Issues with restarting Kaldi `subprocess.Popen` and/or `disconnect()`.

Test Rule without Caster. Test with subprocess.Popen and without just "disconnect()".

import subprocess, sys, time

from dragonfly import (Choice, Dictation, Function, Grammar, IntegerRef, Key,
                       MappingRule, Text, get_current_engine)

def reboot():
    engine = get_current_engine()
    if engine.name == 'kaldi':
        engine.disconnect()
        # time.sleep(3)
        subprocess.Popen([sys.executable, '-m', 'dragonfly', 'load', '_*.py', '--engine', 'kaldi',  '--no-recobs-messages'])

class TestDragonflyRule(MappingRule):
    mapping = {
        "test reboot":
            Function(reboot),
    } 

    extras = [

    ]

    defaults = {

    }

grammar = Grammar('TestExamples')
grammar.add_rule(TestDragonflyRule())
grammar.load()

However there seems to be issues calling Popen on Linux after disconnect.

This problem is semi-intermittent with subprocess.Popen.

INFO:engine:Loading grammar TestExamples
INFO:engine:Listening...
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib/python3.8/threading.py", line 932, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.8/threading.py", line 870, in run
    self._target(*self._args, **self._kwargs)
  File "/home/main/.local/lib/python3.8/site-packages/dragonfly/engines/backend_kaldi/audio.py", line 110, in _reader_thread
    in_data, overflowed = self.stream.read(self.stream.blocksize)
  File "/home/main/.local/lib/python3.8/site-packages/sounddevice.py", line 1196, in read
    _check(err)
  File "/home/main/.local/lib/python3.8/site-packages/sounddevice.py", line 2653, in _check
    raise PortAudioError(errormsg, err)

semi-intermittent Stream is stopped [PaErrorCode -9983] with subprocess.Popen and without.

INFO:engine:Listening...
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib/python3.8/threading.py", line 932, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.8/threading.py", line 870, in run
    self._target(*self._args, **self._kwargs)
  File "/home/main/.local/lib/python3.8/site-packages/dragonfly/engines/backend_kaldi/audio.py", line 110, in _reader_thread
    in_data, overflowed = self.stream.read(self.stream.blocksize)
  File "/home/main/.local/lib/python3.8/site-packages/sounddevice.py", line 1196, in read
    _check(err)
  File "/home/main/.local/lib/python3.8/site-packages/sounddevice.py", line 2653, in _check
    raise PortAudioError(errormsg, err)
sounddevice.PortAudioError: Stream is stopped [PaErrorCode -9983]
main@pop-os:~/Caster$ Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib/python3.8/threading.py", line 932, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.8/threading.py", line 870, in run
    self._target(*self._args, **self._kwargs)
  File "/home/main/.local/lib/python3.8/site-packages/dragonfly/engines/backend_kaldi/audio.py", line 110, in _reader_thread
    in_data, overflowed = self.stream.read(self.stream.blocksize)
  File "/home/main/.local/lib/python3.8/site-packages/sounddevice.py", line 1196, in read
    _check(err)
  File "/home/main/.local/lib/python3.8/site-packages/sounddevice.py", line 2653, in _check
    raise PortAudioError(errormsg, err)
sounddevice.PortAudioError: Stream is stopped [PaErrorCode -9983]
INFO:engine:Loading Kaldi-Active-Grammar v1.8.1 in process 8286.
INFO:engine:Kaldi options: {'model_dir': None, 'tmp_dir': None, 'audio_input_device': None, 'audio_self_threaded': True, 'audio_auto_reconnect': True, 'audio_reconnect_callback': None, 'retain_dir': None, 'retain_audio': False, 'retain_metadata': False, 'retain_approval_func': None, 'vad_aggressiveness': 3, 'vad_padding_start_ms': 150, 'vad_padding_end_ms': 200, 'vad_complex_padding_end_ms': 600, 'auto_add_to_user_lexicon': True, 'lazy_compilation': True, 'invalidate_cache': False, 'expected_error_rate_threshold': None, 'alternative_dictation': None, 'cloud_dictation_lang': 'en-US', 'decoder_init_config': None}
Kaldi-Active-Grammar v1.8.1: 
    If this free, open source engine is valuable to you, please consider donating 
    https://github.com/daanzu/kaldi-active-grammar 
    Disable message by calling `kaldi_active_grammar.disable_donation_message()`
INFO:engine:Loading Kaldi-Active-Grammar v1.8.1 in process 8303.
INFO:engine:Kaldi options: {'model_dir': None, 'tmp_dir': None, 'audio_input_device': None, 'audio_self_threaded': True, 'audio_auto_reconnect': True, 'audio_reconnect_callback': None, 'retain_dir': None, 'retain_audio': False, 'retain_metadata': False, 'retain_approval_func': None, 'vad_aggressiveness': 3, 'vad_padding_start_ms': 150, 'vad_padding_end_ms': 200, 'vad_complex_padding_end_ms': 600, 'auto_add_to_user_lexicon': True, 'lazy_compilation': True, 'invalidate_cache': False, 'expected_error_rate_threshold': None, 'alternative_dictation': None, 'cloud_dictation_lang': 'en-US', 'decoder_init_config': None}
Kaldi-Active-Grammar v1.8.1: 
    If this free, open source engine is valuable to you, please consider donating 
    https://github.com/daanzu/kaldi-active-grammar 
    Disable message by calling `kaldi_active_grammar.disable_donation_message()`
INFO:engine:streaming audio from 'default' using ALSA: 16000 sample_rate, 10 block_duration_ms, 40 latency_ms
INFO:module:CommandModule('_DragonflyExamplesRule.py'): Loading module: '/home/main/Caster/_DragonflyExamplesRule.py'
INFO:engine:Loading grammar TestExamples
INFO:engine:Listening...
INFO:engine:streaming audio from 'default' using ALSA: 16000 sample_rate, 10 block_duration_ms, 40 latency_ms
INFO:module:CommandModule('_DragonflyExamplesRule.py'): Loading module: '/home/main/Caster/_DragonflyExamplesRule.py'
INFO:engine:Loading grammar TestExamples
INFO:engine:Listening...

