twshell: do not install gtk2 reactor automatically

IPython/twshell.py

@@ -1,280 +1,278 b''
 import sys
 
-from twisted.internet import gtk2reactor
-gtk2reactor.install()
-
 from twisted.internet import reactor, threads
 
-""" change here to choose the plot shell with the MT option
-    which should cost extra """
-
 from IPython.ipmaker import make_IPython
 from IPython.iplib import InteractiveShell 
 from IPython.ipstruct import Struct
 import Queue,thread,threading,signal
 from signal import signal, SIGINT
 from IPython.genutils import Term,warn,error,flag_calls, ask_yes_no
 import shellglobals
 
+def install_gtk2():
+    """ Install gtk2 reactor, needs to be called bef """
+    from twisted.internet import gtk2reactor
+    gtk2reactor.install()
+
 
 def hijack_reactor():
     """Modifies Twisted's reactor with a dummy so user code does
     not block IPython.  This function returns the original
     'twisted.internet.reactor' that has been hijacked.
 
     NOTE: Make sure you call this *AFTER* you've installed
     the reactor of your choice.
     """
     from twisted import internet
     orig_reactor = internet.reactor
 
     class DummyReactor(object):
         def run(self):
             pass
         def __getattr__(self, name):
             return getattr(orig_reactor, name)
         def __setattr__(self, name, value):
             return setattr(orig_reactor, name, value)
     
     internet.reactor = DummyReactor()
     return orig_reactor
 
 class TwistedInteractiveShell(InteractiveShell):
     """Simple multi-threaded shell."""
 
     # Threading strategy taken from:
     # http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/65109, by Brian
     # McErlean and John Finlay.  Modified with corrections by Antoon Pardon,
     # from the pygtk mailing list, to avoid lockups with system calls.
 
     # class attribute to indicate whether the class supports threads or not.
     # Subclasses with thread support should override this as needed.
     isthreaded = True
 
     def __init__(self,name,usage=None,rc=Struct(opts=None,args=None),
                  user_ns=None,user_global_ns=None,banner2='',**kw):
         """Similar to the normal InteractiveShell, but with threading control"""
         
         InteractiveShell.__init__(self,name,usage,rc,user_ns,
                                   user_global_ns,banner2)
 
 
         # A queue to hold the code to be executed. 
         self.code_queue = Queue.Queue()
 
         # Stuff to do at closing time
         self._kill = None
         on_kill = kw.get('on_kill', [])
         # Check that all things to kill are callable:
         for t in on_kill:
             if not callable(t):
                 raise TypeError,'on_kill must be a list of callables'
         self.on_kill = on_kill
         # thread identity of the "worker thread" (that may execute code directly)
         self.worker_ident = None
         self.reactor_started = False
         self.first_run = True
         
     def runsource(self, source, filename="<input>", symbol="single"):
         """Compile and run some source in the interpreter.
 
         Modified version of code.py's runsource(), to handle threading issues.
         See the original for full docstring details."""
         
         # If Ctrl-C was typed, we reset the flag and return right away
         if shellglobals.KBINT:
             shellglobals.KBINT = False
             return False
 
         if self._kill:
             # can't queue new code if we are being killed
             return True
         
         try:
             code = self.compile(source, filename, symbol)
         except (OverflowError, SyntaxError, ValueError):
             # Case 1
             self.showsyntaxerror(filename)
             return False
 
         if code is None:
             # Case 2
             return True
 
         # shortcut - if we are in worker thread, or the worker thread is not running, 
         # execute directly (to allow recursion and prevent deadlock if code is run early 
         # in IPython construction)
         
         if (not self.reactor_started or (self.worker_ident is None and not self.first_run) 
             or self.worker_ident == thread.get_ident()):
             InteractiveShell.runcode(self,code)
             return
 
         # Case 3
         # Store code in queue, so the execution thread can handle it.
  
         self.first_run = False
         completed_ev, received_ev = threading.Event(), threading.Event() 
         
         self.code_queue.put((code,completed_ev, received_ev))
 
         reactor.callLater(0.0,self.runcode)
         received_ev.wait(5)
         if not received_ev.isSet():
             # the mainloop is dead, start executing code directly
             print "Warning: Timeout for mainloop thread exceeded"
             print "switching to nonthreaded mode (until mainloop wakes up again)"
             self.worker_ident = None
-        else:
-            shellglobals.CURRENT_COMPLETE_EV = completed_ev
+        else:            
             completed_ev.wait()
         
         return False
 
     def runcode(self):
         """Execute a code object.
 
