fail/src/core/efw/JobClient.cc

#include "JobClient.hpp"

using namespace std;

namespace fail {

JobClient::JobClient(const std::string& server, int port)
{
	m_server_port = port;
	m_server = server;
	m_server_ent = gethostbyname(m_server.c_str());
	if(m_server_ent == NULL) {
		perror("[Client@gethostbyname()]");
		// TODO: Log-level?
		exit(1);
	}
	srand(time(NULL)); // needed for random backoff (see connectToServer)
	m_server_runid = 0; // server accepts this for virgin clients
	m_job_throughput = 1; // client gets only one job at the first request
}

bool JobClient::connectToServer()
{
	// Connect to server
	struct sockaddr_in serv_addr;
	m_sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if(m_sockfd < 0) {
		perror("[Client@socket()]");
		// TODO: Log-level?
		exit(0);
	}

	/* Enable address reuse */
	int on = 1;
	setsockopt( m_sockfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on) );
	
	memset(&serv_addr, 0, sizeof(serv_addr));
	serv_addr.sin_family = AF_INET;
	memcpy(&serv_addr.sin_addr.s_addr, m_server_ent->h_addr, m_server_ent->h_length);
	serv_addr.sin_port = htons(m_server_port);
	
	int retries = CLIENT_RETRY_COUNT;
	while (true) {
		if (connect(m_sockfd, (sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
			perror("[Client@connect()]");
			// TODO: Log-level?
			if (retries > 0) {
				// Wait CLIENT_RAND_BACKOFF_TSTART to RAND_BACKOFF_TEND seconds:
				int delay = rand() % (CLIENT_RAND_BACKOFF_TEND-CLIENT_RAND_BACKOFF_TSTART) + CLIENT_RAND_BACKOFF_TSTART;
				cout << "[Client] Retrying to connect to server in ~" << delay << "s..." << endl;
				// TODO: Log-level?
				sleep(delay);
				usleep(rand() % 1000000);
				--retries;
				continue;
			}
			cout << "[Client] Unable to reconnect (tried " << CLIENT_RETRY_COUNT << " times); "
			     << "I'll give it up!" << endl;
			     // TODO: Log-level?
			return false; // finally: unable to connect, give it up :-(
		}
		break; // connected! :-)
	}
	cout << "[Client] Connection established!" << endl;
	// TODO: Log-level?

	return true;
}

bool JobClient::getParam(ExperimentData& exp)
{
	while (1) { // Here we try to acquire a parameter set
		switch (tryToGetExperimentData(exp)) {
			// Jobserver will sent workload, params are set in \c exp
		case FailControlMessage::WORK_FOLLOWS: 
			return true;
			// Nothing to do right now, but maybe later
		case FailControlMessage::COME_AGAIN:
			sleep(1);
			continue;
		default:
			return false;
		}
	}
}

FailControlMessage_Command JobClient::tryToGetExperimentData(ExperimentData& exp)
{
	//Are there other jobs for the experiment
	if (m_parameters.size() != 0) {
		exp.getMessage().CopyFrom(m_parameters.front()->getMessage());
		exp.setWorkloadID(m_parameters.front()->getWorkloadID());
		
		delete &m_parameters.front()->getMessage();
		delete m_parameters.front();
		m_parameters.erase(m_parameters.begin());
		
		return FailControlMessage::WORK_FOLLOWS;
	} else {
		FailControlMessage ctrlmsg;

		// Connection failed, minion can die
		if (!connectToServer()) {
			return FailControlMessage::DIE;
		}

		// Retrieve ExperimentData
		ctrlmsg.set_command(FailControlMessage::NEED_WORK);
		ctrlmsg.set_build_id(42);
		ctrlmsg.set_run_id(m_server_runid);
		ctrlmsg.set_job_size(m_job_throughput); //Request for a number of jobs

		if (!SocketComm::sendMsg(m_sockfd, ctrlmsg)) {
			// Failed to send message?  Retry.
			close(m_sockfd);
			return FailControlMessage::COME_AGAIN;
		}
		ctrlmsg.Clear();
		if (!SocketComm::rcvMsg(m_sockfd, ctrlmsg)) {
			// Failed to receive message?  Retry.
			close(m_sockfd);
			return FailControlMessage::COME_AGAIN;
		}

