#ifndef _SERVER_H
#define _SERVER_H 1
-#include <stdint.h>
#include <pthread.h>
+#include <stddef.h>
+#include <stdint.h>
#include <sys/epoll.h>
-#include <string>
+#include <sys/types.h>
+#include <time.h>
#include <map>
+#include <queue>
+#include <string>
#include <vector>
-#define BACKLOG_SIZE 1048576
+#include "client.h"
+#include "stream.h"
+#include "thread.h"
+
+class ClientProto;
+struct Stream;
+
#define EPOLL_MAX_EVENTS 8192
#define EPOLL_TIMEOUT_MS 20
#define MAX_CLIENT_REQUEST 16384
+#define REQUEST_READ_TIMEOUT_SEC 60
-class ClientProto;
class CubemapStateProto;
class StreamProto;
-struct Client {
- Client() {}
- Client(int sock);
-
- // Serialization/deserialization.
- Client(const ClientProto &serialized);
- ClientProto serialize() const;
-
- // The file descriptor associated with this socket.
- int sock;
-
- 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,
- // this might not be finished.
- std::string request;
-
- // What stream we're connecting to; parsed from <request>.
- // Not relevant for READING_REQUEST.
- std::string stream_id;
-
- // 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 or SENDING_ERROR; blank otherwise.
- std::string header_or_error;
-
- // 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;
-
- // How many bytes <data> contains. Can very well be larger than BACKLOG_SIZE,
- // since the buffer wraps.
- size_t data_size;
-
-private:
- Stream(const Stream& other);
-};
-
-class Server {
+class Server : public Thread {
public:
Server();
~Server();
- // Start a new thread that handles clients.
- void run();
-
- // Stop the thread.
- void stop();
+ // Get the list of all currently connected clients.
+ std::vector<ClientStats> get_client_stats() const;
- CubemapStateProto serialize() const;
+ // Set header (both HTTP header and any stream headers) for the given stream.
+ void set_header(int stream_index,
+ const std::string &http_header,
+ const std::string &stream_header);
- void add_client(int sock);
- void add_client_from_serialized(const ClientProto &client);
+ // Set that the given stream should use the given max pacing rate from now on.
+ // NOTE: This should be set before any clients are connected!
+ void set_pacing_rate(int stream_index, uint32_t pacing_rate);
- void add_stream(const std::string &stream_id);
- void add_stream_from_serialized(const StreamProto &stream);
+ // 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(int stream_index, const char *data, size_t bytes, StreamStartSuitability suitable_for_stream_start);
- 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 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);
+ int add_stream(const std::string &url, size_t bytes_received, size_t prebuffering_bytes, Stream::Encoding encoding);
+ int add_stream_from_serialized(const StreamProto &stream, int data_fd);
+ int lookup_stream_by_url(const std::string &url) const;
+ void set_backlog_size(int stream_index, size_t new_size);
+ void set_prebuffering_bytes(int stream_index, size_t new_amount);
+ void set_encoding(int stream_index, Stream::Encoding encoding);
private:
- pthread_t worker_thread;
+ // Mutex protecting queued_add_clients.
+ // Note that if you want to hold both this and <mutex> below,
+ // you will need to take <mutex> before this one.
+ mutable pthread_mutex_t queued_clients_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_clients_mutex>.
+ std::vector<int> queued_add_clients;
// All variables below this line are protected by the mutex.
- pthread_mutex_t mutex;
+ mutable pthread_mutex_t mutex;
- // If the thread should stop or not.
- bool should_stop;
+ // All streams.
+ std::vector<Stream *> streams;
- // Map from stream ID to stream.
- std::map<std::string, Stream *> streams;
+ // Map from URL to index into <streams>.
+ std::map<std::string, int> url_map;
// Map from file descriptor to client.
std::map<int, Client> clients;
+ // A list of all clients, ordered by the time they connected (first element),
+ // and their file descriptor (second element). It is ordered by connection time
+ // (and thus also by read timeout time) so that we can read clients from the
+ // start and stop processing once we get to one that isn't ready to be
+ // timed out yet (which means we only have to look at each client exactly once,
+ // save for the first element of the queue, which is always checked).
+ //
+ // Note that when we delete a client, we don't update this queue.
+ // This means that when reading it, we need to check if the client it
+ // describes is still exists (ie., that the fd still exists, and that
+ // the timespec matches).
+ std::queue<std::pair<timespec, int> > clients_ordered_by_connect_time;
+
// Used for epoll implementation (obviously).
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();
-
+ virtual 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 construct_header(Client *client);
// Construct a generic error with the given line, and set the client into
- // the SENDING_ERROR state.
+ // the SENDING_SHORT_RESPONSE state.
void construct_error(Client *client, int error_code);
- // 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);
+ void process_queued_data();
+ void skip_lost_data(Client *client);
- // 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 add_client(int sock);
};
#endif // !defined(_SERVER_H)
projects / cubemap / blobdiff