--- /dev/null
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/ext/filters/client_channel/subchannel.h"
+
+#include <inttypes.h>
+#include <limits.h>
+
+#include <algorithm>
+#include <cstring>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/ext/filters/client_channel/client_channel.h"
+#include "src/core/ext/filters/client_channel/health/health_check_client.h"
+#include "src/core/ext/filters/client_channel/parse_address.h"
+#include "src/core/ext/filters/client_channel/proxy_mapper_registry.h"
+#include "src/core/ext/filters/client_channel/service_config.h"
+#include "src/core/ext/filters/client_channel/subchannel_pool_interface.h"
+#include "src/core/lib/backoff/backoff.h"
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/channel/connected_channel.h"
+#include "src/core/lib/debug/stats.h"
+#include "src/core/lib/gpr/alloc.h"
+#include "src/core/lib/gprpp/debug_location.h"
+#include "src/core/lib/gprpp/manual_constructor.h"
+#include "src/core/lib/gprpp/ref_counted_ptr.h"
+#include "src/core/lib/gprpp/sync.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
+#include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/slice/slice_internal.h"
+#include "src/core/lib/surface/channel.h"
+#include "src/core/lib/surface/channel_init.h"
+#include "src/core/lib/transport/connectivity_state.h"
+#include "src/core/lib/transport/error_utils.h"
+#include "src/core/lib/transport/status_metadata.h"
+#include "src/core/lib/uri/uri_parser.h"
+
+// Strong and weak refs.
+#define INTERNAL_REF_BITS 16
+#define STRONG_REF_MASK (~(gpr_atm)((1 << INTERNAL_REF_BITS) - 1))
+
+// Backoff parameters.
+#define GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS 1
+#define GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER 1.6
+#define GRPC_SUBCHANNEL_RECONNECT_MIN_TIMEOUT_SECONDS 20
+#define GRPC_SUBCHANNEL_RECONNECT_MAX_BACKOFF_SECONDS 120
+#define GRPC_SUBCHANNEL_RECONNECT_JITTER 0.2
+
+// Conversion between subchannel call and call stack.
+#define SUBCHANNEL_CALL_TO_CALL_STACK(call) \
+ (grpc_call_stack*)((char*)(call) + \
+ GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(SubchannelCall)))
+#define CALL_STACK_TO_SUBCHANNEL_CALL(callstack) \
+ (SubchannelCall*)(((char*)(call_stack)) - \
+ GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(SubchannelCall)))
+
+namespace grpc_core {
+
+TraceFlag grpc_trace_subchannel(false, "subchannel");
+DebugOnlyTraceFlag grpc_trace_subchannel_refcount(false, "subchannel_refcount");
+
+//
+// ConnectedSubchannel
+//
+
+ConnectedSubchannel::ConnectedSubchannel(
+ grpc_channel_stack* channel_stack, const grpc_channel_args* args,
+ RefCountedPtr<channelz::SubchannelNode> channelz_subchannel)
+ : RefCounted<ConnectedSubchannel>(&grpc_trace_subchannel_refcount),
+ channel_stack_(channel_stack),
+ args_(grpc_channel_args_copy(args)),
+ channelz_subchannel_(std::move(channelz_subchannel)) {}
+
+ConnectedSubchannel::~ConnectedSubchannel() {
+ grpc_channel_args_destroy(args_);
+ GRPC_CHANNEL_STACK_UNREF(channel_stack_, "connected_subchannel_dtor");
+}
+
+void ConnectedSubchannel::NotifyOnStateChange(
+ grpc_pollset_set* interested_parties, grpc_connectivity_state* state,
+ grpc_closure* closure) {
+ grpc_transport_op* op = grpc_make_transport_op(nullptr);
+ grpc_channel_element* elem;
+ op->connectivity_state = state;
+ op->on_connectivity_state_change = closure;
+ op->bind_pollset_set = interested_parties;
+ elem = grpc_channel_stack_element(channel_stack_, 0);
+ elem->filter->start_transport_op(elem, op);
+}
+
+void ConnectedSubchannel::Ping(grpc_closure* on_initiate,
+ grpc_closure* on_ack) {
+ grpc_transport_op* op = grpc_make_transport_op(nullptr);
+ grpc_channel_element* elem;
+ op->send_ping.on_initiate = on_initiate;
+ op->send_ping.on_ack = on_ack;
+ elem = grpc_channel_stack_element(channel_stack_, 0);
+ elem->filter->start_transport_op(elem, op);
+}
+
+size_t ConnectedSubchannel::GetInitialCallSizeEstimate(
+ size_t parent_data_size) const {
+ size_t allocation_size =
+ GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(SubchannelCall));
+ if (parent_data_size > 0) {
+ allocation_size +=
+ GPR_ROUND_UP_TO_ALIGNMENT_SIZE(channel_stack_->call_stack_size) +
+ parent_data_size;
+ } else {
+ allocation_size += channel_stack_->call_stack_size;
+ }
+ return allocation_size;
+}
+
+//
+// SubchannelCall
+//
+
+RefCountedPtr<SubchannelCall> SubchannelCall::Create(Args args,
+ grpc_error** error) {
+ const size_t allocation_size =
+ args.connected_subchannel->GetInitialCallSizeEstimate(
+ args.parent_data_size);
+ Arena* arena = args.arena;
+ return RefCountedPtr<SubchannelCall>(new (
+ arena->Alloc(allocation_size)) SubchannelCall(std::move(args), error));
+}
+
+SubchannelCall::SubchannelCall(Args args, grpc_error** error)
+ : connected_subchannel_(std::move(args.connected_subchannel)),
+ deadline_(args.deadline) {
+ grpc_call_stack* callstk = SUBCHANNEL_CALL_TO_CALL_STACK(this);
+ const grpc_call_element_args call_args = {
+ callstk, /* call_stack */
+ nullptr, /* server_transport_data */
+ args.context, /* context */
+ args.path, /* path */
+ args.start_time, /* start_time */
+ args.deadline, /* deadline */
+ args.arena, /* arena */
+ args.call_combiner /* call_combiner */
+ };
+ *error = grpc_call_stack_init(connected_subchannel_->channel_stack(), 1,
+ SubchannelCall::Destroy, this, &call_args);
+ if (GPR_UNLIKELY(*error != GRPC_ERROR_NONE)) {
+ const char* error_string = grpc_error_string(*error);
