fix possible crash while removing peer under highload because request context contents pointer to peer from zone shm -> lazy free memory

Author: ZigzagAK

README.md

@@ -43,13 +43,13 @@ http {
         listen 6000;
 
         location /dynamic {
-		        allow 127.0.0.1;
+            allow 127.0.0.1;
             deny all;
             dynamic_upstream;
         }
 
         location / {
-	          proxy_pass http://backends;
+            proxy_pass http://backends;
         }
     }
 }
@@ -87,19 +87,19 @@ $
 
 ```bash
 $ curl "http://127.0.0.1:6000/dynamic?upstream=zone_for_backends&verbose="
-server 127.0.0.1:6001 weight=1 max_fails=1 fail_timeout=10;
-server 127.0.0.1:6002 weight=1 max_fails=1 fail_timeout=10;
-server 127.0.0.1:6003 weight=1 max_fails=1 fail_timeout=10;
+server 127.0.0.1:6001 weight=1 max_fails=1 fail_timeout=10 max_conns=0 conns=0;
+server 127.0.0.1:6002 weight=1 max_fails=1 fail_timeout=10 max_conns=0 conns=0;
+server 127.0.0.1:6003 weight=1 max_fails=1 fail_timeout=10 max_conns=0 conns=0;
 $
 ```
 
 ## update_parameters
 
 ```bash
-$ curl "http://127.0.0.1:6000/dynamic?upstream=zone_for_backends&server=127.0.0.1:6003&weight=10&max_fails=5&fail_timeout=5"
-server 127.0.0.1:6001 weight=1 max_fails=1 fail_timeout=10;
-server 127.0.0.1:6002 weight=1 max_fails=1 fail_timeout=10;
-server 127.0.0.1:6003 weight=10 max_fails=5 fail_timeout=5;
+$ curl "http://127.0.0.1:6000/dynamic?upstream=zone_for_backends&server=127.0.0.1:6003&weight=10&max_fails=5&fail_timeout=5&max_conns=10"
+server 127.0.0.1:6001 weight=1 max_fails=1 fail_timeout=10 max_conns=0 conns=0;
+server 127.0.0.1:6002 weight=1 max_fails=1 fail_timeout=10 max_conns=0 conns=0;
+server 127.0.0.1:6003 weight=10 max_fails=5 fail_timeout=5 max_conns=10 conns=0;
 $
 ```
 
@@ -113,19 +113,19 @@ The supported parameters are below.
 
 ```bash
 $ curl "http://127.0.0.1:6000/dynamic?upstream=zone_for_backends&server=127.0.0.1:6003&down="
-server 127.0.0.1:6001 weight=1 max_fails=1 fail_timeout=10;
-server 127.0.0.1:6002 weight=1 max_fails=1 fail_timeout=10;
-server 127.0.0.1:6003 weight=1 max_fails=1 fail_timeout=10 down;
+server 127.0.0.1:6001 weight=1 max_fails=1 fail_timeout=10 max_conns=0 conns=0;
+server 127.0.0.1:6002 weight=1 max_fails=1 fail_timeout=10 max_conns=0 conns=0;
+server 127.0.0.1:6003 weight=1 max_fails=1 fail_timeout=10 max_conns=0 conns=0 down;
 $
 ```
 
 ## up
 
 ```bash
 $ curl "http://127.0.0.1:6000/dynamic?upstream=zone_for_backends&server=127.0.0.1:6003&up="
-server 127.0.0.1:6001 weight=1 max_fails=1 fail_timeout=10;
-server 127.0.0.1:6002 weight=1 max_fails=1 fail_timeout=10;
-server 127.0.0.1:6003 weight=1 max_fails=1 fail_timeout=10;
+server 127.0.0.1:6001 weight=1 max_fails=1 fail_timeout=10 max_conns=0 conns=0;
+server 127.0.0.1:6002 weight=1 max_fails=1 fail_timeout=10 max_conns=0 conns=0;
+server 127.0.0.1:6003 weight=1 max_fails=1 fail_timeout=10 max_conns=0 conns=0;
 $
 ```
 

config

@@ -1,9 +1,9 @@
-ngx_addon_name=ngx_dynamic_upstream_module
+ngx_addon_name="ngx_http_dynamic_upstream_module"
 
-DYNAMIC_UPSTREAM_SRCS="                                          \
-                $ngx_addon_dir/src/ngx_dynamic_upstream_module.c \
-                $ngx_addon_dir/src/ngx_dynamic_upstream_op.c     \
-                $ngx_addon_dir/src/ngx_inet_slab.c               \
+DYNAMIC_UPSTREAM_SRCS="                                                 \
+                $ngx_addon_dir/src/ngx_http_dynamic_upstream_module.c   \
+                $ngx_addon_dir/src/ngx_dynamic_upstream_op.c            \
+                $ngx_addon_dir/src/ngx_inet_slab.c                      \
                "
 
 DYNAMIC_UPSTREAM_DEPS="                                          \