faster single threaded web server implementation

diff --git a/src/main.c b/src/main.c
index b988f0dece7ce50529eaf4720b0bd8b461a73775..945728b90fd42e0cc251e9125e11d4a46dd41101 100644 (file)
--- a/src/main.c
+++ b/src/main.c
@@ -99,6 +99,9 @@ void web_server_threading_selection(void) {
                if(static_threads[i].start_routine == socket_listen_main_single_threaded)
                        static_threads[i].enabled = threaded?0:1;
        }
+
+       web_client_timeout = (int) config_get_number("global", "disconnect idle web clients after seconds", DEFAULT_DISCONNECT_IDLE_WEB_CLIENTS_AFTER_SECONDS);
+       web_enable_gzip = config_get_boolean("global", "enable web responses gzip compression", web_enable_gzip);
 }
 
 

diff --git a/src/web_server.c b/src/web_server.c
index d49923a075f12075dc97156a577a0c813129c46a..c3821202703a4f99c324893919b9edd76acce12a 100644 (file)
--- a/src/web_server.c
+++ b/src/web_server.c
@@ -220,10 +220,7 @@ void *socket_listen_main_multi_threaded(void *ptr) {
        if(pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL) != 0)
                error("Cannot set pthread cancel state to ENABLE.");
 
-       web_client_timeout = (int) config_get_number("global", "disconnect idle web clients after seconds", DEFAULT_DISCONNECT_IDLE_WEB_CLIENTS_AFTER_SECONDS);
-       web_enable_gzip = config_get_boolean("global", "enable web responses gzip compression", web_enable_gzip);
-
-       if(listen_fd < 0) fatal("LISTENER: Listen socket is not ready.");
+       if(listen_fd < 0 || listen_fd >= FD_SETSIZE) fatal("LISTENER: Listen socket %d is not ready, or invalid.", listen_fd);
 
        fd_set ifds;
        FD_ZERO (&ifds);
@@ -299,15 +296,57 @@ void *socket_listen_main_multi_threaded(void *ptr) {
        }
 
        error("LISTENER: exit!");
+       close(listen_fd);
+       listen_fd = -1;
+       return NULL;
+}
 
-       if(listen_fd >= 0) close(listen_fd);
-       exit(2);
+struct web_client *single_threaded_clients[FD_SETSIZE];
 
-       return NULL;
+static inline int single_threaded_link_client(struct web_client *w, fd_set *ifds, fd_set *ofds, fd_set *efds, int *max) {
+       if(unlikely(w->obsolete || w->dead || (!w->wait_receive && !w->wait_send)))
+               return 1;
+
+       if(unlikely(w->ifd < 0 || w->ifd >= FD_SETSIZE || w->ofd < 0 || w->ofd >= FD_SETSIZE)) {
+               error("%llu: invalid file descriptor, ifd = %d, ofd = %d (required 0 <= fd < FD_SETSIZE (%d)", w->id, w->ifd, w->ofd, FD_SETSIZE);
+               return 1;
+       }
+
+       FD_SET(w->ifd, efds);
+       if(unlikely(*max < w->ifd)) *max = w->ifd;
+
+       if(unlikely(w->ifd != w->ofd)) {
+               if(*max < w->ofd) *max = w->ofd;
+               FD_SET(w->ofd, efds);
+       }
+
+       if(w->wait_receive) FD_SET(w->ifd, ifds);
+       if(w->wait_send)    FD_SET(w->ofd, ofds);
+
+       single_threaded_clients[w->ifd] = w;
+       single_threaded_clients[w->ofd] = w;
+
+       return 0;
+}
+
+static inline int single_threaded_unlink_client(struct web_client *w, fd_set *ifds, fd_set *ofds, fd_set *efds) {
+       FD_CLR(w->ifd, efds);
+       if(unlikely(w->ifd != w->ofd)) FD_CLR(w->ofd, efds);
+
+       if(w->wait_receive) FD_CLR(w->ifd, ifds);
+       if(w->wait_send)    FD_CLR(w->ofd, ofds);
+
+       single_threaded_clients[w->ifd] = NULL;
+       single_threaded_clients[w->ofd] = NULL;
+
+       if(unlikely(w->obsolete || w->dead || (!w->wait_receive && !w->wait_send)))
+               return 1;
+
+       return 0;
 }
 
 void *socket_listen_main_single_threaded(void *ptr) {
-       if(ptr) { ; }
+       (void)ptr;
 
        web_server_mode = WEB_SERVER_MODE_SINGLE_THREADED;
 
