fix: grpc service must be registered and grpc context state must be handled for threads

Signed-off-by: Leonardo Di Donato <leodidonato@gmail.com>

userspace/falco/grpc_server.cpp

@@ -16,16 +16,14 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-#include <iostream>
-
 #ifdef GRPC_INCLUDE_IS_GRPCPP
 #include <grpcpp/grpcpp.h>
 #else
 #include <grpc++/grpc++.h>
 #endif
-
 #include <unistd.h> // sleep
 
+#include "logger.h"
 #include "grpc_server.h"
 #include "grpc_context.h"
 
@@ -100,7 +98,10 @@ void request_stream_context<falco_output_request, falco_output_response>::end(fa
 
 bool falco_grpc_server_impl::is_running()
 {
-	// TODO: this must act as a switch to shut down the server
+	if(m_stop)
+	{
+		return false;
+	}
 	return true;
 }
 
@@ -115,15 +116,14 @@ void falco_grpc_server_impl::subscribe(const stream_context& ctx, const falco_ou
 	else
 	{
 		// Start (or continue) streaming
-
 		// ctx.m_status == stream_context::STREAMING
 
 		// todo > do we want batching?
-
+		sleep(15);
 		res.set_source(source::SYSCALL);
-		res.set_rule("regola 1");
+		res.set_rule("rule X");
 
-		ctx.m_has_more = false;
+		ctx.m_has_more = true;
 	}
 	// todo > print/store statistics
 }
@@ -144,10 +144,46 @@ void falco_grpc_server::thread_process(int thread_index)
 	{
 		if(tag == nullptr)
 		{
-			// TODO: empty tag returned, log, what to do?
+			// TODO: empty tag returned, log "completion queue with empty tag"
 			continue;
 		}
+
+		// Obtain the context for a given tag
+		request_context_base* ctx = static_cast<request_context_base*>(tag);
+
+		// When event has not been read successfully
+		if(!event_read_success)
+		{
+			if(ctx->m_state != request_context_base::REQUEST)
+			{
+				// todo > log "server completion queue failed to read event for tag `tag`"
+				// End the context with error
+				ctx->end(this, true);
+			}
+			continue;
+		}
+
+		// Process the event
+		switch(ctx->m_state)
+		{
+		case request_context_base::REQUEST:
+			// Completion of m_request_func
+		case request_context_base::WRITE:
+			// Completion of ServerAsyncWriter::Write()
+			ctx->process(this);
+			break;
+		case request_context_base::FINISH:
+			// Completion of ServerAsyncWriter::Finish()
+			ctx->end(this, false);
+
+		default:
+			// todo > log "unkown completion queue event"
+			// todo > abort?
+			break;
+		}
 	}
+
+	// todo > log "thread `thread_index` complete"
 }
 
 //
@@ -164,16 +200,19 @@ void falco_grpc_server::thread_process(int thread_index)
 
 void falco_grpc_server::run()
 {
+	// Setup server
 	grpc::ServerBuilder builder;
 	// Listen on the given address without any authentication mechanism.
 	builder.AddListeningPort(m_server_addr, grpc::InsecureServerCredentials());
-	// builder.RegisterService(&falco_output_svc); // TODO: enable this when we do the impl
+	builder.RegisterService(&m_svc);
+	// builder.SetMaxSendMessageSize(GRPC_MAX_MESSAGE_SIZE);     // testing max message size?
+	// builder.SetMaxReceiveMessageSize(GRPC_MAX_MESSAGE_SIZE);  // testing max message size?
 
 	m_completion_queue = builder.AddCompletionQueue();
 	m_server = builder.BuildAndStart();
-	std::cout << "Server listening on " << m_server_addr << std::endl;
+	falco_logger::log(LOG_INFO, "Starting gRPC webserver at " + m_server_addr + "\n");
 
-	int context_count = m_threadiness * 10;
+	int context_count = m_threadiness * 1; // todo > 10 or 100?
 	PROCESS_STREAM(falco_output_request, falco_output_response, subscribe, subscribe, context_count)
 
 	m_threads.resize(m_threadiness);

userspace/falco/grpc_server.h

@@ -20,6 +20,7 @@ limitations under the License.
 
 #include <thread>
 #include <string>
+#include <atomic>
 
 #include "falco_output.grpc.pb.h"
 #include "falco_output.pb.h"
@@ -35,6 +36,9 @@ protected:
 	bool is_running();
 
 	void subscribe(const stream_context& ctx, const falco_output_request& req, falco_output_response& res);
+
+private:
+	std::atomic<bool> m_stop{false};
 };
 
 class falco_grpc_server : public falco_grpc_server_impl