class Process(object):
def __init__(self,
name,
params,
cwd=None,
env=None,
debug=False,
shell=False,
bufsize=-1):
self.name = name
self.service_stopped = Signal("stopped signal for " +
strings.quote(name))
self.stdin = Queue("stdin for process " + strings.quote(name),
silent=True)
self.stdout = Queue("stdout for process " + strings.quote(name),
silent=True)
self.stderr = Queue("stderr for process " + strings.quote(name),
silent=True)
try:
if cwd == None:
cwd = os.getcwd()
else:
cwd = str(cwd)
self.debug = debug or DEBUG
self.service = service = subprocess.Popen(
[str(p) for p in params],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
bufsize=bufsize,
cwd=cwd,
env={
str(k): str(v)
for k, v in set_default(env, os.environ).items()
},
shell=shell)
self.please_stop = Signal()
self.please_stop.then(self._kill)
self.child_locker = Lock()
self.children = [
Thread.run(self.name + " stdin",
self._writer,
service.stdin,
self.stdin,
please_stop=self.service_stopped,
parent_thread=self),
Thread.run(self.name + " stdout",
self._reader,
"stdout",
service.stdout,
self.stdout,
please_stop=self.service_stopped,
parent_thread=self),
Thread.run(self.name + " stderr",
self._reader,
"stderr",
service.stderr,
self.stderr,
please_stop=self.service_stopped,
parent_thread=self),
Thread.run(self.name + " waiter",
self._monitor,
parent_thread=self),
]
except Exception as e:
Log.error("Can not call", e)
self.debug and Log.note("{{process}} START: {{command}}",
process=self.name,
command=" ".join(map(strings.quote, params)))
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.join(raise_on_error=True)
def stop(self):
self.stdin.add(THREAD_STOP) # ONE MORE SEND
self.please_stop.go()
def join(self, raise_on_error=False):
self.service_stopped.wait()
with self.child_locker:
child_threads, self.children = self.children, []
for c in child_threads:
c.join()
if raise_on_error and self.returncode != 0:
Log.error("{{process}} FAIL: returncode={{code}}\n{{stderr}}",
process=self.name,
code=self.service.returncode,
stderr=list(self.stderr))
return self
def remove_child(self, child):
with self.child_locker:
try:
self.children.remove(child)
except Exception:
pass
@property
def pid(self):
return self.service.pid
@property
def returncode(self):
return self.service.returncode
def _monitor(self, please_stop):
with Timer(self.name):
self.service.wait()
self.debug and Log.note(
"{{process}} STOP: returncode={{returncode}}",
process=self.name,
returncode=self.service.returncode)
self.service_stopped.go()
please_stop.go()
def _reader(self, name, pipe, receive, please_stop):
try:
while not please_stop and self.service.returncode is None:
line = to_text(pipe.readline().rstrip())
if line:
receive.add(line)
self.debug and Log.note("{{process}} ({{name}}): {{line}}",
name=name,
process=self.name,
line=line)
continue
# GRAB A FEW MORE LINES
for _ in range(100):
try:
line = to_text(pipe.readline().rstrip())
if line:
receive.add(line)
self.debug and Log.note(
"{{process}} ({{name}}): {{line}}",
name=name,
process=self.name,
line=line)
break
except Exception:
break
else:
Till(seconds=5).wait()
# GRAB A FEW MORE LINES
max = 100
while max:
try:
line = to_text(pipe.readline().rstrip())
if line:
max = 100
receive.add(line)
self.debug and Log.note(
"{{process}} ({{name}}): {{line}}",
name=name,
process=self.name,
line=line)
else:
max -= 1
except Exception:
break
finally:
pipe.close()
receive.add(THREAD_STOP)
self.debug and Log.note(
"{{process}} ({{name}} is closed)", name=name, process=self.name)
receive.add(THREAD_STOP)
def _writer(self, pipe, send, please_stop):
while not please_stop:
line = send.pop(till=please_stop)
if line is THREAD_STOP:
please_stop.go()
break
elif line is None:
continue
self.debug and Log.note("{{process}} (stdin): {{line}}",
process=self.name,
line=line.rstrip())
pipe.write(line.encode('utf8') + b"\n")
pipe.flush()
def _kill(self):
try:
self.service.kill()
Log.note("Service was successfully terminated.")
