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forked from 0ad/0ad
0ad/source/lib/allocators/mem_util.cpp
janwas ffdff6888d add NUMA and shared-L2-cache detect code (required at work)
enable most of IA-32 specific code to be used in amd64 (resides in
directory lib/sysdep/x86_x64)

bits: add IsBitSet
remove mem_PageSize (use os_cpu_PageSize instead)
cpuid: change interface to allow gracefully supporting later
subfunctions that require input parameters
amd64_asm.asm: add amd64 implementation of cpuid
cpu: move functions provided by OS to sysdep/os_cpu.cpp
cpu topology: avoid trouble when process affinity is set by remapping
processor numbers to 0..PopulationCount(processAffinity)
topology.cpp: move ex-ia32 topology code here.

This was SVN commit r5945.
2008-05-12 18:15:08 +00:00

121 lines
2.9 KiB
C++

/**
* =========================================================================
* File : mem_util.cpp
* Project : 0 A.D.
* Description : memory allocator helper routines.
* =========================================================================
*/
// license: GPL; see lib/license.txt
#include "precompiled.h"
#include "mem_util.h"
#include "lib/bits.h" // round_up
#include "lib/posix/posix_mman.h"
#include "lib/sysdep/os_cpu.h" // os_cpu_PageSize
bool mem_IsPageMultiple(uintptr_t x)
{
return (x & (os_cpu_PageSize()-1)) == 0;
}
size_t mem_RoundUpToPage(size_t size)
{
return round_up(size, os_cpu_PageSize());
}
size_t mem_RoundUpToAlignment(size_t size)
{
// all allocators should align to at least this many bytes:
const size_t alignment = 8;
return round_up(size, alignment);
}
//-----------------------------------------------------------------------------
static inline LibError LibError_from_mmap(void* ret, bool warn_if_failed = true)
{
if(ret != MAP_FAILED)
return INFO::OK;
return LibError_from_errno(warn_if_failed);
}
// "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;
LibError 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 LibError_from_mmap(ret);
}
LibError mem_Release(u8* p, size_t size)
{
errno = 0;
int ret = munmap(p, size);
return LibError_from_posix(ret);
}
LibError 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 LibError_from_mmap(ret);
}
LibError 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 LibError_from_mmap(ret);
}
LibError mem_Protect(u8* p, size_t size, int prot)
{
errno = 0;
int ret = mprotect(p, size, prot);
return LibError_from_posix(ret);
}
//-----------------------------------------------------------------------------
// "freelist" is a pointer to the first unused element (0 if there are none);
// its memory holds a pointer to the next free one in list.
void mem_freelist_AddToFront(void*& freelist, void* el)
{
debug_assert(el != 0);
void* prev_el = freelist;
freelist = el;
*(void**)el = prev_el;
}
void* mem_freelist_Detach(void*& freelist)
{
void* el = freelist;
// nothing in list
if(!el)
return 0;
freelist = *(void**)el;
return el;
}