@@ -324,179 +363,125 @@ void *socket_listen_main_single_threaded(void *ptr) {
        if(pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL) != 0)
                error("Cannot set pthread cancel state to ENABLE.");
 
-       web_client_timeout = (int) config_get_number("global", "disconnect idle web clients after seconds", DEFAULT_DISCONNECT_IDLE_WEB_CLIENTS_AFTER_SECONDS);
-       web_enable_gzip = config_get_boolean("global", "enable web responses gzip compression", web_enable_gzip);
+       if(listen_fd < 0 || listen_fd >= FD_SETSIZE)
+               fatal("LISTENER: Listen socket %d is not ready, or invalid.", listen_fd);
 
-       if(listen_fd < 0) fatal("LISTENER: Listen socket is not ready.");
+       int i;
+       for(i = 0; i < FD_SETSIZE ; i++)
+               single_threaded_clients[i] = NULL;
 
-       fd_set ifds, ofds, efds;
+       fd_set ifds, ofds, efds, rifds, rofds, refds;
+       FD_ZERO (&ifds);
+       FD_ZERO (&ofds);
+       FD_ZERO (&efds);
+       FD_SET(listen_fd, &ifds);
+       FD_SET(listen_fd, &efds);
        int fdmax = listen_fd;
 
        for(;;) {
-               int has_obsolete = 0;
-               FD_ZERO (&ifds);
-               FD_ZERO (&ofds);
-               FD_ZERO (&efds);
-
-               if(listen_fd >= 0) {
-                       // debug(D_WEB_CLIENT_ACCESS, "LISTENER: adding listen socket %d to ifds, efds", listen_fd);
-                       FD_SET(listen_fd, &ifds);
-                       FD_SET(listen_fd, &efds);
-               }
-
-               for(w = web_clients; w ; w = w->next) {
-                       if(unlikely(w->dead)) {
-                               error("%llu: client is dead.", w->id);
-                               w->obsolete = 1;
-                       }
-                       else if(unlikely(!w->wait_receive && !w->wait_send)) {
-                               error("%llu: client is not set for neither receiving nor sending data.");
-                               w->obsolete = 1;
-                       }
-
-                       if(w->ifd < 0 || w->ifd >= FD_SETSIZE || w->ofd < 0 || w->ofd >= FD_SETSIZE) {
-                               error("%llu: invalid file descriptor, ifd = %d, ofd = %d (required 0 <= fd < FD_SETSIZE (%d)", w->id, w->ifd, w->ofd, FD_SETSIZE);
-                               w->obsolete = 1;
-                       }
-
-                       if(unlikely(w->obsolete)) {
-                               has_obsolete++;
-                               continue;
-                       }
-
-                       // debug(D_WEB_CLIENT_ACCESS, "%llu: adding input socket %d to efds", w->id, w->ifd);
-                       FD_SET(w->ifd, &efds);
-                       if(w->ifd > fdmax) fdmax = w->ifd;
-
-                       if(w->ifd != w->ofd) {
-                               // debug(D_WEB_CLIENT_ACCESS, "%llu: adding output socket %d to efds", w->id, w->ofd);
-                               FD_SET(w->ofd, &efds);
-                               if(w->ofd > fdmax) fdmax = w->ofd;
-                       }
-
-                       if (w->wait_receive) {
-                               // debug(D_WEB_CLIENT_ACCESS, "%llu: adding input socket %d to ifds", w->id, w->ifd);
-                               FD_SET(w->ifd, &ifds);
-                               if(w->ifd > fdmax) fdmax = w->ifd;
-                       }
-
-                       if (w->wait_send) {
-                               // debug(D_WEB_CLIENT_ACCESS, "%llu: adding output socket %d to ofds", w->id, w->ofd);
-                               FD_SET(w->ofd, &ofds);
-                               if(w->ofd > fdmax) fdmax = w->ofd;
-                       }
-               }
-
-               // cleanup unused clients
-               if(unlikely(has_obsolete)) {
-                       for (w = web_clients; w; ) {
-                               if (w->obsolete) {
-                                       debug(D_WEB_CLIENT, "%llu: Removing client.", w->id);
-                                       w = web_client_free(w);
-#ifdef NETDATA_INTERNAL_CHECKS
-                                       log_allocations();
-#endif
-                               }
-                               else w = w->next;
-                       }
-               }
+               debug(D_WEB_CLIENT_ACCESS, "LISTENER: single threaded web server waiting (listen fd = %d, fdmax = %d)...", listen_fd, fdmax);
 
