[src/trunk]: src Our hdestroy implementation was non-conformant because it fr...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/4be67dc477d1
branches:  trunk
changeset: 330755:4be67dc477d1
user:      christos <christos%NetBSD.org@localhost>
date:      Sun Jul 20 13:34:17 2014 +0000

description:
Our hdestroy implementation was non-conformant because it freed the key of
each entry. Add a new function hdestroy1 that allows the user to control
what gets freed. Pointed out by Pedro Giffuni at FreeBSD.

diffstat:

 include/search.h             |   6 ++-
 lib/libc/stdlib/Makefile.inc |   3 +-
 lib/libc/stdlib/hcreate.3    |  91 ++++++++++++++++++++++++++-----------------
 lib/libc/stdlib/hcreate.c    |  27 ++++++++++--
 4 files changed, 82 insertions(+), 45 deletions(-)

diffs (266 lines):

diff -r b2e1a1583dbe -r 4be67dc477d1 include/search.h
--- a/include/search.h  Sun Jul 20 13:34:14 2014 +0000
+++ b/include/search.h  Sun Jul 20 13:34:17 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: search.h,v 1.20 2013/04/27 21:35:25 joerg Exp $        */
+/*     $NetBSD: search.h,v 1.21 2014/07/20 13:34:17 christos Exp $     */
 
 /*
  * Written by J.T. Conklin <jtc%NetBSD.org@localhost>
@@ -62,8 +62,12 @@
 ENTRY  *hsearch(ENTRY, ACTION);
 
 #ifdef _NETBSD_SOURCE
+#define FREE_KEY 1
+#define FREE_DATA 2
+void    hdestroy1(int);
 int     hcreate_r(size_t, struct hsearch_data *);
 void    hdestroy_r(struct hsearch_data *);
+void    hdestroy1_r(struct hsearch_data *, int);
 int     hsearch_r(ENTRY, ACTION, ENTRY **, struct hsearch_data *);
 #endif /* _NETBSD_SOURCE */
 
diff -r b2e1a1583dbe -r 4be67dc477d1 lib/libc/stdlib/Makefile.inc
--- a/lib/libc/stdlib/Makefile.inc      Sun Jul 20 13:34:14 2014 +0000
+++ b/lib/libc/stdlib/Makefile.inc      Sun Jul 20 13:34:17 2014 +0000
@@ -1,4 +1,4 @@
-#      $NetBSD: Makefile.inc,v 1.81 2014/01/08 02:15:42 christos Exp $
+#      $NetBSD: Makefile.inc,v 1.82 2014/07/20 13:34:17 christos Exp $
 #      from: @(#)Makefile.inc  8.3 (Berkeley) 2/4/95
 
