From: Ruslan Ermilov <ru@nginx.com>
Date: Wed, 7 Dec 2016 19:25:37 +0000 (+0300)
Subject: Slab: added comment about list heads.
X-Git-Url: http://www.kaiwu.me/postgresql/commit/?a=commitdiff_plain;h=4cf89436d10b32f9be4373e00c03518d713d1437;p=nginx.git

Slab: added comment about list heads.
---

diff --git a/src/core/ngx_slab.c b/src/core/ngx_slab.c
index b6473eaf7..4357e8dd9 100644
--- a/src/core/ngx_slab.c
+++ b/src/core/ngx_slab.c
@@ -113,6 +113,7 @@ ngx_slab_init(ngx_slab_pool_t *pool)
     n = ngx_pagesize_shift - pool->min_shift;
 
     for (i = 0; i < n; i++) {
+        /* only "next" is used in list head */
         slots[i].slab = 0;
         slots[i].next = &slots[i];
         slots[i].prev = 0;
@@ -127,8 +128,10 @@ ngx_slab_init(ngx_slab_pool_t *pool)
 
     page = pool->pages;
 
-    pool->free.prev = 0;
+    /* only "next" is used in list head */
+    pool->free.slab = 0;
     pool->free.next = page;
+    pool->free.prev = 0;
 
     page->slab = pages;
     page->next = &pool->free;