except Exception as e:
ee = Except.wrap(e)
if 'The operation completed successfully' in ee:
return
if 'No such process' in ee:
return
Log.warning("Failure to kill process {{process|quote}}",
process=self.name,
cause=ee)
class MainThread(BaseThread):
def __init__(self):
BaseThread.__init__(self, get_ident())
self.name = "Main Thread"
self.please_stop = Signal()
self.stopped = Signal()
self.stop_logging = Log.stop
self.timers = None
self.shutdown_locker = allocate_lock()
def stop(self):
"""
BLOCKS UNTIL ALL KNOWN THREADS, EXCEPT MainThread, HAVE STOPPED
"""
global DEBUG
self_thread = Thread.current()
if self_thread != MAIN_THREAD or self_thread != self:
Log.error("Only the main thread can call stop() on main thread")
DEBUG = True
self.please_stop.go()
join_errors = []
with self.child_locker:
children = copy(self.children)
for c in reversed(children):
DEBUG and c.name and Log.note("Stopping thread {{name|quote}}", name=c.name)
try:
c.stop()
except Exception as e:
join_errors.append(e)
for c in children:
DEBUG and c.name and Log.note(
"Joining on thread {{name|quote}}", name=c.name
)
try:
c.join()
except Exception as e:
join_errors.append(e)
DEBUG and c.name and Log.note(
"Done join on thread {{name|quote}}", name=c.name
)
if join_errors:
Log.error(
"Problem while stopping {{name|quote}}",
name=self.name,
cause=unwraplist(join_errors),
)
with self.shutdown_locker:
if self.stopped:
return
self.stop_logging()
self.timers.stop()
self.timers.join()
write_profiles(self.cprofiler)
DEBUG and Log.note("Thread {{name|quote}} now stopped", name=self.name)
self.stopped.go()
def wait_for_shutdown_signal(
self,
please_stop=False, # ASSIGN SIGNAL TO STOP EARLY
allow_exit=False, # ALLOW "exit" COMMAND ON CONSOLE TO ALSO STOP THE APP
wait_forever=True, # IGNORE CHILD THREADS, NEVER EXIT. False => IF NO CHILD THREADS LEFT, THEN EXIT
):
"""
FOR USE BY PROCESSES THAT NEVER DIE UNLESS EXTERNAL SHUTDOWN IS REQUESTED
CALLING THREAD WILL SLEEP UNTIL keyboard interrupt, OR please_stop, OR "exit"
:param please_stop:
:param allow_exit:
:param wait_forever:: Assume all needed threads have been launched. When done
:return:
"""
self_thread = Thread.current()
if self_thread != MAIN_THREAD or self_thread != self:
Log.error(
"Only the main thread can sleep forever (waiting for KeyboardInterrupt)"
)
if isinstance(please_stop, Signal):
# MUTUAL SIGNALING MAKES THESE TWO EFFECTIVELY THE SAME SIGNAL
self.please_stop.then(please_stop.go)
please_stop.then(self.please_stop.go)
else:
please_stop = self.please_stop
if not wait_forever:
# TRIGGER SIGNAL WHEN ALL CHILDREN THREADS ARE DONE
with self_thread.child_locker:
pending = copy(self_thread.children)
children_done = AndSignals(self.please_stop, len(pending))
children_done.signal.then(self.please_stop.go)
for p in pending:
p.stopped.then(children_done.done)
try:
if allow_exit:
_wait_for_exit(self.please_stop)
else:
_wait_for_interrupt(self.please_stop)
Log.alert("Stop requested! Stopping...")
except KeyboardInterrupt as _:
Log.alert("SIGINT Detected! Stopping...")
except SystemExit as _:
Log.alert("SIGTERM Detected! Stopping...")
finally:
self.stop()
class Process(object):
next_process_id = 0
def __init__(self,
name,
params,
cwd=None,
env=None,
debug=False,
shell=False,
bufsize=-1):
"""
Spawns multiple threads to manage the stdin/stdout/stderr of the child process; communication is done
via proper thread-safe queues of the same name.
