Add re-entrant versions of the hash functions based on the GNU api.

While testing this I found a conformance issue in hdestroy()
that will be fixed in a subsequent commit.

Obtained from:	NetBSD (hcreate.c, CVS Rev. 1.7)

1 files changed, 68 insertions, 29 deletions

diff --git a/lib/libc/stdlib/hcreate.c b/lib/libc/stdlib/hcreate.c
index cfcd115..8bb4d3e 100644
--- a/lib/libc/stdlib/hcreate.c
+++ b/lib/libc/stdlib/hcreate.c
@@ -1,4 +1,4 @@
-/* $NetBSD: hcreate.c,v 1.6 2008/07/21 12:05:43 lukem Exp $ */
+/* $NetBSD: hcreate.c,v 1.7 2011/09/14 23:33:51 christos Exp $ */
 
 /*
  * Copyright (c) 2001 Christopher G. Demetriou
@@ -49,7 +49,7 @@
 #include <sys/cdefs.h>
 #if 0
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: hcreate.c,v 1.6 2008/07/21 12:05:43 lukem Exp $");
+__RCSID("$NetBSD: hcreate.c,v 1.7 2011/09/14 23:33:51 christos Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
 __FBSDID("$FreeBSD$");
@@ -84,20 +84,27 @@ SLIST_HEAD(internal_head, internal_entry);
 /* Default hash function, from db/hash/hash_func.c */
 extern u_int32_t (*__default_hash)(const void *, size_t);
 
-static struct internal_head *htable;
-static size_t htablesize;
+static struct hsearch_data htable;
 
 int
 hcreate(size_t nel)
 {
-	size_t idx;
-	unsigned int p2;
 
 	/* Make sure this is not called when a table already exists. */
-	if (htable != NULL) {
+	if (htable.table != NULL) {
 		errno = EINVAL;
 		return 0;
 	}
+	return hcreate_r(nel, &htable);
+}
+
+int
+hcreate_r(size_t nel, struct hsearch_data *head)
+{
+	struct internal_head *table;
+	size_t idx;
+	unsigned int p2;
+	void *p;
 
 	/* If nel is too small, make it min sized. */
 	if (nel < MIN_BUCKETS)
@@ -115,16 +122,19 @@ hcreate(size_t nel)
 	}
 	
 	/* Allocate the table. */
-	htablesize = nel;
-	htable = malloc(htablesize * sizeof htable[0]);
-	if (htable == NULL) {
+	head->size = nel;
+	head->filled = 0;
+	p = malloc(nel * sizeof table[0]);
+	if (p == NULL) {
 		errno = ENOMEM;
 		return 0;
 	}
+	head->table = p;
+	table = p;
 
 	/* Initialize it. */
-	for (idx = 0; idx < htablesize; idx++)
-		SLIST_INIT(&htable[idx]);
+	for (idx = 0; idx < nel; idx++)
+		SLIST_INIT(&table[idx]);
 
 	return 1;
 }
@@ -132,54 +142,83 @@ hcreate(size_t nel)
 void
 hdestroy(void)
 {
+	hdestroy_r(&htable);
+}
+
+void
+hdestroy_r(struct hsearch_data *head)
+{
 	struct internal_entry *ie;
 	size_t idx;
+	void *p;
+	struct internal_head *table;
 
-	if (htable == NULL)
+	if (head == NULL)
 		return;
 
-	for (idx = 0; idx < htablesize; idx++) {
-		while (!SLIST_EMPTY(&htable[idx])) {
-			ie = SLIST_FIRST(&htable[idx]);
-			SLIST_REMOVE_HEAD(&htable[idx], link);
+	p = head->table;
+	head->table = NULL;
+	table = p;
+
+	for (idx = 0; idx < head->size; idx++) {
+		while (!SLIST_EMPTY(&table[idx])) {
+			ie = SLIST_FIRST(&table[idx]);
+			SLIST_REMOVE_HEAD(&table[idx], link);
 			free(ie->ent.key);
 			free(ie);
 		}
 	}
-	free(htable);
-	htable = NULL;
+	free(table);
 }
 
 ENTRY *
 hsearch(ENTRY item, ACTION action)
 {
-	struct internal_head *head;
+	ENTRY *ep;
+	(void)hsearch_r(item, action, &ep, &htable);
+	return ep;
+}
+
+int
+hsearch_r(ENTRY item, ACTION action, ENTRY **itemp, struct hsearch_data *head)
+{
+	struct internal_head *table, *chain;
 	struct internal_entry *ie;
 	uint32_t hashval;
 	size_t len;
+	void *p;
+
+	p = head->table;
+	table = p;
 
 	len = strlen(item.key);
 	hashval = (*__default_hash)(item.key, len);
 
-	head = &htable[hashval & (htablesize - 1)];
-	ie = SLIST_FIRST(head);
+	chain = &table[hashval & (head->size - 1)];
+	ie = SLIST_FIRST(chain);
 	while (ie != NULL) {
 		if (strcmp(ie->ent.key, item.key) == 0)
 			break;
 		ie = SLIST_NEXT(ie, link);
 	}
 
-	if (ie != NULL)
-		return &ie->ent;
-	else if (action == FIND)
-		return NULL;
+	if (ie != NULL) {
+		*itemp = &ie->ent;
+		return 1;
+	} else if (action == FIND) {
+		*itemp = NULL;
+		errno = ESRCH;
+		return 1;
+	}
 
 	ie = malloc(sizeof *ie);
 	if (ie == NULL)
-		return NULL;
+		return 0;
 	ie->ent.key = item.key;
 	ie->ent.data = item.data;
 
-	SLIST_INSERT_HEAD(head, ie, link);
-	return &ie->ent;
+	SLIST_INSERT_HEAD(chain, ie, link);
+	*itemp = &ie->ent;
+	head->filled++;
+	return 1;
 }