WDT 0.1.0

Watch Dog Timer for python.

Watch Dog Timer and Timer for python

Github PyPI

Instalation

% pip install WDT

class WatchDogTimer

The WatchDogTimer is used to invoke a callback function when the timeout happens. After starting the WatchDogTimer, the application need “feed” the WatchDogTimer periodically if you want to prevent to invoke the callback.

If you do not “feed”, the callback function would be invoked after the setting time from the last “feed”.

Methods

• init( self, callback, args_dict={}, time_sec=1, daemon=True )

  callback: a function or a functor,

  args_dict: an arguemnts of the function in the dictionary format,

  time_sec: a setting time,

  daemon: If it is true, the thread is daemonized.

• start( self ) -> None

  Start the WatchDogTimer.

• stop( self ) -> None

  Stop the WatchDogTimer. The callback function is not invoked.

• feed( self ) -> None

  Feed to the WatchDogTimer.

• set_callback( self, callback=None, args_dict=None ) -> None

  Change the callback and the args_dict if they are not None.

• set_time_sec( self, time_sec ) -> None

  Change the time_sec.

Variables

• ret

  It holds a retun velue of the callback function. If the callback function is not invoked, it is None.

• is_timeout

  It is boolean which represents the WatchDogTimer is timeout or not.

class PerfTimer

It is a timer to measure the time with time.perf_counter.

Methods

• init( self )

  The constructor

• start( self ) -> None

  Start the timer.

• stop( self ) -> float

  Stop the timer. It return the time in seconds.

• reset( self )

  It reset the accumulate time to zero.

• restart( self )

  Reset and start.

• get_time( self ) -> float

  Return the time.

Sample code

from WDT import *

import time

def callback_func1( x ):
    y = x+1
    print( 'func1: ', x, '->', y )
    return y

pt0 = PerfTimer()
pt1 = PerfTimer()

# the callback is not invoked because wdt is feed before timeout
pt0.start()
pt1.start()
print( 'Sample1' )
wdt = WatchDogTimer( callback_func1, {'x':1}, 0.2 )
wdt.start()
for i in range(5):
    wdt.feed()
    time.sleep(0.1)
wdt.stop()
pt0.stop()
pt1.stop()
print( pt0.get_time(), pt1.get_time() )

# invoke callback after some seconds
pt0.restart()
pt1.start()
print( 'Sample2' )
wdt = WatchDogTimer( callback_func1, {'x':1}, 0.2 )
wdt.start()
time.sleep(0.3)
pt0.stop()
pt1.stop()
print( pt0.get_time(), pt1.get_time() )

###
pt0.restart()
pt1.start()
print( 'Sample3' )
wdt = WatchDogTimer( callback_func1, {'x':1}, 0.2 )
wdt.start()
for i in range(5):
    wdt.feed()
    wdt.set_callback( None, {'x':i} )
    time.sleep(0.1)
time.sleep(0.3)
pt0.stop()
pt1.stop()
print( pt0.get_time(), pt1.get_time() )