Remove the 'http_lock' and 'file_lock' code from webkitpy.

Tools/Scripts/webkitpy/common/system/file_lock.py

-# Copyright (C) 2010 Gabor Rapcsanyi (rgabor@inf.u-szeged.hu), University of Szeged
-#
-# All rights reserved.
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions
-# are met:
-# 1. Redistributions of source code must retain the above copyright
-#    notice, this list of conditions and the following disclaimer.
-# 2. 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.
-#
-# THIS SOFTWARE IS PROVIDED BY UNIVERSITY OF SZEGED ``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 UNIVERSITY OF SZEGED OR
-# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
-# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
-# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
-# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
-# OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-"""This class helps to lock files exclusively across processes."""
-
-import logging
-import os
-import sys
-import time
-
-
-_log = logging.getLogger(__name__)
-
-
-class FileLock(object):
-
-    def __init__(self, lock_file_path, max_wait_time_sec=20):
-        self._lock_file_path = lock_file_path
-        self._lock_file_descriptor = None
-        self._max_wait_time_sec = max_wait_time_sec
-
-    def _create_lock(self):
-        if sys.platform == 'win32':
-            import msvcrt
-            msvcrt.locking(self._lock_file_descriptor, msvcrt.LK_NBLCK, 32)
-        else:
-            import fcntl
-            fcntl.flock(self._lock_file_descriptor, fcntl.LOCK_EX | fcntl.LOCK_NB)
-
-    def _remove_lock(self):
-        if sys.platform == 'win32':
-            import msvcrt
-            msvcrt.locking(self._lock_file_descriptor, msvcrt.LK_UNLCK, 32)
-        else:
-            import fcntl
-            fcntl.flock(self._lock_file_descriptor, fcntl.LOCK_UN)
-
-    def acquire_lock(self):
-        self._lock_file_descriptor = os.open(self._lock_file_path, os.O_TRUNC | os.O_CREAT)
-        start_time = time.time()
-        while True:
-            try:
-                self._create_lock()
-                return True
-            except IOError:
-                if time.time() - start_time > self._max_wait_time_sec:
-                    _log.debug("File locking failed: %s" % str(sys.exc_info()))
-                    os.close(self._lock_file_descriptor)
-                    self._lock_file_descriptor = None
-                    return False
-                # There's no compelling reason to spin hard here, so sleep for a bit.
-                time.sleep(0.01)
-
-    def release_lock(self):
-        try:
-            if self._lock_file_descriptor:
-                self._remove_lock()
-                os.close(self._lock_file_descriptor)
-                self._lock_file_descriptor = None
-            os.unlink(self._lock_file_path)
-        except (IOError, OSError):
-            _log.debug("Warning in release lock: %s" % str(sys.exc_info()))