Moved handling of wev->delayed to the connection event handler.

With post_action or subrequests, it is possible that the timer set for
wev->delayed will expire while the active subrequest write event handler
is not ready to handle this.  This results in request hangs as observed
with limit_rate / sendfile_max_chunk and post_action (ticket #776) or
subrequests (ticket #1228).

Moving the handling to the connection event handler fixes the hangs observed,
and also slightly simplifies the code.

1 files changed, 14 insertions, 21 deletions

diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index dd5491021..8619552ee 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -2198,6 +2198,11 @@ ngx_http_request_handler(ngx_event_t *ev)
     ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                    "http run request: \"%V?%V\"", &r->uri, &r->args);
 
+    if (ev->delayed && ev->timedout) {
+        ev->delayed = 0;
+        ev->timedout = 0;
+    }
+
     if (ev->write) {
         r->write_event_handler(r);
 
@@ -2621,34 +2626,22 @@ ngx_http_writer(ngx_http_request_t *r)
     clcf = ngx_http_get_module_loc_conf(r->main, ngx_http_core_module);
 
     if (wev->timedout) {
-        if (!wev->delayed) {
-            ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT,
-                          "client timed out");
-            c->timedout = 1;
-
-            ngx_http_finalize_request(r, NGX_HTTP_REQUEST_TIME_OUT);
-            return;
-        }
-
-        wev->timedout = 0;
-        wev->delayed = 0;
-
-        if (!wev->ready) {
-            ngx_add_timer(wev, clcf->send_timeout);
-
-            if (ngx_handle_write_event(wev, clcf->send_lowat) != NGX_OK) {
-                ngx_http_close_request(r, 0);
-            }
-
-            return;
-        }
+        ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT,
+                      "client timed out");
+        c->timedout = 1;
 
+        ngx_http_finalize_request(r, NGX_HTTP_REQUEST_TIME_OUT);
+        return;
     }
 
     if (wev->delayed || r->aio) {
         ngx_log_debug0(NGX_LOG_DEBUG_HTTP, wev->log, 0,
                        "http writer delayed");
 
+        if (!wev->delayed) {
+            ngx_add_timer(wev, clcf->send_timeout);
+        }
+
         if (ngx_handle_write_event(wev, clcf->send_lowat) != NGX_OK) {
             ngx_http_close_request(r, 0);
         }