--- /dev/null
+/*
+ *
+ * Copyright 2018 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 <stdint.h>
+#include <stdio.h>
+
+#include "src/core/ext/filters/client_channel/health/health_check_client.h"
+
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gprpp/sync.h"
+#include "src/core/lib/slice/slice_internal.h"
+#include "src/core/lib/transport/error_utils.h"
+#include "src/core/lib/transport/status_metadata.h"
+#include "src/proto/grpc/health/v1/health.upb.h"
+
+#define HEALTH_CHECK_INITIAL_CONNECT_BACKOFF_SECONDS 1
+#define HEALTH_CHECK_RECONNECT_BACKOFF_MULTIPLIER 1.6
+#define HEALTH_CHECK_RECONNECT_MAX_BACKOFF_SECONDS 120
+#define HEALTH_CHECK_RECONNECT_JITTER 0.2
+
+namespace grpc_core {
+
+TraceFlag grpc_health_check_client_trace(false, "health_check_client");
+
+//
+// HealthCheckClient
+//
+
+HealthCheckClient::HealthCheckClient(
+ const char* service_name,
+ RefCountedPtr<ConnectedSubchannel> connected_subchannel,
+ grpc_pollset_set* interested_parties,
+ RefCountedPtr<channelz::SubchannelNode> channelz_node)
+ : InternallyRefCounted<HealthCheckClient>(&grpc_health_check_client_trace),
+ service_name_(service_name),
+ connected_subchannel_(std::move(connected_subchannel)),
+ interested_parties_(interested_parties),
+ channelz_node_(std::move(channelz_node)),
+ retry_backoff_(
+ BackOff::Options()
+ .set_initial_backoff(
+ HEALTH_CHECK_INITIAL_CONNECT_BACKOFF_SECONDS * 1000)
+ .set_multiplier(HEALTH_CHECK_RECONNECT_BACKOFF_MULTIPLIER)
+ .set_jitter(HEALTH_CHECK_RECONNECT_JITTER)
+ .set_max_backoff(HEALTH_CHECK_RECONNECT_MAX_BACKOFF_SECONDS *
+ 1000)) {
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
+ gpr_log(GPR_INFO, "created HealthCheckClient %p", this);
+ }
+ GRPC_CLOSURE_INIT(&retry_timer_callback_, OnRetryTimer, this,
+ grpc_schedule_on_exec_ctx);
+ StartCall();
+}
+
+HealthCheckClient::~HealthCheckClient() {
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
+ gpr_log(GPR_INFO, "destroying HealthCheckClient %p", this);
+ }
+ GRPC_ERROR_UNREF(error_);
+}
+
+void HealthCheckClient::NotifyOnHealthChange(grpc_connectivity_state* state,
+ grpc_closure* closure) {
+ MutexLock lock(&mu_);
+ GPR_ASSERT(notify_state_ == nullptr);
+ if (*state != state_) {
+ *state = state_;
+ GRPC_CLOSURE_SCHED(closure, GRPC_ERROR_REF(error_));
+ return;
+ }
+ notify_state_ = state;
+ on_health_changed_ = closure;
+}
+
+void HealthCheckClient::SetHealthStatus(grpc_connectivity_state state,
+ grpc_error* error) {
+ MutexLock lock(&mu_);
+ SetHealthStatusLocked(state, error);
+}
+
+void HealthCheckClient::SetHealthStatusLocked(grpc_connectivity_state state,
+ grpc_error* error) {
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
+ gpr_log(GPR_INFO, "HealthCheckClient %p: setting state=%d error=%s", this,
+ state, grpc_error_string(error));
+ }
+ if (notify_state_ != nullptr && *notify_state_ != state) {
+ *notify_state_ = state;
+ notify_state_ = nullptr;
+ GRPC_CLOSURE_SCHED(on_health_changed_, GRPC_ERROR_REF(error));
+ on_health_changed_ = nullptr;
+ }
+ state_ = state;
+ GRPC_ERROR_UNREF(error_);
+ error_ = error;
+}
+
+void HealthCheckClient::Orphan() {
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
+ gpr_log(GPR_INFO, "HealthCheckClient %p: shutting down", this);
+ }
+ {
