From: Eric Biggers <ebiggers3@gmail.com>
Date: Thu, 12 Jun 2014 04:15:40 +0000 (-0500)
Subject: Add aligned malloc and free
X-Git-Tag: v1.7.0~41
X-Git-Url: https://wimlib.net/git/?p=wimlib;a=commitdiff_plain;h=e3a7c6c725964662f4ad1fcfe21d2da742499b8a

Add aligned malloc and free

Don't make dependent on OS support, since that would break the custom
memory allocation functions and also would need to be different between
UNIX and Windows anyway.
---

diff --git a/include/wimlib/util.h b/include/wimlib/util.h
index 869388fe..91bed5a4 100644
--- a/include/wimlib/util.h
+++ b/include/wimlib/util.h
@@ -72,12 +72,20 @@ wimlib_wcsdup(const wchar_t *str) _malloc_attribute;
 extern char *
 wimlib_strdup(const char *str) _malloc_attribute;
 
+extern void *
+wimlib_aligned_malloc(size_t size, size_t alignment) _malloc_attribute;
+
+extern void
+wimlib_aligned_free(void *ptr);
+
 #define	MALLOC	wimlib_malloc
 #define	FREE	wimlib_free_memory
 #define	REALLOC	wimlib_realloc
 #define	CALLOC	wimlib_calloc
 #define	STRDUP	wimlib_strdup
 #define	WCSDUP  wimlib_wcsdup
+#define	ALIGNED_MALLOC	wimlib_aligned_malloc
+#define	ALIGNED_FREE	wimlib_aligned_free
 
 extern void *
 memdup(const void *mem, size_t size) _malloc_attribute;
diff --git a/src/util.c b/src/util.c
index fceae14b..54e29444 100644
--- a/src/util.c
+++ b/src/util.c
@@ -37,6 +37,7 @@
 #endif
 
 #include "wimlib.h"
+#include "wimlib/assert.h"
 #include "wimlib/compiler.h"
 #include "wimlib/encoding.h"
 #include "wimlib/error.h"
@@ -432,6 +433,36 @@ wimlib_wcsdup(const wchar_t *str)
 }
 #endif
 
+void *
+wimlib_aligned_malloc(size_t size, size_t alignment)
+{
+	u8 *raw_ptr;
+	u8 *ptr;
+	uintptr_t mask;
+
+	wimlib_assert(alignment != 0 && is_power_of_2(alignment) &&
+		      alignment <= 4096);
+	mask = alignment - 1;
+
+	raw_ptr = MALLOC(size + alignment - 1 + sizeof(size_t));
+	if (!raw_ptr)
+		return NULL;
+
+	ptr = (u8 *)raw_ptr + sizeof(size_t);
+	while ((uintptr_t)ptr & mask)
+		ptr++;
+	*((size_t *)ptr - 1) = (ptr - raw_ptr);
+
+	return ptr;
+}
+
+void
+wimlib_aligned_free(void *ptr)
+{
+	if (ptr)
+		FREE((u8 *)ptr - *((size_t *)ptr - 1));
+}
+
 void *
 memdup(const void *mem, size_t size)
 {