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/* Copyright (C) 2018 Wildfire Games.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "precompiled.h"
#include "lib/allocators/page_aligned.h"
#include "lib/alignment.h"
#include "lib/sysdep/cpu.h" // cpu_CAS
//-----------------------------------------------------------------------------
static inline Status StatusFromMap(void* ret)
{
if(ret != MAP_FAILED)
return INFO::OK;
WARN_RETURN(StatusFromErrno());
}
// "anonymous" effectively means mapping /dev/zero, but is more efficient.
// MAP_ANONYMOUS is not in SUSv3, but is a very common extension.
// unfortunately, MacOS X only defines MAP_ANON, which Solaris says is
// deprecated. workaround there: define MAP_ANONYMOUS in terms of MAP_ANON.
#ifndef MAP_ANONYMOUS
# define MAP_ANONYMOUS MAP_ANON
#endif
static const int mmap_flags = MAP_PRIVATE|MAP_ANONYMOUS;
Status mem_Reserve(size_t size, u8** pp)
{
errno = 0;
void* ret = mmap(0, size, PROT_NONE, mmap_flags|MAP_NORESERVE, -1, 0);
*pp = (u8*)ret;
return StatusFromMap(ret);
}
Status mem_Release(u8* p, size_t size)
{
errno = 0;
if(munmap(p, size) != 0)
WARN_RETURN(StatusFromErrno());
return 0;
}
Status mem_Commit(u8* p, size_t size, int prot)
{
// avoid misinterpretation by mmap.
if(prot == PROT_NONE)
WARN_RETURN(ERR::INVALID_PARAM);
errno = 0;
void* ret = mmap(p, size, prot, mmap_flags|MAP_FIXED, -1, 0);
return StatusFromMap(ret);
}
Status mem_Decommit(u8* p, size_t size)
{
errno = 0;
void* ret = mmap(p, size, PROT_NONE, mmap_flags|MAP_NORESERVE|MAP_FIXED, -1, 0);
return StatusFromMap(ret);
}
Status mem_Protect(u8* p, size_t size, int prot)
{
errno = 0;
if(mprotect(p, size, prot) != 0)
WARN_RETURN(StatusFromErrno());
return 0;
}
//-----------------------------------------------------------------------------
void* page_aligned_alloc(size_t size)
{
const size_t alignedSize = Align<g_PageSize>(size);
u8* p = 0;
RETURN_0_IF_ERR(mem_Reserve(alignedSize, &p));
RETURN_0_IF_ERR(mem_Commit(p, alignedSize, PROT_READ|PROT_WRITE));
return p;
}
void page_aligned_free(void* p, size_t size)
{
if(!p)
return;
ENSURE(IsAligned(p, g_PageSize));
const size_t alignedSize = Align<g_PageSize>(size);
(void)mem_Release((u8*)p, alignedSize);
}
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