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/* System call limits
Copyright 2018-2021 Free Software Foundation, Inc.
This file 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.
This file 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 this program. If not, see <https://www.gnu.org/licenses/>. */
#ifndef _GL_SYS_LIMITS_H
#define _GL_SYS_LIMITS_H
#include <limits.h>
/* Maximum number of bytes to read or write in a single system call.
This can be useful for system calls like sendfile on GNU/Linux,
which do not handle more than MAX_RW_COUNT bytes correctly.
The Linux kernel MAX_RW_COUNT is at least INT_MAX >> 20 << 20,
where the 20 comes from the Hexagon port with 1 MiB pages; use that
as an approximation, as the exact value may not be available to us.
Using this also works around a serious Linux bug before 2.6.16; see
<https://bugzilla.redhat.com/show_bug.cgi?id=612839>.
Using this also works around a Tru64 5.1 bug, where attempting
to read INT_MAX bytes fails with errno == EINVAL. See
<https://lists.gnu.org/r/bug-gnu-utils/2002-04/msg00010.html>.
Using this is likely to work around similar bugs in other operating
systems. */
enum { SYS_BUFSIZE_MAX = INT_MAX >> 20 << 20 };
#endif
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