X-Git-Url: https://git.sesse.net/?p=cubemap;a=blobdiff_plain;f=server.cpp;h=079b629dcaa9b601b31033c3a4c55626711f7662;hp=6fa4991b209f389da7f940aa73ff9462f472b8cd;hb=ce7802e5d5291c414883efbad93a9d165c03f40c;hpb=0e96bbf9ee0fbebd5fe3fba4d186c0e0d73c9a32

diff --git a/server.cpp b/server.cpp
index 6fa4991..079b629 100644
--- a/server.cpp
+++ b/server.cpp
@@ -35,6 +35,23 @@ using namespace std;
 
 extern AccessLogThread *access_log;
 
+namespace {
+
+inline bool is_equal(timespec a, timespec b)
+{
+	return a.tv_sec == b.tv_sec &&
+	       a.tv_nsec == b.tv_nsec;
+}
+
+inline bool is_earlier(timespec a, timespec b)
+{
+	if (a.tv_sec != b.tv_sec)
+		return a.tv_sec < b.tv_sec;
+	return a.tv_nsec < b.tv_nsec;
+}
+
+}  // namespace
+
 Server::Server()
 {
 	pthread_mutex_init(&mutex, NULL);
@@ -90,6 +107,7 @@ void Server::do_work()
 	
 		process_queued_data();
 
+		// Process each client where we have socket activity.
 		for (int i = 0; i < nfds; ++i) {
 			Client *client = reinterpret_cast<Client *>(events[i].data.u64);
 
@@ -101,6 +119,8 @@ void Server::do_work()
 			process_client(client);
 		}
 
+		// Process each client where its stream has new data,
+		// even if there was no socket activity.
 		for (size_t i = 0; i < streams.size(); ++i) {	
 			vector<Client *> to_process;
 			swap(streams[i]->to_process, to_process);
@@ -108,6 +128,49 @@ void Server::do_work()
 				process_client(to_process[i]);
 			}
 		}
+
+		// Finally, go through each client to see if it's timed out
+		// in the READING_REQUEST state. (Seemingly there are clients
+		// that can hold sockets up for days at a time without sending
+		// anything at all.)
+		timespec timeout_time;
+		if (clock_gettime(CLOCK_MONOTONIC_COARSE, &timeout_time) == -1) {
+			log_perror("clock_gettime(CLOCK_MONOTONIC_COARSE)");
+			continue;
+		}
+		timeout_time.tv_sec -= REQUEST_READ_TIMEOUT_SEC;
+		while (!clients_ordered_by_connect_time.empty()) {
+			pair<timespec, int> &connect_time_and_fd = clients_ordered_by_connect_time.front();
+
+			// See if we have reached the end of clients to process.
+			if (is_earlier(timeout_time, connect_time_and_fd.first)) {
+				break;
+			}
+
+			// If this client doesn't exist anymore, just ignore it
+			// (it was deleted earlier).
+			std::map<int, Client>::iterator client_it = clients.find(connect_time_and_fd.second);
+			if (client_it == clients.end()) {
+				clients_ordered_by_connect_time.pop();
+				continue;
+			}
+			Client *client = &client_it->second;
+			if (!is_equal(client->connect_time, connect_time_and_fd.first)) {
+				// Another client has taken this fd in the meantime.
+				clients_ordered_by_connect_time.pop();
+				continue;
+			}
+
+			if (client->state != Client::READING_REQUEST) {
+				// Only READING_REQUEST can time out.
+				clients_ordered_by_connect_time.pop();
+				continue;
+			}
+
+			// OK, it timed out.
+			close_client(client);
+			clients_ordered_by_connect_time.pop();
+		}
 	}
 }
 
@@ -154,6 +217,17 @@ void Server::add_client(int sock)
 	assert(ret.second == true);  // Should not already exist.
 	Client *client_ptr = &ret.first->second;
 
+	// Connection timestamps must be nondecreasing. I can't find any guarantee
+	// that even the monotonic clock can't go backwards by a small amount
+	// (think switching between CPUs with non-synchronized TSCs), so if
+	// this actually should happen, we hack around it by fudging
+	// connect_time.
+	if (!clients_ordered_by_connect_time.empty() &&
+	    is_earlier(client_ptr->connect_time, clients_ordered_by_connect_time.back().first)) {
+		client_ptr->connect_time = clients_ordered_by_connect_time.back().first;
+	}
+	clients_ordered_by_connect_time.push(make_pair(client_ptr->connect_time, sock));
+
 	// Start listening on data from this socket.
 	epoll_event ev;
 	ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
@@ -182,6 +256,11 @@ void Server::add_client_from_serialized(const ClientProto &client)
 	assert(ret.second == true);  // Should not already exist.
 	Client *client_ptr = &ret.first->second;
 
+	// Connection timestamps must be nondecreasing.
+	assert(clients_ordered_by_connect_time.empty() ||
+	       !is_earlier(client_ptr->connect_time, clients_ordered_by_connect_time.back().first));
+	clients_ordered_by_connect_time.push(make_pair(client_ptr->connect_time, client.sock()));
+
 	// Start listening on data from this socket.
 	epoll_event ev;
 	if (client.state() == Client::READING_REQUEST) {