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+/*
+ Copyright (c) 2012-2014, Matthias Schiffer <mschiffer@universe-factory.net>
+ All rights reserved.
+
+ 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,
+ this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+ 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 HOLDERS AND CONTRIBUTORS "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 OR CONTRIBUTORS 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.
+*/
+
+/**
+ \file
+
+ \em Miscellaneous utility functions and macros
+ */
+
+
+#pragma once
+
+/**
+ Returns a pointer to a data structure, given the address of a member contained in the structure
+
+ @param ptr the address of the member
+ @param type the type of the container
+ @param member the name of the member
+
+ \hideinitializer
+ */
+#define container_of(ptr, type, member) ({ \
+ const __typeof__(((type *)0)->member) *_mptr = (ptr); \
+ (type *)((char *)_mptr - offsetof(type, member)); \
+ })
+
+/**
+ Returns the number of elements of an array
+
+ \hideinitializer
+ */
+#define array_size(array) (sizeof(array)/sizeof((array)[0]))
+
+/**
+ Determines how many blocks of a given size \a a are needed to contain some length \a l
+ */
+static inline size_t block_count(size_t l, size_t a) {
+ return (l+a-1)/a;
+}
+
+/**
+ Rounds up a length \a l to the next multiple of a block size \a a
+ */
+static inline size_t alignto(size_t l, size_t a) {
+ return block_count(l, a)*a;
+}