6794660 Optimize realloc() of libmtmalloc for normal sized caches

1 files changed, 54 insertions, 0 deletions

diff --git a/usr/src/lib/libmtmalloc/tests/reallocs.c b/usr/src/lib/libmtmalloc/tests/reallocs.c
new file mode 100644
index 0000000000..c734b005fb
--- /dev/null
+++ b/usr/src/lib/libmtmalloc/tests/reallocs.c
@@ -0,0 +1,54 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+/*
+ * realloc() optimization for Small sized caches.
+ * If a malloc'ed buffer can satisfy a realloc() request
+ * as well, it should return the same buffer.
+ *
+ * cc -O -o reallocs reallocs.c -lmtmalloc
+ */
+
+#define	MAX_CACHE_SZ 65536
+
+int
+main()
+{
+	void *p, *q;
+	size_t size;
+
+	for (size = 1; size <= MAX_CACHE_SZ; size++) {
+		p = malloc(size);
+		q = realloc(p, size);
+		if (p != q)
+			(void) fprintf(stderr, "size: %d, p: 0x%p, q: 0x%p\n",
+			    size, p, q);
+		free(q);
+	}
+	return (0);
+}