+ gpr_log(GPR_ERROR, "error: %s", error_string);
+ return;
+ }
+ grpc_call_stack_set_pollset_or_pollset_set(callstk, args.pollent);
+ auto* channelz_node = connected_subchannel_->channelz_subchannel();
+ if (channelz_node != nullptr) {
+ channelz_node->RecordCallStarted();
+ }
+}
+
+void SubchannelCall::StartTransportStreamOpBatch(
+ grpc_transport_stream_op_batch* batch) {
+ GPR_TIMER_SCOPE("subchannel_call_process_op", 0);
+ MaybeInterceptRecvTrailingMetadata(batch);
+ grpc_call_stack* call_stack = SUBCHANNEL_CALL_TO_CALL_STACK(this);
+ grpc_call_element* top_elem = grpc_call_stack_element(call_stack, 0);
+ GRPC_CALL_LOG_OP(GPR_INFO, top_elem, batch);
+ top_elem->filter->start_transport_stream_op_batch(top_elem, batch);
+}
+
+void* SubchannelCall::GetParentData() {
+ grpc_channel_stack* chanstk = connected_subchannel_->channel_stack();
+ return (char*)this + GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(SubchannelCall)) +
+ GPR_ROUND_UP_TO_ALIGNMENT_SIZE(chanstk->call_stack_size);
+}
+
+grpc_call_stack* SubchannelCall::GetCallStack() {
+ return SUBCHANNEL_CALL_TO_CALL_STACK(this);
+}
+
+void SubchannelCall::SetAfterCallStackDestroy(grpc_closure* closure) {
+ GPR_ASSERT(after_call_stack_destroy_ == nullptr);
+ GPR_ASSERT(closure != nullptr);
+ after_call_stack_destroy_ = closure;
+}
+
+RefCountedPtr<SubchannelCall> SubchannelCall::Ref() {
+ IncrementRefCount();
+ return RefCountedPtr<SubchannelCall>(this);
+}
+
+RefCountedPtr<SubchannelCall> SubchannelCall::Ref(
+ const grpc_core::DebugLocation& location, const char* reason) {
+ IncrementRefCount(location, reason);
+ return RefCountedPtr<SubchannelCall>(this);
+}
+
+void SubchannelCall::Unref() {
+ GRPC_CALL_STACK_UNREF(SUBCHANNEL_CALL_TO_CALL_STACK(this), "");
+}
+
+void SubchannelCall::Unref(const DebugLocation& location, const char* reason) {
+ GRPC_CALL_STACK_UNREF(SUBCHANNEL_CALL_TO_CALL_STACK(this), reason);
+}
+
+void SubchannelCall::Destroy(void* arg, grpc_error* error) {
+ GPR_TIMER_SCOPE("subchannel_call_destroy", 0);
+ SubchannelCall* self = static_cast<SubchannelCall*>(arg);
+ // Keep some members before destroying the subchannel call.
+ grpc_closure* after_call_stack_destroy = self->after_call_stack_destroy_;
+ RefCountedPtr<ConnectedSubchannel> connected_subchannel =
+ std::move(self->connected_subchannel_);
+ // Destroy the subchannel call.
+ self->~SubchannelCall();
+ // Destroy the call stack. This should be after destroying the subchannel
+ // call, because call->after_call_stack_destroy(), if not null, will free the
+ // call arena.
+ grpc_call_stack_destroy(SUBCHANNEL_CALL_TO_CALL_STACK(self), nullptr,
+ after_call_stack_destroy);
+ // Automatically reset connected_subchannel. This should be after destroying
+ // the call stack, because destroying call stack needs access to the channel
+ // stack.
+}
+
+void SubchannelCall::MaybeInterceptRecvTrailingMetadata(
+ grpc_transport_stream_op_batch* batch) {
+ // only intercept payloads with recv trailing.
+ if (!batch->recv_trailing_metadata) {
+ return;
+ }
+ // only add interceptor is channelz is enabled.
+ if (connected_subchannel_->channelz_subchannel() == nullptr) {
+ return;
+ }
+ GRPC_CLOSURE_INIT(&recv_trailing_metadata_ready_, RecvTrailingMetadataReady,
+ this, grpc_schedule_on_exec_ctx);
+ // save some state needed for the interception callback.
+ GPR_ASSERT(recv_trailing_metadata_ == nullptr);
+ recv_trailing_metadata_ =
+ batch->payload->recv_trailing_metadata.recv_trailing_metadata;
+ original_recv_trailing_metadata_ =
+ batch->payload->recv_trailing_metadata.recv_trailing_metadata_ready;
+ batch->payload->recv_trailing_metadata.recv_trailing_metadata_ready =
+ &recv_trailing_metadata_ready_;
+}
+
+namespace {
+
+// Sets *status based on the rest of the parameters.
+void GetCallStatus(grpc_status_code* status, grpc_millis deadline,
+ grpc_metadata_batch* md_batch, grpc_error* error) {
+ if (error != GRPC_ERROR_NONE) {
+ grpc_error_get_status(error, deadline, status, nullptr, nullptr, nullptr);
+ } else {
+ if (md_batch->idx.named.grpc_status != nullptr) {
+ *status = grpc_get_status_code_from_metadata(
+ md_batch->idx.named.grpc_status->md);
+ } else {
+ *status = GRPC_STATUS_UNKNOWN;
+ }
+ }
+ GRPC_ERROR_UNREF(error);
+}
+
+} // namespace
+
+void SubchannelCall::RecvTrailingMetadataReady(void* arg, grpc_error* error) {
+ SubchannelCall* call = static_cast<SubchannelCall*>(arg);
+ GPR_ASSERT(call->recv_trailing_metadata_ != nullptr);
+ grpc_status_code status = GRPC_STATUS_OK;
+ GetCallStatus(&status, call->deadline_, call->recv_trailing_metadata_,
+ GRPC_ERROR_REF(error));
+ channelz::SubchannelNode* channelz_subchannel =
+ call->connected_subchannel_->channelz_subchannel();
+ GPR_ASSERT(channelz_subchannel != nullptr);
+ if (status == GRPC_STATUS_OK) {
+ channelz_subchannel->RecordCallSucceeded();
+ } else {
+ channelz_subchannel->RecordCallFailed();
+ }
+ GRPC_CLOSURE_RUN(call->original_recv_trailing_metadata_,
+ GRPC_ERROR_REF(error));
+}
+
+void SubchannelCall::IncrementRefCount() {
+ GRPC_CALL_STACK_REF(SUBCHANNEL_CALL_TO_CALL_STACK(this), "");
+}
+
+void SubchannelCall::IncrementRefCount(const grpc_core::DebugLocation& location,
+ const char* reason) {
+ GRPC_CALL_STACK_REF(SUBCHANNEL_CALL_TO_CALL_STACK(this), reason);
+}
+
+//
+// Subchannel::ConnectedSubchannelStateWatcher
+//
+
+class Subchannel::ConnectedSubchannelStateWatcher {
+ public:
+ // Must be instantiated while holding c->mu.
