diff options
Diffstat (limited to 'src/common')
| -rw-r--r-- | src/common/compat_libevent.c | 43 |
1 files changed, 42 insertions, 1 deletions
diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c index 3201738701..7a28c9bc9b 100644 --- a/src/common/compat_libevent.c +++ b/src/common/compat_libevent.c @@ -195,16 +195,33 @@ tor_libevent_initialize(tor_libevent_cfg *torcfg) #ifdef HAVE_EVENT2_EVENT_H { - struct event_config *cfg = event_config_new(); + int attempts = 0; + int using_threads; + struct event_config *cfg; + + retry: + ++attempts; + using_threads = 0; + cfg = event_config_new(); + tor_assert(cfg); #if defined(MS_WINDOWS) && defined(USE_BUFFEREVENTS) if (! torcfg->disable_iocp) { evthread_use_windows_threads(); event_config_set_flag(cfg, EVENT_BASE_FLAG_STARTUP_IOCP); using_iocp_bufferevents = 1; + using_threads = 1; + } else { + using_iocp_bufferevents = 0; } #endif + if (!using_threads) { + /* Telling Libevent not to try to turn locking on can avoid a needless + * socketpair() attempt. */ + event_config_set_flag(cfg, EVENT_BASE_FLAG_NOLOCK); + } + #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); @@ -219,11 +236,35 @@ tor_libevent_initialize(tor_libevent_cfg *torcfg) the_event_base = event_base_new_with_config(cfg); event_config_free(cfg); + + if (using_threads && the_event_base == NULL && attempts < 2) { + /* This could be a socketpair() failure, which can happen sometimes on + * windows boxes with obnoxious firewall rules. Downgrade and try + * again. */ +#if defined(MS_WINDOWS) && defined(USE_BUFFEREVENTS) + if (torcfg->disable_iocp == 0) { + log_warn(LD_GENERAL, "Unable to initialize Libevent. Trying again with " + "IOCP disabled."); + } else +#endif + { + log_warn(LD_GENERAL, "Unable to initialize Libevent. Trying again."); + } + + torcfg->disable_iocp = 1; + goto retry; + } + } #else the_event_base = event_init(); #endif + if (!the_event_base) { + log_err(LD_GENERAL, "Unable to initialize Libevent: cannot continue."); + exit(1); + } + #if defined(HAVE_EVENT_GET_VERSION) && defined(HAVE_EVENT_GET_METHOD) /* Making this a NOTICE for now so we can link bugs to a libevent versions * or methods better. */ |