glibc/sysdeps/mach/hurd/sendfile64.c
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

61 lines
2.1 KiB
C

/* sendfile -- copy data directly from one file descriptor to another
Copyright (C) 2002-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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, see
<https://www.gnu.org/licenses/>. */
#include <sys/sendfile.h>
#include <hurd.h>
#include <hurd/fd.h>
#include <sys/mman.h>
/* Send COUNT bytes from file associated with IN_FD starting at OFFSET to
descriptor OUT_FD. */
ssize_t
__sendfile64 (int out_fd, int in_fd, off64_t *offset, size_t count)
{
/* We just do a vanilla io_read followed by a vanilla io_write here.
In theory the IN_FD filesystem can return us out-of-line data that
we then send out-of-line to the OUT_FD filesystem and no copying
takes place until those pages need to be flushed or packaged by
that filesystem (e.g. packetized by a network socket). However,
we momentarily consume COUNT bytes of our local address space,
which might blow if it's huge or address space is real tight. */
char *data = 0;
size_t datalen = 0;
error_t err = HURD_DPORT_USE (in_fd,
__io_read (port, &data, &datalen,
offset ? *offset : (off_t) -1,
count));
if (err == 0)
{
size_t nwrote;
if (datalen == 0)
return 0;
err = HURD_DPORT_USE (out_fd, __io_write (port, data, datalen,
(off_t) -1, &nwrote));
__munmap (data, datalen);
if (err == 0)
{
if (offset)
*offset += datalen;
return nwrote;
}
}
return __hurd_fail (err);
}
strong_alias (__sendfile64, sendfile64)