-               debug(D_WEB_CLIENT_ACCESS, "LISTENER: Waiting...");
                struct timeval tv = { .tv_sec = 1, .tv_usec = 0 };
-               errno = 0;
-               retval = select(fdmax+1, &ifds, &ofds, &efds, &tv);
+               rifds = ifds;
+               rofds = ofds;
+               refds = efds;
+               retval = select(fdmax+1, &rifds, &rofds, &refds, &tv);
 
-               if(retval == -1) {
+               if(unlikely(retval == -1)) {
                        error("LISTENER: select() failed.");
-
-                       if(errno != EAGAIN) {
-                               // debug(D_WEB_CLIENT_ACCESS, "LISTENER: select() failed.");
-                               error("REMOVING ALL %lu WEB CLIENTS !", global_statistics.connected_clients);
-                               while (web_clients) web_client_free(web_clients);
-                       }
-
                        failures++;
                        if(failures > 10) {
+                               if(global_statistics.connected_clients) {
+                                       error("REMOVING ALL %lu WEB CLIENTS !", global_statistics.connected_clients);
+                                       while (web_clients) {
+                                               single_threaded_unlink_client(web_clients, &ifds, &ofds, &efds);
+                                               web_client_free(web_clients);
+                                       }
+                               }
+
                                error("LISTENER: our listen port %d seems dead. Re-opening it.", listen_fd);
+
                                close(listen_fd);
                                listen_fd = -1;
                                sleep(5);
+
                                create_listen_socket();
-                               if(listen_fd < 0)
+                               if(listen_fd < 0 || listen_fd >= FD_SETSIZE)
                                        fatal("Cannot listen for web clients (connected clients %llu).", global_statistics.connected_clients);
 
+                               FD_ZERO (&ifds);
+                               FD_ZERO (&ofds);
+                               FD_ZERO (&efds);
+                               FD_SET(listen_fd, &ifds);
+                               FD_SET(listen_fd, &efds);
                                failures = 0;
                        }
-
-                       continue;
                }
-               else if(retval) {
-                       for(w = web_clients; w ; w = w->next) {
-                               if (unlikely(w->obsolete)) continue;
+               else if(likely(retval)) {
+                       failures = 0;
+                       debug(D_WEB_CLIENT_ACCESS, "LISTENER: got something.");
 
-                               if (unlikely(FD_ISSET(w->ifd, &efds))) {
-                                       debug(D_WEB_CLIENT_ACCESS, "%llu: Received error on input socket.", w->id);
-                                       web_client_reset(w);
-                                       w->obsolete = 1;
+                       if(FD_ISSET(listen_fd, &rifds)) {
+                               debug(D_WEB_CLIENT_ACCESS, "LISTENER: new connection.");
+                               w = web_client_create(listen_fd);
+                               if(single_threaded_link_client(w, &ifds, &ofds, &ifds, &fdmax) != 0) {
+                                       web_client_free(w);
+                               }
+                       }
+
+                       for(i = 0 ; i <= fdmax ; i++) {
+                               if(likely(!FD_ISSET(i, &rifds) && !FD_ISSET(i, &rofds) && !FD_ISSET(i, &refds)))
+                                       continue;
+
+                               w = single_threaded_clients[i];
+                               if(unlikely(!w))
+                                       continue;
+
+                               if(unlikely(single_threaded_unlink_client(w, &ifds, &ofds, &efds) != 0)) {
+                                       web_client_free(w);
                                        continue;
                                }
 
