bin/ebuild-ipc.py

   1 #!/usr/bin/python
   2 # Copyright 2010 Gentoo Foundation
   3 # Distributed under the terms of the GNU General Public License v2
   4 #
   5 # This is a helper which ebuild processes can use
   6 # to communicate with portage's main python process.
   7
   8 import logging
   9 import os
  10 import pickle
  11 import select
  12 import signal
  13 import sys
  14 import time
  15
  16 def debug_signal(signum, frame):
  17         import pdb
  18         pdb.set_trace()
  19 signal.signal(signal.SIGUSR1, debug_signal)
  20
  21 # Avoid sandbox violations after python upgrade.
  22 pym_path = os.path.join(os.path.dirname(
  23         os.path.dirname(os.path.realpath(__file__))), "pym")
  24 if os.environ.get("SANDBOX_ON") == "1":
  25         sandbox_write = os.environ.get("SANDBOX_WRITE", "").split(":")
  26         if pym_path not in sandbox_write:
  27                 sandbox_write.append(pym_path)
  28                 os.environ["SANDBOX_WRITE"] = \
  29                         ":".join(filter(None, sandbox_write))
  30
  31 import portage
  32
  33 class EbuildIpc(object):
  34
  35         _COMMUNICATE_TIMEOUT_SECONDS = 40
  36
  37         def __init__(self):
  38                 self.fifo_dir = os.environ['PORTAGE_BUILDDIR']
  39                 self.ipc_in_fifo = os.path.join(self.fifo_dir, '.ipc_in')
  40                 self.ipc_out_fifo = os.path.join(self.fifo_dir, '.ipc_out')
  41                 self.ipc_lock_file = os.path.join(self.fifo_dir, '.ipc_lock')
  42
  43         def communicate(self, args):
  44
  45                 # Make locks quiet since unintended locking messages displayed on
  46                 # stdout could corrupt the intended output of this program.
  47                 portage.locks._quiet = True
  48                 lock_obj = portage.locks.lockfile(self.ipc_lock_file, unlinkfile=True)
  49                 start_time = time.time()
  50
  51                 try:
  52                         signal.signal(signal.SIGALRM, portage.exception.AlarmSignal.signal_handler)
  53                         signal.alarm(self._COMMUNICATE_TIMEOUT_SECONDS)
  54                         returncode = self._communicate(args)
  55                         signal.alarm(0)
  56                         return returncode
  57                 except portage.exception.AlarmSignal:
  58                         time_elapsed = time.time() - start_time
  59                         portage.util.writemsg_level(
  60                                 ('ebuild-ipc timed out after %d seconds\n') % \
  61                                 (time_elapsed,),
  62                                 level=logging.ERROR, noiselevel=-1)
  63                         return 1
  64                 finally:
  65                         signal.alarm(0)
  66                         portage.locks.unlockfile(lock_obj)
  67
  68         def _communicate(self, args):
  69                 input_fd = os.open(self.ipc_out_fifo, os.O_RDONLY|os.O_NONBLOCK)
  70
  71                 # File streams are in unbuffered mode since we do atomic
  72                 # read and write of whole pickles.
  73                 input_file = os.fdopen(input_fd, 'rb', 0)
  74                 output_file = open(self.ipc_in_fifo, 'wb', 0)
  75
  76                 # Write the whole pickle in a single atomic write() call,
  77                 # since the reader is in non-blocking mode and we want
  78                 # it to get the whole pickle at once.
  79                 output_file.write(pickle.dumps(args))
  80                 output_file.flush()
  81
  82                 events = select.select([input_file], [], [])
  83
  84                 # Read the whole pickle in a single read() call since
  85                 # this stream is in non-blocking mode and pickle.load()
  86                 # has been known to raise the following exception when
  87                 # reading from a non-blocking stream:
  88                 #
  89                 #   File "/usr/lib64/python2.6/pickle.py", line 1370, in load
  90                 #     return Unpickler(file).load()
  91                 #   File "/usr/lib64/python2.6/pickle.py", line 858, in load
  92                 #     dispatch[key](self)
  93                 #   File "/usr/lib64/python2.6/pickle.py", line 1195, in load_setitem
  94                 #     value = stack.pop()
  95                 # IndexError: pop from empty list
  96
  97                 pickle_str = input_file.read()
  98                 reply = pickle.loads(pickle_str)
  99                 output_file.close()
 100                 input_file.close()
 101
 102                 (out, err, rval) = reply
 103
 104                 if out:
 105                         portage.util.writemsg_stdout(out, noiselevel=-1)
 106
 107                 if err:
 108                         portage.util.writemsg(err, noiselevel=-1)
 109
 110                 return rval
 111
 112 def ebuild_ipc_main(args):
 113         ebuild_ipc = EbuildIpc()
 114         return ebuild_ipc.communicate(args)
 115
 116 if __name__ == '__main__':
 117         sys.exit(ebuild_ipc_main(sys.argv[1:]))