260 lines
7.4 KiB
Python
260 lines
7.4 KiB
Python
#
|
|
# Code used to start processes when using the spawn or forkserver
|
|
# start methods.
|
|
#
|
|
# multiprocessing/spawn.py
|
|
#
|
|
# Copyright (c) 2006-2008, R Oudkerk
|
|
# Licensed to PSF under a Contributor Agreement.
|
|
#
|
|
|
|
import os
|
|
import pickle
|
|
import sys
|
|
|
|
from . import process
|
|
from . import util
|
|
from . import popen
|
|
|
|
__all__ = ['_main', 'freeze_support', 'set_executable', 'get_executable',
|
|
'get_preparation_data', 'get_command_line', 'import_main_path']
|
|
|
|
#
|
|
# _python_exe is the assumed path to the python executable.
|
|
# People embedding Python want to modify it.
|
|
#
|
|
|
|
if sys.platform != 'win32':
|
|
WINEXE = False
|
|
WINSERVICE = False
|
|
else:
|
|
WINEXE = (sys.platform == 'win32' and getattr(sys, 'frozen', False))
|
|
WINSERVICE = sys.executable.lower().endswith("pythonservice.exe")
|
|
|
|
if WINSERVICE:
|
|
_python_exe = os.path.join(sys.exec_prefix, 'python.exe')
|
|
else:
|
|
_python_exe = sys.executable
|
|
|
|
def set_executable(exe):
|
|
global _python_exe
|
|
_python_exe = exe
|
|
|
|
def get_executable():
|
|
return _python_exe
|
|
|
|
#
|
|
#
|
|
#
|
|
|
|
def is_forking(argv):
|
|
'''
|
|
Return whether commandline indicates we are forking
|
|
'''
|
|
if len(argv) >= 2 and argv[1] == '--multiprocessing-fork':
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
|
|
def freeze_support():
|
|
'''
|
|
Run code for process object if this in not the main process
|
|
'''
|
|
if is_forking(sys.argv):
|
|
main()
|
|
sys.exit()
|
|
|
|
|
|
def get_command_line(**kwds):
|
|
'''
|
|
Returns prefix of command line used for spawning a child process
|
|
'''
|
|
if getattr(sys, 'frozen', False):
|
|
return [sys.executable, '--multiprocessing-fork']
|
|
else:
|
|
prog = 'from multiprocessing.spawn import spawn_main; spawn_main(%s)'
|
|
prog %= ', '.join('%s=%r' % item for item in kwds.items())
|
|
opts = util._args_from_interpreter_flags()
|
|
return [_python_exe] + opts + ['-c', prog, '--multiprocessing-fork']
|
|
|
|
|
|
def spawn_main(pipe_handle, parent_pid=None, tracker_fd=None):
|
|
'''
|
|
Run code specifed by data received over pipe
|
|
'''
|
|
assert is_forking(sys.argv)
|
|
if sys.platform == 'win32':
|
|
import msvcrt
|
|
from .reduction import steal_handle
|
|
new_handle = steal_handle(parent_pid, pipe_handle)
|
|
fd = msvcrt.open_osfhandle(new_handle, os.O_RDONLY)
|
|
else:
|
|
from . import semaphore_tracker
|
|
semaphore_tracker._semaphore_tracker_fd = tracker_fd
|
|
fd = pipe_handle
|
|
exitcode = _main(fd)
|
|
sys.exit(exitcode)
|
|
|
|
|
|
def _main(fd):
|
|
with os.fdopen(fd, 'rb', closefd=True) as from_parent:
|
|
process.current_process()._inheriting = True
|
|
try:
|
|
preparation_data = pickle.load(from_parent)
|
|
prepare(preparation_data)
|
|
self = pickle.load(from_parent)
|
|
finally:
|
|
del process.current_process()._inheriting
|
|
return self._bootstrap()
|
|
|
|
|
|
def _check_not_importing_main():
|
|
if getattr(process.current_process(), '_inheriting', False):
|
|
raise RuntimeError('''
|
|
An attempt has been made to start a new process before the
|
|
current process has finished its bootstrapping phase.
|
|
|
|
This probably means that you are not using fork to start your
|
|
child processes and you have forgotten to use the proper idiom
|
|
in the main module:
|
|
|
|
if __name__ == '__main__':
|
|
freeze_support()
|
|
...
|
|
|
|
The "freeze_support()" line can be omitted if the program
|
|
is not going to be frozen to produce an executable.''')
