20 files changed, 3352 insertions, 0 deletions

diff --git a/web/server/Makefile.am b/web/server/Makefile.am
new file mode 100644
index 0000000000..843c4cc9bf
--- /dev/null
+++ b/web/server/Makefile.am
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+AUTOMAKE_OPTIONS = subdir-objects
+MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
+
+SUBDIRS = \
+    single \
+    multi \
+    static \
+    $(NULL)
+
+dist_noinst_DATA = \
+	README.md \
+	$(NULL)
diff --git a/web/server/README.md b/web/server/README.md
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/web/server/README.md
diff --git a/web/server/multi/Makefile.am b/web/server/multi/Makefile.am
new file mode 100644
index 0000000000..90cc9ca1eb
--- /dev/null
+++ b/web/server/multi/Makefile.am
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+AUTOMAKE_OPTIONS = subdir-objects
+MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
+
+SUBDIRS = \
+    $(NULL)
+
+dist_noinst_DATA = \
+	README.md \
+	$(NULL)
diff --git a/web/server/multi/README.md b/web/server/multi/README.md
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/web/server/multi/README.md
diff --git a/web/server/multi/multi-threaded.c b/web/server/multi/multi-threaded.c
new file mode 100644
index 0000000000..37bdd38ad2
--- /dev/null
+++ b/web/server/multi/multi-threaded.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#define WEB_SERVER_INTERNALS 1
+#include "multi-threaded.h"
+
+// --------------------------------------------------------------------------------------
+// the thread of a single client - for the MULTI-THREADED web server
+
+// 1. waits for input and output, using async I/O
+// 2. it processes HTTP requests
+// 3. it generates HTTP responses
+// 4. it copies data from input to output if mode is FILECOPY
+
+int web_client_timeout = DEFAULT_DISCONNECT_IDLE_WEB_CLIENTS_AFTER_SECONDS;
+int web_client_first_request_timeout = DEFAULT_TIMEOUT_TO_RECEIVE_FIRST_WEB_REQUEST;
+long web_client_streaming_rate_t = 0L;
+
+static void multi_threaded_web_client_worker_main_cleanup(void *ptr) {
+    struct web_client *w = ptr;
+    WEB_CLIENT_IS_DEAD(w);
+    w->running = 0;
+}
+
+static void *multi_threaded_web_client_worker_main(void *ptr) {
+    netdata_thread_cleanup_push(multi_threaded_web_client_worker_main_cleanup, ptr);
+
+            struct web_client *w = ptr;
+            w->running = 1;
+
+            struct pollfd fds[2], *ifd, *ofd;
+            int retval, timeout_ms;
+            nfds_t fdmax = 0;
+
+            while(!netdata_exit) {
+                if(unlikely(web_client_check_dead(w))) {
+                    debug(D_WEB_CLIENT, "%llu: client is dead.", w->id);
+                    break;
+                }
+                else if(unlikely(!web_client_has_wait_receive(w) && !web_client_has_wait_send(w))) {
+                    debug(D_WEB_CLIENT, "%llu: client is not set for neither receiving nor sending data.", w->id);
+                    break;
+                }
+
+                if(unlikely(w->ifd < 0 || w->ofd < 0)) {
+                    error("%llu: invalid file descriptor, ifd = %d, ofd = %d (required 0 <= fd", w->id, w->ifd, w->ofd);
+                    break;
+                }
+
+                if(w->ifd == w->ofd) {
+                    fds[0].fd = w->ifd;
+                    fds[0].events = 0;
+                    fds[0].revents = 0;
+
+                    if(web_client_has_wait_receive(w)) fds[0].events |= POLLIN;
+                    if(web_client_has_wait_send(w))    fds[0].events |= POLLOUT;
+
+                    fds[1].fd = -1;
+                    fds[1].events = 0;
+                    fds[1].revents = 0;
+
+                    ifd = ofd = &fds[0];
+
+                    fdmax = 1;
+                }
+                else {
+                    fds[0].fd = w->ifd;
+                    fds[0].events = 0;
+                    fds[0].revents = 0;
+                    if(web_client_has_wait_receive(w)) fds[0].events |= POLLIN;
+                    ifd = &fds[0];
+
+                    fds[1].fd = w->ofd;
