# HG changeset patch
# User Valentin Bartenev <vbart@nginx.com>
# Date 1363377649 0
# Node ID a29c574d61facb8e00168e3675a5f6fc36cf5a43
# Parent  a46c1cfe72637324b8a507feef52d591b9b13c34
Status: introduced the "ngx_stat_waiting" counter.

And corresponding variable $connections_waiting was added.

Previously, waiting connections were counted as the difference between
active connections and the sum of reading and writing connections.
That made it impossible to count more than one request in one connection
as reading or writing (as is the case for SPDY).

Also, we no longer count connections in handshake state as waiting.

diff --git a/src/core/ngx_connection.c b/src/core/ngx_connection.c
--- a/src/core/ngx_connection.c
+++ b/src/core/ngx_connection.c
@@ -970,6 +970,10 @@ ngx_reusable_connection(ngx_connection_t
 
     if (c->reusable) {
         ngx_queue_remove(&c->queue);
+
+#if (NGX_STAT_STUB)
+        (void) ngx_atomic_fetch_add(ngx_stat_waiting, -1);
+#endif
     }
 
     c->reusable = reusable;
@@ -979,6 +983,10 @@ ngx_reusable_connection(ngx_connection_t
 
         ngx_queue_insert_head(
             (ngx_queue_t *) &ngx_cycle->reusable_connections_queue, &c->queue);
+
+#if (NGX_STAT_STUB)
+        (void) ngx_atomic_fetch_add(ngx_stat_waiting, 1);
+#endif
     }
 }
 
diff --git a/src/event/ngx_event.c b/src/event/ngx_event.c
--- a/src/event/ngx_event.c
+++ b/src/event/ngx_event.c
@@ -73,6 +73,8 @@ ngx_atomic_t   ngx_stat_reading0;
 ngx_atomic_t  *ngx_stat_reading = &ngx_stat_reading0;
 ngx_atomic_t   ngx_stat_writing0;
 ngx_atomic_t  *ngx_stat_writing = &ngx_stat_writing0;
+ngx_atomic_t   ngx_stat_waiting0;
+ngx_atomic_t  *ngx_stat_waiting = &ngx_stat_waiting0;
 
 #endif
 
@@ -511,7 +513,8 @@ ngx_event_module_init(ngx_cycle_t *cycle
            + cl          /* ngx_stat_requests */
            + cl          /* ngx_stat_active */
            + cl          /* ngx_stat_reading */
-           + cl;         /* ngx_stat_writing */
+           + cl          /* ngx_stat_writing */
+           + cl;         /* ngx_stat_waiting */
 
 #endif
 
@@ -558,6 +561,7 @@ ngx_event_module_init(ngx_cycle_t *cycle
     ngx_stat_active = (ngx_atomic_t *) (shared + 6 * cl);
     ngx_stat_reading = (ngx_atomic_t *) (shared + 7 * cl);
     ngx_stat_writing = (ngx_atomic_t *) (shared + 8 * cl);
+    ngx_stat_waiting = (ngx_atomic_t *) (shared + 9 * cl);
 
 #endif
 
diff --git a/src/event/ngx_event.h b/src/event/ngx_event.h
--- a/src/event/ngx_event.h
+++ b/src/event/ngx_event.h
@@ -511,6 +511,7 @@ extern ngx_atomic_t  *ngx_stat_requests;
 extern ngx_atomic_t  *ngx_stat_active;
 extern ngx_atomic_t  *ngx_stat_reading;
 extern ngx_atomic_t  *ngx_stat_writing;
+extern ngx_atomic_t  *ngx_stat_waiting;
 
 #endif
 
diff --git a/src/http/modules/ngx_http_stub_status_module.c b/src/http/modules/ngx_http_stub_status_module.c
--- a/src/http/modules/ngx_http_stub_status_module.c
+++ b/src/http/modules/ngx_http_stub_status_module.c
@@ -73,6 +73,9 @@ static ngx_http_variable_t  ngx_http_stu
     { ngx_string("connections_writing"), NULL, ngx_http_stub_status_variable,
       2, NGX_HTTP_VAR_NOCACHEABLE, 0 },
 
+    { ngx_string("connections_waiting"), NULL, ngx_http_stub_status_variable,
+      3, NGX_HTTP_VAR_NOCACHEABLE, 0 },
+
     { ngx_null_string, NULL, NULL, 0, 0, 0 }
 };
 
@@ -83,7 +86,7 @@ static ngx_int_t ngx_http_status_handler
     ngx_int_t          rc;
     ngx_buf_t         *b;
     ngx_chain_t        out;
-    ngx_atomic_int_t   ap, hn, ac, rq, rd, wr;
+    ngx_atomic_int_t   ap, hn, ac, rq, rd, wr, wa;
 
     if (r->method != NGX_HTTP_GET && r->method != NGX_HTTP_HEAD) {
         return NGX_HTTP_NOT_ALLOWED;
@@ -126,6 +129,7 @@ static ngx_int_t ngx_http_status_handler
     rq = *ngx_stat_requests;
     rd = *ngx_stat_reading;
     wr = *ngx_stat_writing;
+    wa = *ngx_stat_waiting;
 
     b->last = ngx_sprintf(b->last, "Active connections: %uA \n", ac);
 
@@ -135,7 +139,7 @@ static ngx_int_t ngx_http_status_handler
     b->last = ngx_sprintf(b->last, " %uA %uA %uA \n", ap, hn, rq);
 
     b->last = ngx_sprintf(b->last, "Reading: %uA Writing: %uA Waiting: %uA \n",
-                          rd, wr, ac - (rd + wr));
+                          rd, wr, wa);
 
     r->headers_out.status = NGX_HTTP_OK;
     r->headers_out.content_length_n = b->last - b->pos;
@@ -177,6 +181,10 @@ ngx_http_stub_status_variable(ngx_http_r
         value = *ngx_stat_writing;
         break;
 
+    case 3:
+        value = *ngx_stat_waiting;
+        break;
+
     /* suppress warning */
     default:
         value = 0;