Fix hang-upon exit in terminal version, which was due to the history autosave thread not exiting.

IPython/core/history.py

@@ -1,547 +1,554 b''
 """ History related magics and functionality """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010 The IPython Development Team.
 #
 #  Distributed under the terms of the BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 # Stdlib imports
 import fnmatch
 import json
 import os
 import sys
 import threading
 import time
 
 # Our own packages
 import IPython.utils.io
 
 from IPython.utils.pickleshare import PickleShareDB
 from IPython.utils.io import ask_yes_no
 from IPython.utils.warn import warn
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 class HistoryManager(object):
     """A class to organize all history-related functionality in one place.
     """
     # Public interface
 
     # An instance of the IPython shell we are attached to
     shell = None
     # A list to hold processed history
     input_hist_parsed = None
     # A list to hold raw history (as typed by user)
     input_hist_raw = None
     # A list of directories visited during session
     dir_hist = None
     # A dict of output history, keyed with ints from the shell's execution count
     output_hist = None
     # String with path to the history file
     hist_file = None
     # PickleShareDB instance holding the raw data for the shadow history
     shadow_db = None
     # ShadowHist instance with the actual shadow history
     shadow_hist = None
     
     # Private interface
     # Variables used to store the three last inputs from the user.  On each new
     # history update, we populate the user's namespace with these, shifted as
     # necessary.
     _i00, _i, _ii, _iii = '','','',''
 
     # A set with all forms of the exit command, so that we don't store them in
     # the history (it's annoying to rewind the first entry and land on an exit
     # call).
     _exit_commands = None
     
     def __init__(self, shell):
         """Create a new history manager associated with a shell instance.
         """
         # We need a pointer back to the shell for various tasks.
         self.shell = shell
         
         # List of input with multi-line handling.
         self.input_hist_parsed = []
         # This one will hold the 'raw' input history, without any
         # pre-processing.  This will allow users to retrieve the input just as
         # it was exactly typed in by the user, with %hist -r.
         self.input_hist_raw = []
 
         # list of visited directories
         try:
             self.dir_hist = [os.getcwd()]
         except OSError:
             self.dir_hist = []
 
         # dict of output history
         self.output_hist = {}
 
         # Now the history file
         if shell.profile:
             histfname = 'history-%s' % shell.profile
         else:
             histfname = 'history'
         self.hist_file = os.path.join(shell.ipython_dir, histfname + '.json')
 
         # Objects related to shadow history management
         self._init_shadow_hist()
     
         self._i00, self._i, self._ii, self._iii = '','','',''
 
         self._exit_commands = set(['Quit', 'quit', 'Exit', 'exit', '%Quit',
                                    '%quit', '%Exit', '%exit'])
 
         # Object is fully initialized, we can now call methods on it.
         
         # Fill the history zero entry, user counter starts at 1
         self.store_inputs('\n', '\n')
 
     def _init_shadow_hist(self):
         try:
             self.shadow_db = PickleShareDB(os.path.join(
                                            self.shell.ipython_dir, 'db'))
         except UnicodeDecodeError:
             print("Your ipython_dir can't be decoded to unicode!")
             print("Please set HOME environment variable to something that")
             print(r"only has ASCII characters, e.g. c:\home")
             print("Now it is", self.ipython_dir)
             sys.exit()
         self.shadow_hist = ShadowHist(self.shadow_db, self.shell)
         
     def populate_readline_history(self):
         """Populate the readline history from the raw history.
 
         We only store one copy of the raw history, which is persisted to a json
         file on disk.  The readline history is repopulated from the contents of
         this file."""
 
         try:
             self.shell.readline.clear_history()
         except AttributeError:
             pass
         else:
             for h in self.input_hist_raw:
                 if not h.isspace():
                     for line in h.splitlines():
                         self.shell.readline.add_history(line)
 
     def save_history(self):
         """Save input history to a file (via readline library)."""
         hist = dict(raw=self.input_hist_raw, #[-self.shell.history_length:],
                     parsed=self.input_hist_parsed) #[-self.shell.history_length:])
         with open(self.hist_file,'wt') as hfile:
             json.dump(hist, hfile,
                       sort_keys=True, indent=4)
         
     def reload_history(self):
         """Reload the input history from disk file."""
 
         with open(self.hist_file,'rt') as hfile:
             hist = json.load(hfile)
             self.input_hist_parsed = hist['parsed']
             self.input_hist_raw = hist['raw']
             if self.shell.has_readline:
                 self.populate_readline_history()
         
     def get_history(self, index=None, raw=False, output=True):
         """Get the history list.
 