		// now we know the current run ID
		m_server_runid = ctrlmsg.run_id();

		switch (ctrlmsg.command()) {
		case FailControlMessage::WORK_FOLLOWS:
			uint32_t i;
			for (i = 0 ; i < ctrlmsg.job_size() ; i++) {
				ExperimentData* temp_exp = new ExperimentData(exp.getMessage().New());
				
				if (!SocketComm::rcvMsg(m_sockfd, temp_exp->getMessage())) {
					// Failed to receive message?  Retry.
					close(m_sockfd);
					return FailControlMessage::COME_AGAIN;
				}

				temp_exp->setWorkloadID(ctrlmsg.workloadid(i)); //Store workload id of experiment data
				m_parameters.push_back(temp_exp);
			}
			break;
		case FailControlMessage::COME_AGAIN:
			break;
		default:
			break;  
		}
		
		close(m_sockfd);
		//Take front from m_parameters and copy to exp.
		exp.getMessage().CopyFrom(m_parameters.front()->getMessage());
		exp.setWorkloadID(m_parameters.front()->getWorkloadID());
		//Delete front element of m_parameters
		delete &m_parameters.front()->getMessage();
		delete m_parameters.front();
		m_parameters.erase(m_parameters.begin());
		//start time measurement for throughput calculation
		m_job_runtime.startTimer();
		
		return ctrlmsg.command();
	}
}

bool JobClient::sendResult(ExperimentData& result)
{
	//Create new ExperimentData for result
	ExperimentData* temp_exp = new ExperimentData(result.getMessage().New());
	temp_exp->getMessage().CopyFrom(result.getMessage());
	temp_exp->setWorkloadID(result.getWorkloadID());
	
	if (m_parameters.size() != 0) {
		//If there are more jobs for the experiment store result
		m_results.push_back( temp_exp );
		
		return true;
	} else {
		m_results.push_back( temp_exp );
		
		//Stop time measurement and calculate new throughput 
		m_job_runtime.stopTimer();
		m_job_throughput = CLIENT_JOB_REQUEST_SEC/((double)m_job_runtime/m_results.size());
		
		if (m_job_throughput > CLIENT_JOB_LIMIT_SEC)
			m_job_throughput = CLIENT_JOB_LIMIT_SEC;
			
		if (m_job_throughput < 1)
			m_job_throughput = 1;
		
		//Reset timer for new time measurement
		m_job_runtime.reset();
		
		if (!connectToServer())
			return false;

		//Send back results
		FailControlMessage ctrlmsg;
		ctrlmsg.set_command(FailControlMessage::RESULT_FOLLOWS);
		ctrlmsg.set_build_id(42);
		ctrlmsg.set_run_id(m_server_runid);
		ctrlmsg.set_job_size(m_results.size()); //Store how many results will be sent
		
		cout << "[Client] Sending back result [";
		
		uint32_t i;
		for (i = 0; i < m_results.size() ; i++) {
			ctrlmsg.add_workloadid(m_results[i]->getWorkloadID());
			cout << std::dec << m_results[i]->getWorkloadID();
			cout << " ";
		}
		cout << "]";
		
		// TODO: Log-level?
		SocketComm::sendMsg(m_sockfd, ctrlmsg);
		
		for (i = 0; i < ctrlmsg.job_size() ; i++) {
			SocketComm::sendMsg(m_sockfd, m_results.front()->getMessage());
			delete &m_results.front()->getMessage();
			delete m_results.front();
			m_results.erase(m_results.begin());
		}

		// Close connection.
		close(m_sockfd);
		return true;
	}
}

} // end-of-namespace: fail