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| author | Richard Purdie <rpurdie@linux.intel.com> | 2010-01-20 18:46:02 +0000 | 
|---|---|---|
| committer | Richard Purdie <rpurdie@linux.intel.com> | 2010-01-20 18:46:02 +0000 | 
| commit | 22c29d8651668195f72e2f6a8e059d625eb511c3 (patch) | |
| tree | dd1dd43f0ec47a9964c8a766eb8b3ad75cf51a64 /bitbake-dev/lib/bb/daemonize.py | |
| parent | 1bfd6edef9db9c9175058ae801d1b601e4f15263 (diff) | |
| download | openembedded-core-22c29d8651668195f72e2f6a8e059d625eb511c3.tar.gz openembedded-core-22c29d8651668195f72e2f6a8e059d625eb511c3.tar.bz2 openembedded-core-22c29d8651668195f72e2f6a8e059d625eb511c3.zip | |
bitbake: Switch to bitbake-dev version (bitbake master upstream)
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Diffstat (limited to 'bitbake-dev/lib/bb/daemonize.py')
| -rw-r--r-- | bitbake-dev/lib/bb/daemonize.py | 191 | 
1 files changed, 0 insertions, 191 deletions
| diff --git a/bitbake-dev/lib/bb/daemonize.py b/bitbake-dev/lib/bb/daemonize.py deleted file mode 100644 index 1a8bb379f4..0000000000 --- a/bitbake-dev/lib/bb/daemonize.py +++ /dev/null @@ -1,191 +0,0 @@ -"""
 -Python Deamonizing helper
 -
 -Configurable daemon behaviors:
 -
 -   1.) The current working directory set to the "/" directory.
 -   2.) The current file creation mode mask set to 0.
 -   3.) Close all open files (1024). 
 -   4.) Redirect standard I/O streams to "/dev/null".
 -
 -A failed call to fork() now raises an exception.
 -
 -References:
 -   1) Advanced Programming in the Unix Environment: W. Richard Stevens
 -   2) Unix Programming Frequently Asked Questions:
 -         http://www.erlenstar.demon.co.uk/unix/faq_toc.html
 -
 -Modified to allow a function to be daemonized and return for 
 -bitbake use by Richard Purdie
 -"""
 -
 -__author__ = "Chad J. Schroeder"
 -__copyright__ = "Copyright (C) 2005 Chad J. Schroeder"
 -__version__ = "0.2"
 -
 -# Standard Python modules.
 -import os               # Miscellaneous OS interfaces.
 -import sys              # System-specific parameters and functions.
 -
 -# Default daemon parameters.
 -# File mode creation mask of the daemon.
 -# For BitBake's children, we do want to inherit the parent umask.
 -UMASK = None
 -
 -# Default maximum for the number of available file descriptors.
 -MAXFD = 1024
 -
 -# The standard I/O file descriptors are redirected to /dev/null by default.
 -if (hasattr(os, "devnull")):
 -   REDIRECT_TO = os.devnull
 -else:
 -   REDIRECT_TO = "/dev/null"
 -
 -def createDaemon(function, logfile):
 -   """
 -   Detach a process from the controlling terminal and run it in the
 -   background as a daemon, returning control to the caller.
 -   """
 -
 -   try:
 -      # Fork a child process so the parent can exit.  This returns control to
 -      # the command-line or shell.  It also guarantees that the child will not
 -      # be a process group leader, since the child receives a new process ID
 -      # and inherits the parent's process group ID.  This step is required
 -      # to insure that the next call to os.setsid is successful.
 -      pid = os.fork()
 -   except OSError, e:
 -      raise Exception, "%s [%d]" % (e.strerror, e.errno)
 -
 -   if (pid == 0):	# The first child.
 -      # To become the session leader of this new session and the process group
 -      # leader of the new process group, we call os.setsid().  The process is
 -      # also guaranteed not to have a controlling terminal.
 -      os.setsid()
 -
 -      # Is ignoring SIGHUP necessary?
 -      #
 -      # It's often suggested that the SIGHUP signal should be ignored before
 -      # the second fork to avoid premature termination of the process.  The
 -      # reason is that when the first child terminates, all processes, e.g.
 -      # the second child, in the orphaned group will be sent a SIGHUP.
 -      #
 -      # "However, as part of the session management system, there are exactly
 -      # two cases where SIGHUP is sent on the death of a process:
 -      #
 -      #   1) When the process that dies is the session leader of a session that
 -      #      is attached to a terminal device, SIGHUP is sent to all processes
 -      #      in the foreground process group of that terminal device.
 -      #   2) When the death of a process causes a process group to become
 -      #      orphaned, and one or more processes in the orphaned group are
 -      #      stopped, then SIGHUP and SIGCONT are sent to all members of the
 -      #      orphaned group." [2]
 -      #
 -      # The first case can be ignored since the child is guaranteed not to have
 -      # a controlling terminal.  The second case isn't so easy to dismiss.