+ explicit ConnectedSubchannelStateWatcher(Subchannel* c) : subchannel_(c) {
+ // Steal subchannel ref for connecting.
+ GRPC_SUBCHANNEL_WEAK_REF(subchannel_, "state_watcher");
+ GRPC_SUBCHANNEL_WEAK_UNREF(subchannel_, "connecting");
+ // Start watching for connectivity state changes.
+ GRPC_CLOSURE_INIT(&on_connectivity_changed_, OnConnectivityChanged, this,
+ grpc_schedule_on_exec_ctx);
+ c->connected_subchannel_->NotifyOnStateChange(c->pollset_set_,
+ &pending_connectivity_state_,
+ &on_connectivity_changed_);
+ }
+
+ ~ConnectedSubchannelStateWatcher() {
+ GRPC_SUBCHANNEL_WEAK_UNREF(subchannel_, "state_watcher");
+ }
+
+ private:
+ static void OnConnectivityChanged(void* arg, grpc_error* error) {
+ auto* self = static_cast<ConnectedSubchannelStateWatcher*>(arg);
+ Subchannel* c = self->subchannel_;
+ {
+ MutexLock lock(&c->mu_);
+ switch (self->pending_connectivity_state_) {
+ case GRPC_CHANNEL_TRANSIENT_FAILURE:
+ case GRPC_CHANNEL_SHUTDOWN: {
+ if (!c->disconnected_ && c->connected_subchannel_ != nullptr) {
+ if (grpc_trace_subchannel.enabled()) {
+ gpr_log(GPR_INFO,
+ "Connected subchannel %p of subchannel %p has gone into "
+ "%s. Attempting to reconnect.",
+ c->connected_subchannel_.get(), c,
+ grpc_connectivity_state_name(
+ self->pending_connectivity_state_));
+ }
+ c->connected_subchannel_.reset();
+ if (c->channelz_node() != nullptr) {
+ c->channelz_node()->SetChildSocket(nullptr);
+ }
+ c->SetConnectivityStateLocked(GRPC_CHANNEL_TRANSIENT_FAILURE);
+ c->backoff_begun_ = false;
+ c->backoff_.Reset();
+ }
+ break;
+ }
+ default: {
+ // In principle, this should never happen. We should not get
+ // a callback for READY, because that was the state we started
+ // this watch from. And a connected subchannel should never go
+ // from READY to CONNECTING or IDLE.
+ c->SetConnectivityStateLocked(self->pending_connectivity_state_);
+ c->connected_subchannel_->NotifyOnStateChange(
+ nullptr, &self->pending_connectivity_state_,
+ &self->on_connectivity_changed_);
+ return; // So we don't delete ourself below.
+ }
+ }
+ }
+ // Don't delete until we've released the lock, because this might
+ // cause the subchannel (which contains the lock) to be destroyed.
+ Delete(self);
+ }
+
+ Subchannel* subchannel_;
+ grpc_closure on_connectivity_changed_;
+ grpc_connectivity_state pending_connectivity_state_ = GRPC_CHANNEL_READY;
+};
+
+//
+// Subchannel::ConnectivityStateWatcherList
+//
+
+void Subchannel::ConnectivityStateWatcherList::AddWatcherLocked(
+ OrphanablePtr<ConnectivityStateWatcherInterface> watcher) {
+ watchers_.insert(MakePair(watcher.get(), std::move(watcher)));
+}
+
+void Subchannel::ConnectivityStateWatcherList::RemoveWatcherLocked(
+ ConnectivityStateWatcherInterface* watcher) {
+ watchers_.erase(watcher);
+}
+
+void Subchannel::ConnectivityStateWatcherList::NotifyLocked(
+ Subchannel* subchannel, grpc_connectivity_state state) {
+ for (const auto& p : watchers_) {
+ RefCountedPtr<ConnectedSubchannel> connected_subchannel;
+ if (state == GRPC_CHANNEL_READY) {
+ connected_subchannel = subchannel->connected_subchannel_;
+ }
+ // TODO(roth): In principle, it seems wrong to send this notification
+ // to the watcher while holding the subchannel's mutex, since it could
+ // lead to a deadlock if the watcher calls back into the subchannel
+ // before returning back to us. In practice, this doesn't happen,
+ // because the LB policy code that watches subchannels always bounces
+ // the notification into the client_channel control-plane combiner
+ // before processing it. But if we ever have any other callers here,
+ // we will probably need to change this.
+ p.second->OnConnectivityStateChange(state, std::move(connected_subchannel));
+ }
+}
+
+//
+// Subchannel::HealthWatcherMap::HealthWatcher
+//
+
+// State needed for tracking the connectivity state with a particular
+// health check service name.
+class Subchannel::HealthWatcherMap::HealthWatcher
+ : public InternallyRefCounted<HealthWatcher> {
+ public:
+ HealthWatcher(Subchannel* c, UniquePtr<char> health_check_service_name,
+ grpc_connectivity_state subchannel_state)
+ : subchannel_(c),
+ health_check_service_name_(std::move(health_check_service_name)),
+ state_(subchannel_state == GRPC_CHANNEL_READY ? GRPC_CHANNEL_CONNECTING
+ : subchannel_state) {
+ GRPC_SUBCHANNEL_WEAK_REF(subchannel_, "health_watcher");
+ GRPC_CLOSURE_INIT(&on_health_changed_, OnHealthChanged, this,
+ grpc_schedule_on_exec_ctx);
+ // If the subchannel is already connected, start health checking.