+ MutexLock lock(&mu_);
+ if (on_health_changed_ != nullptr) {
+ *notify_state_ = GRPC_CHANNEL_SHUTDOWN;
+ notify_state_ = nullptr;
+ GRPC_CLOSURE_SCHED(on_health_changed_, GRPC_ERROR_NONE);
+ on_health_changed_ = nullptr;
+ }
+ shutting_down_ = true;
+ call_state_.reset();
+ if (retry_timer_callback_pending_) {
+ grpc_timer_cancel(&retry_timer_);
+ }
+ }
+ Unref(DEBUG_LOCATION, "orphan");
+}
+
+void HealthCheckClient::StartCall() {
+ MutexLock lock(&mu_);
+ StartCallLocked();
+}
+
+void HealthCheckClient::StartCallLocked() {
+ if (shutting_down_) return;
+ GPR_ASSERT(call_state_ == nullptr);
+ SetHealthStatusLocked(GRPC_CHANNEL_CONNECTING, GRPC_ERROR_NONE);
+ call_state_ = MakeOrphanable<CallState>(Ref(), interested_parties_);
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
+ gpr_log(GPR_INFO, "HealthCheckClient %p: created CallState %p", this,
+ call_state_.get());
+ }
+ call_state_->StartCall();
+}
+
+void HealthCheckClient::StartRetryTimer() {
+ MutexLock lock(&mu_);
+ SetHealthStatusLocked(
+ GRPC_CHANNEL_TRANSIENT_FAILURE,
+ GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+ "health check call failed; will retry after backoff"));
+ grpc_millis next_try = retry_backoff_.NextAttemptTime();
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
+ gpr_log(GPR_INFO, "HealthCheckClient %p: health check call lost...", this);
+ grpc_millis timeout = next_try - ExecCtx::Get()->Now();
+ if (timeout > 0) {
+ gpr_log(GPR_INFO,
+ "HealthCheckClient %p: ... will retry in %" PRId64 "ms.", this,
+ timeout);
+ } else {
+ gpr_log(GPR_INFO, "HealthCheckClient %p: ... retrying immediately.",
+ this);
+ }
+ }
+ // Ref for callback, tracked manually.
+ Ref(DEBUG_LOCATION, "health_retry_timer").release();
+ retry_timer_callback_pending_ = true;
+ grpc_timer_init(&retry_timer_, next_try, &retry_timer_callback_);
+}
+
+void HealthCheckClient::OnRetryTimer(void* arg, grpc_error* error) {
+ HealthCheckClient* self = static_cast<HealthCheckClient*>(arg);
+ {
+ MutexLock lock(&self->mu_);
+ self->retry_timer_callback_pending_ = false;
+ if (!self->shutting_down_ && error == GRPC_ERROR_NONE &&
+ self->call_state_ == nullptr) {
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
+ gpr_log(GPR_INFO, "HealthCheckClient %p: restarting health check call",
+ self);
+ }
+ self->StartCallLocked();
+ }
+ }
+ self->Unref(DEBUG_LOCATION, "health_retry_timer");
+}
+
+//
+// protobuf helpers
+//
+
+namespace {
+
+void EncodeRequest(const char* service_name,
+ ManualConstructor<SliceBufferByteStream>* send_message) {
+ upb::Arena arena;
+ grpc_health_v1_HealthCheckRequest* request_struct =
+ grpc_health_v1_HealthCheckRequest_new(arena.ptr());
+ grpc_health_v1_HealthCheckRequest_set_service(
+ request_struct, upb_strview_makez(service_name));
+ size_t buf_length;
+ char* buf = grpc_health_v1_HealthCheckRequest_serialize(
+ request_struct, arena.ptr(), &buf_length);
+ grpc_slice request_slice = GRPC_SLICE_MALLOC(buf_length);
+ memcpy(GRPC_SLICE_START_PTR(request_slice), buf, buf_length);
+ grpc_slice_buffer slice_buffer;
+ grpc_slice_buffer_init(&slice_buffer);
+ grpc_slice_buffer_add(&slice_buffer, request_slice);
+ send_message->Init(&slice_buffer, 0);
+ grpc_slice_buffer_destroy_internal(&slice_buffer);
+}
+
+// Returns true if healthy.