 -      # The process group is orphaned when the first child terminates and
 -      # POSIX.1 requires that every STOPPED process in an orphaned process
 -      # group be sent a SIGHUP signal followed by a SIGCONT signal.  Since the
 -      # second child is not STOPPED though, we can safely forego ignoring the
 -      # SIGHUP signal.  In any case, there are no ill-effects if it is ignored.
 -      #
 -      # import signal           # Set handlers for asynchronous events.
 -      # signal.signal(signal.SIGHUP, signal.SIG_IGN)
 -
 -      try:
 -         # Fork a second child and exit immediately to prevent zombies.  This
 -         # causes the second child process to be orphaned, making the init
 -         # process responsible for its cleanup.  And, since the first child is
 -         # a session leader without a controlling terminal, it's possible for
 -         # it to acquire one by opening a terminal in the future (System V-
 -         # based systems).  This second fork guarantees that the child is no
 -         # longer a session leader, preventing the daemon from ever acquiring
 -         # a controlling terminal.
 -         pid = os.fork()	# Fork a second child.
 -      except OSError, e:
 -         raise Exception, "%s [%d]" % (e.strerror, e.errno)
 -
 -      if (pid == 0):	# The second child.
 -         # We probably don't want the file mode creation mask inherited from
 -         # the parent, so we give the child complete control over permissions.
 -         if UMASK is not None:
 -             os.umask(UMASK)
 -      else:
 -         # Parent (the first child) of the second child.
 -         os._exit(0)
 -   else:
 -      # exit() or _exit()?
 -      # _exit is like exit(), but it doesn't call any functions registered
 -      # with atexit (and on_exit) or any registered signal handlers.  It also
 -      # closes any open file descriptors.  Using exit() may cause all stdio
 -      # streams to be flushed twice and any temporary files may be unexpectedly
 -      # removed.  It's therefore recommended that child branches of a fork()
 -      # and the parent branch(es) of a daemon use _exit().
 -      return
 -
 -   # Close all open file descriptors.  This prevents the child from keeping
 -   # open any file descriptors inherited from the parent.  There is a variety
 -   # of methods to accomplish this task.  Three are listed below.
 -   #
 -   # Try the system configuration variable, SC_OPEN_MAX, to obtain the maximum
 -   # number of open file descriptors to close.  If it doesn't exists, use
 -   # the default value (configurable).
 -   #
 -   # try:
 -   #    maxfd = os.sysconf("SC_OPEN_MAX")
 -   # except (AttributeError, ValueError):
 -   #    maxfd = MAXFD
 -   #
 -   # OR
 -   #
 -   # if (os.sysconf_names.has_key("SC_OPEN_MAX")):
 -   #    maxfd = os.sysconf("SC_OPEN_MAX")
 -   # else:
 -   #    maxfd = MAXFD
 -   #
 -   # OR
 -   #
 -   # Use the getrlimit method to retrieve the maximum file descriptor number
 -   # that can be opened by this process.  If there is not limit on the
 -   # resource, use the default value.
 -   #
 -   import resource		# Resource usage information.
 -   maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
 -   if (maxfd == resource.RLIM_INFINITY):
 -      maxfd = MAXFD
 -  
 -   # Iterate through and close all file descriptors.
 -#   for fd in range(0, maxfd):
 -#      try:
 -#         os.close(fd)
 -#      except OSError:	# ERROR, fd wasn't open to begin with (ignored)
 -#         pass
 -
 -   # Redirect the standard I/O file descriptors to the specified file.  Since
 -   # the daemon has no controlling terminal, most daemons redirect stdin,
 -   # stdout, and stderr to /dev/null.  This is done to prevent side-effects
 -   # from reads and writes to the standard I/O file descriptors.
 -
 -   # This call to open is guaranteed to return the lowest file descriptor,
 -   # which will be 0 (stdin), since it was closed above.
 -#   os.open(REDIRECT_TO, os.O_RDWR)	# standard input (0)
 -
 -   # Duplicate standard input to standard output and standard error.
 -#   os.dup2(0, 1)			# standard output (1)
 -#   os.dup2(0, 2)			# standard error (2)
 -
 -
 -   si = file('/dev/null', 'r')
 -   so = file(logfile, 'w')
 -   se = so
 -
 -
 -   # Replace those fds with our own
 -   os.dup2(si.fileno(), sys.stdin.fileno())
 -   os.dup2(so.fileno(), sys.stdout.fileno())
 -   os.dup2(se.fileno(), sys.stderr.fileno())
 -
 -   function()
 -
 -   os._exit(0)
 -
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