         Multithreaded wrapper around IPython's runcode()."""
         
         
         # we are in worker thread, stash out the id for runsource() 
         self.worker_ident = thread.get_ident()
 
         if self._kill:
             print >>Term.cout, 'Closing threads...',
             Term.cout.flush()
             for tokill in self.on_kill:
                 tokill()
             print >>Term.cout, 'Done.'
             # allow kill() to return
             self._kill.set()
             return True
 
         # Install SIGINT handler.  We do it every time to ensure that if user
         # code modifies it, we restore our own handling.
         try:
             pass
             signal(SIGINT,shellglobals.sigint_handler)
         except SystemError:
             # This happens under Windows, which seems to have all sorts
             # of problems with signal handling.  Oh well...
             pass
 
         # Flush queue of pending code by calling the run methood of the parent
         # class with all items which may be in the queue.
         code_to_run = None
         while 1:
             try:
                 code_to_run, completed_ev, received_ev = self.code_queue.get_nowait()                
             except Queue.Empty:
                 break
             received_ev.set()
 
             
             # Exceptions need to be raised differently depending on which
             # thread is active.  This convoluted try/except is only there to
             # protect against asynchronous exceptions, to ensure that a shellglobals.KBINT
             # at the wrong time doesn't deadlock everything.  The global
             # CODE_TO_RUN is set to true/false as close as possible to the
             # runcode() call, so that the KBINT handler is correctly informed.
             try:
                 try:
                    shellglobals.CODE_RUN = True
                    InteractiveShell.runcode(self,code_to_run)
                 except KeyboardInterrupt:
                    print "Keyboard interrupted in mainloop"
                    while not self.code_queue.empty():
                       code = self.code_queue.get_nowait()
                    break
             finally:
                 shellglobals.CODE_RUN = False
                 # allow runsource() return from wait
                 completed_ev.set()                
         
         # This MUST return true for gtk threading to work
         return True
 
     def kill(self):
         """Kill the thread, returning when it has been shut down."""
         self._kill = threading.Event()
         reactor.callLater(0.0,self.runcode)
         self._kill.wait()
 
 
 
 class IPShellTwisted():
     """Run a Twisted reactor while in an IPython session.
 
     Python commands can be passed to the thread where they will be
     executed.  This is implemented by periodically checking for
     passed code using a Twisted reactor callback.
     """
 
     TIMEOUT = 0.01 # Millisecond interval between reactor runs.
 
     def __init__(self, argv=None, user_ns=None, debug=1,
                  shell_class=TwistedInteractiveShell):
 
         from twisted.internet import reactor
         self.reactor = hijack_reactor()
 
         mainquit = self.reactor.stop
 
         # Make sure IPython keeps going after reactor stop.
         def reactorstop():
             pass
         self.reactor.stop = reactorstop
         reactorrun_orig = self.reactor.run
         self.quitting = False
         def reactorrun():
             while True and not self.quitting:
                 reactorrun_orig()
         self.reactor.run = reactorrun
         
         self.IP = make_IPython(argv, user_ns=user_ns, debug=debug,
                                shell_class=shell_class,
                                on_kill=[mainquit])
 
         # threading.Thread.__init__(self)
 
     def run(self):
         self.IP.mainloop()
         self.quitting = True
         self.IP.kill()
 
     def mainloop(self):
         def mainLoopThreadDeath(r):
             print "mainLoopThreadDeath: ", str(r)
         def spawnMainloopThread():
             d=threads.deferToThread(self.run)
             d.addBoth(mainLoopThreadDeath)
         reactor.callWhenRunning(spawnMainloopThread)
         self.IP.reactor_started = True
         self.reactor.run()
         print "mainloop ending...."   
         
 exists = True
 
 
 if __name__ == '__main__':
     # Sample usage.
 
     # Create the shell object. This steals twisted.internet.reactor
     # for its own purposes, to make sure you've already installed a
     # reactor of your choice.
     shell = IPShellTwisted(
         argv=[],
         user_ns={'__name__': '__example__',
                  'hello': 'world',
                  },
         )
 
     # Run the mainloop.  This runs the actual reactor.run() method.
     # The twisted.internet.reactor object at this point is a dummy
     # object that passes through to the actual reactor, but prevents
     # run() from being called on it again.
     shell.mainloop()
 
     # You must exit IPython to terminate your program.
     print 'Goodbye!'