diff --git a/docs/text/LICENSE b/docs/text/LICENSE
index 2792c44..985470e 100644
--- a/docs/text/LICENSE
+++ b/docs/text/LICENSE
@@ -1,6 +1,6 @@
 /* 
  * Copyright (C) 2002-2021 Igor Sysoev
- * Copyright (C) 2011-2023 Nginx, Inc.
+ * Copyright (C) 2011-2024 Nginx, Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index 36d5882..3fea587 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -5226,6 +5226,9 @@ ngx_ssl_get_curves(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
     }
 
     curves = ngx_palloc(pool, n * sizeof(int));
+    if (curves == NULL) {
+        return NGX_ERROR;
+    }
 
     n = SSL_get1_curves(c->ssl->connection, curves);
     len = 0;
diff --git a/src/event/ngx_event_pipe.c b/src/event/ngx_event_pipe.c
index 54412e1..d774903 100644
--- a/src/event/ngx_event_pipe.c
+++ b/src/event/ngx_event_pipe.c
@@ -57,7 +57,9 @@ ngx_event_pipe(ngx_event_pipe_t *p, ngx_int_t do_write)
         do_write = 1;
     }
 
-    if (p->upstream->fd != (ngx_socket_t) -1) {
+    if (p->upstream
+        && p->upstream->fd != (ngx_socket_t) -1)
+    {
         rev = p->upstream->read;
 
         flags = (rev->eof || rev->error) ? NGX_CLOSE_EVENT : 0;
@@ -108,7 +110,9 @@ ngx_event_pipe_read_upstream(ngx_event_pipe_t *p)
     ngx_msec_t    delay;
     ngx_chain_t  *chain, *cl, *ln;
 
-    if (p->upstream_eof || p->upstream_error || p->upstream_done) {
+    if (p->upstream_eof || p->upstream_error || p->upstream_done
+        || p->upstream == NULL)
+    {
         return NGX_OK;
     }
 
diff --git a/src/http/ngx_http_copy_filter_module.c b/src/http/ngx_http_copy_filter_module.c
index bd3028b..8e5de2b 100644
--- a/src/http/ngx_http_copy_filter_module.c
+++ b/src/http/ngx_http_copy_filter_module.c
@@ -170,6 +170,8 @@ ngx_http_copy_aio_handler(ngx_output_chain_ctx_t *ctx, ngx_file_t *file)
     file->aio->data = r;
     file->aio->handler = ngx_http_copy_aio_event_handler;
 
+    ngx_add_timer(&file->aio->event, 60000);
+
     r->main->blocked++;
     r->aio = 1;
     ctx->aio = 1;
@@ -192,12 +194,32 @@ ngx_http_copy_aio_event_handler(ngx_event_t *ev)
     ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                    "http aio: \"%V?%V\"", &r->uri, &r->args);
 
+    if (ev->timedout) {
+        ngx_log_error(NGX_LOG_ALERT, c->log, 0,
+                      "aio operation took too long");
+        ev->timedout = 0;
+        return;
+    }
+
+    if (ev->timer_set) {
+        ngx_del_timer(ev);
+    }
+
     r->main->blocked--;
     r->aio = 0;
 
-    r->write_event_handler(r);
+    if (r->main->terminated) {
+        /*
+         * trigger connection event handler if the request was
+         * terminated
+         */
 
-    ngx_http_run_posted_requests(c);
+        c->write->handler(c->write);
+
+    } else {
+        r->write_event_handler(r);
+        ngx_http_run_posted_requests(c);
+    }
 }
 
 #endif
@@ -264,6 +286,8 @@ ngx_http_copy_thread_handler(ngx_thread_task_t *task, ngx_file_t *file)
         return NGX_ERROR;
     }
 
+    ngx_add_timer(&task->event, 60000);
+
     r->main->blocked++;
     r->aio = 1;
 
@@ -288,6 +312,17 @@ ngx_http_copy_thread_event_handler(ngx_event_t *ev)
     ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                    "http thread: \"%V?%V\"", &r->uri, &r->args);
 
+    if (ev->timedout) {
+        ngx_log_error(NGX_LOG_ALERT, c->log, 0,
+                      "thread operation took too long");
+        ev->timedout = 0;
+        return;
+    }
+
+    if (ev->timer_set) {
+        ngx_del_timer(ev);
+    }
+
     r->main->blocked--;
     r->aio = 0;
 
@@ -305,11 +340,11 @@ ngx_http_copy_thread_event_handler(ngx_event_t *ev)
 
