| import fcntl |
| import io |
| import os |
| |
| from . import popen |
| from . import popen_fork |
| from . import reduction |
| from . import spawn |
| from . import util |
| |
| from . import current_process |
| |
| __all__ = ['Popen'] |
| |
| |
| # |
| # Wrapper for an fd used while launching a process |
| # |
| |
| class _DupFd(object): |
| def __init__(self, fd): |
| self.fd = fd |
| def detach(self): |
| return self.fd |
| |
| # |
| # Start child process using a fresh interpreter |
| # |
| |
| class Popen(popen_fork.Popen): |
| method = 'spawn' |
| DupFd = _DupFd |
| |
| def __init__(self, process_obj): |
| self._fds = [] |
| super().__init__(process_obj) |
| |
| def duplicate_for_child(self, fd): |
| self._fds.append(fd) |
| return fd |
| |
| def _launch(self, process_obj): |
| from . import semaphore_tracker |
| tracker_fd = semaphore_tracker._semaphore_tracker_fd |
| self._fds.append(tracker_fd) |
| prep_data = spawn.get_preparation_data(process_obj._name) |
| fp = io.BytesIO() |
| popen.set_spawning_popen(self) |
| try: |
| reduction.dump(prep_data, fp) |
| reduction.dump(process_obj, fp) |
| finally: |
| popen.set_spawning_popen(None) |
| |
| parent_r = child_w = child_r = parent_w = None |
| try: |
| parent_r, child_w = os.pipe() |
| child_r, parent_w = os.pipe() |
| cmd = spawn.get_command_line(tracker_fd=tracker_fd, |
| pipe_handle=child_r) |
| self._fds.extend([child_r, child_w]) |
| self.pid = util.spawnv_passfds(spawn.get_executable(), |
| cmd, self._fds) |
| self.sentinel = parent_r |
| with open(parent_w, 'wb', closefd=False) as f: |
| f.write(fp.getbuffer()) |
| finally: |
| if parent_r is not None: |
| util.Finalize(self, os.close, (parent_r,)) |
| for fd in (child_r, child_w, parent_w): |
| if fd is not None: |
| os.close(fd) |
| |
| @staticmethod |
| def ensure_helpers_running(): |
| from . import semaphore_tracker |
| semaphore_tracker.ensure_running() |