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-rw-r--r--src/cpp/server/health/default_health_check_service.cc475
-rw-r--r--src/cpp/server/health/default_health_check_service.h234
-rw-r--r--src/cpp/server/health/health.pb.c24
-rw-r--r--src/cpp/server/health/health.pb.h72
4 files changed, 626 insertions, 179 deletions
diff --git a/src/cpp/server/health/default_health_check_service.cc b/src/cpp/server/health/default_health_check_service.cc
index bfda67d086..c951c69d51 100644
--- a/src/cpp/server/health/default_health_check_service.cc
+++ b/src/cpp/server/health/default_health_check_service.cc
@@ -26,79 +26,199 @@
#include "pb_decode.h"
#include "pb_encode.h"
+#include "src/core/ext/filters/client_channel/health/health.pb.h"
#include "src/cpp/server/health/default_health_check_service.h"
-#include "src/cpp/server/health/health.pb.h"
namespace grpc {
+
+//
+// DefaultHealthCheckService
+//
+
+DefaultHealthCheckService::DefaultHealthCheckService() {
+ services_map_[""].SetServingStatus(SERVING);
+}
+
+void DefaultHealthCheckService::SetServingStatus(
+ const grpc::string& service_name, bool serving) {
+ std::unique_lock<std::mutex> lock(mu_);
+ services_map_[service_name].SetServingStatus(serving ? SERVING : NOT_SERVING);
+}
+
+void DefaultHealthCheckService::SetServingStatus(bool serving) {
+ const ServingStatus status = serving ? SERVING : NOT_SERVING;
+ std::unique_lock<std::mutex> lock(mu_);
+ for (auto& p : services_map_) {
+ ServiceData& service_data = p.second;
+ service_data.SetServingStatus(status);
+ }
+}
+
+DefaultHealthCheckService::ServingStatus
+DefaultHealthCheckService::GetServingStatus(
+ const grpc::string& service_name) const {
+ std::lock_guard<std::mutex> lock(mu_);
+ auto it = services_map_.find(service_name);
+ if (it == services_map_.end()) {
+ return NOT_FOUND;
+ }
+ const ServiceData& service_data = it->second;
+ return service_data.GetServingStatus();
+}
+
+void DefaultHealthCheckService::RegisterCallHandler(
+ const grpc::string& service_name,
+ std::shared_ptr<HealthCheckServiceImpl::CallHandler> handler) {
+ std::unique_lock<std::mutex> lock(mu_);
+ ServiceData& service_data = services_map_[service_name];
+ service_data.AddCallHandler(handler /* copies ref */);
+ HealthCheckServiceImpl::CallHandler* h = handler.get();
+ h->SendHealth(std::move(handler), service_data.GetServingStatus());
+}
+
+void DefaultHealthCheckService::UnregisterCallHandler(
+ const grpc::string& service_name,
+ const std::shared_ptr<HealthCheckServiceImpl::CallHandler>& handler) {
+ std::unique_lock<std::mutex> lock(mu_);
+ auto it = services_map_.find(service_name);
+ if (it == services_map_.end()) return;
+ ServiceData& service_data = it->second;
+ service_data.RemoveCallHandler(handler);
+ if (service_data.Unused()) {
+ services_map_.erase(it);
+ }
+}
+
+DefaultHealthCheckService::HealthCheckServiceImpl*
+DefaultHealthCheckService::GetHealthCheckService(
+ std::unique_ptr<ServerCompletionQueue> cq) {
+ GPR_ASSERT(impl_ == nullptr);
+ impl_.reset(new HealthCheckServiceImpl(this, std::move(cq)));
+ return impl_.get();
+}
+
+//
+// DefaultHealthCheckService::ServiceData
+//
+
+void DefaultHealthCheckService::ServiceData::SetServingStatus(
+ ServingStatus status) {
+ status_ = status;
+ for (auto& call_handler : call_handlers_) {
+ call_handler->SendHealth(call_handler /* copies ref */, status);
+ }
+}
+
+void DefaultHealthCheckService::ServiceData::AddCallHandler(
+ std::shared_ptr<HealthCheckServiceImpl::CallHandler> handler) {
+ call_handlers_.insert(std::move(handler));
+}
+
+void DefaultHealthCheckService::ServiceData::RemoveCallHandler(
+ const std::shared_ptr<HealthCheckServiceImpl::CallHandler>& handler) {
+ call_handlers_.erase(handler);
+}
+
+//
+// DefaultHealthCheckService::HealthCheckServiceImpl
+//
+
namespace {
const char kHealthCheckMethodName[] = "/grpc.health.v1.Health/Check";
+const char kHealthWatchMethodName[] = "/grpc.health.v1.Health/Watch";
} // namespace
DefaultHealthCheckService::HealthCheckServiceImpl::HealthCheckServiceImpl(
- DefaultHealthCheckService* service)
- : service_(service), method_(nullptr) {
- internal::MethodHandler* handler =
- new internal::RpcMethodHandler<HealthCheckServiceImpl, ByteBuffer,
- ByteBuffer>(
- std::mem_fn(&HealthCheckServiceImpl::Check), this);
- method_ = new internal::RpcServiceMethod(
- kHealthCheckMethodName, internal::RpcMethod::NORMAL_RPC, handler);
- AddMethod(method_);
-}
-
-Status DefaultHealthCheckService::HealthCheckServiceImpl::Check(
- ServerContext* context, const ByteBuffer* request, ByteBuffer* response) {
- // Decode request.