 #endif
 
-    if (r->done) {
+    if (r->done || r->main->terminated) {
         /*
          * trigger connection event handler if the subrequest was
-         * already finalized; this can happen if the handler is used
-         * for sendfile() in threads
+         * already finalized (this can happen if the handler is used
+         * for sendfile() in threads), or if the request was terminated
          */
 
         c->write->handler(c->write);
diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
index 97a91ae..033a3bf 100644
--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c
@@ -3961,7 +3961,7 @@ ngx_http_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 
     ngx_str_t              *value, size;
     ngx_url_t               u;
-    ngx_uint_t              n, i;
+    ngx_uint_t              n, i, backlog;
     ngx_http_listen_opt_t   lsopt;
 
     cscf->listen = 1;
@@ -4000,6 +4000,8 @@ ngx_http_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
     lsopt.ipv6only = 1;
 #endif
 
+    backlog = 0;
+
     for (n = 2; n < cf->args->nelts; n++) {
 
         if (ngx_strcmp(value[n].data, "default_server") == 0
@@ -4058,6 +4060,8 @@ ngx_http_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
                 return NGX_CONF_ERROR;
             }
 
+            backlog = 1;
+
             continue;
         }
 
@@ -4305,9 +4309,29 @@ ngx_http_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         return NGX_CONF_ERROR;
     }
 
-#if (NGX_HTTP_V3)
-
     if (lsopt.quic) {
+#if (NGX_HAVE_TCP_FASTOPEN)
+        if (lsopt.fastopen != -1) {
+            return "\"fastopen\" parameter is incompatible with \"quic\"";
+        }
+#endif
+
+        if (backlog) {
+            return "\"backlog\" parameter is incompatible with \"quic\"";
+        }
+
+#if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER)
+        if (lsopt.accept_filter) {
+            return "\"accept_filter\" parameter is incompatible with \"quic\"";
+        }
+#endif
+
+#if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT)
+        if (lsopt.deferred_accept) {
+            return "\"deferred\" parameter is incompatible with \"quic\"";
+        }
+#endif
+
 #if (NGX_HTTP_SSL)
         if (lsopt.ssl) {
             return "\"ssl\" parameter is incompatible with \"quic\"";
@@ -4320,13 +4344,15 @@ ngx_http_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         }
 #endif
 
+        if (lsopt.so_keepalive) {
+            return "\"so_keepalive\" parameter is incompatible with \"quic\"";
+        }
+
         if (lsopt.proxy_protocol) {
             return "\"proxy_protocol\" parameter is incompatible with \"quic\"";
         }
     }
 
-#endif
-
     for (n = 0; n < u.naddrs; n++) {
 
         for (i = 0; i < n; i++) {
diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
index aa5fd19..5209f00 100644
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c
@@ -14,7 +14,7 @@
 static ngx_int_t ngx_http_file_cache_lock(ngx_http_request_t *r,
     ngx_http_cache_t *c);
 static void ngx_http_file_cache_lock_wait_handler(ngx_event_t *ev);
-static void ngx_http_file_cache_lock_wait(ngx_http_request_t *r,
+static ngx_int_t ngx_http_file_cache_lock_wait(ngx_http_request_t *r,
     ngx_http_cache_t *c);
 static ngx_int_t ngx_http_file_cache_read(ngx_http_request_t *r,
     ngx_http_cache_t *c);
@@ -463,6 +463,7 @@ ngx_http_file_cache_lock(ngx_http_request_t *r, ngx_http_cache_t *c)
 static void
 ngx_http_file_cache_lock_wait_handler(ngx_event_t *ev)
 {
+    ngx_int_t            rc;
     ngx_connection_t    *c;
     ngx_http_request_t  *r;
 
@@ -474,13 +475,31 @@ ngx_http_file_cache_lock_wait_handler(ngx_event_t *ev)
     ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                    "http file cache wait: \"%V?%V\"", &r->uri, &r->args);
 
-    ngx_http_file_cache_lock_wait(r, r->cache);
+    rc = ngx_http_file_cache_lock_wait(r, r->cache);
 
-    ngx_http_run_posted_requests(c);
+    if (rc == NGX_AGAIN) {
+        return;
+    }
+
+    r->cache->waiting = 0;
+    r->main->blocked--;
+
+    if (r->main->terminated) {
+        /*
+         * trigger connection event handler if the request was
+         * terminated
+         */
+
+        c->write->handler(c->write);
+
+    } else {
+        r->write_event_handler(r);
+        ngx_http_run_posted_requests(c);
+    }
 }
 
