Implement epoll main loop in Server, and parse header.
authorSteinar H. Gunderson <sgunderson@bigfoot.com>
Sat, 6 Apr 2013 14:58:54 +0000 (16:58 +0200)
committerSteinar H. Gunderson <sgunderson@bigfoot.com>
Sat, 6 Apr 2013 14:58:54 +0000 (16:58 +0200)
Makefile
server.cpp
server.h

index c80ab9d537d5bee77f999c646997b2d733eb553f..78ec5a6e26edb10dd26191c9ccc46f6ff5447095 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,9 +1,9 @@
 CC=gcc
 CXX=g++
 CXXFLAGS=-Wall -O2 -g
-LDLIBS=-lcurl
+LDLIBS=-lcurl -lpthread
 
-OBJS=cubemap.o server.o mutexlock.o
+OBJS=cubemap.o server.o mutexlock.o input.o
 
 all: cubemap
 
index 31e5c0a31da327bc80499c543bbb4dee932b74bb..25da16cba4c341e0c07b8d06eb4239a63a0f476c 100644 (file)
@@ -47,9 +47,26 @@ void *Server::do_work_thunk(void *arg)
 void Server::do_work()
 {
        for ( ;; ) {
-               MutexLock lock(&mutex);
-               printf("server thread running\n");
-               sleep(1);
+               int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
+
+               MutexLock lock(&mutex);  // We release the mutex between iterations.
+               if (nfds == -1) {
+                       perror("epoll_wait");
+                       exit(1);
+               }
+               
+               for (int i = 0; i < nfds; ++i) {
+                       int fd = events[i].data.fd;
+                       assert(clients.count(fd) != 0);
+                       Client *client = &clients[fd];
+
+                       if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
+                               close_client(client);
+                               continue;
+                       }
+
+                       process_client(client);
+               }
        }
 }
        
@@ -57,6 +74,8 @@ void Server::add_client(int sock)
 {
        MutexLock lock(&mutex);
        Client new_client;
+       new_client.sock = sock;
+       new_client.client_request.reserve(1024);
        new_client.state = Client::READING_REQUEST;
        new_client.header_bytes_sent = 0;
        new_client.bytes_sent = 0;
@@ -65,7 +84,7 @@ void Server::add_client(int sock)
 
        // Start listening on data from this socket.
        epoll_event ev;
-       ev.events = EPOLLIN;
+       ev.events = EPOLLIN | EPOLLRDHUP;
        ev.data.fd = sock;
        if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
                perror("epoll_ctl(EPOLL_CTL_ADD)");
@@ -88,3 +107,80 @@ void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 {
        // TODO
 }
+       
+void Server::process_client(Client *client)
+{
+       switch (client->state) {
+       case Client::READING_REQUEST: {
+               // Try to read more of the request.
+               char buf[1024];
+               int ret = read(client->sock, buf, sizeof(buf));
+               if (ret == -1) {
+                       perror("read");
+                       close_client(client);
+                       return;
+               }
+               if (ret == 0) {
+                       // No data? This really means that we were triggered for something else than
+                       // POLLIN (which suggests a logic error in epoll).
+                       fprintf(stderr, "WARNING: fd %d returned unexpectedly 0 bytes!\n", client->sock);
+                       close_client(client);
+                       return;
+               }
+
+               // Guard against overlong requests gobbling up all of our space.
+               if (client->client_request.size() + ret > MAX_CLIENT_REQUEST) {
+                       fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
+                       close_client(client);
+                       return;
+               }       
+
+               // See if we have \r\n\r\n anywhere in the request. We start three bytes
+               // before what we just appended, in case we just got the final character.
+               size_t existing_req_bytes = client->client_request.size();
+               client->client_request.append(string(buf, buf + ret));
+       
+               size_t start_at = (existing_req_bytes >= 3 ? existing_req_bytes - 3 : 0);
+               const char *ptr = reinterpret_cast<char *>(
+                       memmem(client->client_request.data() + start_at, client->client_request.size() - start_at,
+                              "\r\n\r\n", 4));
+               if (ptr == NULL) {
+                       // OK, we don't have the entire header yet. Fine; we'll get it later.
+                       return;
+               }
+
+               if (ptr != client->client_request.data() + client->client_request.size() - 4) {
+                       fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
+                       close_client(client);
+                       return;
+               }
+
+               client->state = Client::SENDING_HEADER;
+
+               epoll_event ev;
+               ev.events = EPOLLOUT | 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);
+               }
+               break;
+       }
+       default:
+               // TODO
+               assert(false);
+       }
+}
+       
+void Server::close_client(Client *client)
+{
+       if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
+               perror("epoll_ctl(EPOLL_CTL_DEL)");
+               exit(1);
+       }
+       
+       // Bye-bye!
+       close(client->sock);
+       clients.erase(client->sock);
+}
index d8b9064f492f2ad12e333747b389bd1093b2564a..c44b81ee357b7ed3e2d6cd629d8690b009334ddd 100644 (file)
--- a/server.h
+++ b/server.h
@@ -6,9 +6,16 @@
 #include <string>
 #include <map>
 
+#define NUM_SERVERS 4
 #define BACKLOG_SIZE 1048576
+#define EPOLL_MAX_EVENTS 8192
+#define EPOLL_TIMEOUT_MS 20
+#define MAX_CLIENT_REQUEST 16384
 
 struct Client {
+       // The file descriptor associated with this socket.
+       int sock;
+
        enum State { READING_REQUEST, SENDING_HEADER, SENDING_DATA };
        State state;
 
@@ -53,6 +60,9 @@ public:
        void add_data(const std::string &stream_id, const char *data, size_t bytes);
 
 private:
+       void process_client(Client *client);
+       void close_client(Client *client);
+
        pthread_mutex_t mutex;
 
        // Map from stream ID to stream.
@@ -61,7 +71,9 @@ private:
        // Map from file descriptor to client.
        std::map<int, Client> clients;
 
+       // Used for epoll implementation (obviously).
        int epoll_fd;
+       epoll_event events[EPOLL_MAX_EVENTS];
 
        // Recover the this pointer, and call do_work().
        static void *do_work_thunk(void *arg);