- std::vector<Slice> slices;
- if (!request->Dump(&slices).ok()) {
- return Status(StatusCode::INVALID_ARGUMENT, "");
+ DefaultHealthCheckService* database,
+ std::unique_ptr<ServerCompletionQueue> cq)
+ : database_(database), cq_(std::move(cq)) {
+ // Add Check() method.
+ AddMethod(new internal::RpcServiceMethod(
+ kHealthCheckMethodName, internal::RpcMethod::NORMAL_RPC, nullptr));
+ // Add Watch() method.
+ AddMethod(new internal::RpcServiceMethod(
+ kHealthWatchMethodName, internal::RpcMethod::SERVER_STREAMING, nullptr));
+ // Create serving thread.
+ thread_ = std::unique_ptr<::grpc_core::Thread>(
+ new ::grpc_core::Thread("grpc_health_check_service", Serve, this));
+}
+
+DefaultHealthCheckService::HealthCheckServiceImpl::~HealthCheckServiceImpl() {
+ // We will reach here after the server starts shutting down.
+ shutdown_ = true;
+ {
+ std::unique_lock<std::mutex> lock(cq_shutdown_mu_);
+ cq_->Shutdown();
}
+ thread_->Join();
+}
+
+void DefaultHealthCheckService::HealthCheckServiceImpl::StartServingThread() {
+ // Request the calls we're interested in.
+ // We do this before starting the serving thread, so that we know it's
+ // done before server startup is complete.
+ CheckCallHandler::CreateAndStart(cq_.get(), database_, this);
+ WatchCallHandler::CreateAndStart(cq_.get(), database_, this);
+ // Start serving thread.
+ thread_->Start();
+}
+
+void DefaultHealthCheckService::HealthCheckServiceImpl::Serve(void* arg) {
+ HealthCheckServiceImpl* service =
+ reinterpret_cast<HealthCheckServiceImpl*>(arg);
+ void* tag;
+ bool ok;
+ while (true) {
+ if (!service->cq_->Next(&tag, &ok)) {
+ // The completion queue is shutting down.
+ GPR_ASSERT(service->shutdown_);
+ break;
+ }
+ auto* next_step = static_cast<CallableTag*>(tag);
+ next_step->Run(ok);
+ }
+}
+
+bool DefaultHealthCheckService::HealthCheckServiceImpl::DecodeRequest(
+ const ByteBuffer& request, grpc::string* service_name) {
+ std::vector<Slice> slices;
+ if (!request.Dump(&slices).ok()) return false;
uint8_t* request_bytes = nullptr;
- bool request_bytes_owned = false;
size_t request_size = 0;
grpc_health_v1_HealthCheckRequest request_struct;
- if (slices.empty()) {
- request_struct.has_service = false;
- } else if (slices.size() == 1) {
+ request_struct.has_service = false;
+ if (slices.size() == 1) {
request_bytes = const_cast<uint8_t*>(slices[0].begin());
request_size = slices[0].size();
- } else {
- request_bytes_owned = true;
- request_bytes = static_cast<uint8_t*>(gpr_malloc(request->Length()));
+ } else if (slices.size() > 1) {
+ request_bytes = static_cast<uint8_t*>(gpr_malloc(request.Length()));
uint8_t* copy_to = request_bytes;
for (size_t i = 0; i < slices.size(); i++) {
memcpy(copy_to, slices[i].begin(), slices[i].size());
copy_to += slices[i].size();
}
}
-
- if (request_bytes != nullptr) {
- pb_istream_t istream = pb_istream_from_buffer(request_bytes, request_size);
- bool decode_status = pb_decode(
- &istream, grpc_health_v1_HealthCheckRequest_fields, &request_struct);
- if (request_bytes_owned) {
- gpr_free(request_bytes);
- }
- if (!decode_status) {
- return Status(StatusCode::INVALID_ARGUMENT, "");
- }
- }
-
- // Check status from the associated default health checking service.
