1#!/usr/bin/env python3 2# 3# Copyright 2012 The Chromium Authors 4# Use of this source code is governed by a BSD-style license that can be 5# found in the LICENSE file. 6 7"""Saves logcats from all connected devices. 8 9Usage: adb_logcat_monitor.py <base_dir> [<adb_binary_path>] 10 11This script will repeatedly poll adb for new devices and save logcats 12inside the <base_dir> directory, which it attempts to create. The 13script will run until killed by an external signal. To test, run the 14script in a shell and <Ctrl>-C it after a while. It should be 15resilient across phone disconnects and reconnects and start the logcat 16early enough to not miss anything. 17""" 18 19 20import logging 21import os 22import re 23import shutil 24import signal 25import subprocess 26import sys 27import time 28 29# Map from device_id -> (process, logcat_num) 30devices = {} 31 32 33class TimeoutException(Exception): 34 """Exception used to signal a timeout.""" 35 36 37class SigtermError(Exception): 38 """Exception used to catch a sigterm.""" 39 40 41def StartLogcatIfNecessary(device_id, adb_cmd, base_dir): 42 """Spawns a adb logcat process if one is not currently running.""" 43 process, logcat_num = devices[device_id] 44 if process: 45 if process.poll() is None: 46 # Logcat process is still happily running 47 return 48 logging.info('Logcat for device %s has died', device_id) 49 error_filter = re.compile('- waiting for device -') 50 for line in process.stderr: 51 line_str = line.decode('utf8', 'replace') 52 if not error_filter.match(line_str): 53 logging.error(device_id + ': ' + line_str) 54 55 logging.info('Starting logcat %d for device %s', logcat_num, 56 device_id) 57 logcat_filename = 'logcat_%s_%03d' % (device_id, logcat_num) 58 logcat_file = open(os.path.join(base_dir, logcat_filename), 'w') 59 process = subprocess.Popen([adb_cmd, '-s', device_id, 60 'logcat', '-v', 'threadtime'], 61 stdout=logcat_file, 62 stderr=subprocess.PIPE) 63 devices[device_id] = (process, logcat_num + 1) 64 65 66def GetAttachedDevices(adb_cmd): 67 """Gets the device list from adb. 68 69 We use an alarm in this function to avoid deadlocking from an external 70 dependency. 71 72 Args: 73 adb_cmd: binary to run adb 74 75 Returns: 76 list of devices or an empty list on timeout 77 """ 78 signal.alarm(2) 79 try: 80 out, err = subprocess.Popen([adb_cmd, 'devices'], 81 stdout=subprocess.PIPE, 82 stderr=subprocess.PIPE).communicate() 83 if err: 84 logging.warning('adb device error %s', err.strip()) 85 return re.findall('^(\\S+)\tdevice$', out.decode('latin1'), re.MULTILINE) 86 except TimeoutException: 87 logging.warning('"adb devices" command timed out') 88 return [] 89 except (IOError, OSError): 90 logging.exception('Exception from "adb devices"') 91 return [] 92 finally: 93 signal.alarm(0) 94 95 96def main(base_dir, adb_cmd='adb'): 97 """Monitor adb forever. Expects a SIGINT (Ctrl-C) to kill.""" 98 # We create the directory to ensure 'run once' semantics 99 if os.path.exists(base_dir): 100 print('adb_logcat_monitor: %s already exists? Cleaning' % base_dir) 101 shutil.rmtree(base_dir, ignore_errors=True) 102 103 os.makedirs(base_dir) 104 logging.basicConfig(filename=os.path.join(base_dir, 'eventlog'), 105 level=logging.INFO, 106 format='%(asctime)-2s %(levelname)-8s %(message)s') 107 108 # Set up the alarm for calling 'adb devices'. This is to ensure 109 # our script doesn't get stuck waiting for a process response 110 def TimeoutHandler(_signum, _unused_frame): 111 raise TimeoutException() 112 signal.signal(signal.SIGALRM, TimeoutHandler) 113 114 # Handle SIGTERMs to ensure clean shutdown 115 def SigtermHandler(_signum, _unused_frame): 116 raise SigtermError() 117 signal.signal(signal.SIGTERM, SigtermHandler) 118 119 logging.info('Started with pid %d', os.getpid()) 120 pid_file_path = os.path.join(base_dir, 'LOGCAT_MONITOR_PID') 121 122 try: 123 with open(pid_file_path, 'w') as f: 124 f.write(str(os.getpid())) 125 while True: 126 for device_id in GetAttachedDevices(adb_cmd): 127 if not device_id in devices: 128 subprocess.call([adb_cmd, '-s', device_id, 'logcat', '-c']) 129 devices[device_id] = (None, 0) 130 131 for device in devices: 132 # This will spawn logcat watchers for any device ever detected 133 StartLogcatIfNecessary(device, adb_cmd, base_dir) 134 135 time.sleep(5) 136 except SigtermError: 137 logging.info('Received SIGTERM, shutting down') 138 except: # pylint: disable=bare-except 139 logging.exception('Unexpected exception in main.') 140 finally: 141 for process, _ in devices.values(): 142 if process: 143 try: 144 process.terminate() 145 except OSError: 146 pass 147 os.remove(pid_file_path) 148 149 150if __name__ == '__main__': 151 if 2 <= len(sys.argv) <= 3: 152 print('adb_logcat_monitor: Initializing') 153 if len(sys.argv) == 2: 154 sys.exit(main(sys.argv[1])) 155 sys.exit(main(sys.argv[1], sys.argv[2])) 156 157 print('Usage: %s <base_dir> [<adb_binary_path>]' % sys.argv[0]) 158