diff options
3 files changed, 101 insertions, 74 deletions
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc index 6ac9a77635..c3c62b60bf 100644 --- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc +++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc @@ -363,6 +363,15 @@ void AresDnsResolver::OnResolvedLocked(void* arg, grpc_error* error) { } void AresDnsResolver::MaybeStartResolvingLocked() { + // If there is an existing timer, the time it fires is the earliest time we + // can start the next resolution. + if (have_next_resolution_timer_) { + // TODO(dgq): remove the following two lines once Pick First stops + // discarding subchannels after selecting. + ++resolved_version_; + MaybeFinishNextLocked(); + return; + } if (last_resolution_timestamp_ >= 0) { const grpc_millis earliest_next_resolution = last_resolution_timestamp_ + min_time_between_resolutions_; @@ -375,17 +384,15 @@ void AresDnsResolver::MaybeStartResolvingLocked() { "In cooldown from last resolution (from %" PRIdPTR " ms ago). Will resolve again in %" PRIdPTR " ms", last_resolution_ago, ms_until_next_resolution); - if (!have_next_resolution_timer_) { - have_next_resolution_timer_ = true; - // TODO(roth): We currently deal with this ref manually. Once the - // new closure API is done, find a way to track this ref with the timer - // callback as part of the type system. - RefCountedPtr<Resolver> self = - Ref(DEBUG_LOCATION, "next_resolution_timer_cooldown"); - self.release(); - grpc_timer_init(&next_resolution_timer_, ms_until_next_resolution, - &on_next_resolution_); - } + have_next_resolution_timer_ = true; + // TODO(roth): We currently deal with this ref manually. Once the + // new closure API is done, find a way to track this ref with the timer + // callback as part of the type system. + RefCountedPtr<Resolver> self = + Ref(DEBUG_LOCATION, "next_resolution_timer_cooldown"); + self.release(); + grpc_timer_init(&next_resolution_timer_, ms_until_next_resolution, + &on_next_resolution_); // TODO(dgq): remove the following two lines once Pick First stops // discarding subchannels after selecting. ++resolved_version_; @@ -397,6 +404,7 @@ void AresDnsResolver::MaybeStartResolvingLocked() { } void AresDnsResolver::StartResolvingLocked() { + gpr_log(GPR_DEBUG, "Start resolving."); // TODO(roth): We currently deal with this ref manually. Once the // new closure API is done, find a way to track this ref with the timer // callback as part of the type system. diff --git a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc index fbab136421..e7842a7951 100644 --- a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc +++ b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc @@ -236,6 +236,15 @@ void NativeDnsResolver::OnResolvedLocked(void* arg, grpc_error* error) { } void NativeDnsResolver::MaybeStartResolvingLocked() { + // If there is an existing timer, the time it fires is the earliest time we + // can start the next resolution. + if (have_next_resolution_timer_) { + // TODO(dgq): remove the following two lines once Pick First stops + // discarding subchannels after selecting. + ++resolved_version_; + MaybeFinishNextLocked(); + return; + } if (last_resolution_timestamp_ >= 0) { const grpc_millis earliest_next_resolution = last_resolution_timestamp_ + min_time_between_resolutions_; @@ -248,17 +257,15 @@ void NativeDnsResolver::MaybeStartResolvingLocked() { "In cooldown from last resolution (from %" PRIdPTR " ms ago). Will resolve again in %" PRIdPTR " ms", last_resolution_ago, ms_until_next_resolution); - if (!have_next_resolution_timer_) { - have_next_resolution_timer_ = true; - // TODO(roth): We currently deal with this ref manually. Once the - // new closure API is done, find a way to track this ref with the timer - // callback as part of the type system. - RefCountedPtr<Resolver> self = - Ref(DEBUG_LOCATION, "next_resolution_timer_cooldown"); - self.release(); - grpc_timer_init(&next_resolution_timer_, ms_until_next_resolution, - &on_next_resolution_); - } + have_next_resolution_timer_ = true; + // TODO(roth): We currently deal with this ref manually. Once the + // new closure API is done, find a way to track this ref with the timer + // callback as part of the type system. + RefCountedPtr<Resolver> self = + Ref(DEBUG_LOCATION, "next_resolution_timer_cooldown"); + self.release(); + grpc_timer_init(&next_resolution_timer_, ms_until_next_resolution, + &on_next_resolution_); // TODO(dgq): remove the following two lines once Pick First stops // discarding subchannels after selecting. ++resolved_version_; @@ -270,6 +277,7 @@ void NativeDnsResolver::MaybeStartResolvingLocked() { } void NativeDnsResolver::StartResolvingLocked() { + gpr_log(GPR_DEBUG, "Start resolving."); // TODO(roth): We currently deal with this ref manually. Once the // new closure API is done, find a way to track this ref with the timer // callback as part of the type system. diff --git a/test/core/client_channel/resolvers/dns_resolver_cooldown_test.cc b/test/core/client_channel/resolvers/dns_resolver_cooldown_test.cc index 01c61a9f18..37e1d714ca 100644 --- a/test/core/client_channel/resolvers/dns_resolver_cooldown_test.cc +++ b/test/core/client_channel/resolvers/dns_resolver_cooldown_test.cc @@ -145,7 +145,6 @@ struct OnResolutionCallbackArg { grpc_core::OrphanablePtr<grpc_core::Resolver> resolver; grpc_channel_args* result = nullptr; grpc_millis delay_before_second_resolution = 0; - bool using_cares = false; }; // Counter for the number of times a resolution notification callback has been @@ -155,81 +154,100 @@ static int g_on_resolution_invocations_count; // Set to true by the last callback in the resolution chain. bool g_all_callbacks_invoked; -void on_third_resolution(void* arg, grpc_error* error) { +void on_fourth_resolution(void* arg, grpc_error* error) { OnResolutionCallbackArg* cb_arg = static_cast<OnResolutionCallbackArg*>(arg); + grpc_channel_args_destroy(cb_arg->result); GPR_ASSERT(error == GRPC_ERROR_NONE); ++g_on_resolution_invocations_count; - grpc_channel_args_destroy(cb_arg->result); gpr_log(GPR_INFO, - "3rd: g_on_resolution_invocations_count: %d, g_resolution_count: %d", + "4th: g_on_resolution_invocations_count: %d, g_resolution_count: %d", g_on_resolution_invocations_count, g_resolution_count); // In this case we expect to have incurred in another system-level resolution - // because on_second_resolution slept for longer than the min resolution + // because on_third_resolution slept for longer than the min resolution // period. - GPR_ASSERT(g_on_resolution_invocations_count == 3); - GPR_ASSERT(g_resolution_count == 2); + GPR_ASSERT(g_on_resolution_invocations_count == 4); + GPR_ASSERT(g_resolution_count == 3); cb_arg->resolver.reset(); - if (cb_arg->using_cares) { - gpr_atm_rel_store(&g_iomgr_args.done_atm, 1); - gpr_mu_lock(g_iomgr_args.mu); - GRPC_LOG_IF_ERROR("pollset_kick", - grpc_pollset_kick(g_iomgr_args.pollset, nullptr)); - gpr_mu_unlock(g_iomgr_args.mu); - } + gpr_atm_rel_store(&g_iomgr_args.done_atm, 1); + gpr_mu_lock(g_iomgr_args.mu); + GRPC_LOG_IF_ERROR("pollset_kick", + grpc_pollset_kick(g_iomgr_args.pollset, nullptr)); + gpr_mu_unlock(g_iomgr_args.mu); grpc_core::Delete(cb_arg); g_all_callbacks_invoked = true; } -void on_second_resolution(void* arg, grpc_error* error) { +void on_third_resolution(void* arg, grpc_error* error) { OnResolutionCallbackArg* cb_arg = static_cast<OnResolutionCallbackArg*>(arg); - ++g_on_resolution_invocations_count; grpc_channel_args_destroy(cb_arg->result); + GPR_ASSERT(error == GRPC_ERROR_NONE); + ++g_on_resolution_invocations_count; + gpr_log(GPR_INFO, + "3rd: g_on_resolution_invocations_count: %d, g_resolution_count: %d", + g_on_resolution_invocations_count, g_resolution_count); + // The timer set because of the previous re-resolution request fires, so a new + // system-level resolution happened. + GPR_ASSERT(g_on_resolution_invocations_count == 3); + GPR_ASSERT(g_resolution_count == 2); + grpc_core::ExecCtx::Get()->TestOnlySetNow( + cb_arg->delay_before_second_resolution * 2); + cb_arg->resolver->NextLocked( + &cb_arg->result, + GRPC_CLOSURE_CREATE(on_fourth_resolution, arg, + grpc_combiner_scheduler(g_combiner))); + cb_arg->resolver->RequestReresolutionLocked(); + gpr_mu_lock(g_iomgr_args.mu); + GRPC_LOG_IF_ERROR("pollset_kick", + grpc_pollset_kick(g_iomgr_args.pollset, nullptr)); + gpr_mu_unlock(g_iomgr_args.mu); +} +void on_second_resolution(void* arg, grpc_error* error) { + OnResolutionCallbackArg* cb_arg = static_cast<OnResolutionCallbackArg*>(arg); + grpc_channel_args_destroy(cb_arg->result); + GPR_ASSERT(error == GRPC_ERROR_NONE); + ++g_on_resolution_invocations_count; gpr_log(GPR_INFO, "2nd: g_on_resolution_invocations_count: %d, g_resolution_count: %d", g_on_resolution_invocations_count, g_resolution_count); // The resolution request for which this function is the callback happened // before the min resolution period. Therefore, no new system-level - // resolutions happened, as indicated by g_resolution_count. + // resolutions happened, as indicated by g_resolution_count. But a resolution + // timer was set to fire when the cooldown finishes. GPR_ASSERT(g_on_resolution_invocations_count == 2); GPR_ASSERT(g_resolution_count == 1); - grpc_core::ExecCtx::Get()->TestOnlySetNow( - cb_arg->delay_before_second_resolution * 2); + // Register a new callback to capture the timer firing. cb_arg->resolver->NextLocked( &cb_arg->result, GRPC_CLOSURE_CREATE(on_third_resolution, arg, grpc_combiner_scheduler(g_combiner))); - cb_arg->resolver->RequestReresolutionLocked(); - if (cb_arg->using_cares) { - gpr_mu_lock(g_iomgr_args.mu); - GRPC_LOG_IF_ERROR("pollset_kick", - grpc_pollset_kick(g_iomgr_args.pollset, nullptr)); - gpr_mu_unlock(g_iomgr_args.mu); - } + gpr_mu_lock(g_iomgr_args.mu); + GRPC_LOG_IF_ERROR("pollset_kick", + grpc_pollset_kick(g_iomgr_args.pollset, nullptr)); + gpr_mu_unlock(g_iomgr_args.mu); } void on_first_resolution(void* arg, grpc_error* error) { OnResolutionCallbackArg* cb_arg = static_cast<OnResolutionCallbackArg*>(arg); - ++g_on_resolution_invocations_count; grpc_channel_args_destroy(cb_arg->result); - cb_arg->resolver->NextLocked( - &cb_arg->result, - GRPC_CLOSURE_CREATE(on_second_resolution, arg, - grpc_combiner_scheduler(g_combiner))); - cb_arg->resolver->RequestReresolutionLocked(); + GPR_ASSERT(error == GRPC_ERROR_NONE); + ++g_on_resolution_invocations_count; gpr_log(GPR_INFO, "1st: g_on_resolution_invocations_count: %d, g_resolution_count: %d", g_on_resolution_invocations_count, g_resolution_count); - // Theres one initial system-level resolution and one invocation of a + // There's one initial system-level resolution and one invocation of a // notification callback (the current function). GPR_ASSERT(g_on_resolution_invocations_count == 1); GPR_ASSERT(g_resolution_count == 1); - if (cb_arg->using_cares) { - gpr_mu_lock(g_iomgr_args.mu); - GRPC_LOG_IF_ERROR("pollset_kick", - grpc_pollset_kick(g_iomgr_args.pollset, nullptr)); - gpr_mu_unlock(g_iomgr_args.mu); - } + cb_arg->resolver->NextLocked( + &cb_arg->result, + GRPC_CLOSURE_CREATE(on_second_resolution, arg, + grpc_combiner_scheduler(g_combiner))); + cb_arg->resolver->RequestReresolutionLocked(); + gpr_mu_lock(g_iomgr_args.mu); + GRPC_LOG_IF_ERROR("pollset_kick", + grpc_pollset_kick(g_iomgr_args.pollset, nullptr)); + gpr_mu_unlock(g_iomgr_args.mu); } static void start_test_under_combiner(void* arg, grpc_error* error) { @@ -269,22 +287,19 @@ static void start_test_under_combiner(void* arg, grpc_error* error) { grpc_uri_destroy(uri); } -static void test_cooldown(bool using_cares) { +static void test_cooldown() { grpc_core::ExecCtx exec_ctx; - if (using_cares) iomgr_args_init(&g_iomgr_args); + iomgr_args_init(&g_iomgr_args); OnResolutionCallbackArg* res_cb_arg = grpc_core::New<OnResolutionCallbackArg>(); res_cb_arg->uri_str = "dns:127.0.0.1"; - res_cb_arg->using_cares = using_cares; GRPC_CLOSURE_SCHED(GRPC_CLOSURE_CREATE(start_test_under_combiner, res_cb_arg, grpc_combiner_scheduler(g_combiner)), GRPC_ERROR_NONE); - if (using_cares) { - grpc_core::ExecCtx::Get()->Flush(); - poll_pollset_until_request_done(&g_iomgr_args); - iomgr_args_finish(&g_iomgr_args); - } + grpc_core::ExecCtx::Get()->Flush(); + poll_pollset_until_request_done(&g_iomgr_args); + iomgr_args_finish(&g_iomgr_args); } int main(int argc, char** argv) { @@ -293,16 +308,12 @@ int main(int argc, char** argv) { g_combiner = grpc_combiner_create(); - bool using_cares = false; -#if GRPC_ARES == 1 - using_cares = true; -#endif g_default_dns_lookup_ares = grpc_dns_lookup_ares; grpc_dns_lookup_ares = test_dns_lookup_ares; default_resolve_address = grpc_resolve_address_impl; grpc_set_resolver_impl(&test_resolver); - test_cooldown(using_cares); + test_cooldown(); { grpc_core::ExecCtx exec_ctx; |