- DefaultHealthCheckService::ServingStatus serving_status =
- service_->GetServingStatus(
- request_struct.has_service ? request_struct.service : "");
- if (serving_status == DefaultHealthCheckService::NOT_FOUND) {
- return Status(StatusCode::NOT_FOUND, "");
+ pb_istream_t istream = pb_istream_from_buffer(request_bytes, request_size);
+ bool decode_status = pb_decode(
+ &istream, grpc_health_v1_HealthCheckRequest_fields, &request_struct);
+ if (slices.size() > 1) {
+ gpr_free(request_bytes);
}
+ if (!decode_status) return false;
+ *service_name = request_struct.has_service ? request_struct.service : "";
+ return true;
+}
- // Encode response
+bool DefaultHealthCheckService::HealthCheckServiceImpl::EncodeResponse(
+ ServingStatus status, ByteBuffer* response) {
grpc_health_v1_HealthCheckResponse response_struct;
response_struct.has_status = true;
response_struct.status =
- serving_status == DefaultHealthCheckService::SERVING
- ? grpc_health_v1_HealthCheckResponse_ServingStatus_SERVING
- : grpc_health_v1_HealthCheckResponse_ServingStatus_NOT_SERVING;
+ status == NOT_FOUND
+ ? grpc_health_v1_HealthCheckResponse_ServingStatus_SERVICE_UNKNOWN
+ : status == SERVING
+ ? grpc_health_v1_HealthCheckResponse_ServingStatus_SERVING
+ : grpc_health_v1_HealthCheckResponse_ServingStatus_NOT_SERVING;
pb_ostream_t ostream;
memset(&ostream, 0, sizeof(ostream));
pb_encode(&ostream, grpc_health_v1_HealthCheckResponse_fields,
@@ -108,48 +228,253 @@ Status DefaultHealthCheckService::HealthCheckServiceImpl::Check(
GRPC_SLICE_LENGTH(response_slice));
bool encode_status = pb_encode(
&ostream, grpc_health_v1_HealthCheckResponse_fields, &response_struct);
- if (!encode_status) {
- return Status(StatusCode::INTERNAL, "Failed to encode response.");
- }
+ if (!encode_status) return false;
Slice encoded_response(response_slice, Slice::STEAL_REF);
ByteBuffer response_buffer(&encoded_response, 1);
response->Swap(&response_buffer);
- return Status::OK;
+ return true;
}
-DefaultHealthCheckService::DefaultHealthCheckService() {
- services_map_.emplace("", true);
+//
+// DefaultHealthCheckService::HealthCheckServiceImpl::CheckCallHandler
+//
+
+void DefaultHealthCheckService::HealthCheckServiceImpl::CheckCallHandler::
+ CreateAndStart(ServerCompletionQueue* cq,
+ DefaultHealthCheckService* database,
+ HealthCheckServiceImpl* service) {
+ std::shared_ptr<CallHandler> self =
+ std::make_shared<CheckCallHandler>(cq, database, service);
+ CheckCallHandler* handler = static_cast<CheckCallHandler*>(self.get());
+ {
+ std::unique_lock<std::mutex> lock(service->cq_shutdown_mu_);
+ if (service->shutdown_) return;
+ // Request a Check() call.
+ handler->next_ =
+ CallableTag(std::bind(&CheckCallHandler::OnCallReceived, handler,
+ std::placeholders::_1, std::placeholders::_2),
+ std::move(self));
+ service->RequestAsyncUnary(0, &handler->ctx_, &handler->request_,
+ &handler->writer_, cq, cq, &handler->next_);
+ }
}
-void DefaultHealthCheckService::SetServingStatus(
- const grpc::string& service_name, bool serving) {
- std::lock_guard<std::mutex> lock(mu_);
- services_map_[service_name] = serving;
+DefaultHealthCheckService::HealthCheckServiceImpl::CheckCallHandler::
+ CheckCallHandler(ServerCompletionQueue* cq,
+ DefaultHealthCheckService* database,
+ HealthCheckServiceImpl* service)
+ : cq_(cq), database_(database), service_(service), writer_(&ctx_) {}
+
+void DefaultHealthCheckService::HealthCheckServiceImpl::CheckCallHandler::
+ OnCallReceived(std::shared_ptr<CallHandler> self, bool ok) {
+ if (!ok) {
+ // The value of ok being false means that the server is shutting down.
+ return;
+ }
+ // Spawn a new handler instance to serve the next new client. Every handler
+ // instance will deallocate itself when it's done.
+ CreateAndStart(cq_, database_, service_);
+ // Process request.
+ gpr_log(GPR_DEBUG, "[HCS %p] Health check started for handler %p", service_,
+ this);
+ grpc::string service_name;
+ grpc::Status status = Status::OK;
+ ByteBuffer response;
+ if (!service_->DecodeRequest(request_, &service_name)) {
+ status = Status(StatusCode::INVALID_ARGUMENT, "could not parse request");
+ } else {
+ ServingStatus serving_status = database_->GetServingStatus(service_name);
+ if (serving_status == NOT_FOUND) {
+ status = Status(StatusCode::NOT_FOUND, "service name unknown");
+ } else if (!service_->EncodeResponse(serving_status, &response)) {
+ status = Status(StatusCode::INTERNAL, "could not encode response");
+ }
+ }
+ // Send response.
