diff options
Diffstat (limited to 'shellutils.py')
| -rw-r--r-- | shellutils.py | 40 |
1 files changed, 29 insertions, 11 deletions
diff --git a/shellutils.py b/shellutils.py index 6a7509d..4cfe9a3 100644 --- a/shellutils.py +++ b/shellutils.py @@ -15,9 +15,11 @@ import sys import tempfile import time import fnmatch +import errno from os.path import exists, isdir, islink, basename, join, walk from logilab.common import STD_BLACKLIST +from logilab.common.proc import ProcInfo, NoSuchProcess def chown(path, login=None, group=None): @@ -199,21 +201,37 @@ 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.""" - count = 0 - while max_try <= 0 or count < max_try: - if not exists(lock_file): - break - count += 1 - time.sleep(delay) + count = abs(max_try) + while count: + try: + fd = os.open(lock_file, os.O_EXCL | os.O_RDWR | os.O_CREAT) + os.write(fd, str(os.getpid())) + os.close(fd) + return True + except OSError, e: + if e.errno == errno.EEXIST: + try: + 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) have locked the file '%s' for %s minutes.\nWaiting..." % (pi.name(), pid, lock_file, diff)) + except NoSuchProcess: + raise NoSuchProcess('You can delete the lock file "%s" safely' % lock_file) + except: + # process information are not accessible + pass + else: + raise + count -= 1 + time.sleep(delay) else: raise Exception('Unable to acquire %s' % lock_file) - stream = open(lock_file, 'w') - stream.write(str(os.getpid())) - stream.close() - + def release_lock(lock_file): """Release a lock represented by a file on the file system.""" os.remove(lock_file) |