fix(userspace/falco): grpc server implementation subscribe handle output queue stop

Signed-off-by: Lorenzo Fontana <lo@linux.com>

userspace/falco/grpc_server.cpp

@@ -21,7 +21,6 @@ limitations under the License.
 #else
 #include <grpc++/grpc++.h>
 #endif
-#include <signal.h> // pthread_sigmask
 
 #include "logger.h"
 #include "grpc_server.h"
@@ -36,7 +35,6 @@ void request_stream_context<request, response>::start(falco_grpc_server* srv)
 	m_res_writer.reset(new grpc::ServerAsyncWriter<response>(srvctx));
 	m_stream_ctx.reset();
 	m_req.Clear();
-
 	auto cq = srv->m_completion_queue.get();
 	(srv->m_svc.*m_request_func)(srvctx, &m_req, m_res_writer.get(), cq, cq, this);
 }
@@ -71,40 +69,22 @@ void request_stream_context<request, response>::process(falco_grpc_server* srv)
 }
 
 template<>
-void request_stream_context<request, response>::end(falco_grpc_server* srv, bool isError)
+void request_stream_context<request, response>::end(falco_grpc_server* srv, bool errored)
 {
 	if(m_stream_ctx)
 	{
-		m_stream_ctx->m_status = stream_context::SUCCESS;
-		if(isError)
-		{
-			m_stream_ctx->m_status = stream_context::ERROR;
-			// todo > log error
-		}
+		m_stream_ctx->m_status = errored ? stream_context::ERROR : stream_context::SUCCESS;
 
 		// Complete the processing
 		response res;
 		(srv->*m_process_func)(*m_stream_ctx, m_req, res); // subscribe()
 	}
-	else
-	{
-		// Handle the edge case when `m_request_func` event failed
-		// which means `m_stream_ctx` was not set
-		// todo > log error
-	}
 
 	start(srv);
 }
 
 void falco_grpc_server::thread_process(int thread_index)
 {
-	// Tell pthread to not handle termination signals in the current thread
-	sigset_t set;
-	sigemptyset(&set);
-	sigaddset(&set, SIGTERM);
-	// sigaddset(&set, SIGHUP); // todo > SIGHUP should restart Falco, what to do?
-	sigaddset(&set, SIGINT);
-	pthread_sigmask(SIG_BLOCK, &set, nullptr);
 
 	void* tag = nullptr;
 	bool event_read_success = false;
@@ -143,15 +123,13 @@ void falco_grpc_server::thread_process(int thread_index)
 		case request_context_base::FINISH:
 			// Completion of ServerAsyncWriter::Finish()
 			ctx->end(this, false);
-
+			break;
 		default:
 			// todo > log "unkown completion queue event"
 			// todo > abort?
 			break;
 		}
 	}
-
-	// todo > log "thread `thread_index` complete"
 }
 
 //
@@ -240,32 +218,36 @@ void falco_grpc_server::run()
 		thread = std::thread(&falco_grpc_server::thread_process, this, thread_idx++);
 	}
 
-	while(is_running())
+	while(falco_grpc_server_impl::is_running())
 	{
+		sleep(1);
 	}
-
 	stop();
 }
 
 void falco_grpc_server::stop()
 {
+	falco_logger::log(LOG_INFO, "Shutting down gRPC server. Waiting until external connections are closed by clients\n");
 	m_server->Shutdown();
 	m_completion_queue->Shutdown();
 
-	// todo > log "waiting for the server threads to complete"
-
+	falco_logger::log(LOG_INFO, "Waiting for the gRPC threads to complete\n");
 	for(std::thread& t : m_threads)
 	{
-		t.join();
+		if(t.joinable())
+		{
+			t.join();
+		}
 	}
 	m_threads.clear();
 
-	// todo > log "all server threads complete"
-
+	falco_logger::log(LOG_INFO, "Ignoring all the remaining gRPC events\n");
 	// Ignore remaining events
 	void* ignore_tag = nullptr;
 	bool ignore_ok = false;
 	while(m_completion_queue->Next(&ignore_tag, &ignore_ok))
 	{
 	}
+
+	falco_logger::log(LOG_INFO, "gRPC shutdown is now complete\n");
 }

userspace/falco/grpc_server.h

@@ -21,8 +21,6 @@ limitations under the License.
 #include <thread>
 #include <string>
 
-#include <queue>
-
 #include "grpc_server_impl.h"
 
 class falco_grpc_server : public falco_grpc_server_impl

userspace/falco/grpc_server_impl.cpp

@@ -44,15 +44,15 @@ void falco_grpc_server_impl::subscribe(const stream_context& ctx, const request&
 			ctx.m_has_more = true;
 			return;
 		}
-		while(!falco_output_queue::get().try_pop(res) && req.keepalive())
+		while(is_running() && !falco_output_queue::get().try_pop(res) && req.keepalive())
 		{
 		}
 
-		ctx.m_has_more = req.keepalive();
+		ctx.m_has_more = !is_running() ? false : req.keepalive();
 	}
 }
 
 void falco_grpc_server_impl::shutdown()
 {
 	m_stop = true;
-}
+}

userspace/falco/grpc_server_impl.h

@@ -41,4 +41,4 @@ protected:
 
 private:
 	std::atomic<bool> m_stop{false};
-};
+};