         Get the input and output history.
 
         Parameters
         ----------
         index : n or (n1, n2) or None
             If n, then the last entries. If a tuple, then all in
             range(n1, n2). If None, then all entries. Raises IndexError if
             the format of index is incorrect.
         raw : bool
             If True, return the raw input.
         output : bool
             If True, then return the output as well.
 
         Returns
         -------
         If output is True, then return a dict of tuples, keyed by the prompt
         numbers and with values of (input, output). If output is False, then
         a dict, keyed by the prompt number with the values of input. Raises
         IndexError if no history is found.
         """
         if raw:
             input_hist = self.input_hist_raw
         else:
             input_hist = self.input_hist_parsed
         if output:
             output_hist = self.output_hist
         n = len(input_hist)
         if index is None:
             start=0; stop=n
         elif isinstance(index, int):
             start=n-index; stop=n
         elif isinstance(index, tuple) and len(index) == 2:
             start=index[0]; stop=index[1]
         else:
             raise IndexError('Not a valid index for the input history: %r'
                              % index)
         hist = {}
         for i in range(start, stop):
             if output:
                 hist[i] = (input_hist[i], output_hist.get(i))
             else:
                 hist[i] = input_hist[i]
         if not hist:
             raise IndexError('No history for range of indices: %r' % index)
         return hist
 
     def store_inputs(self, source, source_raw=None):
         """Store source and raw input in history and create input cache
         variables _i*.
         
         Parameters
         ----------
         source : str
           Python input.
 
         source_raw : str, optional
           If given, this is the raw input without any IPython transformations
           applied to it.  If not given, ``source`` is used.
         """
         if source_raw is None:
             source_raw = source
             
         # do not store exit/quit commands
         if source_raw.strip() in self._exit_commands:
             return
         
         self.input_hist_parsed.append(source.rstrip())
         self.input_hist_raw.append(source_raw.rstrip())
         self.shadow_hist.add(source)
 
         # update the auto _i variables
         self._iii = self._ii
         self._ii = self._i
         self._i = self._i00
         self._i00 = source_raw
 
         # hackish access to user namespace to create _i1,_i2... dynamically
         new_i = '_i%s' % self.shell.execution_count
         to_main = {'_i': self._i,
                    '_ii': self._ii,
                    '_iii': self._iii,
                    new_i : self._i00 }
         self.shell.user_ns.update(to_main)
 
     def sync_inputs(self):
         """Ensure raw and translated histories have same length."""
         if len(self.input_hist_parsed) != len (self.input_hist_raw):
             self.input_hist_raw[:] = self.input_hist_parsed
 
     def reset(self):
         """Clear all histories managed by this object."""
         self.input_hist_parsed[:] = []
         self.input_hist_raw[:] = []
         self.output_hist.clear()
         # The directory history can't be completely empty
         self.dir_hist[:] = [os.getcwd()]
 
 class HistorySaveThread(threading.Thread):
     """Thread to save history periodically"""
-
+    daemon = True
+    
     def __init__(self, IPython_object, time_interval, exit_now):
         threading.Thread.__init__(self)
         self.IPython_object = IPython_object
         self.time_interval = time_interval
         self.exit_now = exit_now
         self.cond = threading.Condition()
 
     def run(self):
         while 1:
             self.cond.acquire()
             self.cond.wait(self.time_interval)
             self.cond.release()
             if self.exit_now==True:
                 break
             #printing for debug
             #print("Saving...")
             self.IPython_object.save_history()
+            
+    def stop(self):
+        self.exit_now=True
+        self.cond.acquire()
+        self.cond.notify()
+        self.cond.release()
 
 def magic_history(self, parameter_s = ''):
     """Print input history (_i<n> variables), with most recent last.
     
     %history       -> print at most 40 inputs (some may be multi-line)\\
     %history n     -> print at most n inputs\\
     %history n1 n2 -> print inputs between n1 and n2 (n2 not included)\\
 
     By default, input history is printed without line numbers so it can be
     directly pasted into an editor.
 
     With -n, each input's number <n> is shown, and is accessible as the
     automatically generated variable _i<n> as well as In[<n>].  Multi-line
     statements are printed starting at a new line for easy copy/paste.
 
     Options:
 
       -n: print line numbers for each input.
       This feature is only available if numbered prompts are in use.
 
       -o: also print outputs for each input.
 
       -p: print classic '>>>' python prompts before each input.  This is useful
        for making documentation, and in conjunction with -o, for producing
        doctest-ready output.
 
       -r: (default) print the 'raw' history, i.e. the actual commands you typed.
       
