tests/sort/sort-merge-fdlimit.sh

   1 #!/bin/sh
   2 # Test whether sort avoids opening more file descriptors than it is
   3 # allowed when merging files.
   4
   5 # Copyright (C) 2009-2024 Free Software Foundation, Inc.
   6
   7 # This program is free software: you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation, either version 3 of the License, or
  10 # (at your option) any later version.
  11
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19
  20 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  21 print_ver_ sort
  22
  23 mkdir in err || framework_failure_
  24
  25
  26 for i in $(seq 17); do
  27   echo $i >in/$i
  28 done
  29 seq 17 >some-data
  30
  31 # When these tests are run inside the automated testing framework, they
  32 # have one less available file descriptor than when run outside the
  33 # automated testing framework. If a test with a batch size of b fails
  34 # inside the ATF, then the same test with batch size b+1 may pass outside
  35 # the ATF but fail inside it.
  36
  37 # The default batch size (nmerge) is 16.
  38 (ulimit -n 19 \
  39    && sort -m --batch-size=16 in/* 2>err/merge-default-err \
  40    || ! grep "open failed" err/merge-default-err) || fail=1
  41
  42 # If sort opens a file to sort by random hashes of keys,
  43 # it needs to consider this file against its limit on open file
  44 # descriptors.  Test once with the default random source
  45 # and once with an explicit source.
  46 for randsource in '' --random-source=some-data; do
  47   (ulimit -n 20 \
  48      && sort -mR $randsource --batch-size=16 in/* 2>err/merge-random-err \
  49      || ! grep "open failed" err/merge-random-err) || fail=1
  50 done
  51
  52 # 'sort -m' should work in a limited file descriptor
  53 # environment when the output is repeatedly one of its inputs.
  54 # In coreutils 8.7 and earlier, 'sort' would dump core on this test.
  55 #
  56 # This test uses 'exec' to redirect file descriptors rather than
  57 # ordinary redirection on the 'sort' command.  This is intended to
  58 # work around bugs in OpenBSD /bin/sh, and some other sh variants,
  59 # that squirrel away file descriptors before closing them; see
  60 # <https://lists.gnu.org/r/bug-tar/2010-10/msg00075.html>.
  61 # This test finds the bug only with shells that do not close FDs on
  62 # exec, and will miss the bug (if present) on other shells, but it's
  63 # not easy to fix this without running afoul of the OpenBSD-like sh bugs.
  64 #
  65 # This script uses 'ulimit -n 10' with 7, 8 and 9 open
  66 # to limit 'sort' to at most 7 open files:
  67 # stdin, stdout, stderr, two input and one output files when merging,
  68 # and an extra.  The extra is for old-fashioned platforms like Solaris 10
  69 # where opening a temp file also requires opening /dev/urandom to
  70 # calculate the temp file's name.
  71 (seq 6 && echo 6) >exp || framework_failure_
  72 echo 6 >out || framework_failure_
  73 (exec 3<&- 4<&- 5<&- 6<&- 7</dev/null 8<&7 9<&7 &&
  74  ulimit -n 10 &&
  75  sort -n -m --batch-size=7 -o out out in/1 in/2 in/3 in/4 in/5 out
  76 ) &&
  77 compare exp out || fail=1
  78
  79 Exit $fail