From: Howard Chu <hyc@openldap.org>
Date: Sat, 14 Nov 2009 23:25:14 +0000 (+0000)
Subject: Add a note about sl_malloc stack-based behavior
X-Git-Tag: ACLCHECK_0~122
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=1eebd221513c2c1d79610d55744ae8b78756c038;p=openldap

Add a note about sl_malloc stack-based behavior
---

diff --git a/servers/slapd/sl_malloc.c b/servers/slapd/sl_malloc.c
index 660c59842d..ad4c1d6e7a 100644
--- a/servers/slapd/sl_malloc.c
+++ b/servers/slapd/sl_malloc.c
@@ -90,6 +90,14 @@ slap_sl_mem_init()
 static struct slab_heap *slheap;
 #endif
 
+/* This allocator always returns memory aligned on a 2-int boundary.
+ *
+ * The stack-based allocator stores the size as a ber_len_t at both
+ * the head and tail of the allocated block. When freeing a block, the
+ * tail length is ORed with 1 to mark it as free. Freed space can only
+ * be reclaimed from the tail forward. If the tail block is never freed,
+ * nothing else will be reclaimed until the slab is reset...
+ */
 void *
 slap_sl_mem_create(
 	ber_len_t size,