Function reap_children

Lib/test/support/__init__.py:1521–1548

Use this function at the end of test_main() whenever sub-processes are started. This will help ensure that no extra children (zombies) stick around to hog resources and create problems when looking for refleaks.

()

environment_altered = False

def reap_children():
    """Use this function at the end of test_main() whenever sub-processes
    are started.  This will help ensure that no extra children (zombies)
    stick around to hog resources and create problems when looking
    for refleaks.
    """
    global environment_altered

    # Need os.waitpid(-1, os.WNOHANG): Windows is not supported
    if not (hasattr(os, 'waitpid') and hasattr(os, 'WNOHANG')):
        return
    elif not has_subprocess_support:
        return

    # Reap all our dead child processes so we don't leave zombies around.
    # These hog resources and might be causing some of the buildbots to die.
    while True:
        try:
            # Read the exit status of any child process which already completed
            pid, status = os.waitpid(-1, os.WNOHANG)
        except OSError:
            break

        if pid == 0:
            break

        print_warning(f"reap_children() reaped child process {pid}")
        environment_altered = True


@contextlib.contextmanager