#!/usr/bin/env python3
# pylint: disable=missing-type-doc
"""Pymodbus Performance Example.
The following is an quick performance check of the synchronous
modbus client.
"""
from concurrent.futures import ThreadPoolExecutor as eWorker, as_completed
# --------------------------------------------------------------------------- #
# import the necessary modules
# --------------------------------------------------------------------------- #
import logging
import os
from threading import Lock, Thread as tWorker
from time import time
from pymodbus.client import ModbusTcpClient
try:
from multiprocessing import Process as mWorker, log_to_stderr
except ImportError:
log_to_stderr = logging.getLogger
# --------------------------------------------------------------------------- #
# choose between threads or processes
# --------------------------------------------------------------------------- #
# from multiprocessing import Process as Worker
# from threading import Thread as Worker
_thread_lock = Lock()
# --------------------------------------------------------------------------- #
# initialize the test
# --------------------------------------------------------------------------- #
# Modify the parameters below to control how we are testing the client:
#
# * workers - the number of workers to use at once
# * cycles - the total number of requests to send
# * host - the host to send the requests to
# --------------------------------------------------------------------------- #
workers = 10 # pylint: disable=invalid-name
cycles = 1000 # pylint: disable=invalid-name
host = "127.0.0.1" # pylint: disable=invalid-name
# --------------------------------------------------------------------------- #
# perform the test
# --------------------------------------------------------------------------- #
# This test is written such that it can be used by many threads of processes
# although it should be noted that there are performance penalties
# associated with each strategy.
# --------------------------------------------------------------------------- #
def single_client_test(n_host, n_cycles):
"""Perform a single threaded test of a synchronous client against the specified host
:param n_host: The host to connect to
:param n_cycles: The number of iterations to perform
"""
logger = log_to_stderr()
logger.setLevel(logging.WARNING)
txt = f"starting worker: {os.getpid()}"
logger.debug(txt)
try:
count = 0
client = ModbusTcpClient(n_host, port=5020)
while count < n_cycles:
client.read_holding_registers(10, 123, slave=1)
count += 1
except Exception: # pylint: disable=broad-except
logger.exception("failed to run test successfully")
txt = f"finished worker: {os.getpid()}"
logger.debug(txt)
def multiprocessing_test(func, extras):
"""Multiprocessing test."""
start_time = time()
procs = [mWorker(target=func, args=extras) for _ in range(workers)]
any(p.start() for p in procs) # start the workers
any(p.join() for p in procs) # wait for the workers to finish
return start_time
def thread_test(func, extras):
"""Thread test."""
start_time = time()
procs = [tWorker(target=func, args=extras) for _ in range(workers)]
any(p.start() for p in procs) # start the workers
any(p.join() for p in procs) # wait for the workers to finish
return start_time
def thread_pool_exe_test(func, extras):
"""Thread pool exe."""
start_time = time()
with eWorker(max_workers=workers, thread_name_prefix="Perform") as exe:
futures = {exe.submit(func, *extras): job for job in range(workers)}
for future in as_completed(futures):
future.result()
return start_time
# --------------------------------------------------------------------------- #
# run our test and check results
# --------------------------------------------------------------------------- #
# We shard the total number of requests to perform between the number of
# threads that was specified. We then start all the threads and block on
# them to finish. This may need to switch to another mechanism to signal
# finished as the process/thread start up/shut down may skew the test a bit.
# RTU 32 requests/second @9600
# TCP 31430 requests/second
# --------------------------------------------------------------------------- #
if __name__ == "__main__":
args = (host, int(cycles * 1.0 / workers))
# with Worker(max_workers=workers, thread_name_prefix="Perform") as exe:
# futures = {exe.submit(single_client_test, *args): job for job in range(workers)}
# for future in as_completed(futures):
# data = future.result()
# for _ in range(workers):
# futures.append(Worker.submit(single_client_test, args=args))
# procs = [Worker(target=single_client_test, args=args)
# for _ in range(workers)]
# any(p.start() for p in procs) # start the workers
# any(p.join() for p in procs) # wait for the workers to finish
# start = multiprocessing_test(single_client_test, args)
# start = thread_pool_exe_test(single_client_test, args)
for tester in (multiprocessing_test, thread_test, thread_pool_exe_test):
print(tester.__name__)
start = tester(single_client_test, args)
stop = time()
print(f"{(1.0 * cycles) / (stop - start)} requests/second")
print(
f"time taken to complete {cycles} cycle by "
f"{workers} workers is {stop - start} seconds"
)
print()