Source code for pypdevs.realtime.threadingPython
# Copyright 2014 Modelling, Simulation and Design Lab (MSDL) at
# McGill University and the University of Antwerp (http://msdl.cs.mcgill.ca/)
#
# 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.
from threading import Event, Thread, Lock
import pypdevs.accurate_time as time
from pypdevs.infinity import INFINITY
[docs]class ThreadingPython(object):
"""
Simple Python threads subsystem
"""
[docs] def __init__(self):
"""
Constructor
"""
self.evt = Event()
self.evt_lock = Lock()
[docs] def wait(self, delay, func):
"""
Wait for the specified time, or faster if interrupted
:param delay: time to wait
:param func: the function to call
"""
if delay == INFINITY:
return
#NOTE this call has a granularity of 5ms in Python <= 2.7.x in the worst case, so beware!
# the granularity seems to be much better in Python >= 3.x
p = Thread(target=ThreadingPython.callFunc, args=[self, delay, func])
p.daemon = True
p.start()
[docs] def interrupt(self):
"""
Interrupt the waiting thread
"""
self.evt.set()
[docs] def callFunc(self, delay, func):
"""
Function to call on a seperate thread: will block for the specified time and call the function afterwards
"""
with self.evt_lock:
self.evt.wait(delay)
func()
self.evt.clear()