import os import sys 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._launch(process_obj) def duplicate_for_child(self, fd): return fd def poll(self, flag=os.WNOHANG): if self.returncode is None: while True: 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 else: break if pid == self.pid: if os.WIFSIGNALED(sts): self.returncode = -os.WTERMSIG(sts) else: assert os.WIFEXITED(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 terminate(self): if self.returncode is None: try: os.kill(self.pid, signal.SIGTERM) except ProcessLookupError: pass except OSError: if self.wait(timeout=0.1) is None: raise def _launch(self, process_obj): code = 1 parent_r, child_w = os.pipe() self.pid = os.fork() if self.pid == 0: try: os.close(parent_r) if 'random' in sys.modules: import random random.seed() code = process_obj._bootstrap() finally: os._exit(code) else: os.close(child_w) util.Finalize(self, os.close, (parent_r,)) self.sentinel = parent_r