xref: /openbmc/u-boot/test/py/tests/test_sleep.py (revision 2c0d6971)
1# Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
2#
3# SPDX-License-Identifier: GPL-2.0
4
5import pytest
6import time
7
8def test_sleep(u_boot_console):
9    '''Test the sleep command, and validate that it sleeps for approximately
10    the correct amount of time.'''
11
12    # Do this before we time anything, to make sure U-Boot is already running.
13    # Otherwise, the system boot time is included in the time measurement.
14    u_boot_console.ensure_spawned()
15
16    # 3s isn't too long, but is enough to cross a few second boundaries.
17    sleep_time = 3
18    tstart = time.time()
19    u_boot_console.run_command('sleep %d' % sleep_time)
20    tend = time.time()
21    elapsed = tend - tstart
22    delta_to_expected = abs(elapsed - sleep_time)
23    # 0.25s margin is hopefully enough to account for any system overhead.
24    assert delta_to_expected < 0.25
25