+ {
+ std::unique_lock<std::mutex> lock(service_->cq_shutdown_mu_);
+ if (!service_->shutdown_) {
+ next_ =
+ CallableTag(std::bind(&CheckCallHandler::OnFinishDone, this,
+ std::placeholders::_1, std::placeholders::_2),
+ std::move(self));
+ if (status.ok()) {
+ writer_.Finish(response, status, &next_);
+ } else {
+ writer_.FinishWithError(status, &next_);
+ }
+ }
+ }
}
-void DefaultHealthCheckService::SetServingStatus(bool serving) {
- std::lock_guard<std::mutex> lock(mu_);
- for (auto iter = services_map_.begin(); iter != services_map_.end(); ++iter) {
- iter->second = serving;
+void DefaultHealthCheckService::HealthCheckServiceImpl::CheckCallHandler::
+ OnFinishDone(std::shared_ptr<CallHandler> self, bool ok) {
+ if (ok) {
+ gpr_log(GPR_DEBUG, "[HCS %p] Health check call finished for handler %p",
+ service_, this);
}
+ self.reset(); // To appease clang-tidy.
}
-DefaultHealthCheckService::ServingStatus
-DefaultHealthCheckService::GetServingStatus(
- const grpc::string& service_name) const {
- std::lock_guard<std::mutex> lock(mu_);
- const auto& iter = services_map_.find(service_name);
- if (iter == services_map_.end()) {
- return NOT_FOUND;
+//
+// DefaultHealthCheckService::HealthCheckServiceImpl::WatchCallHandler
+//
+
+void DefaultHealthCheckService::HealthCheckServiceImpl::WatchCallHandler::
+ CreateAndStart(ServerCompletionQueue* cq,
+ DefaultHealthCheckService* database,
+ HealthCheckServiceImpl* service) {
+ std::shared_ptr<CallHandler> self =
+ std::make_shared<WatchCallHandler>(cq, database, service);
+ WatchCallHandler* handler = static_cast<WatchCallHandler*>(self.get());
+ {
+ std::unique_lock<std::mutex> lock(service->cq_shutdown_mu_);
+ if (service->shutdown_) return;
+ // Request AsyncNotifyWhenDone().
+ handler->on_done_notified_ =
+ CallableTag(std::bind(&WatchCallHandler::OnDoneNotified, handler,
+ std::placeholders::_1, std::placeholders::_2),
+ self /* copies ref */);
+ handler->ctx_.AsyncNotifyWhenDone(&handler->on_done_notified_);
+ // Request a Watch() call.
+ handler->next_ =
+ CallableTag(std::bind(&WatchCallHandler::OnCallReceived, handler,
+ std::placeholders::_1, std::placeholders::_2),
+ std::move(self));
+ service->RequestAsyncServerStreaming(1, &handler->ctx_, &handler->request_,
+ &handler->stream_, cq, cq,
+ &handler->next_);
}
- return iter->second ? SERVING : NOT_SERVING;
}
-DefaultHealthCheckService::HealthCheckServiceImpl*
-DefaultHealthCheckService::GetHealthCheckService() {
- GPR_ASSERT(impl_ == nullptr);
- impl_.reset(new HealthCheckServiceImpl(this));
- return impl_.get();
+DefaultHealthCheckService::HealthCheckServiceImpl::WatchCallHandler::
+ WatchCallHandler(ServerCompletionQueue* cq,
+ DefaultHealthCheckService* database,
+ HealthCheckServiceImpl* service)
+ : cq_(cq), database_(database), service_(service), stream_(&ctx_) {}
+
+void DefaultHealthCheckService::HealthCheckServiceImpl::WatchCallHandler::
+ OnCallReceived(std::shared_ptr<CallHandler> self, bool ok) {
+ if (!ok) {
+ // Server shutting down.
+ //
+ // AsyncNotifyWhenDone() needs to be called before the call starts, but the
+ // tag will not pop out if the call never starts (
+ // https://github.com/grpc/grpc/issues/10136). So we need to manually
+ // release the ownership of the handler in this case.
+ GPR_ASSERT(on_done_notified_.ReleaseHandler() != nullptr);
+ return;
+ }
+ // Spawn a new handler instance to serve the next new client. Every handler
+ // instance will deallocate itself when it's done.
+ CreateAndStart(cq_, database_, service_);
+ // Parse request.
+ if (!service_->DecodeRequest(request_, &service_name_)) {
+ SendFinish(std::move(self),
+ Status(StatusCode::INVALID_ARGUMENT, "could not parse request"));
+ return;
+ }
+ // Register the call for updates to the service.
+ gpr_log(GPR_DEBUG,
+ "[HCS %p] Health watch started for service \"%s\" (handler: %p)",
+ service_, service_name_.c_str(), this);
+ database_->RegisterCallHandler(service_name_, std::move(self));
+}
+
+void DefaultHealthCheckService::HealthCheckServiceImpl::WatchCallHandler::
+ SendHealth(std::shared_ptr<CallHandler> self, ServingStatus status) {
+ std::unique_lock<std::mutex> lock(send_mu_);
+ // If there's already a send in flight, cache the new status, and
+ // we'll start a new send for it when the one in flight completes.
+ if (send_in_flight_) {
+ pending_status_ = status;
+ return;
+ }
+ // Start a send.