+                    fds[1].events = 0;
+                    fds[1].revents = 0;
+                    if(web_client_has_wait_send(w))    fds[1].events |= POLLOUT;
+                    ofd = &fds[1];
+
+                    fdmax = 2;
+                }
+
+                debug(D_WEB_CLIENT, "%llu: Waiting socket async I/O for %s %s", w->id, web_client_has_wait_receive(w)?"INPUT":"", web_client_has_wait_send(w)?"OUTPUT":"");
+                errno = 0;
+                timeout_ms = web_client_timeout * 1000;
+                retval = poll(fds, fdmax, timeout_ms);
+
+                if(unlikely(netdata_exit)) break;
+
+                if(unlikely(retval == -1)) {
+                    if(errno == EAGAIN || errno == EINTR) {
+                        debug(D_WEB_CLIENT, "%llu: EAGAIN received.", w->id);
+                        continue;
+                    }
+
+                    debug(D_WEB_CLIENT, "%llu: LISTENER: poll() failed (input fd = %d, output fd = %d). Closing client.", w->id, w->ifd, w->ofd);
+                    break;
+                }
+                else if(unlikely(!retval)) {
+                    debug(D_WEB_CLIENT, "%llu: Timeout while waiting socket async I/O for %s %s", w->id, web_client_has_wait_receive(w)?"INPUT":"", web_client_has_wait_send(w)?"OUTPUT":"");
+                    break;
+                }
+
+                if(unlikely(netdata_exit)) break;
+
+                int used = 0;
+                if(web_client_has_wait_send(w) && ofd->revents & POLLOUT) {
+                    used++;
+                    if(web_client_send(w) < 0) {
+                        debug(D_WEB_CLIENT, "%llu: Cannot send data to client. Closing client.", w->id);
+                        break;
+                    }
+                }
+
+                if(unlikely(netdata_exit)) break;
+
+                if(web_client_has_wait_receive(w) && (ifd->revents & POLLIN || ifd->revents & POLLPRI)) {
+                    used++;
+                    if(web_client_receive(w) < 0) {
+                        debug(D_WEB_CLIENT, "%llu: Cannot receive data from client. Closing client.", w->id);
+                        break;
+                    }
+
+                    if(w->mode == WEB_CLIENT_MODE_NORMAL) {
+                        debug(D_WEB_CLIENT, "%llu: Attempting to process received data.", w->id);
+                        web_client_process_request(w);
+
+                        // if the sockets are closed, may have transferred this client
+                        // to plugins.d
+                        if(unlikely(w->mode == WEB_CLIENT_MODE_STREAM))
+                            break;
+                    }
+                }
+
+                if(unlikely(!used)) {
+                    debug(D_WEB_CLIENT_ACCESS, "%llu: Received error on socket.", w->id);
+                    break;
+                }
+            }
+
+            if(w->mode != WEB_CLIENT_MODE_STREAM)
+                web_server_log_connection(w, "DISCONNECTED");
+
+            web_client_request_done(w);
+
+            debug(D_WEB_CLIENT, "%llu: done...", w->id);
+
+            // close the sockets/files now
+            // to free file descriptors
+            if(w->ifd == w->ofd) {
+                if(w->ifd != -1) close(w->ifd);
+            }
+            else {
+                if(w->ifd != -1) close(w->ifd);
+                if(w->ofd != -1) close(w->ofd);
+            }
+            w->ifd = -1;
+            w->ofd = -1;
+
+    netdata_thread_cleanup_pop(1);
+    return NULL;
+}
+
+// --------------------------------------------------------------------------------------
+// the main socket listener - MULTI-THREADED
+
+// 1. it accepts new incoming requests on our port
+// 2. creates a new web_client for each connection received
+// 3. spawns a new netdata_thread to serve the client (this is optimal for keep-alive clients)
+// 4. cleans up old web_clients that their netdata_threads have been exited
+
+static void web_client_multi_threaded_web_server_release_clients(void) {
+    struct web_client *w;
+    for(w = web_clients_cache.used; w ; ) {
