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/* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
#include "mysys_priv.h"
#ifdef HAVE_SYS_MMAN_H
/*
system msync() only syncs mmap'ed area to fs cache.
fsync() is required to really sync to disc
*/
int my_msync(int fd, void *addr, size_t len, int flags)
{
msync(addr, len, flags);
return my_sync(fd, MYF(0));
}
#elif defined(_WIN32)
#ifndef FILE_DAX_VOLUME
#define FILE_DAX_VOLUME 0x20000000
#endif
static SECURITY_ATTRIBUTES mmap_security_attributes=
{sizeof(SECURITY_ATTRIBUTES), 0, TRUE};
void *my_mmap(void *addr, size_t len, int prot,
int flags, File fd, my_off_t offset)
{
HANDLE hFileMap;
LPVOID ptr;
HANDLE hFile= (HANDLE)my_get_osfhandle(fd);
DBUG_ENTER("my_mmap");
DBUG_PRINT("mysys", ("map fd: %d", fd));
if (hFile == INVALID_HANDLE_VALUE)
DBUG_RETURN(MAP_FAILED);
hFileMap=CreateFileMapping(hFile, &mmap_security_attributes,
PAGE_READWRITE, 0, (DWORD) len, NULL);
if (hFileMap == 0)
DBUG_RETURN(MAP_FAILED);
ptr=MapViewOfFile(hFileMap,
prot & PROT_WRITE ? FILE_MAP_WRITE : FILE_MAP_READ,
(DWORD)(offset >> 32), (DWORD)offset, len);
/*
MSDN explicitly states that it's possible to close File Mapping Object
even when a view is not unmapped - then the object will be held open
implicitly until unmap, as every view stores internally a handler of
a corresponding File Mapping Object
*/
CloseHandle(hFileMap);
if (flags & MAP_SYNC)
{
DWORD filesystemFlags;
if (!GetVolumeInformationByHandleW(hFile, NULL, 0, NULL, NULL,
&filesystemFlags, NULL, 0) ||
!(filesystemFlags & FILE_DAX_VOLUME))
{
UnmapViewOfFile(ptr);
ptr= NULL;
}
}
if (ptr)
{
DBUG_PRINT("mysys", ("mapped addr: %p", ptr));
DBUG_RETURN(ptr);
}
DBUG_RETURN(MAP_FAILED);
}
int my_munmap(void *addr, size_t len)
{
DBUG_ENTER("my_munmap");
DBUG_PRINT("mysys", ("unmap addr: %p", addr));
DBUG_RETURN(UnmapViewOfFile(addr) ? 0 : -1);
}
int my_msync(int fd, void *addr, size_t len, int flags)
{
return FlushViewOfFile(addr, len) &&
FlushFileBuffers(my_get_osfhandle(fd)) ? 0 : -1;
}
#else
#warning "no mmap!"
#endif
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