+ SendHealthLocked(std::move(self), status);
+}
+
+void DefaultHealthCheckService::HealthCheckServiceImpl::WatchCallHandler::
+ SendHealthLocked(std::shared_ptr<CallHandler> self, ServingStatus status) {
+ send_in_flight_ = true;
+ // Construct response.
+ ByteBuffer response;
+ bool success = service_->EncodeResponse(status, &response);
+ // Grab shutdown lock and send response.
+ std::unique_lock<std::mutex> cq_lock(service_->cq_shutdown_mu_);
+ if (service_->shutdown_) {
+ SendFinishLocked(std::move(self), Status::CANCELLED);
+ return;
+ }
+ if (!success) {
+ SendFinishLocked(std::move(self),
+ Status(StatusCode::INTERNAL, "could not encode response"));
+ return;
+ }
+ next_ = CallableTag(std::bind(&WatchCallHandler::OnSendHealthDone, this,
+ std::placeholders::_1, std::placeholders::_2),
+ std::move(self));
+ stream_.Write(response, &next_);
+}
+
+void DefaultHealthCheckService::HealthCheckServiceImpl::WatchCallHandler::
+ OnSendHealthDone(std::shared_ptr<CallHandler> self, bool ok) {
+ if (!ok) {
+ SendFinish(std::move(self), Status::CANCELLED);
+ return;
+ }
+ std::unique_lock<std::mutex> lock(send_mu_);
+ send_in_flight_ = false;
+ // If we got a new status since we started the last send, start a
+ // new send for it.
+ if (pending_status_ != NOT_FOUND) {
+ auto status = pending_status_;
+ pending_status_ = NOT_FOUND;
+ SendHealthLocked(std::move(self), status);
+ }
+}
+
+void DefaultHealthCheckService::HealthCheckServiceImpl::WatchCallHandler::
+ SendFinish(std::shared_ptr<CallHandler> self, const Status& status) {
+ if (finish_called_) return;
+ std::unique_lock<std::mutex> cq_lock(service_->cq_shutdown_mu_);
+ if (service_->shutdown_) return;
+ SendFinishLocked(std::move(self), status);
+}
+
+void DefaultHealthCheckService::HealthCheckServiceImpl::WatchCallHandler::
+ SendFinishLocked(std::shared_ptr<CallHandler> self, const Status& status) {
+ on_finish_done_ =
+ CallableTag(std::bind(&WatchCallHandler::OnFinishDone, this,
+ std::placeholders::_1, std::placeholders::_2),
+ std::move(self));
+ stream_.Finish(status, &on_finish_done_);
+ finish_called_ = true;
+}
+
+void DefaultHealthCheckService::HealthCheckServiceImpl::WatchCallHandler::
+ OnFinishDone(std::shared_ptr<CallHandler> self, bool ok) {
+ if (ok) {
+ gpr_log(GPR_DEBUG,
+ "[HCS %p] Health watch call finished (service_name: \"%s\", "
+ "handler: %p).",
+ service_, service_name_.c_str(), this);
+ }
+ self.reset(); // To appease clang-tidy.
+}
+
+// TODO(roth): This method currently assumes that there will be only one
+// thread polling the cq and invoking the corresponding callbacks. If
+// that changes, we will need to add synchronization here.
+void DefaultHealthCheckService::HealthCheckServiceImpl::WatchCallHandler::
+ OnDoneNotified(std::shared_ptr<CallHandler> self, bool ok) {
+ GPR_ASSERT(ok);
+ gpr_log(GPR_DEBUG,
+ "[HCS %p] Health watch call is notified done (handler: %p, "
+ "is_cancelled: %d).",
+ service_, this, static_cast<int>(ctx_.IsCancelled()));
+ database_->UnregisterCallHandler(service_name_, self);
+ SendFinish(std::move(self), Status::CANCELLED);
}
} // namespace grpc
diff --git a/src/cpp/server/health/default_health_check_service.h b/src/cpp/server/health/default_health_check_service.h
index a1ce5aa64e..450bd543f5 100644
--- a/src/cpp/server/health/default_health_check_service.h
+++ b/src/cpp/server/health/default_health_check_service.h
@@ -19,42 +19,260 @@
#ifndef GRPC_INTERNAL_CPP_SERVER_DEFAULT_HEALTH_CHECK_SERVICE_H
#define GRPC_INTERNAL_CPP_SERVER_DEFAULT_HEALTH_CHECK_SERVICE_H
+#include <atomic>
#include <mutex>
+#include <set>
+#include <grpc/support/log.h>
+#include <grpcpp/grpcpp.h>
#include <grpcpp/health_check_service_interface.h>
+#include <grpcpp/impl/codegen/async_generic_service.h>
+#include <grpcpp/impl/codegen/async_unary_call.h>
#include <grpcpp/impl/codegen/service_type.h>
#include <grpcpp/support/byte_buffer.h>
+#include "src/core/lib/gprpp/thd.h"
+
namespace grpc {
// Default implementation of HealthCheckServiceInterface. Server will create and
// own it.
class DefaultHealthCheckService final : public HealthCheckServiceInterface {
public:
+ enum ServingStatus { NOT_FOUND, SERVING, NOT_SERVING };
+
// The service impl to register with the server.
class HealthCheckServiceImpl : public Service {
public:
- explicit HealthCheckServiceImpl(DefaultHealthCheckService* service);
+ // Base class for call handlers.
