Initial commit of Hyperscan

src/util/alloc.h

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+/*
+ * Copyright (c) 2015, Intel Corporation
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  * Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *  * 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.
+ *  * Neither the name of Intel Corporation nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * 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 OWNER 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
+ * \brief Aligned memory alloc/free.
+ */
+
+#ifndef UTIL_ALLOC_H
+#define UTIL_ALLOC_H
+
+#include <cassert>
+#include <cstddef> // size_t
+#include <limits>
+#include <memory>
+#include <new>     // std::bad_alloc
+
+namespace ue2 {
+
+/** \brief 64-byte aligned, zeroed malloc.
+ *
+ * Pointers should be freed with \ref aligned_free. If we are unable to
+ * allocate the requested number of bytes, this function will throw
+ * std::bad_alloc. */
+void *aligned_zmalloc(size_t size);
+
+/** \brief Free a pointer allocated with \ref aligned_zmalloc. */
+void aligned_free(void *ptr);
+
+template <typename T> struct AlignedDeleter {
+    void operator()(T *ptr) const { aligned_free(ptr); }
+};
+template <typename T>
+using aligned_unique_ptr = std::unique_ptr<T, AlignedDeleter<T>>;
+
+/** \brief 64-byte aligned, zeroed malloc that returns an appropriately-typed
+ * aligned_unique_ptr.
+ *
+ * If the requested size cannot be allocated, throws std::bad_alloc.
+ */
+template <typename T>
+inline
+aligned_unique_ptr<T> aligned_zmalloc_unique(size_t size) {
+    T* ptr = static_cast<T *>(aligned_zmalloc(size));
+    assert(ptr); // Guaranteed by aligned_zmalloc.
+    return aligned_unique_ptr<T>(ptr);
+}
+
+/** \brief Internal use only, used by AlignedAllocator. */
+void *aligned_malloc_internal(size_t size, size_t align);
+
+/** \brief Internal use only, used by AlignedAllocator. */
+void aligned_free_internal(void *ptr);
+
+/** \brief Aligned allocator class for use with STL containers. Ensures that
+ * your objects are aligned to N bytes. */
+template <typename T, std::size_t N> class AlignedAllocator {
+public:
+    typedef T value_type;
+    typedef std::size_t size_type;
+    typedef std::ptrdiff_t difference_type;
+    typedef T *pointer;
+    typedef const T *const_pointer;
+    typedef T &reference;
+    typedef const T &const_reference;
+
+    template <typename U> struct rebind {
+        typedef AlignedAllocator<U, N> other;
+    };
+
+    pointer address(reference x) const { return &x; }
+    const_pointer address(const_reference x) const { return &x; }
+
+    size_type max_size() const {
+        return std::numeric_limits<size_type>::max() / sizeof(value_type);
+    }
+
+    pointer allocate(size_type size) const {
+        return static_cast<pointer>(
+            aligned_malloc_internal(size * sizeof(value_type), N));
+    }
+
+    void deallocate(pointer x, size_type) const { aligned_free_internal(x); }
+
+    void construct(pointer x, const value_type &val) const {
+        new (x) value_type(val);
+    }
+
+    void destroy(pointer p) const { p->~value_type(); }
+
+    bool operator==(const AlignedAllocator<T, N> &) const {
+        // All instances of AlignedAllocator can dealloc each others' memory.
+        return true;
+    }
+
+    bool operator!=(const AlignedAllocator<T, N> &) const {
+        // All instances of AlignedAllocator can dealloc each others' memory.
+        return false;
+    }
+};
+
+} // namespace ue2
+
+#endif