beremiz

SVGHMI: prevent browser and watchdog commands to become zombie once finished.

2022-10-18, Edouard Tisserant
7c427418396f
Parents db87744d8900
Children ff42600fddd7
SVGHMI: prevent browser and watchdog commands to become zombie once finished.
2 files changed, 42 insertions(+), 7 deletions(-)
  • +20 -7
    svghmi/svghmi.py
  • +22 -0
    svghmi/svghmi_server.py
    • --- a/svghmi/svghmi.py Wed Oct 12 11:59:47 2022 +0200
    +++ b/svghmi/svghmi.py Tue Oct 18 11:09:40 2022 +0200
    @@ -636,19 +636,29 @@
    svghmi_cmds[thing] = (
    "Popen(" +
    repr(shlex.split(given_command.format(**svghmi_options))) +
    - ")") if given_command else "pass # no command given"
    + ")") if given_command else "None # no command given"
    runtimefile_path = os.path.join(buildpath, "runtime_%s_svghmi_.py" % location_str)
    runtimefile = open(runtimefile_path, 'w')
    runtimefile.write("""
    -# TODO : multiple watchdog (one for each svghmi instance)
    +#!/usr/bin/env python
    +# -*- coding: utf-8 -*-
    +
    +# generated by beremiz/svghmi/svghmi.py
    +
    +browser_proc = None
    +
    def svghmi_{location}_watchdog_trigger():
    - {svghmi_cmds[Watchdog]}
    + global browser_proc
    + restart_proc = {svghmi_cmds[Watchdog]}
    + waitpid_timeout(restart_proc, "SVGHMI watchdog triggered command")
    + waitpid_timeout(browser_proc, "SVGHMI browser process")
    + browser_proc = None
    max_svghmi_sessions = {maxConnections_total}
    def _runtime_{location}_svghmi_start():
    - global svghmi_watchdog, svghmi_servers
    + global svghmi_watchdog, svghmi_servers, browser_proc
    srv = svghmi_servers.get("{interface}:{port}", None)
    if srv is not None:
    @@ -673,7 +683,7 @@
    path_list.append("{path}")
    - {svghmi_cmds[Start]}
    + browser_proc = {svghmi_cmds[Start]}
    if {enable_watchdog}:
    if svghmi_watchdog is None:
    @@ -686,7 +696,7 @@
    def _runtime_{location}_svghmi_stop():
    - global svghmi_watchdog, svghmi_servers
    + global svghmi_watchdog, svghmi_servers, browser_proc
    if svghmi_watchdog is not None:
    svghmi_watchdog.cancel()
    @@ -702,7 +712,10 @@
    svghmi_listener.stopListening()
    svghmi_servers.pop("{interface}:{port}")
    - {svghmi_cmds[Stop]}
    + stop_proc = {svghmi_cmds[Stop]}
    + waitpid_timeout(stop_proc, "SVGHMI stop command")
    + waitpid_timeout(browser_proc, "SVGHMI browser process")
    + browser_proc = None
    """.format(location=location_str,
    xhtml=target_fname,
    --- a/svghmi/svghmi_server.py Wed Oct 12 11:59:47 2022 +0200
    +++ b/svghmi/svghmi_server.py Tue Oct 18 11:09:40 2022 +0200
    @@ -8,6 +8,7 @@
    from __future__ import absolute_import
    import errno
    from threading import RLock, Timer
    +import os, time
    try:
    from runtime.spawn_subprocess import Popen
    @@ -23,6 +24,9 @@
    from autobahn.websocket.protocol import WebSocketProtocol
    from autobahn.twisted.resource import WebSocketResource
    +from runtime.loglevels import LogLevelsDict
    +from runtime import GetPLCObjectSingleton
    +
    max_svghmi_sessions = None
    svghmi_watchdog = None
    @@ -299,3 +303,21 @@
    render_HEAD = render_GET
    +def waitpid_timeout(proc, helpstr="", timeout = 3):
    + if proc is None:
    + return
    + def waitpid_timeout_loop(pid=proc.pid, timeout = timeout):
    + try:
    + while os.waitpid(pid,os.WNOHANG) == (0,0):
    + time.sleep(1)
    + timeout = timeout - 1
    + if not timeout:
    + GetPLCObjectSingleton().LogMessage(
    + LogLevelsDict["WARNING"],
    + "Timeout waiting for {} PID: {}".format(helpstr, str(pid)))
    + break
    + except OSError:
    + # workaround exception "OSError: [Errno 10] No child processes"
    + pass
    + Thread(target=waitpid_timeout_loop, name="Zombie hunter").start()
    +