tools/dev/lock-check.py

   1 #!/usr/bin/env python
   2
   3 ### Repository lock checker.  Gets an exclusive lock on the provided
   4 ### repository, then runs db_stat to see if the lock counts have been
   5 ### reset to 0.  If not, prints the timestamp of the run and a message
   6 ### about accumulation.
   7
   8 DB_STAT = 'db_stat'
   9
  10
  11 import sys
  12 import os
  13 import os.path
  14 import time
  15 import fcntl
  16 import getopt
  17 try:
  18   my_getopt = getopt.gnu_getopt
  19 except AttributeError:
  20   my_getopt = getopt.getopt
  21
  22 def usage_and_exit(retval):
  23   if retval:
  24     out = sys.stderr
  25   else:
  26     out = sys.stdout
  27   out.write("""Usage: %s [OPTIONS] REPOS-PATH
  28
  29 Options:
  30   --help (-h)    : Show this usage message
  31   --non-blocking : Don't wait for a lock that can't be immediately obtained
  32
  33 Obtain an exclusive lock (waiting for one unless --non-blocking is
  34 passed) on REPOS-PATH, then check its lock usage counts.  If there is
  35 any accumulation present, report that accumulation to stdout.
  36 """ % (os.path.basename(sys.argv[0])))
  37   sys.exit(retval)
  38
  39 def main():
  40   now_time = time.asctime()
  41   repos_path = None
  42   nonblocking = 0
  43
  44   # Parse the options.
  45   optlist, args = my_getopt(sys.argv[1:], "h", ['non-blocking', 'help'])
  46   for opt, arg in optlist:
  47     if opt == '--help' or opt == '-h':
  48       usage_and_exit(0)
  49     if opt == '--non-blocking':
  50       nonblocking = 1
  51     else:
  52       usage_and_exit(1)
  53
  54   # We need at least a path to work with, here.
  55   argc = len(args)
  56   if argc < 1 or argc > 1:
  57     usage_and_exit(1)
  58   repos_path = args[0]
  59
  60   fd = open(os.path.join(repos_path, 'locks', 'db.lock'), 'a')
  61   try:
  62     # Get an exclusive lock on the repository lock file, but maybe
  63     # don't wait for it.
  64     try:
  65       mode = fcntl.LOCK_EX
  66       if nonblocking:
  67         mode = mode | fcntl.LOCK_NB
  68       fcntl.lockf(fd, mode)
  69     except IOError:
  70       sys.stderr.write("Error obtaining exclusive lock.\n")
  71       sys.exit(1)
  72
  73     # Grab the db_stat results.
  74     lines = os.popen('%s -ch %s' % (DB_STAT, os.path.join(repos_path, 'db')))
  75     log_lines = []
  76     for line in lines:
  77       pieces = line.split('\t')
  78       if (pieces[1].find('current lock') != -1) and (int(pieces[0]) > 0):
  79         log = ''
  80         if not len(log_lines):
  81           log = log + "[%s] Lock accumulation for '%s'\n" \
  82                 % (now_time, repos_path)
  83         log = log + ' ' * 27
  84         log = log + "%s\t%s" % (pieces[0], pieces[1])
  85         log_lines.append(log)
  86     if len(log_lines):
  87       sys.stdout.write(''.join(log_lines))
  88   finally:
  89     # Unlock the lockfile
  90     fcntl.lockf(fd, fcntl.LOCK_UN)
  91   fd.close()
  92
  93 if __name__ == "__main__":
  94   main()