From c612ddee17c2f6e70fde9f0bdd7116516f384ae8 Mon Sep 17 00:00:00 2001 From: Nick Mathewson Date: Tue, 28 Sep 2010 14:01:45 -0400 Subject: [PATCH] Add a new option to enable/disable IOCP support --- changes/bufferevent-support | 3 +++ doc/tor.1.txt | 5 +++++ src/common/compat_libevent.c | 18 ++++++++++++++++-- src/common/compat_libevent.h | 7 ++++++- src/or/config.c | 16 ++++++++++++---- src/or/or.h | 4 ++++ 6 files changed, 46 insertions(+), 7 deletions(-) diff --git a/changes/bufferevent-support b/changes/bufferevent-support index 22ee50ebff..e39c36f13b 100644 --- a/changes/bufferevent-support +++ b/changes/bufferevent-support @@ -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. diff --git a/doc/tor.1.txt b/doc/tor.1.txt index 620f938741..e9ef55166c 100644 --- a/doc/tor.1.txt +++ b/doc/tor.1.txt @@ -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 -------------- diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c index bbab06e8d4..6afd3c1d29 100644 --- a/src/common/compat_libevent.c +++ b/src/common/compat_libevent.c @@ -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 diff --git a/src/common/compat_libevent.h b/src/common/compat_libevent.h index f483d6ee6d..ecf25806d5 100644 --- a/src/common/compat_libevent.h +++ b/src/common/compat_libevent.h @@ -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, diff --git a/src/or/config.c b/src/or/config.c index 6d8addeb2d..c5b0ccf586 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -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); diff --git a/src/or/or.h b/src/or/or.h index 4741cc341b..d2a7714db3 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -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. */