+ if (subchannel_state == GRPC_CHANNEL_READY) StartHealthCheckingLocked();
+ }
+
+ ~HealthWatcher() {
+ GRPC_SUBCHANNEL_WEAK_UNREF(subchannel_, "health_watcher");
+ }
+
+ const char* health_check_service_name() const {
+ return health_check_service_name_.get();
+ }
+
+ grpc_connectivity_state state() const { return state_; }
+
+ void AddWatcherLocked(
+ grpc_connectivity_state initial_state,
+ OrphanablePtr<ConnectivityStateWatcherInterface> watcher) {
+ if (state_ != initial_state) {
+ RefCountedPtr<ConnectedSubchannel> connected_subchannel;
+ if (state_ == GRPC_CHANNEL_READY) {
+ connected_subchannel = subchannel_->connected_subchannel_;
+ }
+ watcher->OnConnectivityStateChange(state_,
+ std::move(connected_subchannel));
+ }
+ watcher_list_.AddWatcherLocked(std::move(watcher));
+ }
+
+ void RemoveWatcherLocked(ConnectivityStateWatcherInterface* watcher) {
+ watcher_list_.RemoveWatcherLocked(watcher);
+ }
+
+ bool HasWatchers() const { return !watcher_list_.empty(); }
+
+ void NotifyLocked(grpc_connectivity_state state) {
+ if (state == GRPC_CHANNEL_READY) {
+ // If we had not already notified for CONNECTING state, do so now.
+ // (We may have missed this earlier, because if the transition
+ // from IDLE to CONNECTING to READY was too quick, the connected
+ // subchannel may not have sent us a notification for CONNECTING.)
+ if (state_ != GRPC_CHANNEL_CONNECTING) {
+ state_ = GRPC_CHANNEL_CONNECTING;
+ watcher_list_.NotifyLocked(subchannel_, state_);
+ }
+ // If we've become connected, start health checking.
+ StartHealthCheckingLocked();
+ } else {
+ state_ = state;
+ watcher_list_.NotifyLocked(subchannel_, state_);
+ // We're not connected, so stop health checking.
+ health_check_client_.reset();
+ }
+ }
+
+ void Orphan() override {
+ watcher_list_.Clear();
+ health_check_client_.reset();
+ Unref();
+ }
+
+ private:
+ void StartHealthCheckingLocked() {
+ GPR_ASSERT(health_check_client_ == nullptr);
+ health_check_client_ = MakeOrphanable<HealthCheckClient>(
+ health_check_service_name_.get(), subchannel_->connected_subchannel_,
+ subchannel_->pollset_set_, subchannel_->channelz_node_);
+ Ref().release(); // Ref for health callback tracked manually.
+ health_check_client_->NotifyOnHealthChange(&state_, &on_health_changed_);
+ }
+
+ static void OnHealthChanged(void* arg, grpc_error* error) {
+ auto* self = static_cast<HealthWatcher*>(arg);
+ Subchannel* c = self->subchannel_;
+ {
+ MutexLock lock(&c->mu_);
+ if (self->state_ != GRPC_CHANNEL_SHUTDOWN &&
+ self->health_check_client_ != nullptr) {
+ self->watcher_list_.NotifyLocked(c, self->state_);
+ // Renew watch.
+ self->health_check_client_->NotifyOnHealthChange(
+ &self->state_, &self->on_health_changed_);
+ return; // So we don't unref below.
+ }
+ }
+ // Don't unref until we've released the lock, because this might
+ // cause the subchannel (which contains the lock) to be destroyed.
+ self->Unref();
+ }
+
+ Subchannel* subchannel_;
+ UniquePtr<char> health_check_service_name_;
+ OrphanablePtr<HealthCheckClient> health_check_client_;
+ grpc_closure on_health_changed_;
+ grpc_connectivity_state state_;
+ ConnectivityStateWatcherList watcher_list_;
+};
+
+//
+// Subchannel::HealthWatcherMap
+//
+
+void Subchannel::HealthWatcherMap::AddWatcherLocked(
+ Subchannel* subchannel, grpc_connectivity_state initial_state,
+ UniquePtr<char> health_check_service_name,
+ OrphanablePtr<ConnectivityStateWatcherInterface> watcher) {
+ // If the health check service name is not already present in the map,
+ // add it.
+ auto it = map_.find(health_check_service_name.get());
+ HealthWatcher* health_watcher;
+ if (it == map_.end()) {
+ const char* key = health_check_service_name.get();
+ auto w = MakeOrphanable<HealthWatcher>(
+ subchannel, std::move(health_check_service_name), subchannel->state_);
+ health_watcher = w.get();
+ map_[key] = std::move(w);
+ } else {
+ health_watcher = it->second.get();
+ }
+ // Add the watcher to the entry.
+ health_watcher->AddWatcherLocked(initial_state, std::move(watcher));
+}
+
+void Subchannel::HealthWatcherMap::RemoveWatcherLocked(
+ const char* health_check_service_name,
+ ConnectivityStateWatcherInterface* watcher) {
+ auto it = map_.find(health_check_service_name);
+ GPR_ASSERT(it != map_.end());
+ it->second->RemoveWatcherLocked(watcher);
+ // If we just removed the last watcher for this service name, remove
+ // the map entry.
+ if (!it->second->HasWatchers()) map_.erase(it);
+}
+
+void Subchannel::HealthWatcherMap::NotifyLocked(grpc_connectivity_state state) {
+ for (const auto& p : map_) {
+ p.second->NotifyLocked(state);
+ }
+}
+
+grpc_connectivity_state
+Subchannel::HealthWatcherMap::CheckConnectivityStateLocked(
+ Subchannel* subchannel, const char* health_check_service_name) {
+ auto it = map_.find(health_check_service_name);
+ if (it == map_.end()) {
+ // If the health check service name is not found in the map, we're
+ // not currently doing a health check for that service name. If the
+ // subchannel's state without health checking is READY, report
+ // CONNECTING, since that's what we'd be in as soon as we do start a
+ // watch. Otherwise, report the channel's state without health checking.
