root_cache.py 文件源码

def _rootCacheLock(self, shared=1):
        lockType = fcntl.LOCK_EX
        if shared:
            lockType = fcntl.LOCK_SH
        try:
            fcntl.lockf(self.rootCacheLock.fileno(), lockType | fcntl.LOCK_NB)
        except IOError:
            self.state.start("Waiting for rootcache lock")
            fcntl.lockf(self.rootCacheLock.fileno(), lockType)
            self.state.finish("Waiting for rootcache lock")