       -t: print the 'translated' history, as IPython understands it.  IPython
       filters your input and converts it all into valid Python source before
       executing it (things like magics or aliases are turned into function
       calls, for example). With this option, you'll see the native history
       instead of the user-entered version: '%cd /' will be seen as
       'get_ipython().magic("%cd /")' instead of '%cd /'.
       
       -g: treat the arg as a pattern to grep for in (full) history.
       This includes the "shadow history" (almost all commands ever written).
       Use '%hist -g' to show full shadow history (may be very long).
       In shadow history, every index nuwber starts with 0.
 
       -f FILENAME: instead of printing the output to the screen, redirect it to
        the given file.  The file is always overwritten, though IPython asks for
        confirmation first if it already exists.
     """
 
     if not self.shell.displayhook.do_full_cache:
         print('This feature is only available if numbered prompts are in use.')
         return
     opts,args = self.parse_options(parameter_s,'gnoptsrf:',mode='list')
 
     # Check if output to specific file was requested.
     try:
         outfname = opts['f']
     except KeyError:
         outfile = IPython.utils.io.Term.cout  # default
         # We don't want to close stdout at the end!
         close_at_end = False
     else:
         if os.path.exists(outfname):
             if not ask_yes_no("File %r exists. Overwrite?" % outfname): 
                 print('Aborting.')
                 return
 
         outfile = open(outfname,'w')
         close_at_end = True
 
     if 't' in opts:
         input_hist = self.shell.history_manager.input_hist_parsed
     elif 'r' in opts:
         input_hist = self.shell.history_manager.input_hist_raw
     else:
         # Raw history is the default
         input_hist = self.shell.history_manager.input_hist_raw
             
     default_length = 40
     pattern = None
     if 'g' in opts:
         init = 1
         final = len(input_hist)
         parts = parameter_s.split(None, 1)
         if len(parts) == 1:
             parts += '*'
         head, pattern = parts
         pattern = "*" + pattern + "*"
     elif len(args) == 0:
         final = len(input_hist)-1
         init = max(1,final-default_length)
     elif len(args) == 1:
         final = len(input_hist)
         init = max(1, final-int(args[0]))
     elif len(args) == 2:
         init, final = map(int, args)
     else:
         warn('%hist takes 0, 1 or 2 arguments separated by spaces.')
         print(self.magic_hist.__doc__, file=IPython.utils.io.Term.cout)
         return
     
     width = len(str(final))
     line_sep = ['','\n']
     print_nums = 'n' in opts
     print_outputs = 'o' in opts
     pyprompts = 'p' in opts
     
     found = False
     if pattern is not None:
         sh = self.shell.history_manager.shadowhist.all()
         for idx, s in sh:
             if fnmatch.fnmatch(s, pattern):
                 print("0%d: %s" %(idx, s.expandtabs(4)), file=outfile)
                 found = True
     
     if found:
         print("===", file=outfile)
         print("shadow history ends, fetch by %rep <number> (must start with 0)",
               file=outfile)
         print("=== start of normal history ===", file=outfile)
         
     for in_num in range(init, final):
         # Print user history with tabs expanded to 4 spaces.  The GUI clients
         # use hard tabs for easier usability in auto-indented code, but we want
         # to produce PEP-8 compliant history for safe pasting into an editor.
         inline = input_hist[in_num].expandtabs(4).rstrip()+'\n'
 
         if pattern is not None and not fnmatch.fnmatch(inline, pattern):
             continue
             
         multiline = int(inline.count('\n') > 1)
         if print_nums:
             print('%s:%s' % (str(in_num).ljust(width), line_sep[multiline]),
                   file=outfile)
         if pyprompts:
             print('>>>', file=outfile)
             if multiline:
                 lines = inline.splitlines()
                 print('\n... '.join(lines), file=outfile)
                 print('... ', file=outfile)
             else:
                 print(inline, end='', file=outfile)
         else:
             print(inline, end='', file=outfile)
         if print_outputs:
             output = self.shell.history_manager.output_hist.get(in_num)
             if output is not None:
                 print(repr(output), file=outfile)
 
     if close_at_end:
         outfile.close()
 
 
 def magic_hist(self, parameter_s=''):
     """Alternate name for %history."""
     return self.magic_history(parameter_s)
 
 
 def rep_f(self, arg):
     r""" Repeat a command, or get command to input line for editing
 
     - %rep (no arguments):
     
     Place a string version of last computation result (stored in the special '_'
     variable) to the next input prompt. Allows you to create elaborate command
     lines without using copy-paste::
     
         $ l = ["hei", "vaan"]       
         $ "".join(l)        
         ==> heivaan        
         $ %rep        
         $ heivaan_ <== cursor blinking    
     
     %rep 45
     
     Place history line 45 to next input prompt. Use %hist to find out the
     number.
     
