| # Copyright 2015, Google Inc. |
| # All rights reserved. |
| # |
| # Redistribution and use in source and binary forms, with or without |
| # modification, are permitted provided that the following conditions are |
| # met: |
| # |
| # * Redistributions of source code must retain the above copyright |
| # notice, this list of conditions and the following disclaimer. |
| # * Redistributions in binary form must reproduce the above |
| # copyright notice, this list of conditions and the following disclaimer |
| # in the documentation and/or other materials provided with the |
| # distribution. |
| # * Neither the name of Google Inc. nor the names of its |
| # contributors may be used to endorse or promote products derived from |
| # this software without specific prior written permission. |
| # |
| # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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| # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| """A thread pool that logs exceptions raised by tasks executed within it.""" |
| |
| import logging |
| |
| from concurrent import futures |
| |
| |
| def _wrap(behavior): |
| """Wraps an arbitrary callable behavior in exception-logging.""" |
| def _wrapping(*args, **kwargs): |
| try: |
| return behavior(*args, **kwargs) |
| except Exception as e: |
| logging.exception( |
| 'Unexpected exception from %s executed in logging pool!', behavior) |
| raise |
| return _wrapping |
| |
| |
| class _LoggingPool(object): |
| """An exception-logging futures.ThreadPoolExecutor-compatible thread pool.""" |
| |
| def __init__(self, backing_pool): |
| self._backing_pool = backing_pool |
| |
| def __enter__(self): |
| return self |
| |
| def __exit__(self, exc_type, exc_val, exc_tb): |
| self._backing_pool.shutdown(wait=True) |
| |
| def submit(self, fn, *args, **kwargs): |
| return self._backing_pool.submit(_wrap(fn), *args, **kwargs) |
| |
| def map(self, func, *iterables, **kwargs): |
| return self._backing_pool.map( |
| _wrap(func), *iterables, timeout=kwargs.get('timeout', None)) |
| |
| def shutdown(self, wait=True): |
| self._backing_pool.shutdown(wait=wait) |
| |
| |
| def pool(max_workers): |
| """Creates a thread pool that logs exceptions raised by the tasks within it. |
| |
| Args: |
| max_workers: The maximum number of worker threads to allow the pool. |
| |
| Returns: |
| A futures.ThreadPoolExecutor-compatible thread pool that logs exceptions |
| raised by the tasks executed within it. |
| """ |
| return _LoggingPool(futures.ThreadPoolExecutor(max_workers)) |