def main():
"""
This is the main entry of the program. We do the following:
* Create the screen for displaying the data
* Create the 2 daemon threads that handle 2 tasks:
* Making the measurements
* Writing the measurements on the screen
* Handle the termination which either happens if one of the threads
terminates, or if Ctrl-C is pressed
"""
# Utility's usage and command line arguments
usage = "usage: %prog arg1 arg2 ...argn"
description=\
"Monitoring utility. "\
"Outputs a list of processes indicated by ``arg1``, ``arg2``, ...,"\
"``argn`` and the system resources that they occupy."
parser = OptionParser(usage=usage, description=description)
(options, args) = parser.parse_args()
# List where the latest measurements will be kept
measurements = []
# Used to lock access to ``measurements`` list
lock = threading.Lock()
try:
# create a virtual screen
s = Screen()
except curses.error:
print 'ERROR: Please maximize the terminal'
exit()
workers = (
Measurement(measurements, lock, args),
Presentation(measurements, lock, s),
)
for worker in workers:
worker.start()
try:
while threading.active_count() == 3:
time.sleep(0.1)
except KeyboardInterrupt:
pass
# Gracefully destroy the screen
s.kill()