     %rep 1-4 6-7 3
     
     Repeat the specified lines immediately. Input slice syntax is the same as
     in %macro and %save.
     
     %rep foo
     
     Place the most recent line that has the substring "foo" to next input.
     (e.g. 'svn ci -m foobar').    
     """
     
     opts,args = self.parse_options(arg,'',mode='list')
     if not args:
         self.set_next_input(str(self.shell.user_ns["_"]))
         return
 
     if len(args) == 1 and not '-' in args[0]:
         arg = args[0]
         if len(arg) > 1 and arg.startswith('0'):
             # get from shadow hist
             num = int(arg[1:])
             line = self.shell.shadowhist.get(num)
             self.set_next_input(str(line))
             return
         try:
             num = int(args[0])
             self.set_next_input(str(self.shell.input_hist_raw[num]).rstrip())
             return
         except ValueError:
             pass
         
         for h in reversed(self.shell.input_hist_raw):
             if 'rep' in h:
                 continue
             if fnmatch.fnmatch(h,'*' + arg + '*'):
                 self.set_next_input(str(h).rstrip())
                 return
         
     try:
         lines = self.extract_input_slices(args, True)
         print("lines", lines)
         self.run_cell(lines)
     except ValueError:
         print("Not found in recent history:", args)
         
 
 _sentinel = object()
 
 class ShadowHist(object):
     def __init__(self, db, shell):
         # cmd => idx mapping
         self.curidx = 0
         self.db = db
         self.disabled = False
         self.shell = shell
     
     def inc_idx(self):
         idx = self.db.get('shadowhist_idx', 1)
         self.db['shadowhist_idx'] = idx + 1
         return idx
         
     def add(self, ent):
         if self.disabled:
             return
         try:
             old = self.db.hget('shadowhist', ent, _sentinel)
             if old is not _sentinel:
                 return
             newidx = self.inc_idx()
             #print("new", newidx) # dbg
             self.db.hset('shadowhist',ent, newidx)
         except:
             self.shell.showtraceback()
             print("WARNING: disabling shadow history")
             self.disabled = True
     
     def all(self):
         d = self.db.hdict('shadowhist')
         items = [(i,s) for (s,i) in d.iteritems()]
         items.sort()
         return items
 
     def get(self, idx):
         all = self.all()
         
         for k, v in all:
             if k == idx:
                 return v
 
 
 def init_ipython(ip):
     ip.define_magic("rep",rep_f)        
     ip.define_magic("hist",magic_hist)            
     ip.define_magic("history",magic_history)
 
     # XXX - ipy_completers are in quarantine, need to be updated to new apis
     #import ipy_completers
     #ipy_completers.quick_completer('%hist' ,'-g -t -r -n')

IPython/frontend/terminal/interactiveshell.py

@@ -1,619 +1,615 b''
 # -*- coding: utf-8 -*-
 """Subclass of InteractiveShell for terminal based frontends."""
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2001 Janko Hauser <[e-mail]>
 #  Copyright (C) 2001-2007 Fernando Perez. <[e-mail]>
 #  Copyright (C) 2008-2010  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import __builtin__
 import bdb
 from contextlib import nested
 import os
 import re
 import sys
 
 from IPython.core.error import TryNext
 from IPython.core.usage import interactive_usage, default_banner
 from IPython.core.interactiveshell import InteractiveShell, InteractiveShellABC
 from IPython.core.history import HistorySaveThread
 from IPython.lib.inputhook import enable_gui
 from IPython.lib.pylabtools import pylab_activate
 from IPython.utils.terminal import toggle_set_term_title, set_term_title
 from IPython.utils.process import abbrev_cwd
 from IPython.utils.warn import warn
 from IPython.utils.text import num_ini_spaces
 from IPython.utils.traitlets import Int, Str, CBool
 
 
 #-----------------------------------------------------------------------------
 # Utilities
 #-----------------------------------------------------------------------------
 
 
 def get_default_editor():
     try:
         ed = os.environ['EDITOR']
     except KeyError:
         if os.name == 'posix':
             ed = 'vi'  # the only one guaranteed to be there!
         else:
             ed = 'notepad' # same in Windows!
     return ed
 
 
 # store the builtin raw_input globally, and use this always, in case user code
 # overwrites it (like wx.py.PyShell does)
 raw_input_original = raw_input
 