+// If there was an error parsing the response, sets *error and returns false.
+bool DecodeResponse(grpc_slice_buffer* slice_buffer, grpc_error** error) {
+ // If message is empty, assume unhealthy.
+ if (slice_buffer->length == 0) {
+ *error =
+ GRPC_ERROR_CREATE_FROM_STATIC_STRING("health check response was empty");
+ return false;
+ }
+ // Concatenate the slices to form a single string.
+ UniquePtr<uint8_t> recv_message_deleter;
+ uint8_t* recv_message;
+ if (slice_buffer->count == 1) {
+ recv_message = GRPC_SLICE_START_PTR(slice_buffer->slices[0]);
+ } else {
+ recv_message = static_cast<uint8_t*>(gpr_malloc(slice_buffer->length));
+ recv_message_deleter.reset(recv_message);
+ size_t offset = 0;
+ for (size_t i = 0; i < slice_buffer->count; ++i) {
+ memcpy(recv_message + offset,
+ GRPC_SLICE_START_PTR(slice_buffer->slices[i]),
+ GRPC_SLICE_LENGTH(slice_buffer->slices[i]));
+ offset += GRPC_SLICE_LENGTH(slice_buffer->slices[i]);
+ }
+ }
+ // Deserialize message.
+ upb::Arena arena;
+ grpc_health_v1_HealthCheckResponse* response_struct =
+ grpc_health_v1_HealthCheckResponse_parse(
+ reinterpret_cast<char*>(recv_message), slice_buffer->length,
+ arena.ptr());
+ if (response_struct == nullptr) {
+ // Can't parse message; assume unhealthy.
+ *error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+ "cannot parse health check response");
+ return false;
+ }
+ int32_t status = grpc_health_v1_HealthCheckResponse_status(response_struct);
+ return status == grpc_health_v1_HealthCheckResponse_SERVING;
+}
+
+} // namespace
+
+//
+// HealthCheckClient::CallState
+//
+
+HealthCheckClient::CallState::CallState(
+ RefCountedPtr<HealthCheckClient> health_check_client,
+ grpc_pollset_set* interested_parties)
+ : health_check_client_(std::move(health_check_client)),
+ pollent_(grpc_polling_entity_create_from_pollset_set(interested_parties)),
+ arena_(Arena::Create(health_check_client_->connected_subchannel_
+ ->GetInitialCallSizeEstimate(0))),
+ payload_(context_) {}
+
+HealthCheckClient::CallState::~CallState() {
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
+ gpr_log(GPR_INFO, "HealthCheckClient %p: destroying CallState %p",
+ health_check_client_.get(), this);
+ }
+ for (size_t i = 0; i < GRPC_CONTEXT_COUNT; i++) {
+ if (context_[i].destroy != nullptr) {
+ context_[i].destroy(context_[i].value);
+ }
+ }
+ // Unset the call combiner cancellation closure. This has the
+ // effect of scheduling the previously set cancellation closure, if
+ // any, so that it can release any internal references it may be
+ // holding to the call stack. Also flush the closures on exec_ctx so that
+ // filters that schedule cancel notification closures on exec_ctx do not
+ // need to take a ref of the call stack to guarantee closure liveness.
+ call_combiner_.SetNotifyOnCancel(nullptr);
+ ExecCtx::Get()->Flush();
+ arena_->Destroy();
+}
+
+void HealthCheckClient::CallState::Orphan() {
+ call_combiner_.Cancel(GRPC_ERROR_CANCELLED);
+ Cancel();
+}
+
+void HealthCheckClient::CallState::StartCall() {
+ SubchannelCall::Args args = {
+ health_check_client_->connected_subchannel_,
+ &pollent_,
+ GRPC_MDSTR_SLASH_GRPC_DOT_HEALTH_DOT_V1_DOT_HEALTH_SLASH_WATCH,
+ gpr_get_cycle_counter(), // start_time
+ GRPC_MILLIS_INF_FUTURE, // deadline
+ arena_,
+ context_,
+ &call_combiner_,
+ 0, // parent_data_size
+ };
+ grpc_error* error = GRPC_ERROR_NONE;
+ call_ = SubchannelCall::Create(std::move(args), &error).release();
+ // Register after-destruction callback.