+        if(unlikely(!w->running && web_client_check_dead(w))) {
+            struct web_client *t = w->next;
+            web_client_release(w);
+            w = t;
+        }
+        else
+            w = w->next;
+    }
+}
+
+static void web_client_multi_threaded_web_server_stop_all_threads(void) {
+    struct web_client *w;
+
+    int found = 1;
+    usec_t max = 2 * USEC_PER_SEC, step = 50000;
+    for(w = web_clients_cache.used; w ; w = w->next) {
+        if(w->running) {
+            found++;
+            info("stopping web client %s, id %llu", w->client_ip, w->id);
+            netdata_thread_cancel(w->thread);
+        }
+    }
+
+    while(found && max > 0) {
+        max -= step;
+        info("Waiting %d web threads to finish...", found);
+        sleep_usec(step);
+        found = 0;
+        for(w = web_clients_cache.used; w ; w = w->next)
+            if(w->running) found++;
+    }
+
+    if(found)
+        error("%d web threads are taking too long to finish. Giving up.", found);
+}
+
+static struct pollfd *socket_listen_main_multi_threaded_fds = NULL;
+
+static void socket_listen_main_multi_threaded_cleanup(void *data) {
+    struct netdata_static_thread *static_thread = (struct netdata_static_thread *)data;
+    static_thread->enabled = NETDATA_MAIN_THREAD_EXITING;
+
+    info("cleaning up...");
+
+    info("releasing allocated memory...");
+    freez(socket_listen_main_multi_threaded_fds);
+
+    info("closing all sockets...");
+    listen_sockets_close(&api_sockets);
+
+    info("stopping all running web server threads...");
+    web_client_multi_threaded_web_server_stop_all_threads();
+
+    info("freeing web clients cache...");
+    web_client_cache_destroy();
+
+    info("cleanup completed.");
+    static_thread->enabled = NETDATA_MAIN_THREAD_EXITED;
+}
+
+#define CLEANUP_EVERY_EVENTS 60
+void *socket_listen_main_multi_threaded(void *ptr) {
+    netdata_thread_cleanup_push(socket_listen_main_multi_threaded_cleanup, ptr);
+
+            web_server_mode = WEB_SERVER_MODE_MULTI_THREADED;
+            web_server_is_multithreaded = 1;
+
+            struct web_client *w;
+            int retval, counter = 0;
+
+            if(!api_sockets.opened)
+                fatal("LISTENER: No sockets to listen to.");
+
+            socket_listen_main_multi_threaded_fds = callocz(sizeof(struct pollfd), api_sockets.opened);
+
+            size_t i;
+            for(i = 0; i < api_sockets.opened ;i++) {
+                socket_listen_main_multi_threaded_fds[i].fd = api_sockets.fds[i];
+                socket_listen_main_multi_threaded_fds[i].events = POLLIN;
+                socket_listen_main_multi_threaded_fds[i].revents = 0;
+
+                info("Listening on '%s'", (api_sockets.fds_names[i])?api_sockets.fds_names[i]:"UNKNOWN");
+            }
+
+            int timeout_ms = 1 * 1000;
+
+            while(!netdata_exit) {
+
+                // debug(D_WEB_CLIENT, "LISTENER: Waiting...");
+                retval = poll(socket_listen_main_multi_threaded_fds, api_sockets.opened, timeout_ms);
+
+                if(unlikely(retval == -1)) {
+                    error("LISTENER: poll() failed.");
+                    continue;
+                }
+                else if(unlikely(!retval)) {
+                    debug(D_WEB_CLIENT, "LISTENER: poll() timeout.");
+                    counter++;
+                    continue;
+                }
+
+                for(i = 0 ; i < api_sockets.opened ; i++) {
+                    short int revents = socket_listen_main_multi_threaded_fds[i].revents;
+
+                    // check for new incoming connections
+                    if(revents & POLLIN || revents & POLLPRI) {
+                        socket_listen_main_multi_threaded_fds[i].revents = 0;
+
+                        w = web_client_create_on_listenfd(socket_listen_main_multi_threaded_fds[i].fd);
+                        if(unlikely(!w)) {
+                            // no need for error log - web_client_create_on_listenfd already logged the error
+                            continue;
