since: 2.38


g_test_trap_subprocess (
  const char* test_path,
  guint64 usec_timeout,
  GTestSubprocessFlags test_flags


Respawns the test program to run only test_path in a subprocess. This can be used for a test case that might not return, or that might abort.

If test_path is NULL then the same test is re-run in a subprocess. You can use g_test_subprocess() to determine whether the test is in a subprocess or not.

test_path can also be the name of the parent test, followed by “/subprocess/” and then a name for the specific subtest (or just ending with “/subprocess” if the test only has one child test); tests with names of this form will automatically be skipped in the parent process.

If usec_timeout is non-0, the test subprocess is aborted and considered failing if its run time exceeds it.

The subprocess behavior can be configured with the GTestSubprocessFlags flags.

You can use methods such as g_test_trap_assert_passed(), g_test_trap_assert_failed(), and g_test_trap_assert_stderr() to check the results of the subprocess. (But note that g_test_trap_assert_stdout() and g_test_trap_assert_stderr() cannot be used if test_flags specifies that the child should inherit the parent stdout/stderr.)

If your main () needs to behave differently in the subprocess, you can call g_test_subprocess() (after calling g_test_init()) to see whether you are in a subprocess.

The following example tests that calling my_object_new(1000000) will abort with an error message.

  static void
  test_create_large_object (void)
    if (g_test_subprocess ())
        my_object_new (1000000);

    // Reruns this same test in a subprocess
    g_test_trap_subprocess (NULL, 0, G_TEST_SUBPROCESS_DEFAULT);
    g_test_trap_assert_failed ();
    g_test_trap_assert_stderr ("*ERROR*too large*");

  main (int argc, char **argv)
    g_test_init (&argc, &argv, NULL);

    g_test_add_func ("/myobject/create_large_object",
    return g_test_run ();

Available since: 2.38



Type: const char*

Test to run in a subprocess.

The argument can be NULL.
The data is owned by the caller of the function.
The value is a NUL terminated UTF-8 string.

Type: guint64

Timeout for the subprocess test in micro seconds.


Type: GTestSubprocessFlags

Flags to modify subprocess behaviour.