1 files changed, 75 insertions, 0 deletions
diff --git a/stdlib/tst-getenv-unsetenv.c b/stdlib/tst-getenv-unsetenv.c
new file mode 100644
index 0000000..031619b
--- /dev/null
+++ b/stdlib/tst-getenv-unsetenv.c
@@ -0,0 +1,75 @@
+/* Test getenv with concurrent unsetenv.
+   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 <array_length.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xthread.h>
+
+/* Used to synchronize the start of each test iteration.  */
+static pthread_barrier_t barrier;
+
+/* Number of iterations.  */
+enum { iterations = 10000 };
+
+/* Check that even with concurrent unsetenv, a variable that is known
+   to be there is found.  */
+static void *
+getenv_thread (void *ignored)
+{
+  for (int i = 0; i < iterations; ++i)
+    {
+      xpthread_barrier_wait (&barrier);
+      TEST_COMPARE_STRING (getenv ("variable"), "value");
+      xpthread_barrier_wait (&barrier);
+    }
+  return NULL;
+}
+
+static int
+do_test (void)
+{
+  xpthread_barrier_init (&barrier, NULL, 2);
+  pthread_t thr = xpthread_create (NULL, getenv_thread, NULL);
+
+  char *variables[50];
+  for (int i = 0; i < array_length (variables); ++i)
+    variables[i] = xasprintf ("V%d", i);
+
+  for (int i = 0; i < iterations; ++i)
+    {
+      clearenv ();
+      for (int j = 0; j < array_length (variables); ++j)
+        TEST_COMPARE (setenv (variables[j], variables[j] + 1, 1), 0);
+      TEST_COMPARE (setenv ("variable", "value", 1), 0);
+      xpthread_barrier_wait (&barrier);
+      /* Test runs.  */
+      for (int j = 0; j < array_length (variables); ++j)
+        TEST_COMPARE (unsetenv (variables[j]), 0);
+      xpthread_barrier_wait (&barrier);
+    }
+  xpthread_join (thr);
+  xpthread_barrier_destroy (&barrier);
+  for (int i = 0; i < array_length (variables); ++i)
+    free (variables[i]);
+  return 0;
+}
+
+#include <support/test-driver.c>