-                               if (unlikely(FD_ISSET(w->ofd, &efds))) {
-                                       debug(D_WEB_CLIENT_ACCESS, "%llu: Received error on output socket.", w->id);
-                                       web_client_reset(w);
-                                       w->obsolete = 1;
+                               if (unlikely(FD_ISSET(w->ifd, &refds) || FD_ISSET(w->ofd, &refds))) {
+                                       web_client_free(w);
                                        continue;
                                }
 
-                               if (unlikely(w->wait_receive && FD_ISSET(w->ifd, &ifds))) {
-                                       long bytes;
-                                       if (unlikely((bytes = web_client_receive(w)) < 0)) {
-                                               debug(D_WEB_CLIENT, "%llu: Cannot receive data from client. Closing client.", w->id);
-                                               errno = 0;
-                                               web_client_reset(w);
-                                               w->obsolete = 1;
+                               if (unlikely(w->wait_receive && FD_ISSET(w->ifd, &rifds))) {
+                                       if (unlikely(web_client_receive(w) < 0)) {
+                                               web_client_free(w);
                                                continue;
                                        }
 
-                                       if (w->mode == WEB_CLIENT_MODE_NORMAL) {
-                                               debug(D_WEB_CLIENT, "%llu: Processing received data (%ld bytes).", w->id, bytes);
-                                               // info("%llu: Attempting to process received data (%ld bytes).", w->id, bytes);
+                                       if (w->mode != WEB_CLIENT_MODE_FILECOPY) {
+                                               debug(D_WEB_CLIENT, "%llu: Processing received data.", w->id);
                                                web_client_process(w);
                                        }
-                                       else {
-                                               debug(D_WEB_CLIENT, "%llu: NO Processing for received data (%ld bytes).", w->id, bytes);
-                                       }
                                }
 
-                               if (unlikely(w->wait_send && FD_ISSET(w->ofd, &ofds))) {
-                                       ssize_t bytes;
-                                       if (unlikely((bytes = web_client_send(w)) < 0)) {
+                               if (unlikely(w->wait_send && FD_ISSET(w->ofd, &rofds))) {
+                                       if (unlikely(web_client_send(w) < 0)) {
                                                debug(D_WEB_CLIENT, "%llu: Cannot send data to client. Closing client.", w->id);
-                                               errno = 0;
-                                               web_client_reset(w);
-                                               w->obsolete = 1;
+                                               web_client_free(w);
                                                continue;
                                        }
                                }
-                       }
 
-                       // check for new incoming connections
-                       if(FD_ISSET(listen_fd, &ifds)) {
-                               debug(D_WEB_CLIENT_ACCESS, "LISTENER: new connection.");
-                               web_client_create(listen_fd);
+                               if(unlikely(single_threaded_link_client(w, &ifds, &ofds, &efds, &fdmax) != 0)) {
+                                       web_client_free(w);
+                               }
                        }
                }
                else {
-                       debug(D_WEB_CLIENT_ACCESS, "LISTENER: timeout.");
+                       debug(D_WEB_CLIENT_ACCESS, "LISTENER: single threaded web server timeout.");
+#ifdef NETDATA_INTERNAL_CHECKS
+                       log_allocations();
+#endif
                }
-
-               failures = 0;
        }
 
        error("LISTENER: exit!");
-
-       if(listen_fd >= 0) close(listen_fd);
-       exit(2);
-
+       close(listen_fd);
+       listen_fd = -1;
        return NULL;
 }