 
 #-----------------------------------------------------------------------------
 # Main class
 #-----------------------------------------------------------------------------
 
 
 class TerminalInteractiveShell(InteractiveShell):
 
     autoedit_syntax = CBool(False, config=True)
     banner = Str('')
     banner1 = Str(default_banner, config=True)
     banner2 = Str('', config=True)
     confirm_exit = CBool(True, config=True)
     # This display_banner only controls whether or not self.show_banner()
     # is called when mainloop/interact are called.  The default is False
     # because for the terminal based application, the banner behavior
     # is controlled by Global.display_banner, which IPythonApp looks at
     # to determine if *it* should call show_banner() by hand or not.
     display_banner = CBool(False) # This isn't configurable!
     embedded = CBool(False)
     embedded_active = CBool(False)
     editor = Str(get_default_editor(), config=True)
     pager = Str('less', config=True)
 
     screen_length = Int(0, config=True)
     term_title = CBool(False, config=True)
 
     def __init__(self, config=None, ipython_dir=None, user_ns=None,
                  user_global_ns=None, custom_exceptions=((),None),
                  usage=None, banner1=None, banner2=None,
                  display_banner=None):
 
         super(TerminalInteractiveShell, self).__init__(
             config=config, ipython_dir=ipython_dir, user_ns=user_ns,
             user_global_ns=user_global_ns, custom_exceptions=custom_exceptions
         )
         self.init_term_title()
         self.init_usage(usage)
         self.init_banner(banner1, banner2, display_banner)
 
     #-------------------------------------------------------------------------
     # Things related to the terminal
     #-------------------------------------------------------------------------
 
     @property
     def usable_screen_length(self):
         if self.screen_length == 0:
             return 0
         else:
             num_lines_bot = self.separate_in.count('\n')+1
             return self.screen_length - num_lines_bot
 
     def init_term_title(self):
         # Enable or disable the terminal title.
         if self.term_title:
             toggle_set_term_title(True)
             set_term_title('IPython: ' + abbrev_cwd())
         else:
             toggle_set_term_title(False)
 
     #-------------------------------------------------------------------------
     # Things related to aliases
     #-------------------------------------------------------------------------
 
     def init_alias(self):
         # The parent class defines aliases that can be safely used with any
         # frontend.
         super(TerminalInteractiveShell, self).init_alias()
 
         # Now define aliases that only make sense on the terminal, because they
         # need direct access to the console in a way that we can't emulate in
         # GUI or web frontend
         if os.name == 'posix':
             aliases = [('clear', 'clear'), ('more', 'more'), ('less', 'less'),
                        ('man', 'man')]
         elif os.name == 'nt':
             aliases = [('cls', 'cls')]
 
 
         for name, cmd in aliases:
             self.alias_manager.define_alias(name, cmd)
 
     #-------------------------------------------------------------------------
     # Things related to the banner and usage
     #-------------------------------------------------------------------------
 
     def _banner1_changed(self):
         self.compute_banner()
 
     def _banner2_changed(self):
         self.compute_banner()
 
     def _term_title_changed(self, name, new_value):
         self.init_term_title()
 
     def init_banner(self, banner1, banner2, display_banner):
         if banner1 is not None:
             self.banner1 = banner1
         if banner2 is not None:
             self.banner2 = banner2
         if display_banner is not None:
             self.display_banner = display_banner
         self.compute_banner()
 
     def show_banner(self, banner=None):
         if banner is None:
             banner = self.banner
         self.write(banner)
 
     def compute_banner(self):
         self.banner = self.banner1
         if self.profile:
             self.banner += '\nIPython profile: %s\n' % self.profile
         if self.banner2:
             self.banner += '\n' + self.banner2
 
     def init_usage(self, usage=None):
         if usage is None:
             self.usage = interactive_usage
         else:
             self.usage = usage
 
     #-------------------------------------------------------------------------
     # Mainloop and code execution logic
     #-------------------------------------------------------------------------
 
     def mainloop(self, display_banner=None):
         """Start the mainloop.
 
         If an optional banner argument is given, it will override the
         internally created default banner.
         """
         
         with nested(self.builtin_trap, self.display_trap):
 
             # if you run stuff with -c <cmd>, raw hist is not updated
             # ensure that it's in sync
             self.history_manager.sync_inputs()
 
             while 1:
                 try:
                     self.interact(display_banner=display_banner)
                     #self.interact_with_readline()                
                     # XXX for testing of a readline-decoupled repl loop, call
                     # interact_with_readline above
                     break
                 except KeyboardInterrupt:
                     # this should not be necessary, but KeyboardInterrupt
                     # handling seems rather unpredictable...
                     self.write("\nKeyboardInterrupt in interact()\n")
 
     def interact(self, display_banner=None):
         """Closely emulate the interactive Python console."""
 
