Mercurial > hg > octave-nkf > gnulib-hg
view lib/sleep.c @ 15988:cd7ac59d8eb5
fts: close parent dir FD before returning from post-traversal fts_read
The problem: the fts-using "mkdir -p A/B; rm -rf A" would attempt to
unlink A, even though an FD open on A remained. This is suboptimal
(holding a file descriptor open longer than needed), but otherwise not
a problem on Unix-like kernels. However, on Cygwin with certain Novell
file systems, (see http://cygwin.com/ml/cygwin/2011-10/msg00365.html),
that represents a real problem: it causes the removal of A to fail
with e.g., "rm: cannot remove `A': Device or resource busy"
fts visits each directory twice and keeps a cache (fts_fd_ring) of
directory file descriptors. After completing the final, FTS_DP,
visit of a directory, RESTORE_INITIAL_CWD intended to clear the FD
cache, but then proceeded to add a new FD to it via the subsequent
FCHDIR (which calls cwd_advance_fd and i_ring_push). Before, the
final file descriptor would be closed only via fts_close's call to
fd_ring_clear. Now, it is usually closed earlier, via the final
FTS_DP-returning fts_read call.
* lib/fts.c (restore_initial_cwd): New function, converted from
the macro. Call fd_ring_clear *after* FCHDIR, not before it.
Update callers.
Reported by Franz Sirl via the above URL, with analysis by Eric Blake
in http://thread.gmane.org/gmane.comp.lib.gnulib.bugs/28739
author | Jim Meyering <meyering@redhat.com> |
---|---|
date | Sun, 23 Oct 2011 22:42:25 +0200 |
parents | 97fc9a21a8fb |
children | 8250f2777afc |
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/* Pausing execution of the current thread. Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc. Written by Bruno Haible <bruno@clisp.org>, 2007. 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 3 of the License, 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 <http://www.gnu.org/licenses/>. */ #include <config.h> /* Specification. */ #include <unistd.h> #include <limits.h> #include "verify.h" #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ # define WIN32_LEAN_AND_MEAN /* avoid including junk */ # include <windows.h> unsigned int sleep (unsigned int seconds) { unsigned int remaining; /* Sleep for 1 second many times, because 1. Sleep is not interruptiple by Ctrl-C, 2. we want to avoid arithmetic overflow while multiplying with 1000. */ for (remaining = seconds; remaining > 0; remaining--) Sleep (1000); return remaining; } #elif HAVE_SLEEP # undef sleep /* Guarantee unlimited sleep and a reasonable return value. Cygwin 1.5.x rejects attempts to sleep more than 49.7 days (2**32 milliseconds), but uses uninitialized memory which results in a garbage answer. Similarly, Linux 2.6.9 with glibc 2.3.4 has a too small return value when asked to sleep more than 24.85 days. */ unsigned int rpl_sleep (unsigned int seconds) { /* This requires int larger than 16 bits. */ verify (UINT_MAX / 24 / 24 / 60 / 60); const unsigned int limit = 24 * 24 * 60 * 60; while (limit < seconds) { unsigned int result; seconds -= limit; result = sleep (limit); if (result) return seconds + result; } return sleep (seconds); } #else /* !HAVE_SLEEP */ #error "Please port gnulib sleep.c to your platform, possibly using usleep() or select(), then report this to bug-gnulib." #endif