Android: capture logcat for all devices on bb_run_sharded_steps.py

build/android/bb_run_sharded_steps.py

Index: build/android/bb_run_sharded_steps.py
diff --git a/build/android/bb_run_sharded_steps.py b/build/android/bb_run_sharded_steps.py
index 9010d774b71066871b9f488fa430ff5aff3a17f2..29343d24fc32ef0f9dbe4d86ab0b0c5072a8b2bb 100755
--- a/build/android/bb_run_sharded_steps.py
+++ b/build/android/bb_run_sharded_steps.py
@@ -45,6 +45,7 @@ import pickle
 import os
 import signal
 import shutil
+import subprocess
 import sys
 
 from pylib import android_commands
@@ -84,6 +85,26 @@ def _RunStepsPerDevice(steps):
   return results
 
 
+class _LogCatMonitor(object):
+  def __init__(self):
+    self._monitor = None
+    self._logcat_dir = os.path.join(constants.CHROME_DIR, 'out',
+                                    'sharded_steps_logcat_monitor')
+
+  def __enter__(self):
+    cmd = [os.path.join(constants.CHROME_DIR, 'build', 'android',
+                        'adb_logcat_monitor.py'), self._logcat_dir]
+    self._monitor = subprocess.Popen(cmd, cwd=constants.CHROME_DIR)
+
+  def __exit__(self, *args):
+    if self._monitor:
+      self._monitor.terminate()

[Isaac (away), 2013/01/11 21:46:36]

Killing the monitor is not needed currently. The logcat printer will do it. 
Though it certainly seems reasonable to change in the future to not have the
printer sending kill signals (ick) pand whatnot.

It's fine to keep it in, but the printer will print a warning. 

[bulach, 2013/01/14 09:14:30]

oh, good point! done.

+      cmd = [os.path.join(constants.CHROME_DIR, 'build', 'android',
+                          'adb_logcat_printer.py'), self._logcat_dir]
+      cmd = subprocess.Popen(cmd, cwd=constants.CHROME_DIR)
+      cmd.wait()
+
+
 def _RunShardedSteps(steps, devices):
   assert steps
   assert devices, 'No devices connected?'
@@ -107,9 +128,12 @@ def _RunShardedSteps(steps, devices):
   print 'Start sharding (note: output is not synchronized...)'
   print '*' * 80
   start_time = datetime.datetime.now()
-  pool = multiprocessing.Pool(processes=num_devices)
-  async_results = pool.map_async(_RunStepsPerDevice, all_params)
-  results_per_device = async_results.get(999999)
+
+  with _LogCatMonitor() as logcat_monitor:
+    pool = multiprocessing.Pool(processes=num_devices)
+    async_results = pool.map_async(_RunStepsPerDevice, all_params)
+    results_per_device = async_results.get(999999)
+
   end_time = datetime.datetime.now()
   print '*' * 80
   print 'Finished sharding.'