You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Paddle/python/paddle/fluid/multiprocess_utils.py

140 lines
4.9 KiB

# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import six
import sys
import signal
import atexit
from . import core
# NOTE: queue has a different name in python2 and python3
if six.PY2:
import Queue as queue
else:
import queue
# NOTE: [ mmap files clear ] If there is still data in the multiprocess queue when the main process finishes reading,
# the data in the queue needs to be popped. Then the LoDTensor read by the main process
# from the child process will automatically clear the memory-mapped file.
multiprocess_queue_set = set()
def _clear_multiprocess_queue_set():
global multiprocess_queue_set
for data_queue in multiprocess_queue_set:
while True:
try:
data_queue.get_nowait()
except queue.Empty:
break
# NOTE: main process clear function at exit
def _cleanup():
# NOTE: inter-process Queue shared memory objects clear function
_clear_multiprocess_queue_set()
# NOTE: main process memory map files clear funciton
core._cleanup_mmap_fds()
# NOTE: for child process clear function at exit
def _cleanup_mmap():
# clear memory map files in child process
core._cleanup_mmap_fds()
# NOTE used for register a function to be executed at interpreter exit.
class CleanupFuncRegistrar():
# Record the cleanup functions that have been executed
_executed_func_set = set()
# Record the cleanup functions that have been registered
_registered_func_set = set()
@classmethod
def register(cls, function, signals=[]):
def _func_exectuor():
if function not in cls._executed_func_set:
try:
function()
finally:
cls._executed_func_set.add(function)
def _func_register(function):
if not callable(function):
raise TypeError("%s is not callable object." % (function))
# check function object whether hash-able
set([function])
if function not in cls._registered_func_set:
atexit.register(_func_exectuor)
cls._registered_func_set.add(function)
def _signal_handler(signum=None, frame=None):
_func_exectuor()
if signum is not None:
if signum == signal.SIGINT:
raise KeyboardInterrupt
sys.exit(signum)
def _signal_register(signals):
signals = set(signals)
for sig in signals:
orig_handler = signal.signal(sig, _signal_handler)
if orig_handler not in (signal.SIG_DFL, signal.SIG_IGN):
if (sig == signal.SIGINT and
orig_handler is signal.default_int_handler):
continue
if orig_handler not in cls._registered_func_set:
atexit.register(orig_handler)
cls._registered_func_set.add(orig_handler)
# deal with signals
_signal_register(signals)
# deal with function
_func_register(function)
# NOTE: [ mmap files clear ] When the main process exits unexpectedly, the remaining
# shared memory objects in the inter-process Queue and the main process (mostly in the
# BlockingQueue) may not be completely released, resulting in the corresponding
# memory-mapped file remaining on the disk (/dev/shm), so register this function
# to clean up shared memory objects in these two queues before the python interpreter exits.
# NOTE: Currently multi-process DataLoader only supports Linux platform
if not (sys.platform == 'darwin' or sys.platform == 'win32'):
CleanupFuncRegistrar.register(_cleanup)
# ------------ SIGCHLD handler setting --------------
_SIGCHLD_handler_set = False
def _set_SIGCHLD_handler():
global _SIGCHLD_handler_set
if _SIGCHLD_handler_set:
return
current_handler = signal.getsignal(signal.SIGCHLD)
if not callable(current_handler):
current_handler = None
def __handler__(signum, frame):
# NOTE: Here the signum is SIGCHLD, when the child process exits,
# this handler will be called whenever the child process exits
# normally or abnormally.
core._throw_error_if_process_failed()
if current_handler is not None:
current_handler(signum, frame)
signal.signal(signal.SIGCHLD, __handler__)
_SIGCHLD_handler_set = True