+ return subchannel->state_ == GRPC_CHANNEL_READY ? GRPC_CHANNEL_CONNECTING
+ : subchannel->state_;
+ }
+ HealthWatcher* health_watcher = it->second.get();
+ return health_watcher->state();
+}
+
+void Subchannel::HealthWatcherMap::ShutdownLocked() { map_.clear(); }
+
+//
+// Subchannel
+//
+
+namespace {
+
+BackOff::Options ParseArgsForBackoffValues(
+ const grpc_channel_args* args, grpc_millis* min_connect_timeout_ms) {
+ grpc_millis initial_backoff_ms =
+ GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS * 1000;
+ *min_connect_timeout_ms =
+ GRPC_SUBCHANNEL_RECONNECT_MIN_TIMEOUT_SECONDS * 1000;
+ grpc_millis max_backoff_ms =
+ GRPC_SUBCHANNEL_RECONNECT_MAX_BACKOFF_SECONDS * 1000;
+ bool fixed_reconnect_backoff = false;
+ if (args != nullptr) {
+ for (size_t i = 0; i < args->num_args; i++) {
+ if (0 == strcmp(args->args[i].key,
+ "grpc.testing.fixed_reconnect_backoff_ms")) {
+ fixed_reconnect_backoff = true;
+ initial_backoff_ms = *min_connect_timeout_ms = max_backoff_ms =
+ grpc_channel_arg_get_integer(
+ &args->args[i],
+ {static_cast<int>(initial_backoff_ms), 100, INT_MAX});
+ } else if (0 ==
+ strcmp(args->args[i].key, GRPC_ARG_MIN_RECONNECT_BACKOFF_MS)) {
+ fixed_reconnect_backoff = false;
+ *min_connect_timeout_ms = grpc_channel_arg_get_integer(
+ &args->args[i],
+ {static_cast<int>(*min_connect_timeout_ms), 100, INT_MAX});
+ } else if (0 ==
+ strcmp(args->args[i].key, GRPC_ARG_MAX_RECONNECT_BACKOFF_MS)) {
+ fixed_reconnect_backoff = false;
+ max_backoff_ms = grpc_channel_arg_get_integer(
+ &args->args[i], {static_cast<int>(max_backoff_ms), 100, INT_MAX});
+ } else if (0 == strcmp(args->args[i].key,
+ GRPC_ARG_INITIAL_RECONNECT_BACKOFF_MS)) {
+ fixed_reconnect_backoff = false;
+ initial_backoff_ms = grpc_channel_arg_get_integer(
+ &args->args[i],
+ {static_cast<int>(initial_backoff_ms), 100, INT_MAX});
+ }
+ }
+ }
+ return BackOff::Options()
+ .set_initial_backoff(initial_backoff_ms)
+ .set_multiplier(fixed_reconnect_backoff
+ ? 1.0
+ : GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER)
+ .set_jitter(fixed_reconnect_backoff ? 0.0
+ : GRPC_SUBCHANNEL_RECONNECT_JITTER)
+ .set_max_backoff(max_backoff_ms);
+}
+
+} // namespace
+
+Subchannel::Subchannel(SubchannelKey* key, grpc_connector* connector,
+ const grpc_channel_args* args)
+ : key_(key),
+ connector_(connector),
+ backoff_(ParseArgsForBackoffValues(args, &min_connect_timeout_ms_)) {
+ GRPC_STATS_INC_CLIENT_SUBCHANNELS_CREATED();
+ gpr_atm_no_barrier_store(&ref_pair_, 1 << INTERNAL_REF_BITS);
+ grpc_connector_ref(connector_);
+ pollset_set_ = grpc_pollset_set_create();
+ grpc_resolved_address* addr =
+ static_cast<grpc_resolved_address*>(gpr_malloc(sizeof(*addr)));
+ GetAddressFromSubchannelAddressArg(args, addr);
+ grpc_resolved_address* new_address = nullptr;
+ grpc_channel_args* new_args = nullptr;
+ if (grpc_proxy_mappers_map_address(addr, args, &new_address, &new_args)) {
+ GPR_ASSERT(new_address != nullptr);
+ gpr_free(addr);
+ addr = new_address;
+ }
+ static const char* keys_to_remove[] = {GRPC_ARG_SUBCHANNEL_ADDRESS};
+ grpc_arg new_arg = CreateSubchannelAddressArg(addr);
+ gpr_free(addr);
+ args_ = grpc_channel_args_copy_and_add_and_remove(
+ new_args != nullptr ? new_args : args, keys_to_remove,
+ GPR_ARRAY_SIZE(keys_to_remove), &new_arg, 1);
+ gpr_free(new_arg.value.string);
+ if (new_args != nullptr) grpc_channel_args_destroy(new_args);
+ GRPC_CLOSURE_INIT(&on_connecting_finished_, OnConnectingFinished, this,
+ grpc_schedule_on_exec_ctx);
+ const grpc_arg* arg = grpc_channel_args_find(args_, GRPC_ARG_ENABLE_CHANNELZ);
+ const bool channelz_enabled =
+ grpc_channel_arg_get_bool(arg, GRPC_ENABLE_CHANNELZ_DEFAULT);
+ arg = grpc_channel_args_find(
+ args_, GRPC_ARG_MAX_CHANNEL_TRACE_EVENT_MEMORY_PER_NODE);
+ const grpc_integer_options options = {
+ GRPC_MAX_CHANNEL_TRACE_EVENT_MEMORY_PER_NODE_DEFAULT, 0, INT_MAX};
+ size_t channel_tracer_max_memory =
+ (size_t)grpc_channel_arg_get_integer(arg, options);
+ if (channelz_enabled) {
+ channelz_node_ = MakeRefCounted<channelz::SubchannelNode>(
+ GetTargetAddress(), channel_tracer_max_memory);
+ channelz_node_->AddTraceEvent(
+ channelz::ChannelTrace::Severity::Info,
+ grpc_slice_from_static_string("subchannel created"));
+ }
+}
+
+Subchannel::~Subchannel() {
+ if (channelz_node_ != nullptr) {
+ channelz_node_->AddTraceEvent(
+ channelz::ChannelTrace::Severity::Info,
+ grpc_slice_from_static_string("Subchannel destroyed"));
+ channelz_node_->UpdateConnectivityState(GRPC_CHANNEL_SHUTDOWN);
+ }
+ grpc_channel_args_destroy(args_);
+ grpc_connector_unref(connector_);
+ grpc_pollset_set_destroy(pollset_set_);
+ Delete(key_);
+}
+
+Subchannel* Subchannel::Create(grpc_connector* connector,
+ const grpc_channel_args* args) {
+ SubchannelKey* key = New<SubchannelKey>(args);
+ SubchannelPoolInterface* subchannel_pool =
+ SubchannelPoolInterface::GetSubchannelPoolFromChannelArgs(args);
+ GPR_ASSERT(subchannel_pool != nullptr);
+ Subchannel* c = subchannel_pool->FindSubchannel(key);
+ if (c != nullptr) {
+ Delete(key);
+ return c;
+ }
+ c = New<Subchannel>(key, connector, args);
+ // Try to register the subchannel before setting the subchannel pool.
