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/*
* Copyright (C) 2013 Max Kellermann <max@duempel.org>
*
* 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.
*
* 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
* FOUNDATION 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.
*/
#ifndef HUGE_ALLOCATOR_HXX
#define HUGE_ALLOCATOR_HXX
#include "Compiler.h"
#include <stddef.h>
#ifdef __linux__
/**
* Allocate a huge amount of memory. This will be done in a way that
* allows giving the memory back to the kernel as soon as we don't
* need it anymore. On the downside, this call is expensive.
*/
gcc_malloc
void *
HugeAllocate(size_t size);
/**
* @param p an allocation returned by HugeAllocate()
* @param size the allocation's size as passed to HugeAllocate()
*/
void
HugeFree(void *p, size_t size);
/**
* Discard any data stored in the allocation and give the memory back
* to the kernel. After returning, the allocation still exists and
* can be reused at any time, but its contents are undefined.
*
* @param p an allocation returned by HugeAllocate()
* @param size the allocation's size as passed to HugeAllocate()
*/
void
HugeDiscard(void *p, size_t size);
#elif defined(WIN32)
#include <windows.h>
gcc_malloc
static inline void *
HugeAllocate(size_t size)
{
// TODO: use MEM_LARGE_PAGES
return VirtualAlloc(nullptr, size, MEM_RESERVE, PAGE_READWRITE);
}
static inline void
HugeFree(void *p, gcc_unused size_t size)
{
VirtualFree(p, 0, MEM_RELEASE);
}
static inline void
HugeDiscard(void *p, size_t size)
{
VirtualAlloc(p, size, MEM_RESET, PAGE_NOACCESS);
}
#else
/* not Linux: fall back to standard C calls */
#include <stdlib.h>
gcc_malloc
static inline void *
HugeAllocate(size_t size)
{
return malloc(size);
}
static inline void
HugeFree(void *p, size_t)
{
free(p);
}
static inline void
HugeDiscard(void *, size_t)
{
}
#endif
#endif
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