         # batch run -> do not interact        
         if self.exit_now:
             return
 
         if display_banner is None:
             display_banner = self.display_banner
         if display_banner:
             self.show_banner()
 
         more = False
         
         # Mark activity in the builtins
         __builtin__.__dict__['__IPYTHON__active'] += 1
         
         if self.has_readline:
             self.readline_startup_hook(self.pre_readline)
         # exit_now is set by a call to %Exit or %Quit, through the
         # ask_exit callback.
 
         while not self.exit_now:
             self.hooks.pre_prompt_hook()
             if more:
                 try:
                     prompt = self.hooks.generate_prompt(True)
                 except:
                     self.showtraceback()
                 if self.autoindent:
                     self.rl_do_indent = True
                     
             else:
                 try:
                     prompt = self.hooks.generate_prompt(False)
                 except:
                     self.showtraceback()
             try:
                 line = self.raw_input(prompt)
                 if self.exit_now:
                     # quick exit on sys.std[in|out] close
                     break
                 if self.autoindent:
                     self.rl_do_indent = False
                     
             except KeyboardInterrupt:
                 #double-guard against keyboardinterrupts during kbdint handling
                 try:
                     self.write('\nKeyboardInterrupt\n')
                     self.resetbuffer()
                     more = False
                 except KeyboardInterrupt:
                     pass
             except EOFError:
                 if self.autoindent:
                     self.rl_do_indent = False
                     if self.has_readline:
                         self.readline_startup_hook(None)
                 self.write('\n')
                 self.exit()
             except bdb.BdbQuit:
                 warn('The Python debugger has exited with a BdbQuit exception.\n'
                      'Because of how pdb handles the stack, it is impossible\n'
                      'for IPython to properly format this particular exception.\n'
                      'IPython will resume normal operation.')
             except:
                 # exceptions here are VERY RARE, but they can be triggered
                 # asynchronously by signal handlers, for example.
                 self.showtraceback()
             else:
                 self.input_splitter.push(line)
                 more = self.input_splitter.push_accepts_more()
                 if (self.SyntaxTB.last_syntax_error and
                     self.autoedit_syntax):
                     self.edit_syntax_error()
                 if not more:
                     source_raw = self.input_splitter.source_raw_reset()[1]
                     self.run_cell(source_raw)
                 
         # We are off again...
         __builtin__.__dict__['__IPYTHON__active'] -= 1
 
         # Turn off the exit flag, so the mainloop can be restarted if desired
         self.exit_now = False
 
     def raw_input(self, prompt='', continue_prompt=False):
         """Write a prompt and read a line.
 
         The returned line does not include the trailing newline.
         When the user enters the EOF key sequence, EOFError is raised.
 
         Optional inputs:
 
           - prompt(''): a string to be printed to prompt the user.
 
           - continue_prompt(False): whether this line is the first one or a
           continuation in a sequence of inputs.
         """
         # Code run by the user may have modified the readline completer state.
         # We must ensure that our completer is back in place.
 
         if self.has_readline:
             self.set_readline_completer()
         
         try:
             line = raw_input_original(prompt).decode(self.stdin_encoding)
         except ValueError:
             warn("\n********\nYou or a %run:ed script called sys.stdin.close()"
                  " or sys.stdout.close()!\nExiting IPython!")
             self.ask_exit()
             return ""
 
         # Try to be reasonably smart about not re-indenting pasted input more
         # than necessary.  We do this by trimming out the auto-indent initial
         # spaces, if the user's actual input started itself with whitespace.
         if self.autoindent:
             if num_ini_spaces(line) > self.indent_current_nsp:
                 line = line[self.indent_current_nsp:]
                 self.indent_current_nsp = 0
             
         # store the unfiltered input before the user has any chance to modify
         # it.
         if line.strip():
             if continue_prompt:
                 if self.has_readline and self.readline_use:
                     histlen = self.readline.get_current_history_length()
                     if histlen > 1:
                         newhist = self.history_manager.input_hist_raw[-1].rstrip()
                         self.readline.remove_history_item(histlen-1)
                         self.readline.replace_history_item(histlen-2,
                                         newhist.encode(self.stdin_encoding))
             else:
                 self.history_manager.input_hist_raw.append('%s\n' % line)                
         elif not continue_prompt:
             self.history_manager.input_hist_raw.append('\n')
         try:
             lineout = self.prefilter_manager.prefilter_lines(line,continue_prompt)
         except:
             # blanket except, in case a user-defined prefilter crashes, so it
             # can't take all of ipython with it.
             self.showtraceback()
             return ''
         else:
             return lineout
 
 
     def raw_input(self, prompt=''):
         """Write a prompt and read a line.
 
