Revert "Merge pull request #16600 from grpc/revert-16574-health_checking_service"

This reverts commit de11358660b6474ffea480d8d756c23e58a7cf07, reversing
changes made to 107d10ea73f77dc9bb498c9b91e1fcd0188dfb45.

1 files changed, 19 insertions, 8 deletions

diff --git a/src/cpp/server/server_cc.cc b/src/cpp/server/server_cc.cc
index 36f7eb81f9..bf612d2d24 100644
--- a/src/cpp/server/server_cc.cc
+++ b/src/cpp/server/server_cc.cc
@@ -559,16 +559,20 @@ void Server::Start(ServerCompletionQueue** cqs, size_t num_cqs) {
 
   // Only create default health check service when user did not provide an
   // explicit one.
+  ServerCompletionQueue* health_check_cq = nullptr;
+  DefaultHealthCheckService::HealthCheckServiceImpl*
+      default_health_check_service_impl = nullptr;
   if (health_check_service_ == nullptr && !health_check_service_disabled_ &&
       DefaultHealthCheckServiceEnabled()) {
-    if (sync_server_cqs_ == nullptr || sync_server_cqs_->empty()) {
-      gpr_log(GPR_INFO,
-              "Default health check service disabled at async-only server.");
-    } else {
-      auto* default_hc_service = new DefaultHealthCheckService;
-      health_check_service_.reset(default_hc_service);
-      RegisterService(nullptr, default_hc_service->GetHealthCheckService());
-    }
+    auto* default_hc_service = new DefaultHealthCheckService;
+    health_check_service_.reset(default_hc_service);
+    health_check_cq = new ServerCompletionQueue(GRPC_CQ_DEFAULT_POLLING);
+    grpc_server_register_completion_queue(server_, health_check_cq->cq(),
+                                          nullptr);
+    default_health_check_service_impl =
+        default_hc_service->GetHealthCheckService(
+            std::unique_ptr<ServerCompletionQueue>(health_check_cq));
+    RegisterService(nullptr, default_health_check_service_impl);
   }
 
   grpc_server_start(server_);
@@ -583,6 +587,9 @@ void Server::Start(ServerCompletionQueue** cqs, size_t num_cqs) {
         new UnimplementedAsyncRequest(this, cqs[i]);
       }
     }
+    if (health_check_cq != nullptr) {
+      new UnimplementedAsyncRequest(this, health_check_cq);
+    }
   }
 
   // If this server has any support for synchronous methods (has any sync
@@ -595,6 +602,10 @@ void Server::Start(ServerCompletionQueue** cqs, size_t num_cqs) {
   for (auto it = sync_req_mgrs_.begin(); it != sync_req_mgrs_.end(); it++) {
     (*it)->Start();
   }
+
+  if (default_health_check_service_impl != nullptr) {
+    default_health_check_service_impl->StartServingThread();
+  }
 }
 
 void Server::ShutdownInternal(gpr_timespec deadline) {