continuous-threading 2.0.6

Problem

import time
import threading

c = 0

def count_loop():
    global c

    while True:
        c += 1
        time.sleep(1)

th = threading.Thread(target=count_loop)
th.start()

time.sleep(5)
print('Count:', c)

# Process will not exit, because thread is running and cannot end

Solution

Added an allow_shutdown() method and a shutdown() function. The “ContinuousThread”, “PausableThread”, “OperationThread”, and “PeriodicThread” do not have this problem. The continuous_threading library overrides threading._shutdown and has fixes to allow ContinuousThread’s to close automatically.

import time
import continuous_threading

c = 0

def count():
    global c
    c += 1
    time.sleep(1)

th = continuous_threading.ContinuousThread(target=count)
th.start()

time.sleep(5)
print('Count:', c)

# Process will automatically exit with threading._shutdown() override

import time
import continuous_threading

c = 0

def count_loop():
    global c

    while True:
        c += 1
        time.sleep(1)

th = continuous_threading.Thread(target=count_loop)
th.start()

time.sleep(5)
print('Count:', c)

continuous_threading.shutdown(0)  # Call join on every non-daemon Thread.

# Alternative. This does not call join normally. continuous_threading threading._shutdown override does call "join".
# th.allow_shutdown()  # Release "_tstate_lock" allowing threading._shutdown to continue

# Process will exit, because allow_shutdown or shutdown

Close Infinite Loop Threads Automatically

Control how the override threading._shutdown works.

import time
import continuous_threading

# Change threading._shutdown() to automatically call Thread.allow_shutdown()
continuous_threading.set_allow_shutdown(True)
continuous_threading.set_shutdown_timeout(0)  # Default 1

c = 0

def count_loop():
    global c

    while True:
        c += 1
        time.sleep(1)

th = continuous_threading.Thread(target=count_loop)
th.start()

time.sleep(5)
print('Count:', c)

# Process will exit due to "set_allow_shutdown"

Can also just call continuous_threading.shutdown()

Remove threading._shutdown() override

You can change the threading._shutdown function with

import continuous_threading

# Change back to original threading._shutdown function
continuous_threading.reset_shutdown()

# Set custom function or leave empty to use continuous_threading custom_shutdown()
continuous_threading.set_shutdown()

CommandProcess

Run functions and commands on an object that lives in a different process.

from continuous_threading import CommandProcess


class MyObj(object):
    def __init__(self, x=0, y=0):
        self._x = x
        self._y = y

    def set_x(self, x):
        self._x = x

    def set_y(self, y):
        self._y = y

    def print_obj(self, msg=''):
        print(self._x, self._y, msg)

    def expect(self, x, y, msg=''):
        assert self._x == x, 'X value {} does not match expected {}'.format(self._x, x)
        assert self._y == y, 'Y value {} does not match expected {}'.format(self._y, y)
        self.print_obj(msg=msg)


obj1 = MyObj()
obj2 = MyObj()

proc = CommandProcess(target=obj1)
proc.start()

# Send a command obj1
print('Main Obj1')  # Note: this prints way earlier
proc.send_cmd('print_obj', msg="Obj1")
proc.send_cmd('set_x', 1)
proc.send_cmd('print_obj')
proc.send_cmd('set_y', 2)
proc.send_cmd('print_obj')
proc.send_cmd('expect', 1, 2, msg='Obj1 expected (1,2)')

# Send a command obj2
print('Main Obj2')  # Note: this prints way earlier
proc.obj = obj2
proc.send_cmd('print_obj', msg="Obj2")
proc.send_cmd('set_x', 2)
proc.send_cmd('print_obj')
proc.send_cmd('set_y', 4)
proc.send_cmd('print_obj')
proc.send_cmd('expect', 2, 4, msg='Obj2 expected (2,4)')

# *** IGNORE COMMENTS: I implemented a caching system to save object state. ***
# Change back to obj1 (Remember this obj has attr 0,0 and when sent to other process will be a new obj 0,0).
# Cannot remember objects unless cached (saved in a dict) on the other process. id in process will be different.
#  ... NVM I'll just cache the obj value.
print('Main Obj1 again (Cached)')  # Note: this prints way earlier
proc.obj = obj1
proc.send_cmd('expect', 1, 2, msg="Obj1 Again (Cached)")
proc.send_cmd('set_x', 3)
proc.send_cmd('print_obj')
proc.send_cmd('set_y', 5)
proc.send_cmd('print_obj')
proc.send_cmd('expect', 3, 5, msg='Obj1 Again expected (3,5)')

proc.join()