+ // Otherwise, in case of a registration race, unreffing c in
+ // RegisterSubchannel() will cause c to be tried to be unregistered, while
+ // its key maps to a different subchannel.
+ Subchannel* registered = subchannel_pool->RegisterSubchannel(key, c);
+ if (registered == c) c->subchannel_pool_ = subchannel_pool->Ref();
+ return registered;
+}
+
+Subchannel* Subchannel::Ref(GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ gpr_atm old_refs;
+ old_refs = RefMutate((1 << INTERNAL_REF_BITS),
+ 0 GRPC_SUBCHANNEL_REF_MUTATE_PURPOSE("STRONG_REF"));
+ GPR_ASSERT((old_refs & STRONG_REF_MASK) != 0);
+ return this;
+}
+
+void Subchannel::Unref(GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ gpr_atm old_refs;
+ // add a weak ref and subtract a strong ref (atomically)
+ old_refs = RefMutate(
+ static_cast<gpr_atm>(1) - static_cast<gpr_atm>(1 << INTERNAL_REF_BITS),
+ 1 GRPC_SUBCHANNEL_REF_MUTATE_PURPOSE("STRONG_UNREF"));
+ if ((old_refs & STRONG_REF_MASK) == (1 << INTERNAL_REF_BITS)) {
+ Disconnect();
+ }
+ GRPC_SUBCHANNEL_WEAK_UNREF(this, "strong-unref");
+}
+
+Subchannel* Subchannel::WeakRef(GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ gpr_atm old_refs;
+ old_refs = RefMutate(1, 0 GRPC_SUBCHANNEL_REF_MUTATE_PURPOSE("WEAK_REF"));
+ GPR_ASSERT(old_refs != 0);
+ return this;
+}
+
+namespace {
+
+void subchannel_destroy(void* arg, grpc_error* error) {
+ Subchannel* self = static_cast<Subchannel*>(arg);
+ Delete(self);
+}
+
+} // namespace
+
+void Subchannel::WeakUnref(GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ gpr_atm old_refs;
+ old_refs = RefMutate(-static_cast<gpr_atm>(1),
+ 1 GRPC_SUBCHANNEL_REF_MUTATE_PURPOSE("WEAK_UNREF"));
+ if (old_refs == 1) {
+ GRPC_CLOSURE_SCHED(GRPC_CLOSURE_CREATE(subchannel_destroy, this,
+ grpc_schedule_on_exec_ctx),
+ GRPC_ERROR_NONE);
+ }
+}
+
+Subchannel* Subchannel::RefFromWeakRef(GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ for (;;) {
+ gpr_atm old_refs = gpr_atm_acq_load(&ref_pair_);
+ if (old_refs >= (1 << INTERNAL_REF_BITS)) {
+ gpr_atm new_refs = old_refs + (1 << INTERNAL_REF_BITS);
+ if (gpr_atm_rel_cas(&ref_pair_, old_refs, new_refs)) {
+ return this;
+ }
+ } else {
+ return nullptr;
+ }
+ }
+}
+
+const char* Subchannel::GetTargetAddress() {
+ const grpc_arg* addr_arg =
+ grpc_channel_args_find(args_, GRPC_ARG_SUBCHANNEL_ADDRESS);
+ const char* addr_str = grpc_channel_arg_get_string(addr_arg);
+ GPR_ASSERT(addr_str != nullptr); // Should have been set by LB policy.
