLAG_STARTUP_IOCP);
#endif
#if defined(LIBEVENT_VERSION_NUMBER) && LIBEVENT_VERSION_NUMBER >= V(2,0,7)
if (torcfg->num_cpus > 0)
event_config_set_num_cpus_hint(cfg, torcfg->num_cpus);
#endif
the_event_base = event_base_new_with_config(cfg);
}
#else
the_event_base = event_init();
#endif
......
......@@ -56,7 +56,12 @@ struct timeval;
int tor_event_base_loopexit(struct event_base *base, struct timeval *tv);
#endif
void tor_libevent_initialize(void);
typedef struct tor_libevent_cfg {
int disable_iocp;
int num_cpus;
} tor_libevent_cfg;
void tor_libevent_initialize(tor_libevent_cfg *cfg);
struct event_base *tor_libevent_get_base(void);
const char *tor_libevent_get_method(void);
void tor_check_libevent_version(const char *m, int server,
......
......@@ -224,6 +224,7 @@ static config_var_t _option_vars[] = {
V(DirReqStatistics, BOOL, "0"),
VAR("DirServer", LINELIST, DirServers, NULL),
V(DisableAllSwap, BOOL, "0"),
V(DisableIOCP, BOOL, "1"),
V(DNSPort, UINT, "0"),
V(DNSListenAddress, LINELIST, NULL),
V(DownloadExtraInfo, BOOL, "0"),
......@@ -554,7 +555,7 @@ static int is_listening_on_low_port(uint16_t port_option,
static uint64_t config_parse_memunit(const char *s, int *ok);
static int config_parse_interval(const char *s, int *ok);
static void init_libevent(void);
static void init_libevent(const or_options_t *options);
static int opt_streq(const char *s1, const char *s2);
/** Magic value for or_options_t. */
......@@ -955,7 +956,7 @@ options_act_reversible(or_options_t *old_options, char **msg)
/* Set up libevent. (We need to do this before we can register the
* listeners as listeners.) */
if (running_tor && !libevent_initialized) {
init_libevent();
init_libevent(options);
libevent_initialized = 1;
}
......@@ -4895,9 +4896,12 @@ config_parse_interval(const char *s, int *ok)
* Initialize the libevent library.
*/
static void
init_libevent(void)
init_libevent(const or_options_t *options)
{
const char *badness=NULL;
tor_libevent_cfg cfg;
tor_assert(options);
configure_libevent_logging();
/* If the kernel complains that some method (say, epoll) doesn't
......@@ -4907,7 +4911,11 @@ init_libevent(void)
tor_check_libevent_header_compatibility();
tor_libevent_initialize();
memset(&cfg, 0, sizeof(cfg));
cfg.disable_iocp = options->DisableIOCP;
cfg.num_cpus = options->NumCpus;
tor_libevent_initialize(&cfg);
suppress_libevent_log_msg(NULL);
......
......@@ -2892,6 +2892,10 @@ typedef struct {
*/
double CircuitPriorityHalflife;
/** If true, do not enable IOCP on windows with bufferevents, even if
* we think we could. */
int DisableIOCP;
} or_options_t;
/** Persistent state for an onion router, as saved to disk. */
......
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