[Android] Refactor and reuse reraiser_thread thread stack dumping utility.

build/android/pylib/utils/reraiser_thread.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Thread and ThreadGroup that reraise exceptions on the main thread."""
 
 import logging
 import sys
 import threading
 import time
 import traceback
 
 import watchdog_timer
 
 
 class TimeoutError(Exception):
   """Module-specific timeout exception."""
   pass
 
 
+def LogThreadStack(thread):
+  """Log the stack for the given thread.
+
+  Args:
+    thread: a threading.Thread instance.
+  """
+  stack = sys._current_frames()[thread.ident]
+  logging.critical('*' * 80)
+  logging.critical('Stack dump for thread \'%s\'', thread.name)
+  logging.critical('*' * 80)
+  for filename, lineno, name, line in traceback.extract_stack(stack):
+    logging.critical('File: "%s", line %d, in %s', filename, lineno, name)
+    if line:
+      logging.critical('  %s', line.strip())
+  logging.critical('*' * 80)
+
+
 class ReraiserThread(threading.Thread):
   """Thread class that can reraise exceptions."""
 
   def __init__(self, func, args=[], kwargs={}, name=None):
     """Initialize thread.
 
     Args:
       func: callable to call on a new thread.
       args: list of positional arguments for callable, defaults to empty.
       kwargs: dictionary of keyword arguments for callable, defaults to empty.
@@ skipping 75 matching lines @@
     immediately on exceptions raised on the main thread. Unfinished threads'
     stacks will be logged on watchdog timeout.
 
     Args:
       watcher: Watchdog object providing timeout, by default waits forever.
     """
     try:
       self._JoinAll(watcher)
     except TimeoutError:
       for thread in (t for t in self._threads if t.isAlive()):
-        stack = sys._current_frames()[thread.ident]
-        logging.critical('*' * 80)
-        logging.critical('Stack dump for timed out thread \'%s\'', thread.name)
-        logging.critical('*' * 80)
-        for filename, lineno, name, line in traceback.extract_stack(stack):
-          logging.critical('File: "%s", line %d, in %s', filename, lineno, name)
-          if line:
-            logging.critical('  %s', line.strip())
-        logging.critical('*' * 80)
+        LogThreadStack(thread)
       raise