+ class CallHandler {
+ public:
+ virtual ~CallHandler() = default;
+ virtual void SendHealth(std::shared_ptr<CallHandler> self,
+ ServingStatus status) = 0;
+ };
- Status Check(ServerContext* context, const ByteBuffer* request,
- ByteBuffer* response);
+ HealthCheckServiceImpl(DefaultHealthCheckService* database,
+ std::unique_ptr<ServerCompletionQueue> cq);
+
+ ~HealthCheckServiceImpl();
+
+ void StartServingThread();
private:
- const DefaultHealthCheckService* const service_;
- internal::RpcServiceMethod* method_;
+ // A tag that can be called with a bool argument. It's tailored for
+ // CallHandler's use. Before being used, it should be constructed with a
+ // method of CallHandler and a shared pointer to the handler. The
+ // shared pointer will be moved to the invoked function and the function
+ // can only be invoked once. That makes ref counting of the handler easier,
+ // because the shared pointer is not bound to the function and can be gone
+ // once the invoked function returns (if not used any more).
+ class CallableTag {
+ public:
+ using HandlerFunction =
+ std::function<void(std::shared_ptr<CallHandler>, bool)>;
+
+ CallableTag() {}
+
+ CallableTag(HandlerFunction func, std::shared_ptr<CallHandler> handler)
+ : handler_function_(std::move(func)), handler_(std::move(handler)) {
+ GPR_ASSERT(handler_function_ != nullptr);
+ GPR_ASSERT(handler_ != nullptr);
+ }
+
+ // Runs the tag. This should be called only once. The handler is no
+ // longer owned by this tag after this method is invoked.
+ void Run(bool ok) {
+ GPR_ASSERT(handler_function_ != nullptr);
+ GPR_ASSERT(handler_ != nullptr);
+ handler_function_(std::move(handler_), ok);
+ }
+
+ // Releases and returns the shared pointer to the handler.
+ std::shared_ptr<CallHandler> ReleaseHandler() {
+ return std::move(handler_);
+ }
+
+ private:
+ HandlerFunction handler_function_ = nullptr;
+ std::shared_ptr<CallHandler> handler_;
+ };
+
+ // Call handler for Check method.
+ // Each handler takes care of one call. It contains per-call data and it
+ // will access the members of the parent class (i.e.,
+ // DefaultHealthCheckService) for per-service health data.
+ class CheckCallHandler : public CallHandler {
+ public:
+ // Instantiates a CheckCallHandler and requests the next health check
+ // call. The handler object will manage its own lifetime, so no action is
+ // needed from the caller any more regarding that object.
+ static void CreateAndStart(ServerCompletionQueue* cq,
+ DefaultHealthCheckService* database,
+ HealthCheckServiceImpl* service);
+
+ // This ctor is public because we want to use std::make_shared<> in
+ // CreateAndStart(). This ctor shouldn't be used elsewhere.
+ CheckCallHandler(ServerCompletionQueue* cq,
+ DefaultHealthCheckService* database,
+ HealthCheckServiceImpl* service);
+
+ // Not used for Check.
+ void SendHealth(std::shared_ptr<CallHandler> self,
+ ServingStatus status) override {}
+
+ private:
+ // Called when we receive a call.
+ // Spawns a new handler so that we can keep servicing future calls.
+ void OnCallReceived(std::shared_ptr<CallHandler> self, bool ok);
+
+ // Called when Finish() is done.
+ void OnFinishDone(std::shared_ptr<CallHandler> self, bool ok);
+
+ // The members passed down from HealthCheckServiceImpl.
+ ServerCompletionQueue* cq_;
+ DefaultHealthCheckService* database_;
+ HealthCheckServiceImpl* service_;
+
+ ByteBuffer request_;
+ GenericServerAsyncResponseWriter writer_;
+ ServerContext ctx_;
+
+ CallableTag next_;
+ };
+
+ // Call handler for Watch method.
+ // Each handler takes care of one call. It contains per-call data and it
+ // will access the members of the parent class (i.e.,
+ // DefaultHealthCheckService) for per-service health data.
+ class WatchCallHandler : public CallHandler {
+ public:
+ // Instantiates a WatchCallHandler and requests the next health check
+ // call. The handler object will manage its own lifetime, so no action is
+ // needed from the caller any more regarding that object.
+ static void CreateAndStart(ServerCompletionQueue* cq,
+ DefaultHealthCheckService* database,
+ HealthCheckServiceImpl* service);
+
+ // This ctor is public because we want to use std::make_shared<> in
+ // CreateAndStart(). This ctor shouldn't be used elsewhere.
