1 # Autoreloading launcher.

     2 # Borrowed from Peter Hunt and the CherryPy project (http://www.cherrypy.org).

     3 # Some taken from Ian Bicking's Paste (http://pythonpaste.org/).

     4 #

     5 # Portions copyright (c) 2004, CherryPy Team (team@cherrypy.org)

     6 # All rights reserved.

     7 #

     8 # Redistribution and use in source and binary forms, with or without modification,

     9 # are permitted provided that the following conditions are met:

    10 #

    11 #     * Redistributions of source code must retain the above copyright notice,

    12 #       this list of conditions and the following disclaimer.

    13 #     * Redistributions in binary form must reproduce the above copyright notice,

    14 #       this list of conditions and the following disclaimer in the documentation

    15 #       and/or other materials provided with the distribution.

    16 #     * Neither the name of the CherryPy Team nor the names of its contributors

    17 #       may be used to endorse or promote products derived from this software

    18 #       without specific prior written permission.

    19 #

    20 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND

    21 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

    22 # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

    23 # DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE

    24 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

    25 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

    26 # SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER

    27 # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

    28 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

    29 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    30 

    31 import os, sys, time

    32 

    33 try:

    34     import thread

    35 except ImportError:

    36     import dummy_thread as thread

    37 

    38 # This import does nothing, but it's necessary to avoid some race conditions

    39 # in the threading module. See http://code.djangoproject.com/ticket/2330 .

    40 try:

    41     import threading

    42 except ImportError:

    43     pass

    44 

    45 

    46 RUN_RELOADER = True

    47 

    48 def reloader_thread():

    49     mtimes = {}

    50     win = (sys.platform == "win32")

    51     while RUN_RELOADER:

    52         for filename in filter(lambda v: v, map(lambda m: getattr(m, "__file__", None), sys.modules.values())):

    53             if filename.endswith(".pyc") or filename.endswith("*.pyo"):

    54                 filename = filename[:-1]

    55             if not os.path.exists(filename):

    56                 continue # File might be in an egg, so it can't be reloaded.

    57             stat = os.stat(filename)

    58             mtime = stat.st_mtime

    59             if win:

    60                 mtime -= stat.st_ctime

    61             if filename not in mtimes:

    62                 mtimes[filename] = mtime

    63                 continue

    64             if mtime != mtimes[filename]:

    65                 sys.exit(3) # force reload

    66         time.sleep(1)

    67 

    68 def restart_with_reloader():

    69     while True:

    70         args = [sys.executable] + sys.argv

    71         if sys.platform == "win32":

    72             args = ['"%s"' % arg for arg in args]

    73         new_environ = os.environ.copy()

    74         new_environ["RUN_MAIN"] = 'true'

    75         exit_code = os.spawnve(os.P_WAIT, sys.executable, args, new_environ)

    76         if exit_code != 3:

    77             return exit_code

    78 

    79 def main(main_func, args=None, kwargs=None):

    80     if os.environ.get("RUN_MAIN") == "true":

    81         if args is None:

    82             args = ()

    83         if kwargs is None:

    84             kwargs = {}

    85         thread.start_new_thread(main_func, args, kwargs)

    86         try:

    87             reloader_thread()

    88         except KeyboardInterrupt:

    89             pass

    90     else:

    91         try:

    92             sys.exit(restart_with_reloader())

    93         except KeyboardInterrupt:

    94             pass