+                        }
+
+                        if(api_sockets.fds_families[i] == AF_UNIX)
+                            web_client_set_unix(w);
+                        else
+                            web_client_set_tcp(w);
+
+                        char tag[NETDATA_THREAD_TAG_MAX + 1];
+                        snprintfz(tag, NETDATA_THREAD_TAG_MAX, "WEB_CLIENT[%llu,[%s]:%s]", w->id, w->client_ip, w->client_port);
+
+                        w->running = 1;
+                        if(netdata_thread_create(&w->thread, tag, NETDATA_THREAD_OPTION_DONT_LOG, multi_threaded_web_client_worker_main, w) != 0) {
+                            w->running = 0;
+                            web_client_release(w);
+                        }
+                    }
+                }
+
+                counter++;
+                if(counter > CLEANUP_EVERY_EVENTS) {
+                    counter = 0;
+                    web_client_multi_threaded_web_server_release_clients();
+                }
+            }
+
+    netdata_thread_cleanup_pop(1);
+    return NULL;
+}
+
+
diff --git a/web/server/multi/multi-threaded.h b/web/server/multi/multi-threaded.h
new file mode 100644
index 0000000000..d7ebf3c54d
--- /dev/null
+++ b/web/server/multi/multi-threaded.h
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_WEB_SERVER_MULTI_THREADED_H
+#define NETDATA_WEB_SERVER_MULTI_THREADED_H
+
+#include "web/server/web_server.h"
+
+extern void *socket_listen_main_multi_threaded(void *ptr);
+
+#endif //NETDATA_WEB_SERVER_MULTI_THREADED_H
diff --git a/web/server/single/Makefile.am b/web/server/single/Makefile.am
new file mode 100644
index 0000000000..90cc9ca1eb
--- /dev/null
+++ b/web/server/single/Makefile.am
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+AUTOMAKE_OPTIONS = subdir-objects
+MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
+
+SUBDIRS = \
+    $(NULL)
+
+dist_noinst_DATA = \
+	README.md \
+	$(NULL)
diff --git a/web/server/single/README.md b/web/server/single/README.md
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/web/server/single/README.md
diff --git a/web/server/single/single-threaded.c b/web/server/single/single-threaded.c
new file mode 100644
index 0000000000..7e89ee683b
--- /dev/null
+++ b/web/server/single/single-threaded.c
@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#define WEB_SERVER_INTERNALS 1
+#include "single-threaded.h"
+
+// --------------------------------------------------------------------------------------
+// the main socket listener - SINGLE-THREADED
+
+struct web_client *single_threaded_clients[FD_SETSIZE];
+
+static inline int single_threaded_link_client(struct web_client *w, fd_set *ifds, fd_set *ofds, fd_set *efds, int *max) {
+    if(unlikely(web_client_check_dead(w) || (!web_client_has_wait_receive(w) && !web_client_has_wait_send(w)))) {
+        return 1;
+    }
+
+    if(unlikely(w->ifd < 0 || w->ifd >= (int)FD_SETSIZE || w->ofd < 0 || w->ofd >= (int)FD_SETSIZE)) {
+        error("%llu: invalid file descriptor, ifd = %d, ofd = %d (required 0 <= fd < FD_SETSIZE (%d)", w->id, w->ifd, w->ofd, (int)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(web_client_has_wait_receive(w)) FD_SET(w->ifd, ifds);
+    if(web_client_has_wait_send(w))    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(web_client_has_wait_receive(w)) FD_CLR(w->ifd, ifds);
+    if(web_client_has_wait_send(w))    FD_CLR(w->ofd, ofds);
+
+    single_threaded_clients[w->ifd] = NULL;
+    single_threaded_clients[w->ofd] = NULL;
+
+    if(unlikely(web_client_check_dead(w) || (!web_client_has_wait_receive(w) && !web_client_has_wait_send(w)))) {
+        return 1;
+    }
+
+    return 0;
+}
+
+static void socket_listen_main_single_threaded_cleanup(void *data) {
+    struct netdata_static_thread *static_thread = (struct netdata_static_thread *)data;
+    static_thread->enabled = NETDATA_MAIN_THREAD_EXITING;
+
+    info("closing all sockets...");
+    listen_sockets_close(&api_sockets);
+
+    info("freeing web clients cache...");
+    web_client_cache_destroy();
+