Sometimes initializes twice with subprocess.Popen and (without only once).

main@pop-os:~/Caster$ python3 -m dragonfly load _*.py --engine kaldi  --no-recobs-messages
INFO:engine:Loading Kaldi-Active-Grammar v1.8.1 in process 11548.
INFO:engine:Kaldi options: {'model_dir': None, 'tmp_dir': None, 'audio_input_device': None, 'audio_self_threaded': True, 'audio_auto_reconnect': True, 'audio_reconnect_callback': None, 'retain_dir': None, 'retain_audio': False, 'retain_metadata': False, 'retain_approval_func': None, 'vad_aggressiveness': 3, 'vad_padding_start_ms': 150, 'vad_padding_end_ms': 200, 'vad_complex_padding_end_ms': 600, 'auto_add_to_user_lexicon': True, 'lazy_compilation': True, 'invalidate_cache': False, 'expected_error_rate_threshold': None, 'alternative_dictation': None, 'cloud_dictation_lang': 'en-US', 'decoder_init_config': None}
Kaldi-Active-Grammar v1.8.1: 
    If this free, open source engine is valuable to you, please consider donating 
    https://github.com/daanzu/kaldi-active-grammar 
    Disable message by calling `kaldi_active_grammar.disable_donation_message()`
INFO:engine:streaming audio from 'default' using ALSA: 16000 sample_rate, 10 block_duration_ms, 40 latency_ms
INFO:module:CommandModule('_DragonflyExamplesRule.py'): Loading module: '/home/main/Caster/_DragonflyExamplesRule.py'
INFO:engine:Loading grammar TestExamples
INFO:engine:Listening...
^CException in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib/python3.8/threading.py", line 932, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.8/threading.py", line 870, in run
    self._target(*self._args, **self._kwargs)
  File "/home/main/.local/lib/python3.8/site-packages/dragonfly/engines/backend_kaldi/audio.py", line 110, in _reader_thread
    in_data, overflowed = self.stream.read(self.stream.blocksize)
  File "/home/main/.local/lib/python3.8/site-packages/sounddevice.py", line 1196, in read
    _check(err)
  File "/home/main/.local/lib/python3.8/site-packages/sounddevice.py", line 2653, in _check
    raise PortAudioError(errormsg, err)
sounddevice.PortAudioError: Stream is stopped [PaErrorCode -9983]
main@pop-os:~/Caster$ INFO:engine:Loading Kaldi-Active-Grammar v1.8.1 in process 12113.
INFO:engine:Kaldi options: {'model_dir': None, 'tmp_dir': None, 'audio_input_device': None, 'audio_self_threaded': True, 'audio_auto_reconnect': True, 'audio_reconnect_callback': None, 'retain_dir': None, 'retain_audio': False, 'retain_metadata': False, 'retain_approval_func': None, 'vad_aggressiveness': 3, 'vad_padding_start_ms': 150, 'vad_padding_end_ms': 200, 'vad_complex_padding_end_ms': 600, 'auto_add_to_user_lexicon': True, 'lazy_compilation': True, 'invalidate_cache': False, 'expected_error_rate_threshold': None, 'alternative_dictation': None, 'cloud_dictation_lang': 'en-US', 'decoder_init_config': None}
Kaldi-Active-Grammar v1.8.1: 
    If this free, open source engine is valuable to you, please consider donating 
    https://github.com/daanzu/kaldi-active-grammar 
    Disable message by calling `kaldi_active_grammar.disable_donation_message()`
INFO:engine:streaming audio from 'default' using ALSA: 16000 sample_rate, 10 block_duration_ms, 40 latency_ms
INFO:module:CommandModule('_DragonflyExamplesRule.py'): Loading module: '/home/main/Caster/_DragonflyExamplesRule.py'
INFO:engine:Loading grammar TestExamples
INFO:engine:Listening...
WARNING:engine:<dragonfly.engines.backend_kaldi.audio.VADAudio object at 0x7fe9bdac3040>: no good block received recently, so reconnecting audio
WARNING:engine:<dragonfly.engines.backend_kaldi.audio.VADAudio object at 0x7f5355cad100>: no good block received recently, so reconnecting audio
INFO:engine:streaming audio from 'default' using ALSA: 16000 sample_rate, 10 block_duration_ms, 40 latency_ms
INFO:engine:streaming audio from 'default' using ALSA: 16000 sample_rate, 10 block_duration_ms, 40 latency_ms

The last bit is keyboard interrupt ctrl-c for ^C to end some times after for a short bit i can stlil execute commands.

Originally posted by @LexiconCode in https://github.com/dictation-toolbox/dragonfly/pull/302#issuecomment-707725057

dictation-toolbox / dragonfly

Issues with restarting Kaldi `subprocess.Popen` and/or `disconnect()`. #309