         The returned line does not include the trailing newline.
         When the user enters the EOF key sequence, EOFError is raised.
 
         Optional inputs:
 
           - prompt(''): a string to be printed to prompt the user.
 
           - continue_prompt(False): whether this line is the first one or a
           continuation in a sequence of inputs.
         """
         # Code run by the user may have modified the readline completer state.
         # We must ensure that our completer is back in place.
 
         if self.has_readline:
             self.set_readline_completer()
         
         try:
             line = raw_input_original(prompt).decode(self.stdin_encoding)
         except ValueError:
             warn("\n********\nYou or a %run:ed script called sys.stdin.close()"
                  " or sys.stdout.close()!\nExiting IPython!")
             self.ask_exit()
             return ""
 
         # Try to be reasonably smart about not re-indenting pasted input more
         # than necessary.  We do this by trimming out the auto-indent initial
         # spaces, if the user's actual input started itself with whitespace.
         if self.autoindent:
             if num_ini_spaces(line) > self.indent_current_nsp:
                 line = line[self.indent_current_nsp:]
                 self.indent_current_nsp = 0
         
         return line
 
     #-------------------------------------------------------------------------
     # Methods to support auto-editing of SyntaxErrors.
     #-------------------------------------------------------------------------
 
     def edit_syntax_error(self):
         """The bottom half of the syntax error handler called in the main loop.
 
         Loop until syntax error is fixed or user cancels.
         """
 
         while self.SyntaxTB.last_syntax_error:
             # copy and clear last_syntax_error
             err = self.SyntaxTB.clear_err_state()
             if not self._should_recompile(err):
                 return
             try:
                 # may set last_syntax_error again if a SyntaxError is raised
                 self.safe_execfile(err.filename,self.user_ns)
             except:
                 self.showtraceback()
             else:
                 try:
                     f = file(err.filename)
                     try:
                         # This should be inside a display_trap block and I 
                         # think it is.
                         sys.displayhook(f.read())
                     finally:
                         f.close()
                 except:
                     self.showtraceback()
 
     def _should_recompile(self,e):
         """Utility routine for edit_syntax_error"""
 
         if e.filename in ('<ipython console>','<input>','<string>',
                           '<console>','<BackgroundJob compilation>',
                           None):
                               
             return False
         try:
             if (self.autoedit_syntax and 
                 not self.ask_yes_no('Return to editor to correct syntax error? '
                               '[Y/n] ','y')):
                 return False
         except EOFError:
             return False
 
         def int0(x):
             try:
                 return int(x)
             except TypeError:
                 return 0
         # always pass integer line and offset values to editor hook
         try:
             self.hooks.fix_error_editor(e.filename,
                 int0(e.lineno),int0(e.offset),e.msg)
         except TryNext:
             warn('Could not open editor')
             return False
         return True
 
     #-------------------------------------------------------------------------
     # Things related to GUI support and pylab
     #-------------------------------------------------------------------------
 
     def enable_pylab(self, gui=None):
         """Activate pylab support at runtime.
 
         This turns on support for matplotlib, preloads into the interactive
         namespace all of numpy and pylab, and configures IPython to correcdtly
         interact with the GUI event loop.  The GUI backend to be used can be
         optionally selected with the optional :param:`gui` argument.
 
         Parameters
         ----------
         gui : optional, string
 
           If given, dictates the choice of matplotlib GUI backend to use
           (should be one of IPython's supported backends, 'tk', 'qt', 'wx' or
           'gtk'), otherwise we use the default chosen by matplotlib (as
           dictated by the matplotlib build-time options plus the user's
           matplotlibrc configuration file).
         """
         # We want to prevent the loading of pylab to pollute the user's
         # namespace as shown by the %who* magics, so we execute the activation
         # code in an empty namespace, and we update *both* user_ns and
         # user_ns_hidden with this information.
         ns = {}
         gui = pylab_activate(ns, gui)
         self.user_ns.update(ns)
         self.user_ns_hidden.update(ns)
         # Now we must activate the gui pylab wants to use, and fix %run to take
         # plot updates into account
         enable_gui(gui)
         self.magic_run = self._pylab_magic_run
 
     #-------------------------------------------------------------------------
     # Things related to exiting
     #-------------------------------------------------------------------------
 
     def ask_exit(self):
         """ Ask the shell to exit. Can be overiden and used as a callback. """
         self.exit_now = True
 
     def exit(self):
         """Handle interactive exit.
 