+ GRPC_CLOSURE_INIT(&after_call_stack_destruction_, AfterCallStackDestruction,
+ this, grpc_schedule_on_exec_ctx);
+ call_->SetAfterCallStackDestroy(&after_call_stack_destruction_);
+ // Check if creation failed.
+ if (error != GRPC_ERROR_NONE) {
+ gpr_log(GPR_ERROR,
+ "HealthCheckClient %p CallState %p: error creating health "
+ "checking call on subchannel (%s); will retry",
+ health_check_client_.get(), this, grpc_error_string(error));
+ GRPC_ERROR_UNREF(error);
+ // Schedule instead of running directly, since we must not be
+ // holding health_check_client_->mu_ when CallEnded() is called.
+ call_->Ref(DEBUG_LOCATION, "call_end_closure").release();
+ GRPC_CLOSURE_SCHED(
+ GRPC_CLOSURE_INIT(&batch_.handler_private.closure, CallEndedRetry, this,
+ grpc_schedule_on_exec_ctx),
+ GRPC_ERROR_NONE);
+ return;
+ }
+ // Initialize payload and batch.
+ payload_.context = context_;
+ batch_.payload = &payload_;
+ // on_complete callback takes ref, handled manually.
+ call_->Ref(DEBUG_LOCATION, "on_complete").release();
+ batch_.on_complete = GRPC_CLOSURE_INIT(&on_complete_, OnComplete, this,
+ grpc_schedule_on_exec_ctx);
+ // Add send_initial_metadata op.
+ grpc_metadata_batch_init(&send_initial_metadata_);
+ error = grpc_metadata_batch_add_head(
+ &send_initial_metadata_, &path_metadata_storage_,
+ grpc_mdelem_from_slices(
+ GRPC_MDSTR_PATH,
+ GRPC_MDSTR_SLASH_GRPC_DOT_HEALTH_DOT_V1_DOT_HEALTH_SLASH_WATCH),
+ GRPC_BATCH_PATH);
+ GPR_ASSERT(error == GRPC_ERROR_NONE);
+ payload_.send_initial_metadata.send_initial_metadata =
+ &send_initial_metadata_;
+ payload_.send_initial_metadata.send_initial_metadata_flags = 0;
+ payload_.send_initial_metadata.peer_string = nullptr;
+ batch_.send_initial_metadata = true;
+ // Add send_message op.
+ EncodeRequest(health_check_client_->service_name_, &send_message_);
+ payload_.send_message.send_message.reset(send_message_.get());
+ batch_.send_message = true;
+ // Add send_trailing_metadata op.
+ grpc_metadata_batch_init(&send_trailing_metadata_);
+ payload_.send_trailing_metadata.send_trailing_metadata =
+ &send_trailing_metadata_;
+ batch_.send_trailing_metadata = true;
+ // Add recv_initial_metadata op.
+ grpc_metadata_batch_init(&recv_initial_metadata_);
+ payload_.recv_initial_metadata.recv_initial_metadata =
+ &recv_initial_metadata_;
+ payload_.recv_initial_metadata.recv_flags = nullptr;
+ payload_.recv_initial_metadata.trailing_metadata_available = nullptr;
+ payload_.recv_initial_metadata.peer_string = nullptr;
+ // recv_initial_metadata_ready callback takes ref, handled manually.
+ call_->Ref(DEBUG_LOCATION, "recv_initial_metadata_ready").release();
+ payload_.recv_initial_metadata.recv_initial_metadata_ready =
+ GRPC_CLOSURE_INIT(&recv_initial_metadata_ready_, RecvInitialMetadataReady,
+ this, grpc_schedule_on_exec_ctx);
+ batch_.recv_initial_metadata = true;
+ // Add recv_message op.
+ payload_.recv_message.recv_message = &recv_message_;
+ // recv_message callback takes ref, handled manually.
+ call_->Ref(DEBUG_LOCATION, "recv_message_ready").release();
+ payload_.recv_message.recv_message_ready = GRPC_CLOSURE_INIT(
+ &recv_message_ready_, RecvMessageReady, this, grpc_schedule_on_exec_ctx);
+ batch_.recv_message = true;
+ // Start batch.
