From c5237a8829d591cddf4704e2a51274ae8dc00ea6 Mon Sep 17 00:00:00 2001
From: Igor Sysoev <igor@sysoev.ru>
Date: Wed, 29 Apr 2009 13:42:14 +0000
Subject: [PATCH] handle Winsock select() WSAEINVAL

---
 src/event/modules/ngx_select_module.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/event/modules/ngx_select_module.c b/src/event/modules/ngx_select_module.c
index a50088ba4..f7020809c 100644
--- a/src/event/modules/ngx_select_module.c
+++ b/src/event/modules/ngx_select_module.c
@@ -314,7 +314,21 @@ ngx_select_process_events(ngx_cycle_t *cycle, ngx_msec_t timer,
 
 #if (NGX_WIN32)
 
-    ready = select(0, &work_read_fd_set, &work_write_fd_set, NULL, tp);
+    if (max_read || max_write) {
+        ready = select(0, &work_read_fd_set, &work_write_fd_set, NULL, tp);
+
+    } else {
+
+        /*
+         * Winsock select() requires that at least one descriptor set must be
+         * be non-null, and any non-null descriptor set must contain at least
+         * one handle to a socket.  Otherwise select() returns WSAEINVAL.
+         */
+
+        ngx_msleep(timer);
+
+        ready = 0;
+    }
 
 #else