[U-Boot] [PATCH 3/3] test/py: add a test for the sleep command

[Stephen Warren]

From: Stephen Warren <swarren at nvidia.com>

Execute "sleep", and validate that it sleeps for approximately the correct
amount of time.

Signed-off-by: Stephen Warren <swarren at nvidia.com>
---
This patch depends on both the two previous patches, and on my unrelated
series which adds the test/py code. If I resend that series, I can add
this patch into it.
---
 test/py/tests/test_sleep.py | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 test/py/tests/test_sleep.py

diff --git a/test/py/tests/test_sleep.py b/test/py/tests/test_sleep.py
new file mode 100644
index 000000000000..64f1ddf9a09f
--- /dev/null
+++ b/test/py/tests/test_sleep.py
@@ -0,0 +1,24 @@
+# Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+#
+# SPDX-License-Identifier: GPL-2.0
+
+import pytest
+import time
+
+def test_sleep(u_boot_console):
+    '''Test the sleep command, and validate that it sleeps for approximately
+    the correct amount of time.'''
+
+    # Do this before we time anything, to make sure U-Boot is already running.
+    # Otherwise, the system boot time is included in the time measurement.
+    u_boot_console.ensure_spawned()
+
+    # 3s isn't too long, but is enough to cross a few second boundaries.
+    sleep_time = 3
+    tstart = time.time()
+    u_boot_console.run_command('sleep %d' % sleep_time)
+    tend = time.time()
+    elapsed = tend - tstart
+    delta_to_expected = abs(elapsed - sleep_time)
+    # 0.25s margin is hopefully enough to account for any system overhead.
+    assert delta_to_expected < 0.25
-- 
2.6.4