Merge branch 'takowl-fix-terminal-exit' into trunk

IPython/core/history.py

@@ -13,6 +13,7 b''
 from __future__ import print_function
 
 # Stdlib imports
+import atexit
 import fnmatch
 import json
 import os
@@ -105,6 +106,14 b' class HistoryManager(object):'
         
         # Fill the history zero entry, user counter starts at 1
         self.store_inputs('\n', '\n')
+        
+        # Create and start the autosaver.
+        self.autosave_flag = threading.Event()
+        self.autosave_timer = HistorySaveThread(self.autosave_flag, 60)
+        self.autosave_timer.start()
+        # Register the autosave handler to be triggered as a post execute
+        # callback.
+        self.shell.register_post_execute(self.autosave_if_due)
 
     def _init_shadow_hist(self):
         try:
@@ -142,12 +151,22 b' class HistoryManager(object):'
         with open(self.hist_file,'wt') as hfile:
             json.dump(hist, hfile,
                       sort_keys=True, indent=4)
+                      
+    def autosave_if_due(self):
+        """Check if the autosave event is set; if so, save history. We do it 
+        this way so that the save takes place in the main thread."""
+        if self.autosave_flag.is_set():
+            self.save_history()
+            self.autosave_flag.clear()
         
     def reload_history(self):
         """Reload the input history from disk file."""
 
         with open(self.hist_file,'rt') as hfile:
-            hist = json.load(hfile)
+            try:
+                hist = json.load(hfile)
+            except ValueError:    # Ignore it if JSON is corrupt.
+                return
             self.input_hist_parsed = hist['parsed']
             self.input_hist_raw = hist['raw']
             if self.shell.has_readline:
@@ -254,25 +273,37 b' class HistoryManager(object):'
         self.dir_hist[:] = [os.getcwd()]
 
 class HistorySaveThread(threading.Thread):
-    """Thread to save history periodically"""
+    """This thread makes IPython save history periodically.
 
-    def __init__(self, IPython_object, time_interval, exit_now):
+    Without this class, IPython would only save the history on a clean exit.
+    This saves the history periodically (the current default is once per
+    minute), so that it is not lost in the event of a crash.
+    
+    The implementation sets an event to indicate that history should be saved.
+    The actual save is carried out after executing a user command, to avoid
+    thread issues.
+    """
+    daemon = True
+    
+    def __init__(self, autosave_flag, time_interval=60):
         threading.Thread.__init__(self)
-        self.IPython_object = IPython_object
         self.time_interval = time_interval
-        self.exit_now = exit_now
-        self.cond = threading.Condition()
+        self.autosave_flag = autosave_flag
+        self.exit_now = threading.Event()
+        # Ensure the thread is stopped tidily when exiting normally
+        atexit.register(self.stop)
 
     def run(self):
-        while 1:
-            self.cond.acquire()
-            self.cond.wait(self.time_interval)
-            self.cond.release()
-            if self.exit_now==True:
+        while True:
+            self.exit_now.wait(self.time_interval)
+            if self.exit_now.is_set():
                 break
-            #printing for debug
-            #print("Saving...")
-            self.IPython_object.save_history()
+            self.autosave_flag.set()
+            
+    def stop(self):
+        """Safely and quickly stop the autosave timer thread."""
+        self.exit_now.set()
+        self.join()
 
 def magic_history(self, parameter_s = ''):
     """Print input history (_i<n> variables), with most recent last.

IPython/core/interactiveshell.py

@@ -45,7 +45,6 b' from IPython.core.error import TryNext, UsageError'
 from IPython.core.extensions import ExtensionManager
 from IPython.core.fakemodule import FakeModule, init_fakemod_dict
 from IPython.core.history import HistoryManager
-from IPython.core.history import HistorySaveThread
 from IPython.core.inputsplitter import IPythonInputSplitter
 from IPython.core.logger import Logger
 from IPython.core.magic import Magic
@@ -294,8 +293,6 b' class InteractiveShell(Configurable, Magic):'
         self.init_payload()
         self.hooks.late_startup_hook()
         atexit.register(self.atexit_operations)
-        self.history_thread = HistorySaveThread(self, 60, False)
-        self.history_thread.start()
 
     # While we're trying to have each part of the code directly access what it
     # needs without keeping redundant references to objects, we have too much
@@ -1238,6 +1235,7 b' class InteractiveShell(Configurable, Magic):'
     #-------------------------------------------------------------------------
 
     def init_history(self):
+        """Sets up the command history, and starts regular autosaves."""
         self.history_manager = HistoryManager(shell=self)
 
     def save_history(self):

IPython/frontend/terminal/interactiveshell.py

@@ -24,7 +24,6 b' 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
@@ -499,10 +498,6 b' class TerminalInteractiveShell(InteractiveShell):'
         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()