         This method calls the ask_exit callback."""
         if self.confirm_exit:
             if self.ask_yes_no('Do you really want to exit ([y]/n)?','y'):
-                self.shell.history_thread.exit_now=True
-                self.shell.history_thread.cond.acquire()
-                self.shell.history_thread.cond.notify()
-                self.shell.history_thread.cond.release()
                 self.ask_exit()
         else:
             self.ask_exit()
             
     #------------------------------------------------------------------------
     # Magic overrides
     #------------------------------------------------------------------------
     # Once the base class stops inheriting from magic, this code needs to be
     # moved into a separate machinery as well.  For now, at least isolate here
     # the magics which this class needs to implement differently from the base
     # class, or that are unique to it.
 
     def magic_autoindent(self, parameter_s = ''):
         """Toggle autoindent on/off (if available)."""
 
         self.shell.set_autoindent()
         print "Automatic indentation is:",['OFF','ON'][self.shell.autoindent]
 
     def magic_cpaste(self, parameter_s=''):
         """Paste & execute a pre-formatted code block from clipboard.
         
         You must terminate the block with '--' (two minus-signs) alone on the
         line. You can also provide your own sentinel with '%paste -s %%' ('%%' 
         is the new sentinel for this operation)
         
         The block is dedented prior to execution to enable execution of method
         definitions. '>' and '+' characters at the beginning of a line are
         ignored, to allow pasting directly from e-mails, diff files and
         doctests (the '...' continuation prompt is also stripped).  The
         executed block is also assigned to variable named 'pasted_block' for
         later editing with '%edit pasted_block'.
         
         You can also pass a variable name as an argument, e.g. '%cpaste foo'.
         This assigns the pasted block to variable 'foo' as string, without 
         dedenting or executing it (preceding >>> and + is still stripped)
         
         '%cpaste -r' re-executes the block previously entered by cpaste.
         
         Do not be alarmed by garbled output on Windows (it's a readline bug). 
         Just press enter and type -- (and press enter again) and the block 
         will be what was just pasted.
         
         IPython statements (magics, shell escapes) are not supported (yet).
 
         See also
         --------
         paste: automatically pull code from clipboard.
         """
         
         opts,args = self.parse_options(parameter_s,'rs:',mode='string')
         par = args.strip()
         if opts.has_key('r'):
             self._rerun_pasted()
             return
         
         sentinel = opts.get('s','--')
 
         block = self._strip_pasted_lines_for_code(
             self._get_pasted_lines(sentinel))
 
         self._execute_block(block, par)
 
     def magic_paste(self, parameter_s=''):
         """Paste & execute a pre-formatted code block from clipboard.
         
         The text is pulled directly from the clipboard without user
         intervention and printed back on the screen before execution (unless
         the -q flag is given to force quiet mode).
 
         The block is dedented prior to execution to enable execution of method
         definitions. '>' and '+' characters at the beginning of a line are
         ignored, to allow pasting directly from e-mails, diff files and
         doctests (the '...' continuation prompt is also stripped).  The
         executed block is also assigned to variable named 'pasted_block' for
         later editing with '%edit pasted_block'.
         
         You can also pass a variable name as an argument, e.g. '%paste foo'.
         This assigns the pasted block to variable 'foo' as string, without 
         dedenting or executing it (preceding >>> and + is still stripped)
 
         Options
         -------
         
           -r: re-executes the block previously entered by cpaste.
 
           -q: quiet mode: do not echo the pasted text back to the terminal.
         
         IPython statements (magics, shell escapes) are not supported (yet).
 
         See also
         --------
         cpaste: manually paste code into terminal until you mark its end.
         """
         opts,args = self.parse_options(parameter_s,'rq',mode='string')
         par = args.strip()
         if opts.has_key('r'):
             self._rerun_pasted()
             return
 
         text = self.shell.hooks.clipboard_get()
         block = self._strip_pasted_lines_for_code(text.splitlines())
 
         # By default, echo back to terminal unless quiet mode is requested
         if not opts.has_key('q'):
             write = self.shell.write
             write(self.shell.pycolorize(block))
             if not block.endswith('\n'):
                 write('\n')
             write("## -- End pasted text --\n")
             
         self._execute_block(block, par)
 
 
 InteractiveShellABC.register(TerminalInteractiveShell)