+    info("cleanup completed.");
+    static_thread->enabled = NETDATA_MAIN_THREAD_EXITED;
+}
+
+void *socket_listen_main_single_threaded(void *ptr) {
+    netdata_thread_cleanup_push(socket_listen_main_single_threaded_cleanup, ptr);
+    web_server_mode = WEB_SERVER_MODE_SINGLE_THREADED;
+    web_server_is_multithreaded = 0;
+
+    struct web_client *w;
+
+    if(!api_sockets.opened)
+        fatal("LISTENER: no listen sockets available.");
+
+    size_t i;
+    for(i = 0; i < (size_t)FD_SETSIZE ; i++)
+        single_threaded_clients[i] = NULL;
+
+    fd_set ifds, ofds, efds, rifds, rofds, refds;
+    FD_ZERO (&ifds);
+    FD_ZERO (&ofds);
+    FD_ZERO (&efds);
+    int fdmax = 0;
+
+    for(i = 0; i < api_sockets.opened ; i++) {
+        if (api_sockets.fds[i] < 0 || api_sockets.fds[i] >= (int)FD_SETSIZE)
+            fatal("LISTENER: Listen socket %d is not ready, or invalid.", api_sockets.fds[i]);
+
+        info("Listening on '%s'", (api_sockets.fds_names[i])?api_sockets.fds_names[i]:"UNKNOWN");
+
+        FD_SET(api_sockets.fds[i], &ifds);
+        FD_SET(api_sockets.fds[i], &efds);
+        if(fdmax < api_sockets.fds[i])
+            fdmax = api_sockets.fds[i];
+    }
+
+    while(!netdata_exit) {
+        debug(D_WEB_CLIENT_ACCESS, "LISTENER: single threaded web server waiting (fdmax = %d)...", fdmax);
+
+        struct timeval tv = { .tv_sec = 1, .tv_usec = 0 };
+        rifds = ifds;
+        rofds = ofds;
+        refds = efds;
+        int retval = select(fdmax+1, &rifds, &rofds, &refds, &tv);
+
+        if(unlikely(retval == -1)) {
+            error("LISTENER: select() failed.");
+            continue;
+        }
+        else if(likely(retval)) {
+            debug(D_WEB_CLIENT_ACCESS, "LISTENER: got something.");
+
+            for(i = 0; i < api_sockets.opened ; i++) {
+                if (FD_ISSET(api_sockets.fds[i], &rifds)) {
+                    debug(D_WEB_CLIENT_ACCESS, "LISTENER: new connection.");
+                    w = web_client_create_on_listenfd(api_sockets.fds[i]);
+                    if(unlikely(!w))
+                        continue;
+
+                    if(api_sockets.fds_families[i] == AF_UNIX)
+                        web_client_set_unix(w);
+                    else
+                        web_client_set_tcp(w);
+
+                    if (single_threaded_link_client(w, &ifds, &ofds, &ifds, &fdmax) != 0) {
+                        web_client_release(w);
+                    }
+                }
+            }
+
+            for(i = 0 ; i <= (size_t)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)) {
+                    // error("no client on slot %zu", i);
+                    continue;
+                }
+
+                if(unlikely(single_threaded_unlink_client(w, &ifds, &ofds, &efds) != 0)) {
+                    // error("failed to unlink client %zu", i);
+                    web_client_release(w);
+                    continue;
+                }
+
+                if (unlikely(FD_ISSET(w->ifd, &refds) || FD_ISSET(w->ofd, &refds))) {
+                    // error("no input on client %zu", i);
+                    web_client_release(w);
+                    continue;
+                }
+
+                if (unlikely(web_client_has_wait_receive(w) && FD_ISSET(w->ifd, &rifds))) {
+                    if (unlikely(web_client_receive(w) < 0)) {
+                        // error("cannot read from client %zu", i);
+                        web_client_release(w);
+                        continue;
+                    }
+
+                    if (w->mode != WEB_CLIENT_MODE_FILECOPY) {
+                        debug(D_WEB_CLIENT, "%llu: Processing received data.", w->id);
+                        web_client_process_request(w);
+                    }
+                }
+
+                if (unlikely(web_client_has_wait_send(w) && FD_ISSET(w->ofd, &rofds))) {
+                    if (unlikely(web_client_send(w) < 0)) {
+                        // error("cannot send data to client %zu", i);
+                        debug(D_WEB_CLIENT, "%llu: Cannot send data to client. Closing client.", w->id);
