glibc/stdlib/tst-getenv-thread.c

63 lines
2.0 KiB
C

/* Test getenv with concurrent setenv.
Copyright (C) 2024-2025 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <support/check.h>
#include <support/xthread.h>
/* Set to false by the main thread after doing all the setenv
calls. */
static bool running = true;
/* Used to synchronize the start of the getenv thread. */
static pthread_barrier_t barrier;
/* Invoke getenv for a nonexisting environment variable in a loop.
This checks that concurrent setenv does not invalidate the
environment array while getenv reads it. */
static void *
getenv_thread (void *ignored)
{
xpthread_barrier_wait (&barrier);
while (__atomic_load_n (&running, __ATOMIC_RELAXED))
TEST_VERIFY (getenv ("unset_variable") == NULL);
return NULL;
}
static int
do_test (void)
{
xpthread_barrier_init (&barrier, NULL, 2);
pthread_t thr = xpthread_create (NULL, getenv_thread, NULL);
xpthread_barrier_wait (&barrier);
for (int i = 0; i < 1000; ++i)
{
char buf[30];
snprintf (buf, sizeof (buf), "V%d", i);
TEST_COMPARE (setenv (buf, buf + 1, 1), 0);
}
__atomic_store_n (&running, false, __ATOMIC_RELAXED);
xpthread_join (thr);
xpthread_barrier_destroy (&barrier);
return 0;
}
#include <support/test-driver.c>