+ StartBatch(&batch_);
+ // Initialize recv_trailing_metadata batch.
+ recv_trailing_metadata_batch_.payload = &payload_;
+ // Add recv_trailing_metadata op.
+ grpc_metadata_batch_init(&recv_trailing_metadata_);
+ payload_.recv_trailing_metadata.recv_trailing_metadata =
+ &recv_trailing_metadata_;
+ payload_.recv_trailing_metadata.collect_stats = &collect_stats_;
+ // This callback signals the end of the call, so it relies on the
+ // initial ref instead of taking a new ref. When it's invoked, the
+ // initial ref is released.
+ payload_.recv_trailing_metadata.recv_trailing_metadata_ready =
+ GRPC_CLOSURE_INIT(&recv_trailing_metadata_ready_,
+ RecvTrailingMetadataReady, this,
+ grpc_schedule_on_exec_ctx);
+ recv_trailing_metadata_batch_.recv_trailing_metadata = true;
+ // Start recv_trailing_metadata batch.
+ StartBatch(&recv_trailing_metadata_batch_);
+}
+
+void HealthCheckClient::CallState::StartBatchInCallCombiner(void* arg,
+ grpc_error* error) {
+ grpc_transport_stream_op_batch* batch =
+ static_cast<grpc_transport_stream_op_batch*>(arg);
+ SubchannelCall* call =
+ static_cast<SubchannelCall*>(batch->handler_private.extra_arg);
+ call->StartTransportStreamOpBatch(batch);
+}
+
+void HealthCheckClient::CallState::StartBatch(
+ grpc_transport_stream_op_batch* batch) {
+ batch->handler_private.extra_arg = call_;
+ GRPC_CLOSURE_INIT(&batch->handler_private.closure, StartBatchInCallCombiner,
+ batch, grpc_schedule_on_exec_ctx);
+ GRPC_CALL_COMBINER_START(&call_combiner_, &batch->handler_private.closure,
+ GRPC_ERROR_NONE, "start_subchannel_batch");
+}
+
+void HealthCheckClient::CallState::AfterCallStackDestruction(
+ void* arg, grpc_error* error) {
+ HealthCheckClient::CallState* self =
+ static_cast<HealthCheckClient::CallState*>(arg);
+ Delete(self);
+}
+
+void HealthCheckClient::CallState::OnCancelComplete(void* arg,
+ grpc_error* error) {
+ HealthCheckClient::CallState* self =
+ static_cast<HealthCheckClient::CallState*>(arg);
+ GRPC_CALL_COMBINER_STOP(&self->call_combiner_, "health_cancel");
+ self->call_->Unref(DEBUG_LOCATION, "cancel");
+}
+
+void HealthCheckClient::CallState::StartCancel(void* arg, grpc_error* error) {
+ HealthCheckClient::CallState* self =
+ static_cast<HealthCheckClient::CallState*>(arg);
+ auto* batch = grpc_make_transport_stream_op(
+ GRPC_CLOSURE_CREATE(OnCancelComplete, self, grpc_schedule_on_exec_ctx));
+ batch->cancel_stream = true;
+ batch->payload->cancel_stream.cancel_error = GRPC_ERROR_CANCELLED;
+ self->call_->StartTransportStreamOpBatch(batch);
+}
+
+void HealthCheckClient::CallState::Cancel() {
+ bool expected = false;
+ if (cancelled_.CompareExchangeStrong(&expected, true, MemoryOrder::ACQ_REL,
+ MemoryOrder::ACQUIRE)) {
+ call_->Ref(DEBUG_LOCATION, "cancel").release();
+ GRPC_CALL_COMBINER_START(
+ &call_combiner_,
+ GRPC_CLOSURE_CREATE(StartCancel, this, grpc_schedule_on_exec_ctx),
+ GRPC_ERROR_NONE, "health_cancel");
+ }
+}
+
+void HealthCheckClient::CallState::OnComplete(void* arg, grpc_error* error) {
+ HealthCheckClient::CallState* self =
+ static_cast<HealthCheckClient::CallState*>(arg);
+ GRPC_CALL_COMBINER_STOP(&self->call_combiner_, "on_complete");
+ grpc_metadata_batch_destroy(&self->send_initial_metadata_);
+ grpc_metadata_batch_destroy(&self->send_trailing_metadata_);
+ self->call_->Unref(DEBUG_LOCATION, "on_complete");
+}
+
+void HealthCheckClient::CallState::RecvInitialMetadataReady(void* arg,
+ grpc_error* error) {
+ HealthCheckClient::CallState* self =
