1 # Copyright 2016 The Chromium OS Authors. All rights reserved. 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 5 """Utilities used with Brillo hosts.""" 6 7 _RUN_BACKGROUND_TEMPLATE = '( %(cmd)s ) </dev/null >/dev/null 2>&1 & echo -n $!' 8 9 _WAIT_CMD_TEMPLATE = """\ 10 to=%(timeout)d; \ 11 while test ${to} -ne 0; do \ 12 test $(ps %(pid)d | wc -l) -gt 1 || break; \ 13 sleep 1; \ 14 to=$((to - 1)); \ 15 done; \ 16 test ${to} -ne 0 -o $(ps %(pid)d | wc -l) -eq 1 \ 17 """ 18 19 20 def run_in_background(host, cmd): 21 """Runs a command in the background on the DUT. 22 23 @param host: A host object representing the DUT. 24 @param cmd: The command to run. 25 26 @return The background process ID (integer). 27 """ 28 background_cmd = _RUN_BACKGROUND_TEMPLATE % {'cmd': cmd} 29 return int(host.run_output(background_cmd).strip()) 30 31 32 def wait_for_process(host, pid, timeout=-1): 33 """Waits for a process on the DUT to terminate. 34 35 @param host: A host object representing the DUT. 36 @param pid: The process ID (integer). 37 @param timeout: Number of seconds to wait; default is wait forever. 38 39 @return True if process terminated within the alotted time, False otherwise. 40 """ 41 wait_cmd = _WAIT_CMD_TEMPLATE % {'pid': pid, 'timeout': timeout} 42 return host.run(wait_cmd, ignore_status=True).exit_status == 0 43
