/* getdtablesize() function for platforms that don't have it.
- Copyright (C) 2008-2009 Free Software Foundation, Inc.
+ Copyright (C) 2008-2011 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2008.
This program is free software: you can redistribute it and/or modify
if (dtablesize == 0)
{
/* We are looking for the number N such that the valid file descriptors
- are 0..N-1. It can be obtained through a loop as follows:
- {
- int fd;
- for (fd = 3; fd < 65536; fd++)
- if (dup2 (0, fd) == -1)
- break;
- return fd;
- }
- On Windows XP, the result is 2048.
- The drawback of this loop is that it allocates memory for a libc
- internal array that is never freed.
-
- The number N can also be obtained as the upper bound for
- _getmaxstdio (). _getmaxstdio () returns the maximum number of open
- FILE objects. The sanity check in _setmaxstdio reveals the maximum
- number of file descriptors. This too allocates memory, but it is
- freed when we call _setmaxstdio with the original value. */
+ are 0..N-1. It can be obtained through a loop as follows:
+ {
+ int fd;
+ for (fd = 3; fd < 65536; fd++)
+ if (dup2 (0, fd) == -1)
+ break;
+ return fd;
+ }
+ On Windows XP, the result is 2048.
+ The drawback of this loop is that it allocates memory for a libc
+ internal array that is never freed.
+
+ The number N can also be obtained as the upper bound for
+ _getmaxstdio (). _getmaxstdio () returns the maximum number of open
+ FILE objects. The sanity check in _setmaxstdio reveals the maximum
+ number of file descriptors. This too allocates memory, but it is
+ freed when we call _setmaxstdio with the original value. */
int orig_max_stdio = _getmaxstdio ();
unsigned int bound;
for (bound = 0x10000; _setmaxstdio (bound) < 0; bound = bound / 2)
- ;
+ ;
_setmaxstdio (orig_max_stdio);
dtablesize = bound;
}