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/* Tests for AIO in librt.
Copyright (C) 1998, 2000, 2002, 2006 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
static int
set_o_direct (int fd)
{
int ret = -1;
#ifdef O_DIRECT
if (fcntl (fd, F_SETFL, fcntl (fd, F_GETFL) | O_DIRECT) >= 0)
{
int pgsz = sysconf (_SC_PAGESIZE);
char *buf = mmap (NULL, 16 * pgsz, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON, -1, 0);
if (buf != MAP_FAILED)
{
memset (buf, 0, 16 * pgsz);
for (int sz = 256; sz <= 16 * pgsz; sz *= 2)
if (write (fd, buf, sz) > 0)
{
ret = sz;
break;
}
ftruncate64 (fd, 0);
munmap (buf, 16 * pgsz);
}
if (ret < 0)
fcntl (fd, F_SETFL, fcntl (fd, F_GETFL) & ~O_DIRECT);
}
#endif
return ret;
}
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