| # Copyright (c) 2013 The Chromium OS Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| import logging |
| |
| from autotest_lib.client.common_lib import error |
| from autotest_lib.client.common_lib.cros.network import ping_runner |
| from autotest_lib.client.common_lib.cros.network import xmlrpc_datatypes |
| from autotest_lib.server.cros.network import hostap_config |
| from autotest_lib.server.cros.network import wifi_cell_test_base |
| |
| |
| class network_WiFi_BgscanBackoff(wifi_cell_test_base.WiFiCellTestBase): |
| """Test that background scan backs off when there is foreground traffic.""" |
| version = 1 |
| |
| BGSCAN_SAMPLE_PERIOD_SECONDS = 100 |
| NO_BGSCAN_SAMPLE_PERIOD_SECONDS = 10 |
| PING_INTERVAL_SECONDS = 0.1 |
| LATENCY_MARGIN_MS = 200 |
| THRESHOLD_BASELINE_LATENCY_MS = 100 |
| |
| |
| def run_once(self): |
| """Body of the test.""" |
| get_ap_config = lambda: hostap_config.HostapConfig( |
| frequency=2412, |
| mode=hostap_config.HostapConfig.MODE_11G) |
| get_assoc_params = lambda conf: xmlrpc_datatypes.AssociationParameters( |
| ssid=self.context.router.get_ssid(), bgscan_config=conf) |
| get_ping_config = lambda period: ping_runner.PingConfig( |
| self.context.get_wifi_addr(), |
| interval=self.PING_INTERVAL_SECONDS, |
| count=int(period / self.PING_INTERVAL_SECONDS)) |
| self.context.configure(get_ap_config()) |
| bgscan_config = xmlrpc_datatypes.BgscanConfiguration( |
| short_interval=7, long_interval=7, |
| method=xmlrpc_datatypes.BgscanConfiguration.SCAN_METHOD_SIMPLE) |
| self.context.assert_connect_wifi(get_assoc_params(bgscan_config)) |
| logging.info('Pinging router with background scans for %d seconds.', |
| self.BGSCAN_SAMPLE_PERIOD_SECONDS) |
| result_bgscan = self.context.client.ping( |
| get_ping_config(self.BGSCAN_SAMPLE_PERIOD_SECONDS)) |
| logging.info('Ping statistics with bgscan: %r', result_bgscan) |
| self.context.client.shill.disconnect(self.context.router.get_ssid()) |
| self.context.configure(get_ap_config()) |
| # Gather some statistics about ping latencies without scanning going on. |
| self.context.assert_connect_wifi(get_assoc_params(None)) |
| logging.info('Pinging router without background scans for %d seconds.', |
| self.NO_BGSCAN_SAMPLE_PERIOD_SECONDS) |
| result_no_bgscan = self.context.client.ping( |
| get_ping_config(self.NO_BGSCAN_SAMPLE_PERIOD_SECONDS)) |
| logging.info('Ping statistics without bgscan: %r', result_no_bgscan) |
| if result_no_bgscan.max_latency > self.THRESHOLD_BASELINE_LATENCY_MS: |
| raise error.TestFail('RTT latency is too high even without ' |
| 'background scans: %f' % |
| result_no_bgscan.max_latency) |
| |
| self.context.client.shill.disconnect(self.context.router.get_ssid()) |
| self.context.router.deconfig() |
| # Dwell time for scanning is usually configured to be around 100 ms, |
| # since this is also the standard beacon interval. Tolerate spikes in |
| # latency up to 200 ms as a way of asking that our PHY be servicing |
| # foreground traffic regularly during background scans. |
| if (result_bgscan.max_latency > |
| self.LATENCY_MARGIN_MS + result_no_bgscan.avg_latency): |
| raise error.TestFail('Significant difference in rtt due to bgscan: ' |
| '%.1f > %.1f + %d' % |
| (result_bgscan.max_latency, |
| result_no_bgscan.avg_latency, |
| self.LATENCY_MARGIN_MS)) |