|
|
|
|
|
|
def get_preparation_data(name):
|
|
'''
|
|
Return info about parent needed by child to unpickle process object
|
|
'''
|
|
_check_not_importing_main()
|
|
d = dict(
|
|
log_to_stderr=util._log_to_stderr,
|
|
authkey=process.current_process().authkey,
|
|
)
|
|
|
|
if util._logger is not None:
|
|
d['log_level'] = util._logger.getEffectiveLevel()
|
|
|
|
sys_path=sys.path.copy()
|
|
try:
|
|
i = sys_path.index('')
|
|
except ValueError:
|
|
pass
|
|
else:
|
|
sys_path[i] = process.ORIGINAL_DIR
|
|
|
|
d.update(
|
|
name=name,
|
|
sys_path=sys_path,
|
|
sys_argv=sys.argv,
|
|
orig_dir=process.ORIGINAL_DIR,
|
|
dir=os.getcwd(),
|
|
start_method=popen.get_start_method(),
|
|
)
|
|
|
|
if sys.platform != 'win32' or (not WINEXE and not WINSERVICE):
|
|
main_path = getattr(sys.modules['__main__'], '__file__', None)
|
|
if not main_path and sys.argv[0] not in ('', '-c'):
|
|
main_path = sys.argv[0]
|
|
if main_path is not None:
|
|
if (not os.path.isabs(main_path) and
|
|
process.ORIGINAL_DIR is not None):
|
|
main_path = os.path.join(process.ORIGINAL_DIR, main_path)
|
|
d['main_path'] = os.path.normpath(main_path)
|
|
|
|
return d
|
|
|
|
#
|
|
# Prepare current process
|
|
#
|
|
|
|
old_main_modules = []
|
|
|
|
def prepare(data):
|
|
'''
|
|
Try to get current process ready to unpickle process object
|
|
'''
|
|
if 'name' in data:
|
|
process.current_process().name = data['name']
|
|
|
|
if 'authkey' in data:
|
|
process.current_process().authkey = data['authkey']
|
|
|
|
if 'log_to_stderr' in data and data['log_to_stderr']:
|
|
util.log_to_stderr()
|
|
|
|
if 'log_level' in data:
|
|
util.get_logger().setLevel(data['log_level'])
|
|
|
|
if 'sys_path' in data:
|
|
sys.path = data['sys_path']
|
|
|
|
if 'sys_argv' in data:
|
|
sys.argv = data['sys_argv']
|
|
|
|
if 'dir' in data:
|
|
os.chdir(data['dir'])
|
|
|
|
if 'orig_dir' in data:
|
|
process.ORIGINAL_DIR = data['orig_dir']
|
|
|
|
if 'start_method' in data:
|
|
popen.set_start_method(data['start_method'], start_helpers=False)
|
|
|
|
if 'main_path' in data:
|
|
import_main_path(data['main_path'])
|
|
|
|
|
|
def import_main_path(main_path):
|
|
'''
|
|
Set sys.modules['__main__'] to module at main_path
|
|
'''
|
|
# XXX (ncoghlan): The following code makes several bogus
|
|
# assumptions regarding the relationship between __file__
|
|
# and a module's real name. See PEP 302 and issue #10845
|
|
if getattr(sys.modules['__main__'], '__file__', None) == main_path:
|
|
return
|
|
|
|
main_name = os.path.splitext(os.path.basename(main_path))[0]
|
|
if main_name == '__init__':
|
|
main_name = os.path.basename(os.path.dirname(main_path))
|
|
|
|
if main_name == '__main__':
|
|
main_module = sys.modules['__main__']
|
|
main_module.__file__ = main_path
|
|
elif main_name != 'ipython':
|
|
# Main modules not actually called __main__.py may
|
|
# contain additional code that should still be executed
|
|
import importlib
|
|
import types
|
|
|
|
if main_path is None:
|
|
dirs = None
|
|
elif os.path.basename(main_path).startswith('__init__.py'):
|
|
dirs = [os.path.dirname(os.path.dirname(main_path))]
|
|
else:
|
|
dirs = [os.path.dirname(main_path)]
|
|
|
|
assert main_name not in sys.modules, main_name
|
|
sys.modules.pop('__mp_main__', None)
|
|
# We should not try to load __main__
|
|
# since that would execute 'if __name__ == "__main__"'
|
|
# clauses, potentially causing a psuedo fork bomb.
|
|
loader = importlib.find_loader(main_name, path=dirs)
|
|
main_module = types.ModuleType(main_name)
|
|
try:
|
|
loader.init_module_attrs(main_module)
|
|
except AttributeError: # init_module_attrs is optional
|
|
pass
|
|
main_module.__name__ = '__mp_main__'
|
|
code = loader.get_code(main_name)
|
|
exec(code, main_module.__dict__)
|
|
|
|
old_main_modules.append(sys.modules['__main__'])
|
|
sys.modules['__main__'] = sys.modules['__mp_main__'] = main_module
|