+ static_cast<HealthCheckClient::CallState*>(arg);
+ GRPC_CALL_COMBINER_STOP(&self->call_combiner_, "recv_initial_metadata_ready");
+ grpc_metadata_batch_destroy(&self->recv_initial_metadata_);
+ self->call_->Unref(DEBUG_LOCATION, "recv_initial_metadata_ready");
+}
+
+void HealthCheckClient::CallState::DoneReadingRecvMessage(grpc_error* error) {
+ recv_message_.reset();
+ if (error != GRPC_ERROR_NONE) {
+ GRPC_ERROR_UNREF(error);
+ Cancel();
+ grpc_slice_buffer_destroy_internal(&recv_message_buffer_);
+ call_->Unref(DEBUG_LOCATION, "recv_message_ready");
+ return;
+ }
+ const bool healthy = DecodeResponse(&recv_message_buffer_, &error);
+ const grpc_connectivity_state state =
+ healthy ? GRPC_CHANNEL_READY : GRPC_CHANNEL_TRANSIENT_FAILURE;
+ if (error == GRPC_ERROR_NONE && !healthy) {
+ error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("backend unhealthy");
+ }
+ health_check_client_->SetHealthStatus(state, error);
+ seen_response_.Store(true, MemoryOrder::RELEASE);
+ grpc_slice_buffer_destroy_internal(&recv_message_buffer_);
+ // Start another recv_message batch.
+ // This re-uses the ref we're holding.
+ // Note: Can't just reuse batch_ here, since we don't know that all
+ // callbacks from the original batch have completed yet.
+ recv_message_batch_.payload = &payload_;
+ payload_.recv_message.recv_message = &recv_message_;
+ payload_.recv_message.recv_message_ready = GRPC_CLOSURE_INIT(
+ &recv_message_ready_, RecvMessageReady, this, grpc_schedule_on_exec_ctx);
+ recv_message_batch_.recv_message = true;
+ StartBatch(&recv_message_batch_);
+}
+
+grpc_error* HealthCheckClient::CallState::PullSliceFromRecvMessage() {
+ grpc_slice slice;
+ grpc_error* error = recv_message_->Pull(&slice);
+ if (error == GRPC_ERROR_NONE) {
+ grpc_slice_buffer_add(&recv_message_buffer_, slice);
+ }
+ return error;
+}
+
+void HealthCheckClient::CallState::ContinueReadingRecvMessage() {
+ while (recv_message_->Next(SIZE_MAX, &recv_message_ready_)) {
+ grpc_error* error = PullSliceFromRecvMessage();
+ if (error != GRPC_ERROR_NONE) {
+ DoneReadingRecvMessage(error);
+ return;
+ }
+ if (recv_message_buffer_.length == recv_message_->length()) {
+ DoneReadingRecvMessage(GRPC_ERROR_NONE);
+ break;
+ }
+ }
+}
+
+void HealthCheckClient::CallState::OnByteStreamNext(void* arg,
+ grpc_error* error) {
+ HealthCheckClient::CallState* self =
+ static_cast<HealthCheckClient::CallState*>(arg);
+ if (error != GRPC_ERROR_NONE) {
+ self->DoneReadingRecvMessage(GRPC_ERROR_REF(error));
+ return;
+ }
+ error = self->PullSliceFromRecvMessage();
+ if (error != GRPC_ERROR_NONE) {
+ self->DoneReadingRecvMessage(error);
+ return;
+ }
+ if (self->recv_message_buffer_.length == self->recv_message_->length()) {
+ self->DoneReadingRecvMessage(GRPC_ERROR_NONE);
+ } else {
+ self->ContinueReadingRecvMessage();
+ }
+}
+
+void HealthCheckClient::CallState::RecvMessageReady(void* arg,
+ grpc_error* error) {
+ HealthCheckClient::CallState* self =
+ static_cast<HealthCheckClient::CallState*>(arg);
+ GRPC_CALL_COMBINER_STOP(&self->call_combiner_, "recv_message_ready");
+ if (self->recv_message_ == nullptr) {
+ self->call_->Unref(DEBUG_LOCATION, "recv_message_ready");
+ return;
+ }
+ grpc_slice_buffer_init(&self->recv_message_buffer_);
+ GRPC_CLOSURE_INIT(&self->recv_message_ready_, OnByteStreamNext, self,
+ grpc_schedule_on_exec_ctx);
+ self->ContinueReadingRecvMessage();
+ // Ref will continue to be held until we finish draining the byte stream.
