bugfix: use of C global variables at config time could lead to issues…

… when HUP reload failed in the middle.

src/ngx_http_echo_filter.c

@@ -10,7 +10,6 @@
 #include <ngx_log.h>
 
 
-unsigned ngx_http_echo_filter_used;
 
 ngx_http_output_header_filter_pt ngx_http_echo_next_header_filter;
 
@@ -27,9 +26,13 @@ static ngx_int_t ngx_http_echo_exec_filter_cmds(ngx_http_request_t *r,
 
 
 ngx_int_t
-ngx_http_echo_filter_init (ngx_conf_t *cf)
+ngx_http_echo_filter_init(ngx_conf_t *cf)
 {
-    if (ngx_http_echo_filter_used) {
+    ngx_http_echo_main_conf_t       *emcf;
+
+    emcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_echo_module);
+
+    if (emcf->filter_used) {
         dd("top header filter: %ld",
                 (unsigned long) ngx_http_top_header_filter);
 

src/ngx_http_echo_filter.h

@@ -3,7 +3,6 @@
 
 #include "ngx_http_echo_module.h"
 
-extern unsigned ngx_http_echo_filter_used;
 
 extern ngx_http_output_header_filter_pt ngx_http_echo_next_header_filter;
 

src/ngx_http_echo_handler.c

@@ -19,24 +19,6 @@
 #include <ngx_log.h>
 
 
-ngx_int_t
-ngx_http_echo_handler_init(ngx_conf_t *cf)
-{
-    ngx_int_t         rc;
-
-#if 1
-    ngx_http_echo_filter_used = 0;
-#endif
-
-    rc = ngx_http_echo_echo_init(cf);
-    if (rc != NGX_OK) {
-        return rc;
-    }
-
-    return ngx_http_echo_add_variables(cf);
-}
-
-
 void
 ngx_http_echo_wev_handler(ngx_http_request_t *r)
 {

src/ngx_http_echo_module.c

@@ -5,7 +5,9 @@
 
 #include "ngx_http_echo_handler.h"
 #include "ngx_http_echo_filter.h"
+#include "ngx_http_echo_echo.h"
 #include "ngx_http_echo_request_info.h"
+#include "ngx_http_echo_var.h"
 
 #include <nginx.h>
 #include <ngx_config.h>
@@ -15,6 +17,8 @@
 static void * ngx_http_echo_create_loc_conf(ngx_conf_t *cf);
 static char * ngx_http_echo_merge_loc_conf(ngx_conf_t *cf, void *parent,
     void *child);
+static void *ngx_http_echo_create_main_conf(ngx_conf_t *cf);
+static ngx_int_t ngx_http_echo_post_config(ngx_conf_t *cf);
 
 /* config directive handlers */
 static char * ngx_http_echo_echo(ngx_conf_t *cf, ngx_command_t *cmd,
@@ -59,17 +63,17 @@ static char * ngx_http_echo_helper(ngx_http_echo_opcode_t opcode,
 
 
 static ngx_http_module_t ngx_http_echo_module_ctx = {
-    ngx_http_echo_handler_init,    /* preconfiguration */
-    ngx_http_echo_filter_init,     /* postconfiguration */
+    NULL,                           /* preconfiguration */
+    ngx_http_echo_post_config,      /* postconfiguration */
 
-    NULL,                          /* create main configuration */
-    NULL,                          /* init main configuration */
+    ngx_http_echo_create_main_conf, /* create main configuration */
+    NULL,                           /* init main configuration */
 
-    NULL,                          /* create server configuration */
-    NULL,                          /* merge server configuration */
+    NULL,                           /* create server configuration */
+    NULL,                           /* merge server configuration */
 
-    ngx_http_echo_create_loc_conf, /* create location configuration */
-    ngx_http_echo_merge_loc_conf   /* merge location configuration */
+    ngx_http_echo_create_loc_conf,  /* create location configuration */
+    ngx_http_echo_merge_loc_conf    /* merge location configuration */
 };
 
 
@@ -289,8 +293,11 @@ ngx_http_echo_helper(ngx_http_echo_opcode_t opcode,
     ngx_http_echo_cmd_t             *echo_cmd;
     ngx_http_core_loc_conf_t        *clcf;
     ngx_http_script_compile_t        sc;
+    ngx_http_echo_main_conf_t       *emcf;
     ngx_http_echo_arg_template_t    *arg;
 
+    emcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_echo_module);
+
     /* cmds_ptr points to ngx_http_echo_loc_conf_t's
      * handler_cmds, before_body_cmds, or after_body_cmds
      * array, depending on the actual offset */
@@ -315,7 +322,7 @@ ngx_http_echo_helper(ngx_http_echo_opcode_t opcode,
 
         } else {
             dd("filter used = 1");
-            ngx_http_echo_filter_used = 1;
+            emcf->filter_used = 1;
         }
     }
 
@@ -610,3 +617,36 @@ ngx_http_echo_echo_exec(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
     return ngx_http_echo_helper(echo_opcode_echo_exec, echo_handler_cmd,
                                 cf, cmd, conf);
 }
+
+
+static void *
+ngx_http_echo_create_main_conf(ngx_conf_t *cf)
+{
+    ngx_http_echo_main_conf_t    *emcf;
+
+    emcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_echo_main_conf_t));
+    if (emcf == NULL) {
+        return NULL;
+    }
+
+    return emcf;
+}
+
+
+static ngx_int_t
+ngx_http_echo_post_config(ngx_conf_t *cf)
+{
+    ngx_int_t         rc;
+
+    rc = ngx_http_echo_filter_init(cf);
+    if (rc != NGX_OK) {
+        return rc;
+    }
+
+    rc = ngx_http_echo_echo_init(cf);
+    if (rc != NGX_OK) {
+        return rc;
+    }
+
+    return ngx_http_echo_add_variables(cf);
+}

src/ngx_http_echo_module.h

@@ -86,6 +86,11 @@ typedef struct {
 } ngx_http_echo_loc_conf_t;
 
 
+typedef struct {
+    ngx_int_t       filter_used;
+} ngx_http_echo_main_conf_t;
+
+
 typedef struct {
     ngx_array_t     *choices; /* items after splitting */
     ngx_uint_t      next_choice;  /* current item index */

t/filter-used.t

@@ -0,0 +1,59 @@
+# vi:filetype=
+
+use lib 'lib';
+use Test::Nginx::Socket;
+
+repeat_each(2);
+
+plan tests => repeat_each() * (3 * blocks());
+
+no_long_string();
+log_level('warn');
+
+#master_on();
+#workers(1);
+
+run_tests();
+
+__DATA__
+
+=== TEST 1: filter indeed used
+--- http_config
+    postpone_output 1;
+--- config
+    location /echo {
+        echo_after_body hello;
+        echo world;
+    }
+--- request
+    GET /echo
+--- stap
+F(ngx_http_echo_header_filter) {
+    println("echo header filter called")
+}
+--- stap_out
+echo header filter called
+--- response_body
+world
+hello
+
+
+
+=== TEST 2: filter not used
+--- http_config
+    postpone_output 1;
+--- config
+    location /echo {
+        #echo_after_body hello;
+        echo world;
+    }
+--- request
+    GET /echo
+--- stap
+F(ngx_http_echo_header_filter) {
+    println("echo header filter called")
+}
+--- stap_out
+--- response_body
+world
+