Hi,
On 2009-12-15, we fixed a memory leak in the fprintf replacement. Since it
is quite important to not reintroduce this bug in the future, I'm adding a
unit test against it.
> - Limit the allowed total memory through a setrlimit call
> (cf. tests/test-printf-posix2.c).
> - Run the test in a loop. Determine the iteration count so that when
> the bug is present, the memory would exceed the limit. Of course,
> also consider the running time of the test when the bug is fixed.
2009-12-19 Bruno Haible <br...@clisp.org>
fprintf-posix: Check against memory leak fixed on 2009-12-15.
* tests/test-fprintf-posix3.sh: New file.
* tests/test-fprintf-posix3.c: New file.
* modules/fprintf-posix-tests (Files): Add them.
(Makefile.am): Augment TESTS and CHECK_PROGRAMS.
======================== tests/test-fprintf-posix3.sh ========================
#!/bin/sh
# Test against a memory leak.
(./test-fprintf-posix3${EXEEXT} 0
result=$?
if test $result != 77 && test $result != 78; then result=1; fi
exit $result
) 2>/dev/null
malloc_result=$?
if test $malloc_result = 77; then
echo "Skipping test: getrlimit and setrlimit don't work"
exit 77
fi
./test-fprintf-posix3${EXEEXT} 1 > /dev/null
result=$?
if test $result = 77; then
echo "Skipping test: getrlimit and setrlimit don't work"
exit 77
fi
if test $result != 0; then
exit 1
fi
if test $malloc_result = 78; then
echo "Skipping test: getrlimit and setrlimit don't work"
exit 77
fi
exit 0
========================= tests/test-fprintf-posix3.c =========================
/* Test of POSIX compatible fprintf() function.
Copyright (C) 2009 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 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/>. */
/* Written by Bruno Haible <br...@clisp.org>, 2009. */
#include <config.h>
#include <stdio.h>
#if HAVE_GETRLIMIT && HAVE_SETRLIMIT
#include <stdlib.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <string.h>
#include <errno.h>
/* Test against a memory leak in the fprintf replacement. */
/* Number of iterations across the loop. */
#define NUM_ROUNDS 1000
/* Number of bytes that are allowed to escape per round. */
#define MAX_ALLOC_ROUND 10000
/* Number of bytes that are allowed to escape in total.
This should be at least 10 MB, since it includes the normal memory
or address space of the test program. */
#define MAX_ALLOC_TOTAL (NUM_ROUNDS * MAX_ALLOC_ROUND)
int
main (int argc, char *argv[])
{
struct rlimit limit;
int arg;
int repeat;
/* Limit the amount of malloc()ed memory to MAX_ALLOC_TOTAL or less. */
/* On BSD systems, malloc() is limited by RLIMIT_DATA. */
#ifdef RLIMIT_DATA
if (getrlimit (RLIMIT_DATA, &limit) < 0)
return 77;
if (limit.rlim_max == RLIM_INFINITY || limit.rlim_max > MAX_ALLOC_TOTAL)
limit.rlim_max = MAX_ALLOC_TOTAL;
limit.rlim_cur = limit.rlim_max;
if (setrlimit (RLIMIT_DATA, &limit) < 0)
return 77;
#endif
/* On Linux systems, malloc() is limited by RLIMIT_AS. */
#ifdef RLIMIT_AS
if (getrlimit (RLIMIT_AS, &limit) < 0)
return 77;
if (limit.rlim_max == RLIM_INFINITY || limit.rlim_max > MAX_ALLOC_TOTAL)
limit.rlim_max = MAX_ALLOC_TOTAL;
limit.rlim_cur = limit.rlim_max;
if (setrlimit (RLIMIT_AS, &limit) < 0)
return 77;
#endif
arg = atoi (argv[1]);
if (arg == 0)
{
void *memory = malloc (MAX_ALLOC_TOTAL);
if (memory == NULL)
return 1;
memset (memory, 17, MAX_ALLOC_TOTAL);
return 78;
}
/* Perform the test and test whether it triggers a permanent memory
allocation of more than MAX_ALLOC_TOTAL bytes. */
for (repeat = 0; repeat < NUM_ROUNDS; repeat++)
{
/* This may produce a temporary memory allocation of 11000 bytes.
but should not result in a permanent memory allocation. */
if (fprintf (stdout, "%011000d\n", 17) == -1
&& errno == ENOMEM)
return 1;
}
return 0;
}
#else
int
main (int argc, char *argv[])
{
return 77;
}
#endif
===============================================================================
--- modules/fprintf-posix-tests.orig 2009-12-19 22:09:44.000000000 +0100
+++ modules/fprintf-posix-tests 2009-12-19 21:04:03.000000000 +0100
@@ -5,6 +5,8 @@
tests/test-printf-posix.output
tests/test-fprintf-posix2.sh
tests/test-fprintf-posix2.c
+tests/test-fprintf-posix3.sh
+tests/test-fprintf-posix3.c
Depends-on:
stdint
@@ -13,6 +15,6 @@
AC_CHECK_FUNCS_ONCE([getrlimit setrlimit])
Makefile.am:
-TESTS += test-fprintf-posix.sh test-fprintf-posix2.sh
+TESTS += test-fprintf-posix.sh test-fprintf-posix2.sh test-fprintf-posix3.sh
TESTS_ENVIRONMENT += EXEEXT='@EXEEXT@' srcdir='$(srcdir)'
-check_PROGRAMS += test-fprintf-posix test-fprintf-posix2
+check_PROGRAMS += test-fprintf-posix test-fprintf-posix2 test-fprintf-posix3