 
-static void
+static ngx_int_t
 ngx_http_file_cache_lock_wait(ngx_http_request_t *r, ngx_http_cache_t *c)
 {
     ngx_uint_t              wait;
@@ -495,7 +514,7 @@ ngx_http_file_cache_lock_wait(ngx_http_request_t *r, ngx_http_cache_t *c)
         ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                       "cache lock timeout");
         c->lock_timeout = 0;
-        goto wakeup;
+        return NGX_OK;
     }
 
     cache = c->file_cache;
@@ -513,14 +532,10 @@ ngx_http_file_cache_lock_wait(ngx_http_request_t *r, ngx_http_cache_t *c)
 
     if (wait) {
         ngx_add_timer(&c->wait_event, (timer > 500) ? 500 : timer);
-        return;
+        return NGX_AGAIN;
     }
 
-wakeup:
-
-    c->waiting = 0;
-    r->main->blocked--;
-    r->write_event_handler(r);
+    return NGX_OK;
 }
 
 
@@ -690,6 +705,8 @@ ngx_http_file_cache_aio_read(ngx_http_request_t *r, ngx_http_cache_t *c)
         c->file.aio->data = r;
         c->file.aio->handler = ngx_http_cache_aio_event_handler;
 
+        ngx_add_timer(&c->file.aio->event, 60000);
+
         r->main->blocked++;
         r->aio = 1;
 
@@ -737,12 +754,32 @@ ngx_http_cache_aio_event_handler(ngx_event_t *ev)
     ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                    "http file cache aio: \"%V?%V\"", &r->uri, &r->args);
 
+    if (ev->timedout) {
+        ngx_log_error(NGX_LOG_ALERT, c->log, 0,
+                      "aio operation took too long");
+        ev->timedout = 0;
+        return;
+    }
+
+    if (ev->timer_set) {
+        ngx_del_timer(ev);
+    }
+
     r->main->blocked--;
     r->aio = 0;
 
-    r->write_event_handler(r);
+    if (r->main->terminated) {
+        /*
+         * trigger connection event handler if the request was
+         * terminated
+         */
 
-    ngx_http_run_posted_requests(c);
+        c->write->handler(c->write);
+
+    } else {
+        r->write_event_handler(r);
+        ngx_http_run_posted_requests(c);
+    }
 }
 
 #endif
@@ -786,6 +823,8 @@ ngx_http_cache_thread_handler(ngx_thread_task_t *task, ngx_file_t *file)
         return NGX_ERROR;
     }
 
+    ngx_add_timer(&task->event, 60000);
+
     r->main->blocked++;
     r->aio = 1;
 
@@ -807,12 +846,32 @@ ngx_http_cache_thread_event_handler(ngx_event_t *ev)
     ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                    "http file cache thread: \"%V?%V\"", &r->uri, &r->args);
 
+    if (ev->timedout) {
+        ngx_log_error(NGX_LOG_ALERT, c->log, 0,
+                      "thread operation took too long");
+        ev->timedout = 0;
+        return;
+    }
+
+    if (ev->timer_set) {
+        ngx_del_timer(ev);
+    }
+
     r->main->blocked--;
     r->aio = 0;
 
-    r->write_event_handler(r);
+    if (r->main->terminated) {
+        /*
+         * trigger connection event handler if the request was
+         * terminated
+         */
 
-    ngx_http_run_posted_requests(c);
+        c->write->handler(c->write);
+
+    } else {
+        r->write_event_handler(r);
+        ngx_http_run_posted_requests(c);
+    }
 }
 
 #endif
diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index 21738ff..3cca57c 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -2694,6 +2694,8 @@ ngx_http_terminate_request(ngx_http_request_t *r, ngx_int_t rc)
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "http terminate request count:%d", mr->count);
 
+    mr->terminated = 1;
+
     if (rc > 0 && (mr->headers_out.status == 0 || mr->connection->sent == 0)) {
         mr->headers_out.status = rc;
     }
@@ -2716,8 +2718,11 @@ ngx_http_terminate_request(ngx_http_request_t *r, ngx_int_t rc)
     if (mr->write_event_handler) {
 
         if (mr->blocked) {
+            r = r->connection->data;
+
             r->connection->error = 1;
             r->write_event_handler = ngx_http_request_finalizer;
+
             return;
         }
 
diff --git a/src/http/ngx_http_request.h b/src/http/ngx_http_request.h
index 48b052b..65c8333 100644
--- a/src/http/ngx_http_request.h
+++ b/src/http/ngx_http_request.h
@@ -550,6 +550,7 @@ struct ngx_http_request_s {
     unsigned                          root_tested:1;
     unsigned                          done:1;
     unsigned                          logged:1;
+    unsigned                          terminated:1;
 
     unsigned                          buffered:4;
 
diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index f5db653..2ce9f21 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -3949,6 +3949,8 @@ ngx_http_upstream_thread_handler(ngx_thread_task_t *task, ngx_file_t *file)
     r->aio = 1;
     p->aio = 1;
 
