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author | 2017-02-03 15:52:26 +0800 | |
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committer | 2017-02-07 22:53:49 +0800 | |
commit | ba64ce23c5572b0de5e5596a479d9090115009e4 (patch) | |
tree | a3e4549ed0473e386083e771840b5c1105c4dbaf /lcm/lcm/pub/utils/share_lock.py | |
parent | 38a7066543a27c613a7d5ad85395a4bd4d7e7318 (diff) |
Add code framework of gvnfm-vnflcm
Change-Id: I67e7499293613ad001c73193b4b59536fc087657
Issure-Id: GVNFM-23
Signed-off-by: fujinhua <fu.jinhua@zte.com.cn>
Diffstat (limited to 'lcm/lcm/pub/utils/share_lock.py')
-rw-r--r-- | lcm/lcm/pub/utils/share_lock.py | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/lcm/lcm/pub/utils/share_lock.py b/lcm/lcm/pub/utils/share_lock.py new file mode 100644 index 00000000..cb0e38c4 --- /dev/null +++ b/lcm/lcm/pub/utils/share_lock.py @@ -0,0 +1,78 @@ +# Copyright 2017 ZTE Corporation. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +import time + +import redis + +from lcm.pub.config.config import REDIS_HOST, REDIS_PORT, REDIS_PASSWD + + +class SharedLock: + def __init__(self, lock_key, host=REDIS_HOST, port=REDIS_PORT, password=REDIS_PASSWD, db=9, lock_timeout=5 * 60): + self.lock_key = lock_key + self.lock_timeout = lock_timeout + self.redis = redis.Redis(host=host, port=port, db=db, password=password) + self.acquire_time = -1 + + def acquire(self): + begin = now = int(time.time()) + while (now - begin) < self.lock_timeout: + + result = self.redis.setnx(self.lock_key, now + self.lock_timeout + 1) + if result == 1 or result is True: + self.acquire_time = now + return True + + current_lock_timestamp = self.redis.get(self.lock_key) + if not current_lock_timestamp: + time.sleep(1) + continue + + current_lock_timestamp = int(current_lock_timestamp) + + if now > current_lock_timestamp: + next_lock_timestamp = self.redis.getset(self.lock_key, now + self.lock_timeout + 1) + if not next_lock_timestamp: + time.sleep(1) + continue + next_lock_timestamp = int(next_lock_timestamp) + + if next_lock_timestamp == current_lock_timestamp: + self.acquire_time = now + return True + else: + time.sleep(1) + continue + return False + + def release(self): + now = int(time.time()) + if now > self.acquire_time + self.lock_timeout: + # key expired, do nothing and let other clients handle it + return + self.acquire_time = None + self.redis.delete(self.lock_key) + + +def do_biz_with_share_lock(lock_name, callback): + lock = SharedLock(lock_name) + try: + if not lock.acquire(): + raise Exception(lock_name + " timeout") + callback() + except Exception as e: + raise e + finally: + lock.release() |