X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=tools.py;h=bc4b49e84fd21896b1659e9a76041510e0fa16ca;hb=2377994fe75797399d3cd686432b586f6347b4d8;hp=49441bda94a42af81f0e922565d97f37dc826911;hpb=2f100cd2a78a0f91022bc4a895007975181cf353;p=nodemanager.git diff --git a/tools.py b/tools.py index 49441bd..bc4b49e 100644 --- a/tools.py +++ b/tools.py @@ -7,6 +7,7 @@ import pwd import tempfile import threading import fcntl +import commands import logger @@ -91,9 +92,42 @@ def write_temp_file(do_write, mode=None, uidgid=None): finally: f.close() return temporary_filename +# utilities functions to get (cached) information from the node + +# get node_id from /etc/planetlab/node_id and cache it +_node_id=None +def node_id(): + global _node_id + if _node_id is None: + try: + _node_id=int(file("/etc/planetlab/node_id").read()) + except: + _node_id="" + return _node_id + +# get slicefamily from /etc/planetlab/slicefamily and cache it +# http://svn.planet-lab.org/wiki/SliceFamily +_slicefamily=None +def slicefamily(): + global _slicefamily + if _slicefamily is None: + try: + _slicefamily=file("/etc/planetlab/slicefamily").read().strip() + except: + _slicefamily="" + return _slicefamily + +_root_context_arch=None +def root_context_arch(): + global _root_context_arch + if not _root_context_arch: + _root_context_arch=commands.getoutput("uname -i") + return _root_context_arch + class NMLock: def __init__(self, file): + logger.log("Lock %s initialized." % file, 2) self.fd = os.open(file, os.O_RDWR|os.O_CREAT, 0600) flags = fcntl.fcntl(self.fd, fcntl.F_GETFD) flags |= fcntl.FD_CLOEXEC @@ -101,6 +135,8 @@ class NMLock: def __del__(self): os.close(self.fd) def acquire(self): - fcntl.lockf(self.fd, fcntl.LOCK_EX) + logger.log("Lock acquired.", 2) + fcntl.lockf(self.fd, fcntl.LOCK_SH) def release(self): + logger.log("Lock released.", 2) fcntl.lockf(self.fd, fcntl.LOCK_UN)