Since the process is managed and monitored by threads, the main thread is not blocked when the child process
encounters problems
:param name: name given to this process
:param params: list of strings for program name and parameters
:param cwd: current working directory
:param env: enviroment variables
:param debug: true to be verbose about stdin/stdout
:param shell: true to run as command line
:param bufsize: if you want to screw stuff up
"""
self.debug = debug or DEBUG
self.process_id = Process.next_process_id
Process.next_process_id += 1
self.name = name + " (" + text(self.process_id) + ")"
self.service_stopped = Signal("stopped signal for " +
strings.quote(name))
self.stdin = Queue("stdin for process " + strings.quote(name),
silent=not self.debug)
self.stdout = Queue("stdout for process " + strings.quote(name),
silent=not self.debug)
self.stderr = Queue("stderr for process " + strings.quote(name),
silent=not self.debug)
try:
if cwd == None:
cwd = os.getcwd()
else:
cwd = str(cwd)
command = [str(p) for p in params]
self.debug and Log.note("command: {{command}}", command=command)
self.service = service = subprocess.Popen(
[str(p) for p in params],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
bufsize=bufsize,
cwd=cwd,
env={
str(k): str(v)
for k, v in set_default(env, os.environ).items()
},
shell=shell)
self.please_stop = Signal()
self.please_stop.then(self._kill)
self.child_locker = Lock()
self.children = [
Thread.run(self.name + " stdin",
self._writer,
service.stdin,
self.stdin,
please_stop=self.service_stopped,
parent_thread=self),
Thread.run(self.name + " stdout",
self._reader,
"stdout",
service.stdout,
self.stdout,
please_stop=self.service_stopped,
parent_thread=self),
Thread.run(self.name + " stderr",
self._reader,
"stderr",
service.stderr,
self.stderr,
please_stop=self.service_stopped,
parent_thread=self),
Thread.run(self.name + " waiter",
self._monitor,
parent_thread=self),
]
except Exception as e:
Log.error("Can not call", e)
self.debug and Log.note("{{process}} START: {{command}}",
process=self.name,
command=" ".join(map(strings.quote, params)))
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.join(raise_on_error=True)
def stop(self):
self.stdin.add(THREAD_STOP) # ONE MORE SEND
self.please_stop.go()
def join(self, raise_on_error=False):
self.service_stopped.wait()
with self.child_locker:
child_threads, self.children = self.children, []
for c in child_threads:
c.join()
if raise_on_error and self.returncode != 0:
Log.error("{{process}} FAIL: returncode={{code}}\n{{stderr}}",
process=self.name,
code=self.service.returncode,
stderr=list(self.stderr))
return self
def remove_child(self, child):
with self.child_locker:
try:
self.children.remove(child)
except Exception:
pass
@property
def pid(self):
return self.service.pid
@property
def returncode(self):
return self.service.returncode
def _monitor(self, please_stop):
with Timer(self.name, verbose=self.debug):
self.service.wait()
self.debug and Log.note(
"{{process}} STOP: returncode={{returncode}}",
process=self.name,
returncode=self.service.returncode)
self.service_stopped.go()
please_stop.go()
def _reader(self, name, pipe, receive, please_stop):
try:
while not please_stop and self.service.returncode is None:
line = to_text(pipe.readline().rstrip())
if line:
receive.add(line)
self.debug and Log.note("{{process}} ({{name}}): {{line}}",
name=name,
process=self.name,
line=line)
else:
(Till(seconds=1) | please_stop).wait()
# GRAB A FEW MORE LINES
max = 100
while max:
try:
line = to_text(pipe.readline().rstrip())
if line:
max = 100
receive.add(line)
self.debug and Log.note(
"{{process}} RESIDUE: ({{name}}): {{line}}",
name=name,
process=self.name,
line=line)
else:
max -= 1
except Exception:
break
finally:
pipe.close()
receive.add(THREAD_STOP)
self.debug and Log.note(
"{{process}} ({{name}} is closed)", name=name, process=self.name)
receive.add(THREAD_STOP)
def _writer(self, pipe, send, please_stop):
while not please_stop:
line = send.pop(till=please_stop)
if line is THREAD_STOP:
please_stop.go()
break
elif line is None:
continue
self.debug and Log.note("{{process}} (stdin): {{line}}",
process=self.name,
line=line.rstrip())
pipe.write(line.encode('utf8') + b"\n")
pipe.flush()
def _kill(self):
try:
self.service.kill()
Log.note("Service was successfully terminated.")
except Exception as e:
ee = Except.wrap(e)
if 'The operation completed successfully' in ee:
return
if 'No such process' in ee:
return
Log.warning("Failure to kill process {{process|quote}}",
process=self.name,
cause=ee)