+                        web_client_release(w);
+                        continue;
+                    }
+                }
+
+                if(unlikely(single_threaded_link_client(w, &ifds, &ofds, &efds, &fdmax) != 0)) {
+                    // error("failed to link client %zu", i);
+                    web_client_release(w);
+                }
+            }
+        }
+        else {
+            debug(D_WEB_CLIENT_ACCESS, "LISTENER: single threaded web server timeout.");
+        }
+    }
+
+    netdata_thread_cleanup_pop(1);
+    return NULL;
+}
+
+
diff --git a/web/server/single/single-threaded.h b/web/server/single/single-threaded.h
new file mode 100644
index 0000000000..fab4ceba1d
--- /dev/null
+++ b/web/server/single/single-threaded.h
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_WEB_SERVER_SINGLE_THREADED_H
+#define NETDATA_WEB_SERVER_SINGLE_THREADED_H
+
+#include "web/server/web_server.h"
+
+extern void *socket_listen_main_single_threaded(void *ptr);
+
+#endif //NETDATA_WEB_SERVER_SINGLE_THREADED_H
diff --git a/web/server/static/Makefile.am b/web/server/static/Makefile.am
new file mode 100644
index 0000000000..90cc9ca1eb
--- /dev/null
+++ b/web/server/static/Makefile.am
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+AUTOMAKE_OPTIONS = subdir-objects
+MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
+
+SUBDIRS = \
+    $(NULL)
+
+dist_noinst_DATA = \
+	README.md \
+	$(NULL)
diff --git a/web/server/static/README.md b/web/server/static/README.md
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/web/server/static/README.md
diff --git a/web/server/static/static-threaded.c b/web/server/static/static-threaded.c
new file mode 100644
index 0000000000..a037390b8a
--- /dev/null
+++ b/web/server/static/static-threaded.c
@@ -0,0 +1,422 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#define WEB_SERVER_INTERNALS 1
+#include "static-threaded.h"
+
+// ----------------------------------------------------------------------------
+// high level web clients connection management
+
+static struct web_client *web_client_create_on_fd(int fd, const char *client_ip, const char *client_port) {
+    struct web_client *w;
+
+    w = web_client_get_from_cache_or_allocate();
+    w->ifd = w->ofd = fd;
+
+    strncpyz(w->client_ip, client_ip, sizeof(w->client_ip) - 1);
+    strncpyz(w->client_port, client_port, sizeof(w->client_port) - 1);
+
+    if(unlikely(!*w->client_ip))   strcpy(w->client_ip,   "-");
+    if(unlikely(!*w->client_port)) strcpy(w->client_port, "-");
+
+    web_client_initialize_connection(w);
+    return(w);
+}
+
+// --------------------------------------------------------------------------------------
+// the main socket listener - STATIC-THREADED
+
+struct web_server_static_threaded_worker {
+    netdata_thread_t thread;
+
+    int id;
+    int running;
+
+    size_t max_sockets;
+
+    volatile size_t connected;
+    volatile size_t disconnected;
+    volatile size_t receptions;
+    volatile size_t sends;
+    volatile size_t max_concurrent;
+
+    volatile size_t files_read;
+    volatile size_t file_reads;
+};
+
+static long long static_threaded_workers_count = 1;
+static struct web_server_static_threaded_worker *static_workers_private_data = NULL;
+static __thread struct web_server_static_threaded_worker *worker_private = NULL;
+
+// ----------------------------------------------------------------------------
+
+static inline int web_server_check_client_status(struct web_client *w) {
+    if(unlikely(web_client_check_dead(w) || (!web_client_has_wait_receive(w) && !web_client_has_wait_send(w))))
+        return -1;
+
+    return 0;
+}
+
+// ----------------------------------------------------------------------------
+// web server files
+
+static void *web_server_file_add_callback(POLLINFO *pi, short int *events, void *data) {
+    struct web_client *w = (struct web_client *)data;
+
+    worker_private->files_read++;
+
+    debug(D_WEB_CLIENT, "%llu: ADDED FILE READ ON FD %d", w->id, pi->fd);
+    *events = POLLIN;
