t.i.p.Process(_BaseProcess) : class documentation

Part of twisted.internet.process View Source View In Hierarchy

An operating-system Process.

This represents an operating-system process with arbitrary input/output pipes connected to it. Those pipes may represent standard input, standard output, and standard error, or any other file descriptor.

On UNIX, this is implemented using fork(), exec(), pipe() and fcntl(). These calls may not exist elsewhere so this code is not cross-platform. (also, windows can only select on sockets...)
Method __init__ Spawn an operating-system process.
Method writeToChild Undocumented
Method closeChildFD Undocumented
Method pauseProducing Undocumented
Method resumeProducing Undocumented
Method closeStdin Call this to close standard input on this process.
Method closeStdout Undocumented
Method closeStderr Undocumented
Method loseConnection Undocumented
Method write Call this to write to standard input on this process.
Method registerProducer Call this to register producer for standard input.
Method unregisterProducer Call this to unregister producer for standard input.
Method writeSequence Call this to write to standard input on this process.
Method childDataReceived Undocumented
Method processEnded Undocumented
Method childConnectionLost Undocumented
Method maybeCallProcessEnded Call processEnded on protocol after final cleanup.
Method _setupChild fdmap[childFD] = parentFD

Inherited from _BaseProcess:

Method reapProcess Try to reap a process (without blocking) via waitpid.
Method signalProcess No summary
Method __repr__ String representation of a process.
Method _fork Fork and then exec sub-process.
Method _execChild The exec() which is done in the forked child.

Inherited from Ephemeral (via _BaseProcess):

Method __getstate__ Undocumented
Method __setstate__ Undocumented
def __init__(self, reactor, executable, args, environment, path, proto, uid=None, gid=None, childFDs=None): (source)

Spawn an operating-system process.

This is where the hard work of disconnecting all currently open files / forking / executing the new process happens. (This is executed automatically when a Process is instantiated.)

This will also run the subprocess as a given user ID and group ID, if specified. (Implementation Note: this doesn't support all the arcane nuances of setXXuid on UNIX: it will assume that either your effective or real UID is 0.)
def _setupChild(self, fdmap): (source)

fdmap[childFD] = parentFD

The child wants to end up with 'childFD' attached to what used to be the parent's parentFD. As an example, a bash command run like 'command 2>&1' would correspond to an fdmap of {0:0, 1:1, 2:1}. 'command >foo.txt' would be {0:0, 1:os.open('foo.txt'), 2:2}.

This is accomplished in two steps:
   1. close all file descriptors that aren't values of fdmap.  This
      means 0 .. maxfds.

   2. for each childFD::

        - if fdmap[childFD] == childFD, the descriptor is already in
          place.  Make sure the CLOEXEC flag is not set, then delete
          the entry from fdmap.

        - if childFD is in fdmap.values(), then the target descriptor
          is busy. Use os.dup() to move it elsewhere, update all
          fdmap[childFD] items that point to it, then close the
          original. Then fall through to the next case.

        - now fdmap[childFD] is not in fdmap.values(), and is free.
          Use os.dup2() to move it to the right place, then close the
          original.
def writeToChild(self, childFD, data): (source)
Undocumented
def closeChildFD(self, childFD): (source)
Undocumented
def pauseProducing(self): (source)
Undocumented
def resumeProducing(self): (source)
Undocumented
def closeStdin(self): (source)
Call this to close standard input on this process.
def closeStdout(self): (source)
Undocumented
def closeStderr(self): (source)
Undocumented
def loseConnection(self): (source)
Undocumented
def write(self, data): (source)

Call this to write to standard input on this process.

NOTE: This will silently lose data if there is no standard input.
def registerProducer(self, producer, streaming): (source)

Call this to register producer for standard input.

If there is no standard input producer.stopProducing() will be called immediately.
def unregisterProducer(self): (source)
Call this to unregister producer for standard input.
def writeSequence(self, seq): (source)

Call this to write to standard input on this process.

NOTE: This will silently lose data if there is no standard input.
def childDataReceived(self, name, data): (source)
Undocumented
def processEnded(self, status): (source)
Undocumented
def childConnectionLost(self, childFD, reason): (source)
Undocumented
def maybeCallProcessEnded(self): (source)
Call processEnded on protocol after final cleanup.
API Documentation for Twisted, generated by pydoctor at 2011-10-27 15:57:47.