import io import os from .context import reduction, set_spawning_popen from . import popen_fork from . import spawn from . import util __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.getfd() self._fds.append(tracker_fd) prep_data = spawn.get_preparation_data(process_obj._name) fp = io.BytesIO() set_spawning_popen(self) try: reduction.dump(prep_data, fp) reduction.dump(process_obj, fp) finally: 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)