public unsafe void WriteGather(long position, IntPtr[] pages)
{
if (pages.Length == 0)
{
return; // nothing to do
}
var start = 0;
const int IOV_MAX = 1024;
while (start < pages.Length)
{
var byteLen = 0L;
var locs = new List <Iovec>
{
new Iovec
{
iov_base = pages[start],
iov_len = (ulong)_options.PageSize
}
};
start++;
byteLen += _options.PageSize;
for (int i = 1; i < pages.Length && locs.Count < IOV_MAX; i++, start++)
{
byteLen += _options.PageSize;
var cur = locs[locs.Count - 1];
if (((byte *)cur.iov_base.ToPointer() + cur.iov_len) == (byte *)pages[i].ToPointer())
{
cur.iov_len = cur.iov_len + (ulong)_options.PageSize;
locs[locs.Count - 1] = cur;
}
else
{
locs.Add(new Iovec
{
iov_base = pages[i],
iov_len = (ulong)_options.PageSize
});
}
}
var result = Syscall.pwritev(_fd, locs.ToArray(), position);
position += byteLen;
if (result == -1)
{
var err = Marshal.GetLastWin32Error();
PosixHelper.ThrowLastError(err);
}
}
}
public unsafe void WriteGather(long position, byte *[] pages)
{
var locs = new Iovec[pages.Length];
for (int i = 0; i < locs.Length; i++)
{
locs[i].iov_base = new IntPtr(pages[i]);
locs[i].iov_len = AbstractPager.PageSize;
}
var result = Syscall.pwritev(_fd, locs, position);
if (result == -1)
{
PosixHelper.ThrowLastError(Marshal.GetLastWin32Error());
}
}