+ WatchCallHandler(ServerCompletionQueue* cq,
+ DefaultHealthCheckService* database,
+ HealthCheckServiceImpl* service);
+
+ void SendHealth(std::shared_ptr<CallHandler> self,
+ ServingStatus status) override;
+
+ private:
+ // Called when we receive a call.
+ // Spawns a new handler so that we can keep servicing future calls.
+ void OnCallReceived(std::shared_ptr<CallHandler> self, bool ok);
+
+ // Requires holding send_mu_.
+ void SendHealthLocked(std::shared_ptr<CallHandler> self,
+ ServingStatus status);
+
+ // When sending a health result finishes.
+ void OnSendHealthDone(std::shared_ptr<CallHandler> self, bool ok);
+
+ void SendFinish(std::shared_ptr<CallHandler> self, const Status& status);
+
+ // Requires holding service_->cq_shutdown_mu_.
+ void SendFinishLocked(std::shared_ptr<CallHandler> self,
+ const Status& status);
+
+ // Called when Finish() is done.
+ void OnFinishDone(std::shared_ptr<CallHandler> self, bool ok);
+
+ // Called when AsyncNotifyWhenDone() notifies us.
+ void OnDoneNotified(std::shared_ptr<CallHandler> self, bool ok);
+
+ // The members passed down from HealthCheckServiceImpl.
+ ServerCompletionQueue* cq_;
+ DefaultHealthCheckService* database_;
+ HealthCheckServiceImpl* service_;
+
+ ByteBuffer request_;
+ grpc::string service_name_;
+ GenericServerAsyncWriter stream_;
+ ServerContext ctx_;
+
+ std::mutex send_mu_;
+ bool send_in_flight_ = false; // Guarded by mu_.
+ ServingStatus pending_status_ = NOT_FOUND; // Guarded by mu_.
+
+ bool finish_called_ = false;
+ CallableTag next_;
+ CallableTag on_done_notified_;
+ CallableTag on_finish_done_;
+ };
+
+ // Handles the incoming requests and drives the completion queue in a loop.
+ static void Serve(void* arg);
+
+ // Returns true on success.
+ static bool DecodeRequest(const ByteBuffer& request,
+ grpc::string* service_name);
+ static bool EncodeResponse(ServingStatus status, ByteBuffer* response);
+
+ // Needed to appease Windows compilers, which don't seem to allow
+ // nested classes to access protected members in the parent's
+ // superclass.
+ using Service::RequestAsyncServerStreaming;
+ using Service::RequestAsyncUnary;
+
+ DefaultHealthCheckService* database_;
+ std::unique_ptr<ServerCompletionQueue> cq_;
+
+ // To synchronize the operations related to shutdown state of cq_, so that
+ // we don't enqueue new tags into cq_ after it is already shut down.
+ std::mutex cq_shutdown_mu_;
+ std::atomic_bool shutdown_{false};
+ std::unique_ptr<::grpc_core::Thread> thread_;
};
DefaultHealthCheckService();
+
void SetServingStatus(const grpc::string& service_name,
bool serving) override;
void SetServingStatus(bool serving) override;
- enum ServingStatus { NOT_FOUND, SERVING, NOT_SERVING };
+
ServingStatus GetServingStatus(const grpc::string& service_name) const;
- HealthCheckServiceImpl* GetHealthCheckService();
+
+ HealthCheckServiceImpl* GetHealthCheckService(
+ std::unique_ptr<ServerCompletionQueue> cq);
private:
+ // Stores the current serving status of a service and any call
+ // handlers registered for updates when the service's status changes.
+ class ServiceData {
+ public:
+ void SetServingStatus(ServingStatus status);
+ ServingStatus GetServingStatus() const { return status_; }
+ void AddCallHandler(
+ std::shared_ptr<HealthCheckServiceImpl::CallHandler> handler);
+ void RemoveCallHandler(
+ const std::shared_ptr<HealthCheckServiceImpl::CallHandler>& handler);
+ bool Unused() const {
+ return call_handlers_.empty() && status_ == NOT_FOUND;
+ }
+
+ private:
+ ServingStatus status_ = NOT_FOUND;
+ std::set<std::shared_ptr<HealthCheckServiceImpl::CallHandler>>
+ call_handlers_;
+ };
+
+ void RegisterCallHandler(
+ const grpc::string& service_name,
+ std::shared_ptr<HealthCheckServiceImpl::CallHandler> handler);
+
+ void UnregisterCallHandler(
+ const grpc::string& service_name,
+ const std::shared_ptr<HealthCheckServiceImpl::CallHandler>& handler);
+
mutable std::mutex mu_;
- std::map<grpc::string, bool> services_map_;
+ std::map<grpc::string, ServiceData> services_map_; // Guarded by mu_.
std::unique_ptr<HealthCheckServiceImpl> impl_;
};
diff --git a/src/cpp/server/health/health.pb.c b/src/cpp/server/health/health.pb.c
deleted file mode 100644
index 09bd98a3d9..0000000000
--- a/src/cpp/server/health/health.pb.c
+++ /dev/null
@@ -1,24 +0,0 @@
-/* Automatically generated nanopb constant definitions */
-/* Generated by nanopb-0.3.7-dev */
-
-#include "src/cpp/server/health/health.pb.h"
-
-/* @@protoc_insertion_point(includes) */
-#if PB_PROTO_HEADER_VERSION != 30
-#error Regenerate this file with the current version of nanopb generator.
