| import os |
| import signal |
| |
| from . import util |
| |
| __all__ = ['Popen'] |
| |
| # |
| # Start child process using fork |
| # |
| |
| class Popen(object): |
| method = 'fork' |
| |
| def __init__(self, process_obj): |
| util._flush_std_streams() |
| self.returncode = None |
| self.finalizer = None |
| self._launch(process_obj) |
| |
| def duplicate_for_child(self, fd): |
| return fd |
| |
| def poll(self, flag=os.WNOHANG): |
| if self.returncode is None: |
| try: |
| pid, sts = os.waitpid(self.pid, flag) |
| except OSError as e: |
| # Child process not yet created. See #1731717 |
| # e.errno == errno.ECHILD == 10 |
| return None |
| if pid == self.pid: |
| if os.WIFSIGNALED(sts): |
| self.returncode = -os.WTERMSIG(sts) |
| else: |
| assert os.WIFEXITED(sts), "Status is {:n}".format(sts) |
| self.returncode = os.WEXITSTATUS(sts) |
| return self.returncode |
| |
| def wait(self, timeout=None): |
| if self.returncode is None: |
| if timeout is not None: |
| from multiprocessing.connection import wait |
| if not wait([self.sentinel], timeout): |
| return None |
| # This shouldn't block if wait() returned successfully. |
| return self.poll(os.WNOHANG if timeout == 0.0 else 0) |
| return self.returncode |
| |
| def _send_signal(self, sig): |
| if self.returncode is None: |
| try: |
| os.kill(self.pid, sig) |
| except ProcessLookupError: |
| pass |
| except OSError: |
| if self.wait(timeout=0.1) is None: |
| raise |
| |
| def terminate(self): |
| self._send_signal(signal.SIGTERM) |
| |
| def kill(self): |
| self._send_signal(signal.SIGKILL) |
| |
| def _launch(self, process_obj): |
| code = 1 |
| parent_r, child_w = os.pipe() |
| child_r, parent_w = os.pipe() |
| self.pid = os.fork() |
| if self.pid == 0: |
| try: |
| os.close(parent_r) |
| os.close(parent_w) |
| code = process_obj._bootstrap(parent_sentinel=child_r) |
| finally: |
| os._exit(code) |
| else: |
| os.close(child_w) |
| os.close(child_r) |
| self.finalizer = util.Finalize(self, util.close_fds, |
| (parent_r, parent_w,)) |
| self.sentinel = parent_r |
| |
| def close(self): |
| if self.finalizer is not None: |
| self.finalizer() |
