#include <stdint.h>
#include <pthread.h>
+#include <sys/epoll.h>
#include <string>
#include <map>
+#include <vector>
-#define NUM_SERVERS 4
#define BACKLOG_SIZE 1048576
#define EPOLL_MAX_EVENTS 8192
#define EPOLL_TIMEOUT_MS 20
#define MAX_CLIENT_REQUEST 16384
+class ClientProto;
+class CubemapStateProto;
+class Stream;
+class StreamProto;
+
struct Client {
+ Client() {}
+ Client(int sock);
+
+ // Serialization/deserialization.
+ Client(const ClientProto &serialized, Stream *stream);
+ ClientProto serialize() const;
+
// The file descriptor associated with this socket.
int sock;
- enum State { READING_REQUEST, SENDING_HEADER, SENDING_DATA };
+ enum State { READING_REQUEST, SENDING_HEADER, SENDING_DATA, SENDING_ERROR };
State state;
// The HTTP request, as sent by the client. If we are in READING_REQUEST,
// What stream we're connecting to; parsed from <request>.
// Not relevant for READING_REQUEST.
std::string stream_id;
+ Stream *stream;
// The header we want to send. This is nominally a copy of Stream::header,
// but since that might change on reconnects etc., we keep a local copy here.
- // Only relevant for SENDING_HEADER; blank otherwise.
- std::string header;
+ // Only relevant for SENDING_HEADER or SENDING_ERROR; blank otherwise.
+ std::string header_or_error;
- // Number of bytes we've sent of the header. Only relevant for SENDING_HEADER.
- size_t header_bytes_sent;
+ // Number of bytes we've sent of the header. Only relevant for SENDING_HEADER
+ // or SENDING_ERROR.
+ size_t header_or_error_bytes_sent;
// Number of bytes we've sent of data. Only relevant for SENDING_DATA.
size_t bytes_sent;
};
struct Stream {
+ Stream(const std::string &stream_id);
+ ~Stream();
+
+ // Serialization/deserialization.
+ Stream(const StreamProto &serialized);
+ StreamProto serialize() const;
+
+ std::string stream_id;
+
// The HTTP response header, plus the video stream header (if any).
std::string header;
// The stream data itself, stored in a circular buffer.
- char data[BACKLOG_SIZE];
+ char *data;
// How many bytes <data> contains. Can very well be larger than BACKLOG_SIZE,
// since the buffer wraps.
size_t data_size;
+
+ // 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<Client *> sleeping_clients;
+
+ // Clients that we recently got data for (when they were in
+ // <sleeping_clients>).
+ std::vector<Client *> to_process;
+
+ // 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();
+
+private:
+ Stream(const Stream& other);
};
class Server {
public:
Server();
+ ~Server();
// Start a new thread that handles clients.
void run();
- void add_client(int sock);
- void add_stream(const std::string &stream_id);
+
+ // Stop the thread.
+ void stop();
+
void set_header(const std::string &stream_id, const std::string &header);
- void add_data(const std::string &stream_id, const char *data, size_t bytes);
+
+ // These will be deferred until the next time an iteration in do_work() happens,
+ // and the order between them are undefined.
+ // XXX: header should ideally be ordered with respect to data.
+ void add_client_deferred(int sock);
+ void add_data_deferred(const std::string &stream_id, const char *data, size_t bytes);
+
+ // These should not be called while running, since that would violate
+ // threading assumptions (ie., that epoll is only called from one thread
+ // at the same time).
+ CubemapStateProto serialize();
+ void add_client_from_serialized(const ClientProto &client);
+ void add_stream(const std::string &stream_id);
+ void add_stream_from_serialized(const StreamProto &stream);
private:
+ pthread_t worker_thread;
+
+ // Mutex protecting queued_data only. Note that if you want to hold both this
+ // and <mutex> below, you will need to take <mutex> before this one.
+ pthread_mutex_t queued_data_mutex;
+
+ // Deferred commands that should be run from the do_work() thread as soon as possible.
+ // We defer these for two reasons:
+ //
+ // - We only want to fiddle with epoll from one thread at any given time,
+ // and doing add_client() from the acceptor thread would violate that.
+ // - We don't want the input thread(s) hanging on <mutex> when doing
+ // add_data(), since they want to do add_data() rather often, and <mutex>
+ // can be taken a lot of the time.
+ //
+ // Protected by <queued_data_mutex>.
+ std::vector<int> queued_add_clients;
+ std::map<std::string, std::string> queued_data;
+
+ // All variables below this line are protected by the mutex.
pthread_mutex_t mutex;
+ // If the thread should stop or not.
+ bool should_stop;
+
// Map from stream ID to stream.
- std::map<std::string, Stream> streams;
+ std::map<std::string, Stream *> streams;
// Map from file descriptor to client.
std::map<int, Client> clients;
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();
+ // Process a client; read and write data as far as we can.
+ // After this call, one of these four is true:
+ //
+ // 1. The socket is closed, and the client deleted.
+ // 2. We are still waiting for more data from the client.
+ // 3. We've sent all the data we have to the client,
+ // and put it in <sleeping_clients>.
+ // 4. The socket buffer is full (which means we still have
+ // data outstanding).
+ //
+ // For #2, we listen for EPOLLIN events. For #3 and #4, we listen
+ // for EPOLLOUT in edge-triggered mode; it will never fire for #3,
+ // but it's cheaper than taking it in and out all the time.
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
+ // Parse the HTTP request. Returns a HTTP status code (200/400/404).
+ int parse_request(Client *client);
+
+ // Construct the HTTP header, and set the client into
// the SENDING_HEADER state.
- void parse_request(Client *client);
+ void construct_header(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);
+ // Construct a generic error with the given line, and set the client into
+ // the SENDING_ERROR state.
+ void construct_error(Client *client, int error_code);
- // We have more data, so mark all clients that are sleeping as ready to go.
- void wake_up_all_clients();
+ // TODO: This function should probably die.
+ Stream *find_stream(const std::string &stream_id);
+
+ void process_queued_data();
+
+ void add_client(int sock);
+ void add_data(const std::string &stream_id, const char *data, size_t bytes);
};
#endif // !defined(_SERVER_H)
projects / cubemap / blobdiff