diff options
Diffstat (limited to 'shellutils.py')
| -rw-r--r-- | shellutils.py | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/shellutils.py b/shellutils.py index d964705..337a9dc 100644 --- a/shellutils.py +++ b/shellutils.py @@ -11,6 +11,7 @@ __docformat__ = "restructuredtext en" import os import glob import shutil +import stat import sys import tempfile import time @@ -201,8 +202,13 @@ class Execute: os.remove(outfile) os.remove(errfile) -def acquire_lock(lock_file, max_try=10, delay=10): - """Acquire a lock represented by a file on the file system.""" +def acquire_lock(lock_file, max_try=10, delay=10, max_delay=3600): + """Acquire a lock represented by a file on the file system + + If the process written in lock file doesn't exist anymore, we remove the + lock file immediately + If age of the lock_file is greater than max_delay, then we raise a UserWarning + """ count = abs(max_try) while count: try: @@ -216,14 +222,20 @@ def acquire_lock(lock_file, max_try=10, delay=10): fd = open(lock_file, "r") pid = int(fd.readline()) pi = ProcInfo(pid) - # only print the message one time - if count == max_try: - diff = (int(time.time()) - pi.age()) / 60 - print("Command '%s' (pid %s) has locked the file '%s' for %s minutes.\nWaiting..." % (pi.name(), pid, lock_file, diff)) + age = (time.time() - os.stat(lock_file)[stat.ST_MTIME]) + if age / max_delay > 1 : + raise UserWarning("Command '%s' (pid %s) has locked the " + "file '%s' for %s minutes" + % (pi.name(), pid, lock_file, age/60)) + except UserWarning: + raise except NoSuchProcess: - raise NoSuchProcess('You can delete the lock file "%s" safely' % lock_file) - except: - # process information are not accessible + os.remove(lock_file) + except Exception: + # The try block is not essential. can be skipped. + # Note: ProcInfo object is only available for linux + # process information are not accessible... + # or lock_file is no more present... pass else: raise |