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			80 lines
		
	
	
	
		
			2.3 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			80 lines
		
	
	
	
		
			2.3 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| import os
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| import sys
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| import signal
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| 
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| from . import util
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| 
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| __all__ = ['Popen']
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| 
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| #
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| # Start child process using fork
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| #
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| 
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| class Popen(object):
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|     method = 'fork'
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| 
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|     def __init__(self, process_obj):
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|         sys.stdout.flush()
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|         sys.stderr.flush()
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|         self.returncode = None
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|         self._launch(process_obj)
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| 
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|     def duplicate_for_child(self, fd):
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|         return fd
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| 
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|     def poll(self, flag=os.WNOHANG):
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|         if self.returncode is None:
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|             while True:
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|                 try:
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|                     pid, sts = os.waitpid(self.pid, flag)
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|                 except OSError as e:
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|                     # Child process not yet created. See #1731717
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|                     # e.errno == errno.ECHILD == 10
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|                     return None
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|                 else:
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|                     break
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|             if pid == self.pid:
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|                 if os.WIFSIGNALED(sts):
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|                     self.returncode = -os.WTERMSIG(sts)
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|                 else:
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|                     assert os.WIFEXITED(sts)
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|                     self.returncode = os.WEXITSTATUS(sts)
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|         return self.returncode
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| 
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|     def wait(self, timeout=None):
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|         if self.returncode is None:
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|             if timeout is not None:
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|                 from multiprocessing.connection import wait
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|                 if not wait([self.sentinel], timeout):
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|                     return None
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|             # This shouldn't block if wait() returned successfully.
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|             return self.poll(os.WNOHANG if timeout == 0.0 else 0)
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|         return self.returncode
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| 
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|     def terminate(self):
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|         if self.returncode is None:
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|             try:
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|                 os.kill(self.pid, signal.SIGTERM)
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|             except ProcessLookupError:
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|                 pass
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|             except OSError:
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|                 if self.wait(timeout=0.1) is None:
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|                     raise
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| 
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|     def _launch(self, process_obj):
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|         code = 1
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|         parent_r, child_w = os.pipe()
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|         self.pid = os.fork()
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|         if self.pid == 0:
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|             try:
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|                 os.close(parent_r)
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|                 if 'random' in sys.modules:
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|                     import random
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|                     random.seed()
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|                 code = process_obj._bootstrap()
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|             finally:
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|                 os._exit(code)
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|         else:
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|             os.close(child_w)
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|             util.Finalize(self, os.close, (parent_r,))
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|             self.sentinel = parent_r
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