"""wrappers for stdout/stderr forwarding over zmq """ #----------------------------------------------------------------------------- # Copyright (C) 2013 The IPython Development Team # # Distributed under the terms of the BSD License. The full license is in # the file COPYING, distributed as part of this software. #----------------------------------------------------------------------------- import os import threading import time import uuid from io import StringIO, UnsupportedOperation import zmq from .session import extract_header from IPython.utils import py3compat #----------------------------------------------------------------------------- # Globals #----------------------------------------------------------------------------- MASTER = 0 CHILD = 1 #----------------------------------------------------------------------------- # Stream classes #----------------------------------------------------------------------------- class OutStream(object): """A file like object that publishes the stream to a 0MQ PUB socket.""" # The time interval between automatic flushes, in seconds. _subprocess_flush_limit = 256 flush_interval = 0.05 topic=None def __init__(self, session, pub_socket, name, pipe=True): self.encoding = 'UTF-8' self.session = session self.pub_socket = pub_socket self.name = name self.topic = b'stream.' + py3compat.cast_bytes(name) self.parent_header = {} self._new_buffer() self._buffer_lock = threading.Lock() self._master_pid = os.getpid() self._master_thread = threading.current_thread().ident self._pipe_pid = os.getpid() self._pipe_flag = pipe if pipe: self._setup_pipe_in() def _setup_pipe_in(self): """setup listening pipe for subprocesses""" ctx = self.pub_socket.context # use UUID to authenticate pipe messages self._pipe_uuid = uuid.uuid4().bytes self._pipe_in = ctx.socket(zmq.PULL) self._pipe_in.linger = 0 self._pipe_port = self._pipe_in.bind_to_random_port("tcp://127.0.0.1") self._pipe_poller = zmq.Poller() self._pipe_poller.register(self._pipe_in, zmq.POLLIN) def _setup_pipe_out(self): # must be new context after fork ctx = zmq.Context() self._pipe_pid = os.getpid() self._pipe_out = ctx.socket(zmq.PUSH) self._pipe_out_lock = threading.Lock() self._pipe_out.connect("tcp://127.0.0.1:%i" % self._pipe_port) def _is_master_process(self): return os.getpid() == self._master_pid def _is_master_thread(self): return threading.current_thread().ident == self._master_thread def _have_pipe_out(self): return os.getpid() == self._pipe_pid def _check_mp_mode(self): """check for forks, and switch to zmq pipeline if necessary""" if not self._pipe_flag or self._is_master_process(): return MASTER else: if not self._have_pipe_out(): self._flush_buffer() # setup a new out pipe self._setup_pipe_out() return CHILD def set_parent(self, parent): self.parent_header = extract_header(parent) def close(self): self.pub_socket = None def _flush_from_subprocesses(self): """flush possible pub data from subprocesses into my buffer""" if not self._pipe_flag or not self._is_master_process(): return for i in range(self._subprocess_flush_limit): if self._pipe_poller.poll(0): msg = self._pipe_in.recv_multipart() if msg[0] != self._pipe_uuid: continue else: self._buffer.write(msg[1].decode(self.encoding, 'replace')) # this always means a flush, # so reset our timer self._start = 0 else: break def flush(self): """trigger actual zmq send""" if self.pub_socket is None: raise ValueError(u'I/O operation on closed file') mp_mode = self._check_mp_mode() if mp_mode != CHILD: # we are master if not self._is_master_thread(): # sub-threads must not trigger flush, # but at least they can force the timer. self._start = 0 return self._flush_from_subprocesses() data = self._flush_buffer() if data: content = {u'name':self.name, u'data':data} msg = self.session.send(self.pub_socket, u'stream', content=content, parent=self.parent_header, ident=self.topic) if hasattr(self.pub_socket, 'flush'): # socket itself has flush (presumably ZMQStream) self.pub_socket.flush() else: with self._pipe_out_lock: string = self._flush_buffer() tracker = self._pipe_out.send_multipart([ self._pipe_uuid, string.encode(self.encoding, 'replace'), ], copy=False, track=True) try: tracker.wait(1) except: pass def isatty(self): return False def __next__(self): raise IOError('Read not supported on a write only stream.') if not py3compat.PY3: next = __next__ def read(self, size=-1): raise IOError('Read not supported on a write only stream.') def readline(self, size=-1): raise IOError('Read not supported on a write only stream.') def fileno(self): raise UnsupportedOperation("IOStream has no fileno.") def write(self, string): if self.pub_socket is None: raise ValueError('I/O operation on closed file') else: # Make sure that we're handling unicode if not isinstance(string, unicode): string = string.decode(self.encoding, 'replace') is_child = (self._check_mp_mode() == CHILD) self._buffer.write(string) if is_child: # newlines imply flush in subprocesses # mp.Pool cannot be trusted to flush promptly (or ever), # and this helps. if '\n' in string: self.flush() # do we want to check subprocess flushes on write? # self._flush_from_subprocesses() current_time = time.time() if self._start < 0: self._start = current_time elif current_time - self._start > self.flush_interval: self.flush() def writelines(self, sequence): if self.pub_socket is None: raise ValueError('I/O operation on closed file') else: for string in sequence: self.write(string) def _flush_buffer(self): """clear the current buffer and return the current buffer data""" data = u'' if self._buffer is not None: data = self._buffer.getvalue() self._buffer.close() self._new_buffer() return data def _new_buffer(self): self._buffer = StringIO() self._start = -1