From 4971ba0e48d77b075fc972c13ec2978aa93630a1 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Sat, 6 Apr 2013 18:08:51 +0200
Subject: [PATCH] Implement sleeping/waking clients.

---
 server.cpp | 43 ++++++++++++++++++++++++++++++++++++++-----
 server.h   | 31 ++++++++++++++++++++++---------
 2 files changed, 60 insertions(+), 14 deletions(-)

diff --git a/server.cpp b/server.cpp
index 9b91e03..b914b2e 100644
--- a/server.cpp
+++ b/server.cpp
@@ -107,6 +107,10 @@ void Server::set_header(const string &stream_id, const string &header)
 	
 void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 {
+	if (bytes == 0) {
+		return;
+	}
+
 	MutexLock lock(&mutex);
 	assert(streams.count(stream_id) != 0);
 	Stream *stream = &streams[stream_id];
@@ -122,8 +126,7 @@ void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 	}
 
 	memcpy(stream->data + pos, data, bytes);
-
-	// TODO: wake up clients
+	wake_up_all_clients();
 }
 	
 void Server::process_client(Client *client)
@@ -231,10 +234,12 @@ void Server::process_client(Client *client)
 			close_client(client);
 			return;
 		}
-		client->bytes_sent += ret;	
-
-		// TODO: put clients to sleep
+		client->bytes_sent += ret;
 
+		if (client->bytes_sent == stream.data_size) {
+			// We don't have any more data for this client, so put it to sleep.
+			put_client_to_sleep(client);
+		}
 		break;
 	}
 	default:
@@ -276,3 +281,31 @@ void Server::close_client(Client *client)
 	close(client->sock);
 	clients.erase(client->sock);
 }
+	
+void Server::put_client_to_sleep(Client *client)
+{
+	epoll_event ev;
+	ev.events = EPOLLRDHUP;
+	ev.data.fd = client->sock;
+
+	if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
+		perror("epoll_ctl(EPOLL_CTL_MOD)");
+		exit(1);
+	}
+
+	sleeping_clients.push_back(client->sock);
+}
+
+void Server::wake_up_all_clients()
+{
+	for (unsigned i = 0; i < sleeping_clients.size(); ++i) {
+		epoll_event ev;
+		ev.events = EPOLLOUT | EPOLLRDHUP;
+		ev.data.fd = sleeping_clients[i];
+		if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, sleeping_clients[i], &ev) == -1) {
+			perror("epoll_ctl(EPOLL_CTL_MOD)");
+			exit(1);
+		}
+	}
+	sleeping_clients.clear();
+}
diff --git a/server.h b/server.h
index f1cc7a0..271732b 100644
--- a/server.h
+++ b/server.h
@@ -63,15 +63,6 @@ public:
 	void add_data(const std::string &stream_id, const char *data, size_t bytes);
 
 private:
-	void process_client(Client *client);
-
-	// Close a given client socket, and clean up after it.
-	void close_client(Client *client);
-
-	// Parse the HTTP request, construct the header, and set the client into
-	// the SENDING_HEADER state.
-	void parse_request(Client *client);
-
 	pthread_mutex_t mutex;
 
 	// Map from stream ID to stream.
@@ -84,11 +75,33 @@ private:
 	int epoll_fd;
 	epoll_event events[EPOLL_MAX_EVENTS];
 
+	// Clients that are in SENDING_DATA, but that we don't listen on,
+	// because we currently don't have any data for them.
+	// See put_client_to_sleep() and wake_up_all_clients().
+	std::vector<int> sleeping_clients;
+
 	// Recover the this pointer, and call do_work().
 	static void *do_work_thunk(void *arg);
 
 	// The actual worker thread.
 	void do_work();
+
+	void process_client(Client *client);
+
+	// Close a given client socket, and clean up after it.
+	void close_client(Client *client);
+
+	// Parse the HTTP request, construct the header, and set the client into
+	// the SENDING_HEADER state.
+	void parse_request(Client *client);
+
+	// Put client to sleep, since there is no more data for it; we will on
+	// longer listen on POLLOUT until we get more data. Also, it will be put
+	// in the list of clients to wake up when we do.
+	void put_client_to_sleep(Client *client);
+
+	// We have more data, so mark all clients that are sleeping as ready to go.
+	void wake_up_all_clients();
 };
 
 #endif  // !defined(_SERVER_H)
-- 
2.39.2