+ return addr_str;
+}
+
+channelz::SubchannelNode* Subchannel::channelz_node() {
+ return channelz_node_.get();
+}
+
+grpc_connectivity_state Subchannel::CheckConnectivityState(
+ const char* health_check_service_name,
+ RefCountedPtr<ConnectedSubchannel>* connected_subchannel) {
+ MutexLock lock(&mu_);
+ grpc_connectivity_state state;
+ if (health_check_service_name == nullptr) {
+ state = state_;
+ } else {
+ state = health_watcher_map_.CheckConnectivityStateLocked(
+ this, health_check_service_name);
+ }
+ if (connected_subchannel != nullptr && state == GRPC_CHANNEL_READY) {
+ *connected_subchannel = connected_subchannel_;
+ }
+ return state;
+}
+
+void Subchannel::WatchConnectivityState(
+ grpc_connectivity_state initial_state,
+ UniquePtr<char> health_check_service_name,
+ OrphanablePtr<ConnectivityStateWatcherInterface> watcher) {
+ MutexLock lock(&mu_);
+ grpc_pollset_set* interested_parties = watcher->interested_parties();
+ if (interested_parties != nullptr) {
+ grpc_pollset_set_add_pollset_set(pollset_set_, interested_parties);
+ }
+ if (health_check_service_name == nullptr) {
+ if (state_ != initial_state) {
+ watcher->OnConnectivityStateChange(state_, connected_subchannel_);
+ }
+ watcher_list_.AddWatcherLocked(std::move(watcher));
+ } else {
+ health_watcher_map_.AddWatcherLocked(this, initial_state,
+ std::move(health_check_service_name),
+ std::move(watcher));
+ }
+}
+
+void Subchannel::CancelConnectivityStateWatch(
+ const char* health_check_service_name,
+ ConnectivityStateWatcherInterface* watcher) {
+ MutexLock lock(&mu_);
+ grpc_pollset_set* interested_parties = watcher->interested_parties();
+ if (interested_parties != nullptr) {
+ grpc_pollset_set_del_pollset_set(pollset_set_, interested_parties);
+ }
+ if (health_check_service_name == nullptr) {
+ watcher_list_.RemoveWatcherLocked(watcher);
+ } else {
+ health_watcher_map_.RemoveWatcherLocked(health_check_service_name, watcher);
+ }
+}
+
+void Subchannel::AttemptToConnect() {
+ MutexLock lock(&mu_);
+ MaybeStartConnectingLocked();
+}
+
+void Subchannel::ResetBackoff() {
+ MutexLock lock(&mu_);
+ backoff_.Reset();
+ if (have_retry_alarm_) {
+ retry_immediately_ = true;
+ grpc_timer_cancel(&retry_alarm_);
+ } else {
+ backoff_begun_ = false;
+ MaybeStartConnectingLocked();
+ }
+}
+
+grpc_arg Subchannel::CreateSubchannelAddressArg(
+ const grpc_resolved_address* addr) {
+ return grpc_channel_arg_string_create(
+ (char*)GRPC_ARG_SUBCHANNEL_ADDRESS,
+ addr->len > 0 ? grpc_sockaddr_to_uri(addr) : gpr_strdup(""));
+}
+
+const char* Subchannel::GetUriFromSubchannelAddressArg(
+ const grpc_channel_args* args) {
+ const grpc_arg* addr_arg =
+ grpc_channel_args_find(args, GRPC_ARG_SUBCHANNEL_ADDRESS);
+ const char* addr_str = grpc_channel_arg_get_string(addr_arg);
+ GPR_ASSERT(addr_str != nullptr); // Should have been set by LB policy.
+ return addr_str;
+}
+
+namespace {
+
+void UriToSockaddr(const char* uri_str, grpc_resolved_address* addr) {
+ grpc_uri* uri = grpc_uri_parse(uri_str, 0 /* suppress_errors */);
+ GPR_ASSERT(uri != nullptr);
+ if (!grpc_parse_uri(uri, addr)) memset(addr, 0, sizeof(*addr));
+ grpc_uri_destroy(uri);
+}
+
+} // namespace
+
+void Subchannel::GetAddressFromSubchannelAddressArg(
+ const grpc_channel_args* args, grpc_resolved_address* addr) {
+ const char* addr_uri_str = GetUriFromSubchannelAddressArg(args);
+ memset(addr, 0, sizeof(*addr));
+ if (*addr_uri_str != '\0') {
+ UriToSockaddr(addr_uri_str, addr);
+ }
+}
+
+namespace {
+
+// Returns a string indicating the subchannel's connectivity state change to
+// \a state.
+const char* SubchannelConnectivityStateChangeString(
+ grpc_connectivity_state state) {
+ switch (state) {
+ case GRPC_CHANNEL_IDLE:
+ return "Subchannel state change to IDLE";
+ case GRPC_CHANNEL_CONNECTING:
+ return "Subchannel state change to CONNECTING";
+ case GRPC_CHANNEL_READY:
+ return "Subchannel state change to READY";
+ case GRPC_CHANNEL_TRANSIENT_FAILURE:
+ return "Subchannel state change to TRANSIENT_FAILURE";
+ case GRPC_CHANNEL_SHUTDOWN:
+ return "Subchannel state change to SHUTDOWN";
+ }
+ GPR_UNREACHABLE_CODE(return "UNKNOWN");
+}
+
+} // namespace
+
+// Note: Must be called with a state that is different from the current state.
+void Subchannel::SetConnectivityStateLocked(grpc_connectivity_state state) {
+ state_ = state;
+ if (channelz_node_ != nullptr) {
+ channelz_node_->UpdateConnectivityState(state);
+ channelz_node_->AddTraceEvent(
+ channelz::ChannelTrace::Severity::Info,
+ grpc_slice_from_static_string(
+ SubchannelConnectivityStateChangeString(state)));
+ }
+ // Notify non-health watchers.
+ watcher_list_.NotifyLocked(this, state);
+ // Notify health watchers.
+ health_watcher_map_.NotifyLocked(state);
+}
+
+void Subchannel::MaybeStartConnectingLocked() {
+ if (disconnected_) {
+ // Don't try to connect if we're already disconnected.
+ return;
+ }
+ if (connecting_) {
+ // Already connecting: don't restart.
+ return;
+ }
+ if (connected_subchannel_ != nullptr) {
+ // Already connected: don't restart.
+ return;
+ }
+ connecting_ = true;
+ GRPC_SUBCHANNEL_WEAK_REF(this, "connecting");
+ if (!backoff_begun_) {
+ backoff_begun_ = true;
+ ContinueConnectingLocked();
+ } else {
+ GPR_ASSERT(!have_retry_alarm_);
+ have_retry_alarm_ = true;
+ const grpc_millis time_til_next =
+ next_attempt_deadline_ - ExecCtx::Get()->Now();
+ if (time_til_next <= 0) {
+ gpr_log(GPR_INFO, "Subchannel %p: Retry immediately", this);
+ } else {
+ gpr_log(GPR_INFO, "Subchannel %p: Retry in %" PRId64 " milliseconds",
+ this, time_til_next);
+ }
+ GRPC_CLOSURE_INIT(&on_retry_alarm_, OnRetryAlarm, this,
+ grpc_schedule_on_exec_ctx);
+ grpc_timer_init(&retry_alarm_, next_attempt_deadline_, &on_retry_alarm_);
+ }
+}
+
+void Subchannel::OnRetryAlarm(void* arg, grpc_error* error) {
+ Subchannel* c = static_cast<Subchannel*>(arg);
+ // TODO(soheilhy): Once subchannel refcounting is simplified, we can get use
+ // MutexLock instead of ReleasableMutexLock, here.