-#endif
-
-
-
-const pb_field_t grpc_health_v1_HealthCheckRequest_fields[2] = {
- PB_FIELD( 1, STRING , OPTIONAL, STATIC , FIRST, grpc_health_v1_HealthCheckRequest, service, service, 0),
- PB_LAST_FIELD
-};
-
-const pb_field_t grpc_health_v1_HealthCheckResponse_fields[2] = {
- PB_FIELD( 1, UENUM , OPTIONAL, STATIC , FIRST, grpc_health_v1_HealthCheckResponse, status, status, 0),
- PB_LAST_FIELD
-};
-
-
-/* @@protoc_insertion_point(eof) */
diff --git a/src/cpp/server/health/health.pb.h b/src/cpp/server/health/health.pb.h
deleted file mode 100644
index 29e1f3bacb..0000000000
--- a/src/cpp/server/health/health.pb.h
+++ /dev/null
@@ -1,72 +0,0 @@
-/* Automatically generated nanopb header */
-/* Generated by nanopb-0.3.7-dev */
-
-#ifndef PB_GRPC_HEALTH_V1_HEALTH_PB_H_INCLUDED
-#define PB_GRPC_HEALTH_V1_HEALTH_PB_H_INCLUDED
-#include "pb.h"
-/* @@protoc_insertion_point(includes) */
-#if PB_PROTO_HEADER_VERSION != 30
-#error Regenerate this file with the current version of nanopb generator.
-#endif
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/* Enum definitions */
-typedef enum _grpc_health_v1_HealthCheckResponse_ServingStatus {
- grpc_health_v1_HealthCheckResponse_ServingStatus_UNKNOWN = 0,
- grpc_health_v1_HealthCheckResponse_ServingStatus_SERVING = 1,
- grpc_health_v1_HealthCheckResponse_ServingStatus_NOT_SERVING = 2
-} grpc_health_v1_HealthCheckResponse_ServingStatus;
-#define _grpc_health_v1_HealthCheckResponse_ServingStatus_MIN grpc_health_v1_HealthCheckResponse_ServingStatus_UNKNOWN
-#define _grpc_health_v1_HealthCheckResponse_ServingStatus_MAX grpc_health_v1_HealthCheckResponse_ServingStatus_NOT_SERVING
-#define _grpc_health_v1_HealthCheckResponse_ServingStatus_ARRAYSIZE ((grpc_health_v1_HealthCheckResponse_ServingStatus)(grpc_health_v1_HealthCheckResponse_ServingStatus_NOT_SERVING+1))
-
-/* Struct definitions */
-typedef struct _grpc_health_v1_HealthCheckRequest {
- bool has_service;
- char service[200];
-/* @@protoc_insertion_point(struct:grpc_health_v1_HealthCheckRequest) */
-} grpc_health_v1_HealthCheckRequest;
-
-typedef struct _grpc_health_v1_HealthCheckResponse {
- bool has_status;
- grpc_health_v1_HealthCheckResponse_ServingStatus status;
-/* @@protoc_insertion_point(struct:grpc_health_v1_HealthCheckResponse) */
-} grpc_health_v1_HealthCheckResponse;
-
-/* Default values for struct fields */
-
-/* Initializer values for message structs */
-#define grpc_health_v1_HealthCheckRequest_init_default {false, ""}
-#define grpc_health_v1_HealthCheckResponse_init_default {false, (grpc_health_v1_HealthCheckResponse_ServingStatus)0}
-#define grpc_health_v1_HealthCheckRequest_init_zero {false, ""}
-#define grpc_health_v1_HealthCheckResponse_init_zero {false, (grpc_health_v1_HealthCheckResponse_ServingStatus)0}
-
-/* Field tags (for use in manual encoding/decoding) */
-#define grpc_health_v1_HealthCheckRequest_service_tag 1
-#define grpc_health_v1_HealthCheckResponse_status_tag 1
-
-/* Struct field encoding specification for nanopb */
-extern const pb_field_t grpc_health_v1_HealthCheckRequest_fields[2];
-extern const pb_field_t grpc_health_v1_HealthCheckResponse_fields[2];
-
-/* Maximum encoded size of messages (where known) */
-#define grpc_health_v1_HealthCheckRequest_size 203
-#define grpc_health_v1_HealthCheckResponse_size 2
-
-/* Message IDs (where set with "msgid" option) */
-#ifdef PB_MSGID
-
-#define HEALTH_MESSAGES \
-
-
-#endif
-
-#ifdef __cplusplus
-} /* extern "C" */
-#endif
-/* @@protoc_insertion_point(eof) */
-
-#endif