diff options
author | 2018-07-18 10:23:05 -0700 | |
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committer | 2018-07-18 18:26:40 -0700 | |
commit | af57df5e2a20d1b2628e12a1b50df9856ae21c3a (patch) | |
tree | 0d6e2974bfeefee0ac8aac8009bd16f5ee893442 /src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc | |
parent | 481c1d57e7fc92f74c79b9aa0f7c8f0eaa51000b (diff) |
Support subchannel refs for round_robin
Diffstat (limited to 'src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc')
-rw-r--r-- | src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc | 79 |
1 files changed, 77 insertions, 2 deletions
diff --git a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc index 09634a2ad4..604c926e7d 100644 --- a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc +++ b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc @@ -69,9 +69,8 @@ class RoundRobin : public LoadBalancingPolicy { void HandOffPendingPicksLocked(LoadBalancingPolicy* new_policy) override; void PingOneLocked(grpc_closure* on_initiate, grpc_closure* on_ack) override; void ExitIdleLocked() override; - // TODO(ncteisen): implement this in a follow up PR void FillChildRefsForChannelz(ChildRefsList* child_subchannels, - ChildRefsList* child_channels) override {} + ChildRefsList* ignored) override; private: ~RoundRobin(); @@ -183,11 +182,24 @@ class RoundRobin : public LoadBalancingPolicy { size_t last_ready_index_ = -1; // Index into list of last pick. }; + // Helper class to ensure that any function that modifies the child refs + // data structures will update the channelz snapshot data structures before + // returning. + class AutoChildRefsUpdater { + public: + explicit AutoChildRefsUpdater(RoundRobin* rr) : rr_(rr) {} + ~AutoChildRefsUpdater() { rr_->UpdateChildRefsLocked(); } + + private: + RoundRobin* rr_; + }; + void ShutdownLocked() override; void StartPickingLocked(); bool DoPickLocked(PickState* pick); void DrainPendingPicksLocked(); + void UpdateChildRefsLocked(); /** list of subchannels */ OrphanablePtr<RoundRobinSubchannelList> subchannel_list_; @@ -205,10 +217,16 @@ class RoundRobin : public LoadBalancingPolicy { PickState* pending_picks_ = nullptr; /** our connectivity state tracker */ grpc_connectivity_state_tracker state_tracker_; + /// Lock and data used to capture snapshots of this channels child + /// channels and subchannels. This data is consumed by channelz. + gpr_mu child_refs_mu_; + ChildRefsList child_subchannels_; + ChildRefsList child_channels_; }; RoundRobin::RoundRobin(const Args& args) : LoadBalancingPolicy(args) { GPR_ASSERT(args.client_channel_factory != nullptr); + gpr_mu_init(&child_refs_mu_); grpc_connectivity_state_init(&state_tracker_, GRPC_CHANNEL_IDLE, "round_robin"); UpdateLocked(*args.args); @@ -223,6 +241,7 @@ RoundRobin::~RoundRobin() { if (grpc_lb_round_robin_trace.enabled()) { gpr_log(GPR_INFO, "[RR %p] Destroying Round Robin policy", this); } + gpr_mu_destroy(&child_refs_mu_); GPR_ASSERT(subchannel_list_ == nullptr); GPR_ASSERT(latest_pending_subchannel_list_ == nullptr); GPR_ASSERT(pending_picks_ == nullptr); @@ -242,6 +261,7 @@ void RoundRobin::HandOffPendingPicksLocked(LoadBalancingPolicy* new_policy) { } void RoundRobin::ShutdownLocked() { + AutoChildRefsUpdater guard(this); grpc_error* error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel shutdown"); if (grpc_lb_round_robin_trace.enabled()) { gpr_log(GPR_INFO, "[RR %p] Shutting down", this); @@ -365,6 +385,59 @@ bool RoundRobin::PickLocked(PickState* pick) { return false; } +void RoundRobin::FillChildRefsForChannelz( + ChildRefsList* child_subchannels_to_fill, ChildRefsList* ignored) { + mu_guard guard(&child_refs_mu_); + for (size_t i = 0; i < child_subchannels_.size(); ++i) { + // TODO(ncteisen): implement a de dup loop that is not O(n^2). Might + // have to implement lightweight set. For now, we don't care about + // performance when channelz requests are made. + bool found = false; + for (size_t j = 0; j < child_subchannels_to_fill->size(); ++j) { + if ((*child_subchannels_to_fill)[j] == child_subchannels_[i]) { + found = true; + break; + } + } + if (!found) { + child_subchannels_to_fill->push_back(child_subchannels_[i]); + } + } +} + +void RoundRobin::UpdateChildRefsLocked() { + ChildRefsList cs; + if (subchannel_list_ != nullptr) { + for (size_t i = 0; i < subchannel_list_->num_subchannels(); ++i) { + if (subchannel_list_->subchannel(i)->subchannel() != nullptr) { + grpc_core::channelz::SubchannelNode* subchannel_node = + grpc_subchannel_get_channelz_node( + subchannel_list_->subchannel(i)->subchannel()); + if (subchannel_node != nullptr) { + cs.push_back(subchannel_node->subchannel_uuid()); + } + } + } + } + if (latest_pending_subchannel_list_ != nullptr) { + for (size_t i = 0; i < latest_pending_subchannel_list_->num_subchannels(); + ++i) { + if (latest_pending_subchannel_list_->subchannel(i)->subchannel() != + nullptr) { + grpc_core::channelz::SubchannelNode* subchannel_node = + grpc_subchannel_get_channelz_node( + latest_pending_subchannel_list_->subchannel(i)->subchannel()); + if (subchannel_node != nullptr) { + cs.push_back(subchannel_node->subchannel_uuid()); + } + } + } + } + // atomically update the data that channelz will actually be looking at. + mu_guard guard(&child_refs_mu_); + child_subchannels_ = std::move(cs); +} + void RoundRobin::RoundRobinSubchannelList::StartWatchingLocked() { if (num_subchannels() == 0) return; // Check current state of each subchannel synchronously, since any @@ -455,6 +528,7 @@ void RoundRobin::RoundRobinSubchannelList:: void RoundRobin::RoundRobinSubchannelList:: UpdateRoundRobinStateFromSubchannelStateCountsLocked() { RoundRobin* p = static_cast<RoundRobin*>(policy()); + AutoChildRefsUpdater guard(p); if (num_ready_ > 0) { if (p->subchannel_list_.get() != this) { // Promote this list to p->subchannel_list_. @@ -611,6 +685,7 @@ void RoundRobin::PingOneLocked(grpc_closure* on_initiate, void RoundRobin::UpdateLocked(const grpc_channel_args& args) { const grpc_arg* arg = grpc_channel_args_find(&args, GRPC_ARG_LB_ADDRESSES); + AutoChildRefsUpdater guard(this); if (GPR_UNLIKELY(arg == nullptr || arg->type != GRPC_ARG_POINTER)) { gpr_log(GPR_ERROR, "[RR %p] update provided no addresses; ignoring", this); // If we don't have a current subchannel list, go into TRANSIENT_FAILURE. |