+ ReleasableMutexLock lock(&c->mu_);
+ c->have_retry_alarm_ = false;
+ if (c->disconnected_) {
+ error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING("Disconnected",
+ &error, 1);
+ } else if (c->retry_immediately_) {
+ c->retry_immediately_ = false;
+ error = GRPC_ERROR_NONE;
+ } else {
+ GRPC_ERROR_REF(error);
+ }
+ if (error == GRPC_ERROR_NONE) {
+ gpr_log(GPR_INFO, "Failed to connect to channel, retrying");
+ c->ContinueConnectingLocked();
+ lock.Unlock();
+ } else {
+ lock.Unlock();
+ GRPC_SUBCHANNEL_WEAK_UNREF(c, "connecting");
+ }
+ GRPC_ERROR_UNREF(error);
+}
+
+void Subchannel::ContinueConnectingLocked() {
+ grpc_connect_in_args args;
+ args.interested_parties = pollset_set_;
+ const grpc_millis min_deadline =
+ min_connect_timeout_ms_ + ExecCtx::Get()->Now();
+ next_attempt_deadline_ = backoff_.NextAttemptTime();
+ args.deadline = std::max(next_attempt_deadline_, min_deadline);
+ args.channel_args = args_;
+ SetConnectivityStateLocked(GRPC_CHANNEL_CONNECTING);
+ grpc_connector_connect(connector_, &args, &connecting_result_,
+ &on_connecting_finished_);
+}
+
+void Subchannel::OnConnectingFinished(void* arg, grpc_error* error) {
+ auto* c = static_cast<Subchannel*>(arg);
+ grpc_channel_args* delete_channel_args = c->connecting_result_.channel_args;
+ GRPC_SUBCHANNEL_WEAK_REF(c, "on_connecting_finished");
+ {
+ MutexLock lock(&c->mu_);
+ c->connecting_ = false;
+ if (c->connecting_result_.transport != nullptr &&
+ c->PublishTransportLocked()) {
+ // Do nothing, transport was published.
+ } else if (c->disconnected_) {
+ GRPC_SUBCHANNEL_WEAK_UNREF(c, "connecting");
+ } else {
+ gpr_log(GPR_INFO, "Connect failed: %s", grpc_error_string(error));
+ c->SetConnectivityStateLocked(GRPC_CHANNEL_TRANSIENT_FAILURE);
+ GRPC_SUBCHANNEL_WEAK_UNREF(c, "connecting");
+ }
+ }
+ GRPC_SUBCHANNEL_WEAK_UNREF(c, "on_connecting_finished");
+ grpc_channel_args_destroy(delete_channel_args);
+}
+
+namespace {
+
+void ConnectionDestroy(void* arg, grpc_error* error) {
+ grpc_channel_stack* stk = static_cast<grpc_channel_stack*>(arg);
+ grpc_channel_stack_destroy(stk);
+ gpr_free(stk);
+}
+
+} // namespace
+
+bool Subchannel::PublishTransportLocked() {
+ // Construct channel stack.
+ grpc_channel_stack_builder* builder = grpc_channel_stack_builder_create();
+ grpc_channel_stack_builder_set_channel_arguments(
+ builder, connecting_result_.channel_args);
+ grpc_channel_stack_builder_set_transport(builder,
+ connecting_result_.transport);
+ if (!grpc_channel_init_create_stack(builder, GRPC_CLIENT_SUBCHANNEL)) {
+ grpc_channel_stack_builder_destroy(builder);
+ return false;
+ }
+ grpc_channel_stack* stk;
+ grpc_error* error = grpc_channel_stack_builder_finish(
+ builder, 0, 1, ConnectionDestroy, nullptr,
+ reinterpret_cast<void**>(&stk));
+ if (error != GRPC_ERROR_NONE) {
+ grpc_transport_destroy(connecting_result_.transport);
+ gpr_log(GPR_ERROR, "error initializing subchannel stack: %s",
+ grpc_error_string(error));
+ GRPC_ERROR_UNREF(error);
+ return false;
+ }
+ RefCountedPtr<channelz::SocketNode> socket =
+ std::move(connecting_result_.socket);
+ connecting_result_.reset();
+ if (disconnected_) {
+ grpc_channel_stack_destroy(stk);
+ gpr_free(stk);
+ return false;
+ }
+ // Publish.
+ connected_subchannel_.reset(
+ New<ConnectedSubchannel>(stk, args_, channelz_node_));
+ gpr_log(GPR_INFO, "New connected subchannel at %p for subchannel %p",
+ connected_subchannel_.get(), this);
+ if (channelz_node_ != nullptr) {
+ channelz_node_->SetChildSocket(std::move(socket));
+ }
+ // Instantiate state watcher. Will clean itself up.
+ New<ConnectedSubchannelStateWatcher>(this);
+ // Report initial state.
+ SetConnectivityStateLocked(GRPC_CHANNEL_READY);
+ return true;
+}
+
+void Subchannel::Disconnect() {
+ // The subchannel_pool is only used once here in this subchannel, so the
+ // access can be outside of the lock.
+ if (subchannel_pool_ != nullptr) {
+ subchannel_pool_->UnregisterSubchannel(key_);
+ subchannel_pool_.reset();
+ }
+ MutexLock lock(&mu_);
+ GPR_ASSERT(!disconnected_);
+ disconnected_ = true;
+ grpc_connector_shutdown(connector_, GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+ "Subchannel disconnected"));
+ connected_subchannel_.reset();
+ health_watcher_map_.ShutdownLocked();
+}
+
+gpr_atm Subchannel::RefMutate(
+ gpr_atm delta, int barrier GRPC_SUBCHANNEL_REF_MUTATE_EXTRA_ARGS) {
+ gpr_atm old_val = barrier ? gpr_atm_full_fetch_add(&ref_pair_, delta)
+ : gpr_atm_no_barrier_fetch_add(&ref_pair_, delta);
+#ifndef NDEBUG
+ if (grpc_trace_subchannel_refcount.enabled()) {
+ gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
+ "SUBCHANNEL: %p %12s 0x%" PRIxPTR " -> 0x%" PRIxPTR " [%s]", this,
+ purpose, old_val, old_val + delta, reason);
+ }
+#endif
+ return old_val;
+}
+
+} // namespace grpc_core
git://repos.xcallymotion.com / motion2.git / blobdiff