Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/multiprocessing/popen_spawn_posix.py: 28%

1import io 

2import os 

3 

4from .context import reduction, set_spawning_popen 

5from . import popen_fork 

6from . import spawn 

7from . import util 

8 

9__all__ = ['Popen'] 

10 

11 

12# 

13# Wrapper for an fd used while launching a process 

14# 

15 

16class _DupFd(object): 

17 def __init__(self, fd): 

18 self.fd = fd 

19 def detach(self): 

20 return self.fd 

21 

22# 

23# Start child process using a fresh interpreter 

24# 

25 

26class Popen(popen_fork.Popen): 

27 method = 'spawn' 

28 DupFd = _DupFd 

29 

30 def __init__(self, process_obj): 

31 self._fds = [] 

32 super().__init__(process_obj) 

33 

34 def duplicate_for_child(self, fd): 

35 self._fds.append(fd) 

36 return fd 

37 

38 def _launch(self, process_obj): 

39 from . import resource_tracker 

40 tracker_fd = resource_tracker.getfd() 

41 self._fds.append(tracker_fd) 

42 prep_data = spawn.get_preparation_data(process_obj._name) 

43 fp = io.BytesIO() 

44 set_spawning_popen(self) 

45 try: 

46 reduction.dump(prep_data, fp) 

47 reduction.dump(process_obj, fp) 

48 finally: 

49 set_spawning_popen(None) 

50 

51 parent_r = child_w = child_r = parent_w = None 

52 try: 

53 parent_r, child_w = os.pipe() 

54 child_r, parent_w = os.pipe() 

55 cmd = spawn.get_command_line(tracker_fd=tracker_fd, 

56 pipe_handle=child_r) 

57 self._fds.extend([child_r, child_w]) 

58 self.pid = util.spawnv_passfds(spawn.get_executable(), 

59 cmd, self._fds) 

60 self.sentinel = parent_r 

61 with open(parent_w, 'wb', closefd=False) as f: 

62 f.write(fp.getbuffer()) 

63 finally: 

64 fds_to_close = [] 

65 for fd in (parent_r, parent_w): 

66 if fd is not None: 

67 fds_to_close.append(fd) 

68 self.finalizer = util.Finalize(self, util.close_fds, fds_to_close) 

69 

70 for fd in (child_r, child_w): 

71 if fd is not None: 

72 os.close(fd)