| /* System call limits |
| |
| Copyright 2018-2020 Free Software Foundation, Inc. |
| |
| 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; either version 2, or (at your option) |
| any later version. |
| |
| 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, 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 |