commit 60b42d68f35870f2d72dae5381120146813e9106 Author: Nick Mathewson nickm@torproject.org Date: Sun Feb 12 22:58:49 2012 -0500

Try to have (and maintain!) an invariant about unconfigured_proxies_n

The invariant is: unconfigured_proxies_n is exactly the number of managed_proxy_t not in state PT_PROTO_COMPLETED.

To maintain this, we need to stop overloading unconfigured_proxies_n to also count managed_proxy_t items that are in PT_PROTO_COMPLETED but which might need relaunching. To make it so we can detect those, we introduce another variable.

This commit also adds a function to assert that we haven't broken the invariant.

Fix for bug 5084; bugfix on 0.2.3.6-alpha, I think. --- src/or/transports.c | 49 ++++++++++++++++++++++++++++++++++++++++--------- 1 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/src/or/transports.c b/src/or/transports.c index daa62b5..15d96ca 100644 --- a/src/or/transports.c +++ b/src/or/transports.c @@ -140,12 +140,35 @@ static INLINE void free_execve_args(char **arg); static smartlist_t *managed_proxy_list = NULL; /** Number of still unconfigured proxies. */ static int unconfigured_proxies_n = 0; +/** Boolean: True iff we might need to restart some proxies. */ +static int check_if_restarts_needed = 0;

-/** Return true if there are still unconfigured managed proxies. */ +/** Return true if there are still unconfigured managed proxies, or proxies + * that need restarting. */ int pt_proxies_configuration_pending(void) { - return !! unconfigured_proxies_n; + return unconfigured_proxies_n || check_if_restarts_needed; +} + +/** Assert that the unconfigured_proxies_n value correctly matches the number + * of proxies in a state other than PT_PROTO_COMPLETE. */ +static void +assert_unconfigured_count_ok(void) +{ + int n_completed = 0; + if (!managed_proxy_list) { + tor_assert(unconfigured_proxies_n == 0); + return; + } + + SMARTLIST_FOREACH(managed_proxy_list, managed_proxy_t *, mp, { + if (mp->conf_state == PT_PROTO_COMPLETED) + ++n_completed; + }); + + tor_assert(n_completed + unconfigured_proxies_n == + smartlist_len(managed_proxy_list)); }

/** Return true if <b>mp</b> has the same argv as <b>proxy_argv</b> */ @@ -255,6 +278,7 @@ proxy_prepare_for_restart(managed_proxy_t *mp)

/* flag it as an infant proxy so that it gets launched on next tick */ mp->conf_state = PT_PROTO_INFANT; + unconfigured_proxies_n++; }

/** Launch managed proxy <b>mp</b>. */ @@ -325,6 +349,8 @@ pt_configure_remaining_proxies(void) * remove elements from managed_proxy_list. */ smartlist_add_all(tmp, managed_proxy_list);

+ assert_unconfigured_count_ok(); + SMARTLIST_FOREACH_BEGIN(tmp, managed_proxy_t *, mp) { tor_assert(mp->conf_state != PT_PROTO_BROKEN || mp->conf_state != PT_PROTO_FAILED_LAUNCH); @@ -332,17 +358,14 @@ pt_configure_remaining_proxies(void) if (mp->got_hup) { mp->got_hup = 0;

- /* This proxy is marked by a SIGHUP. Check whether we need to - restart it. */ + /* This proxy is marked by a SIGHUP. Check whether we need to + restart it. */ if (proxy_needs_restart(mp)) { log_info(LD_GENERAL, "Preparing managed proxy for restart."); proxy_prepare_for_restart(mp); - continue; } else { /* it doesn't need to be restarted. */ log_info(LD_GENERAL, "Nothing changed for managed proxy after HUP: " "not restarting."); - unconfigured_proxies_n--; - tor_assert(unconfigured_proxies_n >= 0); }

continue; @@ -356,6 +379,8 @@ pt_configure_remaining_proxies(void) } SMARTLIST_FOREACH_END(mp);

smartlist_free(tmp); + check_if_restarts_needed = 0; + assert_unconfigured_count_ok(); }

#ifdef _WIN32 @@ -1134,6 +1159,8 @@ managed_proxy_create(const smartlist_t *transport_list, smartlist_add(managed_proxy_list, mp); unconfigured_proxies_n++;

+ assert_unconfigured_count_ok(); + return mp; }

@@ -1163,7 +1190,7 @@ pt_kickstart_proxy(const smartlist_t *transport_list, it. */ if (mp->marked_for_removal) { mp->marked_for_removal = 0; - unconfigured_proxies_n++; + check_if_restarts_needed = 1; }

SMARTLIST_FOREACH_BEGIN(transport_list, const char *, transport) { @@ -1202,6 +1229,7 @@ pt_prepare_proxy_list_for_config_read(void) if (!managed_proxy_list) return;

+ assert_unconfigured_count_ok(); SMARTLIST_FOREACH_BEGIN(managed_proxy_list, managed_proxy_t *, mp) { /* Destroy unconfigured proxies. */ if (mp->conf_state != PT_PROTO_COMPLETED) { @@ -1219,6 +1247,8 @@ pt_prepare_proxy_list_for_config_read(void) smartlist_clear(mp->transports_to_launch); } SMARTLIST_FOREACH_END(mp);

+ assert_unconfigured_count_ok(); + tor_assert(unconfigured_proxies_n == 0); }

@@ -1231,13 +1261,14 @@ sweep_proxy_list(void) { if (!managed_proxy_list) return; - + assert_unconfigured_count_ok(); SMARTLIST_FOREACH_BEGIN(managed_proxy_list, managed_proxy_t *, mp) { if (mp->marked_for_removal) { SMARTLIST_DEL_CURRENT(managed_proxy_list, mp); managed_proxy_destroy(mp, 1); } } SMARTLIST_FOREACH_END(mp); + assert_unconfigured_count_ok(); }

/** Release all storage held by the pluggable transports subsystem. */