+    ngx_add_timer(&task->event, 60000);
+
     return NGX_OK;
 }
 
@@ -3967,6 +3969,17 @@ ngx_http_upstream_thread_event_handler(ngx_event_t *ev)
     ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                    "http upstream thread: \"%V?%V\"", &r->uri, &r->args);
 
+    if (ev->timedout) {
+        ngx_log_error(NGX_LOG_ALERT, c->log, 0,
+                      "thread operation took too long");
+        ev->timedout = 0;
+        return;
+    }
+
+    if (ev->timer_set) {
+        ngx_del_timer(ev);
+    }
+
     r->main->blocked--;
     r->aio = 0;
 
@@ -3984,11 +3997,11 @@ ngx_http_upstream_thread_event_handler(ngx_event_t *ev)
 
 #endif
 
-    if (r->done) {
+    if (r->done || r->main->terminated) {
         /*
          * trigger connection event handler if the subrequest was
-         * already finalized; this can happen if the handler is used
-         * for sendfile() in threads
+         * already finalized (this can happen if the handler is used
+         * for sendfile() in threads), or if the request was terminated
          */
 
         c->write->handler(c->write);
@@ -4561,6 +4574,10 @@ ngx_http_upstream_finalize_request(ngx_http_request_t *r,
 
     u->peer.connection = NULL;
 
+    if (u->pipe) {
+        u->pipe->upstream = NULL;
+    }
+
     if (u->pipe && u->pipe->temp_file) {
         ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                        "http upstream temp fd: %d",
diff --git a/src/os/unix/ngx_files.c b/src/os/unix/ngx_files.c
index 1c82a8e..2fec1ec 100644
--- a/src/os/unix/ngx_files.c
+++ b/src/os/unix/ngx_files.c
@@ -110,6 +110,8 @@ ngx_thread_read(ngx_file_t *file, u_char *buf, size_t size, off_t offset,
             return NGX_ERROR;
         }
 
+        task->event.log = file->log;
+
         file->thread_task = task;
     }
 
@@ -493,6 +495,8 @@ ngx_thread_write_chain_to_file(ngx_file_t *file, ngx_chain_t *cl, off_t offset,
             return NGX_ERROR;
         }
 
+        task->event.log = file->log;
+
         file->thread_task = task;
     }
 
diff --git a/src/os/unix/ngx_linux_sendfile_chain.c b/src/os/unix/ngx_linux_sendfile_chain.c
index 101d91a..603f917 100644
--- a/src/os/unix/ngx_linux_sendfile_chain.c
+++ b/src/os/unix/ngx_linux_sendfile_chain.c
@@ -332,6 +332,7 @@ ngx_linux_sendfile_thread(ngx_connection_t *c, ngx_buf_t *file, size_t size)
             return NGX_ERROR;
         }
 
+        task->event.log = c->log;
         task->handler = ngx_linux_sendfile_thread_handler;
 
         c->sendfile_task = task;
diff --git a/src/os/unix/ngx_process_cycle.c b/src/os/unix/ngx_process_cycle.c
index 98d2dd2..5bc5ce9 100644
--- a/src/os/unix/ngx_process_cycle.c
+++ b/src/os/unix/ngx_process_cycle.c
@@ -948,7 +948,7 @@ ngx_worker_process_exit(ngx_cycle_t *cycle)
         }
     }
 
-    if (ngx_exiting) {
+    if (ngx_exiting && !ngx_terminate) {
         c = cycle->connections;
         for (i = 0; i < cycle->connection_n; i++) {
             if (c[i].fd != -1
@@ -963,11 +963,11 @@ ngx_worker_process_exit(ngx_cycle_t *cycle)
                 ngx_debug_quit = 1;
             }
         }
+    }
 
-        if (ngx_debug_quit) {
-            ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "aborting");
-            ngx_debug_point();
-        }
+    if (ngx_debug_quit) {
+        ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "aborting");
+        ngx_debug_point();
     }
 
     /*
diff --git a/src/os/win32/ngx_process_cycle.c b/src/os/win32/ngx_process_cycle.c
index 0c848ef..a39335f 100644
--- a/src/os/win32/ngx_process_cycle.c
+++ b/src/os/win32/ngx_process_cycle.c
@@ -834,7 +834,7 @@ ngx_worker_process_exit(ngx_cycle_t *cycle)
         }
     }
 
-    if (ngx_exiting) {
+    if (ngx_exiting && !ngx_terminate) {
         c = cycle->connections;
         for (i = 0; i < cycle->connection_n; i++) {
             if (c[i].fd != (ngx_socket_t) -1