+    pi->data = w;
+    return w;
+}
+
+static void web_werver_file_del_callback(POLLINFO *pi) {
+    struct web_client *w = (struct web_client *)pi->data;
+    debug(D_WEB_CLIENT, "%llu: RELEASE FILE READ ON FD %d", w->id, pi->fd);
+
+    w->pollinfo_filecopy_slot = 0;
+
+    if(unlikely(!w->pollinfo_slot)) {
+        debug(D_WEB_CLIENT, "%llu: CROSS WEB CLIENT CLEANUP (iFD %d, oFD %d)", w->id, pi->fd, w->ofd);
+        web_client_release(w);
+    }
+}
+
+static int web_server_file_read_callback(POLLINFO *pi, short int *events) {
+    struct web_client *w = (struct web_client *)pi->data;
+
+    // if there is no POLLINFO linked to this, it means the client disconnected
+    // stop the file reading too
+    if(unlikely(!w->pollinfo_slot)) {
+        debug(D_WEB_CLIENT, "%llu: PREVENTED ATTEMPT TO READ FILE ON FD %d, ON CLOSED WEB CLIENT", w->id, pi->fd);
+        return -1;
+    }
+
+    if(unlikely(w->mode != WEB_CLIENT_MODE_FILECOPY || w->ifd == w->ofd)) {
+        debug(D_WEB_CLIENT, "%llu: PREVENTED ATTEMPT TO READ FILE ON FD %d, ON NON-FILECOPY WEB CLIENT", w->id, pi->fd);
+        return -1;
+    }
+
+    debug(D_WEB_CLIENT, "%llu: READING FILE ON FD %d", w->id, pi->fd);
+
+    worker_private->file_reads++;
+    ssize_t ret = unlikely(web_client_read_file(w));
+
+    if(likely(web_client_has_wait_send(w))) {
+        POLLJOB *p = pi->p;                                        // our POLLJOB
+        POLLINFO *wpi = pollinfo_from_slot(p, w->pollinfo_slot);  // POLLINFO of the client socket
+
+        debug(D_WEB_CLIENT, "%llu: SIGNALING W TO SEND (iFD %d, oFD %d)", w->id, pi->fd, wpi->fd);
+        p->fds[wpi->slot].events |= POLLOUT;
+    }
+
+    if(unlikely(ret <= 0 || w->ifd == w->ofd)) {
+        debug(D_WEB_CLIENT, "%llu: DONE READING FILE ON FD %d", w->id, pi->fd);
+        return -1;
+    }
+
+    *events = POLLIN;
+    return 0;
+}
+
+static int web_server_file_write_callback(POLLINFO *pi, short int *events) {
+    (void)pi;
+    (void)events;
+
+    error("Writing to web files is not supported!");
+
+    return -1;
+}
+
+// ----------------------------------------------------------------------------
+// web server clients
+
+static void *web_server_add_callback(POLLINFO *pi, short int *events, void *data) {
+    (void)data;
+
+    worker_private->connected++;
+
+    size_t concurrent = worker_private->connected - worker_private->disconnected;
+    if(unlikely(concurrent > worker_private->max_concurrent))
+        worker_private->max_concurrent = concurrent;
+
+    *events = POLLIN;
+
+    debug(D_WEB_CLIENT_ACCESS, "LISTENER on %d: new connection.", pi->fd);
+    struct web_client *w = web_client_create_on_fd(pi->fd, pi->client_ip, pi->client_port);
+    w->pollinfo_slot = pi->slot;
+
+    if(unlikely(pi->socktype == AF_UNIX))
+        web_client_set_unix(w);
+    else
+        web_client_set_tcp(w);
+
+    debug(D_WEB_CLIENT, "%llu: ADDED CLIENT FD %d", w->id, pi->fd);
+    return w;
+}
+
+// TCP client disconnected
+static void web_server_del_callback(POLLINFO *pi) {
+    worker_private->disconnected++;
+
+    struct web_client *w = (struct web_client *)pi->data;
+
+    w->pollinfo_slot = 0;
+    if(unlikely(w->pollinfo_filecopy_slot)) {
+        POLLINFO *fpi = pollinfo_from_slot(pi->p, w->pollinfo_filecopy_slot);  // POLLINFO of the client socket
+        debug(D_WEB_CLIENT, "%llu: THE CLIENT WILL BE FRED BY READING FILE JOB ON FD %d", w->id, fpi->fd);
+    }
+    else {
+        if(web_client_flag_check(w, WEB_CLIENT_FLAG_DONT_CLOSE_SOCKET))
+            pi->flags |= POLLINFO_FLAG_DONT_CLOSE;
+
+        debug(D_WEB_CLIENT, "%llu: CLOSING CLIENT FD %d", w->id, pi->fd);
+        web_client_release(w);
+    }
+}
+
+static int web_server_rcv_callback(POLLINFO *pi, short int *events) {
+    worker_private->receptions++;
+
+    struct web_client *w = (struct web_client *)pi->data;
+    int fd = pi->fd;
+
+    if(unlikely(web_client_receive(w) < 0))
+        return -1;
+
+    debug(D_WEB_CLIENT, "%llu: processing received data on fd %d.", w->id, fd);
+    web_client_process_request(