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authornros <nros@NetBSD.org>2015-11-07 16:21:42 +0000
committernros <nros@NetBSD.org>2015-11-07 16:21:42 +0000
commitd860259f851aefa9ff709911ef49e3e78db7f8c5 (patch)
tree9156d2df856d6954b78ad4cc1b3188b603362cc4 /lib/libc/stdlib/aligned_alloc.c
parent28732cfe3672102f63503a89ff64a997069b09f1 (diff)
Add the C11 function aligned_alloc to libc.
Diffstat (limited to 'lib/libc/stdlib/aligned_alloc.c')
-rw-r--r--lib/libc/stdlib/aligned_alloc.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/lib/libc/stdlib/aligned_alloc.c b/lib/libc/stdlib/aligned_alloc.c
new file mode 100644
index 00000000000..ab116333a43
--- /dev/null
+++ b/lib/libc/stdlib/aligned_alloc.c
@@ -0,0 +1,70 @@
+/* $NetBSD: aligned_alloc.c,v 1.1 2015/11/07 16:21:42 nros Exp $ */
+
+/*-
+ * Copyright (C) 2015 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Niclas Rosenvik.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice(s), this list of conditions and the following disclaimer as
+ * the first lines of this file unmodified other than the possible
+ * addition of one or more copyright notices.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice(s), this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+ * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+
+void *
+aligned_alloc(size_t alignment, size_t size)
+{
+ void *memptr;
+ int err;
+
+ /*
+ * Check that alignment is a power of 2
+ * and that size is an integer multiple of alignment.
+ */
+ if (alignment == 0 || ((alignment - 1) & alignment) != 0 ||
+ (size & (alignment-1)) != 0) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ /*
+ * Adjust alignment to satisfy posix_memalign,
+ * larger alignments satisfy smaller alignments.
+ */
+ while (alignment < sizeof(void *)) {
+ alignment <<= 1;
+ }
+
+ err = posix_memalign(&memptr, alignment, size);
+
+ if (err) {
+ errno = err;
+ return NULL;
+ }
+
+ return memptr;
+}