 # stdlib sources
@@ -66,6 +66,7 @@
 MLINKS+=getenv.3 getenv_r.3
 MLINKS+=hcreate.3 hdestroy.3 hcreate.3 hsearch.3
 MLINKS+=hcreate.3 hcreate_r.3 hcreate.3 hdestroy_r.3 hcreate.3 hsearch_r.3
+MLINKS+=hcreate.3 hdestroy1.3 hcreate.3 hdestroy1_r.3
 MLINKS+=insque.3 remque.3
 MLINKS+=lsearch.3 lfind.3
 MLINKS+=malloc.3 calloc.3 malloc.3 realloc.3 malloc.3 free.3
diff -r b2e1a1583dbe -r 4be67dc477d1 lib/libc/stdlib/hcreate.3
--- a/lib/libc/stdlib/hcreate.3 Sun Jul 20 13:34:14 2014 +0000
+++ b/lib/libc/stdlib/hcreate.3 Sun Jul 20 13:34:17 2014 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: hcreate.3,v 1.10 2011/09/15 09:14:54 wiz Exp $
+.\"    $NetBSD: hcreate.3,v 1.11 2014/07/20 13:34:17 christos Exp $
 .\"
 .\" Copyright (c) 1999 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -27,14 +27,16 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd September 14, 2011
+.Dd July 20, 2014
 .Dt HCREATE 3
 .Os
 .Sh NAME
 .Nm hcreate ,
 .Nm hcreate_r ,
 .Nm hdestroy ,
+.Nm hdestroy1 ,
 .Nm hdestroy_r ,
+.Nm hdestroy1_r ,
 .Nm hsearch ,
 .Nm hsearch_r
 .Nd manage hash search table
@@ -49,7 +51,11 @@
 .Ft void
 .Fn hdestroy "void"
 .Ft void
+.Fn hdestroy1 "int flags"
+.Ft void
 .Fn hdestroy_r "struct hsearch_data *table"
+.Ft void
+.Fn hdestroy1_r "struct hsearch_data *table" "int flags"
 .Ft ENTRY *
 .Fn hsearch "ENTRY item" "ACTION action"
 .Ft int
@@ -60,6 +66,8 @@
 .Fn hcreate_r ,
 .Fn hdestroy ,
 .Fn hdestroy_r
+.Fn hdestroy1 ,
+.Fn hdestroy1_r
 .Fn hsearch ,
 and
 .Fn hsearch_r
@@ -141,33 +149,49 @@
 .Fa item .
 .El
 .Pp
-Note that the comparison
-.Fa key
-must be allocated using
-.Xr malloc 3
-or
-.Xr calloc 3
-if action is
-.Dv ENTER
-and
+The traditional
 .Fn hdestroy
-will be called.
-This is because
-.Fn hdestroy
-will call
+and
+.Fn hdestroy_r
+functions don't 
 .Xr free 3
-for each comparison
+the data associated with the
+.Fa key
+and
+.Fa value
+of each entry, because they did not allocate them.
+Since there is no
+.Dq iterator
+function provided, the
+.Fn hdestroy1
+and
+.Fn hdestroy1_r
+allow controlling if the
 .Fa key
-(but not
-.Fa data ) .
-Typically the comparison
+or
+.Fa value
+will be freed using the
+.Fa flags
+argument.
+If the bit
+.Dv FREE_KEY
+is set, then the
 .Fa key
-is allocated by using
-.Xr strdup 3 .
+of each entry will be 
+passed to
+.Xr free 3 .
+If the bit
+.Dv FREE_VALUE
+is set, then the
+.Fa value
+of each entry will be 
+passed to
+.Xr free 3 .
 .Pp
 The
 .Fn hcreate_r ,
 .Fn hdestroy_r ,
+.Fn hdestroy1_r ,
 and
 .Fn hsearch_r
 functions are re-entrant versions of the above functions that can
@@ -266,6 +290,7 @@
 .Xr bsearch 3 ,
 .Xr lsearch 3 ,
 .Xr malloc 3 ,
+.Xr free 3 ,
 .Xr strcmp 3
 .Sh STANDARDS
 The
@@ -291,6 +316,13 @@
 functions are
 .Tn GNU
 extensions.
+The
+.Fn hdestroy1
+and
+.Fn hdestroy1_r
+are
+.Nx
+extensions.
 .Sh CAVEATS
 At least the following limitations can be mentioned:
 .Bl -bullet
@@ -301,20 +333,5 @@
 .It
 Individual hash table entries can be added, but not deleted.
 .It
-The standard is indecipherable about the
-internal memory usage of the functions,
-mentioning only that
-.Do
-.Fn hcreate
-and
-.Fn hsearch
-functions may use
-.Fn malloc
-to allocate space
-.Dc .
-This limits the portability of the functions,
-given that other implementations may not
-.Xr free 3
-the buffer pointed by
-.Fa key .
+There is no iterator to scan for all entries in the table.
 .El
diff -r b2e1a1583dbe -r 4be67dc477d1 lib/libc/stdlib/hcreate.c
--- a/lib/libc/stdlib/hcreate.c Sun Jul 20 13:34:14 2014 +0000
+++ b/lib/libc/stdlib/hcreate.c Sun Jul 20 13:34:17 2014 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: hcreate.c,v 1.8 2011/09/17 16:54:39 christos Exp $ */
+/* $NetBSD: hcreate.c,v 1.9 2014/07/20 13:34:17 christos Exp $ */
 
 /*
  * Copyright (c) 2001 Christopher G. Demetriou
@@ -43,7 +43,7 @@
 
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: hcreate.c,v 1.8 2011/09/17 16:54:39 christos Exp $");
+__RCSID("$NetBSD: hcreate.c,v 1.9 2014/07/20 13:34:17 christos Exp $");
 #endif /* LIBC_SCCS and not lint */
 
 #if !defined(lint)
@@ -141,14 +141,20 @@
 }
 
 void
-hdestroy(void)
+hdestroy1(int flags)
 {
        _DIAGASSERT(htable.table != NULL);
-       hdestroy_r(&htable);
+       hdestroy1_r(&htable, flags);
 }
 
 void
-hdestroy_r(struct hsearch_data *head)
+hdestroy(void)
+{
+       hdestroy1(0);
+}
+
+void
+hdestroy1_r(struct hsearch_data *head, int flags)
 {
        struct internal_entry *ie;
        size_t idx;
@@ -166,13 +172,22 @@
                while (!SLIST_EMPTY(&table[idx])) {
                        ie = SLIST_FIRST(&table[idx]);
                        SLIST_REMOVE_HEAD(&table[idx], link);
-                       free(ie->ent.key);
+                       if (flags & FREE_KEY)
+                               free(ie->ent.key);
+                       if (flags & FREE_DATA)
+                               free(ie->ent.data);
                        free(ie);
                }
        }
        free(table);
 }
 
+void
+hdestroy_r(struct hsearch_data *head)
+{
+       hdestroy1_r(head, 0);
+}
+
 ENTRY *
 hsearch(ENTRY item, ACTION action)
 {