+}
+
+void HealthCheckClient::CallState::RecvTrailingMetadataReady(
+ void* arg, grpc_error* error) {
+ HealthCheckClient::CallState* self =
+ static_cast<HealthCheckClient::CallState*>(arg);
+ GRPC_CALL_COMBINER_STOP(&self->call_combiner_,
+ "recv_trailing_metadata_ready");
+ // Get call status.
+ grpc_status_code status = GRPC_STATUS_UNKNOWN;
+ if (error != GRPC_ERROR_NONE) {
+ grpc_error_get_status(error, GRPC_MILLIS_INF_FUTURE, &status,
+ nullptr /* slice */, nullptr /* http_error */,
+ nullptr /* error_string */);
+ } else if (self->recv_trailing_metadata_.idx.named.grpc_status != nullptr) {
+ status = grpc_get_status_code_from_metadata(
+ self->recv_trailing_metadata_.idx.named.grpc_status->md);
+ }
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
+ gpr_log(GPR_INFO,
+ "HealthCheckClient %p CallState %p: health watch failed with "
+ "status %d",
+ self->health_check_client_.get(), self, status);
+ }
+ // Clean up.
+ grpc_metadata_batch_destroy(&self->recv_trailing_metadata_);
+ // For status UNIMPLEMENTED, give up and assume always healthy.
+ bool retry = true;
+ if (status == GRPC_STATUS_UNIMPLEMENTED) {
+ static const char kErrorMessage[] =
+ "health checking Watch method returned UNIMPLEMENTED; "
+ "disabling health checks but assuming server is healthy";
+ gpr_log(GPR_ERROR, kErrorMessage);
+ if (self->health_check_client_->channelz_node_ != nullptr) {
+ self->health_check_client_->channelz_node_->AddTraceEvent(
+ channelz::ChannelTrace::Error,
+ grpc_slice_from_static_string(kErrorMessage));
+ }
+ self->health_check_client_->SetHealthStatus(GRPC_CHANNEL_READY,
+ GRPC_ERROR_NONE);
+ retry = false;
+ }
+ self->CallEnded(retry);
+}
+
+void HealthCheckClient::CallState::CallEndedRetry(void* arg,
+ grpc_error* error) {
+ HealthCheckClient::CallState* self =
+ static_cast<HealthCheckClient::CallState*>(arg);
+ self->CallEnded(true /* retry */);
+ self->call_->Unref(DEBUG_LOCATION, "call_end_closure");
+}
+
+void HealthCheckClient::CallState::CallEnded(bool retry) {
+ // If this CallState is still in use, this call ended because of a failure,
+ // so we need to stop using it and optionally create a new one.
+ // Otherwise, we have deliberately ended this call, and no further action
+ // is required.
+ if (this == health_check_client_->call_state_.get()) {
+ health_check_client_->call_state_.reset();
+ if (retry) {
+ GPR_ASSERT(!health_check_client_->shutting_down_);
+ if (seen_response_.Load(MemoryOrder::ACQUIRE)) {
+ // If the call fails after we've gotten a successful response, reset
+ // the backoff and restart the call immediately.
+ health_check_client_->retry_backoff_.Reset();
+ health_check_client_->StartCall();
+ } else {
+ // If the call failed without receiving any messages, retry later.
+ health_check_client_->StartRetryTimer();
+ }
+ }
+ }
+ // When the last ref to the call stack goes away, the CallState object
+ // will be automatically destroyed.
+ call_->Unref(DEBUG_LOCATION, "call_ended");
+}
+
+} // namespace grpc_core
git://repos.xcallymotion.com / motion2.git / blobdiff