class Queue(object):
"""
SIMPLE MESSAGE QUEUE, multiprocessing.Queue REQUIRES SERIALIZATION, WHICH
IS DIFFICULT TO USE JUST BETWEEN THREADS (SERIALIZATION REQUIRED)
"""
def __init__(self,
name,
max=None,
silent=False,
unique=False,
allow_add_after_close=False):
"""
max - LIMIT THE NUMBER IN THE QUEUE, IF TOO MANY add() AND extend() WILL BLOCK
silent - COMPLAIN IF THE READERS ARE TOO SLOW
unique - SET True IF YOU WANT ONLY ONE INSTANCE IN THE QUEUE AT A TIME
"""
self.name = name
self.max = coalesce(max, 2**10)
self.silent = silent
self.allow_add_after_close = allow_add_after_close
self.unique = unique
self.closed = Signal(
"stop adding signal for " +
name) # INDICATE THE PRODUCER IS DONE GENERATING ITEMS TO QUEUE
self.lock = Lock("lock for queue " + name)
self.queue = deque()
def __iter__(self):
try:
while True:
value = self.pop()
if value is THREAD_STOP:
break
if value is not None:
yield value
except Exception as e:
Log.warning("Tell me about what happened here", e)
def add(self, value, timeout=None, force=False):
"""
:param value: ADDED THE THE QUEUE
:param timeout: HOW LONG TO WAIT FOR QUEUE TO NOT BE FULL
:param force: ADD TO QUEUE, EVEN IF FULL (USE ONLY WHEN CONSUMER IS RETURNING WORK TO THE QUEUE)
:return: self
"""
with self.lock:
if value is THREAD_STOP:
# INSIDE THE lock SO THAT EXITING WILL RELEASE wait()
self.queue.append(value)
self.closed.go()
return
if not force:
self._wait_for_queue_space(timeout=timeout)
if self.closed and not self.allow_add_after_close:
Log.error("Do not add to closed queue")
if self.unique:
if value not in self.queue:
self.queue.append(value)
else:
self.queue.append(value)
return self
def push(self, value):
"""
SNEAK value TO FRONT OF THE QUEUE
"""
if self.closed and not self.allow_add_after_close:
Log.error("Do not push to closed queue")
with self.lock:
self._wait_for_queue_space()
if not self.closed:
self.queue.appendleft(value)
return self
def pop_message(self, till=None):
"""
RETURN TUPLE (message, payload) CALLER IS RESPONSIBLE FOR CALLING message.delete() WHEN DONE
DUMMY IMPLEMENTATION FOR DEBUGGING
"""
if till is not None and not isinstance(till, Signal):
Log.error("Expecting a signal")
return Null, self.pop(till=till)
def extend(self, values):
if self.closed and not self.allow_add_after_close:
Log.error("Do not push to closed queue")
with self.lock:
# ONCE THE queue IS BELOW LIMIT, ALLOW ADDING MORE
self._wait_for_queue_space()
if not self.closed:
if self.unique:
for v in values:
if v is THREAD_STOP:
self.closed.go()
continue
if v not in self.queue:
self.queue.append(v)
else:
for v in values:
if v is THREAD_STOP:
self.closed.go()
continue
self.queue.append(v)
return self
def _wait_for_queue_space(self, timeout=None):
"""
EXPECT THE self.lock TO BE HAD, WAITS FOR self.queue TO HAVE A LITTLE SPACE
:param timeout: IN SECONDS
"""
wait_time = 5
(DEBUG and len(self.queue) > 1 * 1000 * 1000
) and Log.warning("Queue {{name}} has over a million items")
start = time()
stop_waiting = Till(till=start + coalesce(timeout, DEFAULT_WAIT_TIME))
while not self.closed and len(self.queue) >= self.max:
if stop_waiting:
Log.error(THREAD_TIMEOUT)
if self.silent:
self.lock.wait(stop_waiting)
else:
self.lock.wait(Till(seconds=wait_time))
if not stop_waiting and len(self.queue) >= self.max:
now = time()
Log.alert(
"Queue with name {{name|quote}} is full with ({{num}} items), thread(s) have been waiting {{wait_time}} sec",
name=self.name,
num=len(self.queue),
wait_time=now - start)
def __len__(self):
with self.lock:
return len(self.queue)
def __nonzero__(self):
with self.lock:
return any(r != THREAD_STOP for r in self.queue)
def pop(self, till=None):
"""
WAIT FOR NEXT ITEM ON THE QUEUE
RETURN THREAD_STOP IF QUEUE IS CLOSED
RETURN None IF till IS REACHED AND QUEUE IS STILL EMPTY
:param till: A `Signal` to stop waiting and return None
:return: A value, or a THREAD_STOP or None
"""
if till is not None and not isinstance(till, Signal):
Log.error("expecting a signal")
with self.lock:
while True:
if self.queue:
return self.queue.popleft()
if self.closed:
break
if not self.lock.wait(till=self.closed | till):
if self.closed:
break
return None
(DEBUG or not self.silent) and Log.note(self.name + " queue closed")
return THREAD_STOP
def pop_all(self):
"""
NON-BLOCKING POP ALL IN QUEUE, IF ANY
"""
with self.lock:
output = list(self.queue)
self.queue.clear()
return output
def pop_one(self):
"""
NON-BLOCKING POP IN QUEUE, IF ANY
"""
with self.lock:
if self.closed:
return THREAD_STOP
elif not self.queue:
return None
else:
v = self.queue.pop()
if v is THREAD_STOP: # SENDING A STOP INTO THE QUEUE IS ALSO AN OPTION
self.closed.go()
return v
def close(self):
self.closed.go()
def commit(self):
pass
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.close()
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)
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)
class Thread(BaseThread):
"""
join() ENHANCED TO ALLOW CAPTURE OF CTRL-C, AND RETURN POSSIBLE THREAD EXCEPTIONS
run() ENHANCED TO CAPTURE EXCEPTIONS
"""
num_threads = 0
def __init__(self, name, target, *args, **kwargs):
BaseThread.__init__(self, -1)
self.name = coalesce(name, "thread_" + text(object.__hash__(self)))
self.target = target
self.end_of_thread = Data()
self.synch_lock = Lock("response synch lock")
self.args = args
# ENSURE THERE IS A SHARED please_stop SIGNAL
self.kwargs = copy(kwargs)
self.please_stop = self.kwargs.get(PLEASE_STOP)
if self.please_stop is None:
self.please_stop = self.kwargs[PLEASE_STOP] = Signal(
"please_stop for " + self.name
)
self.thread = None
self.join_attempt = Signal("joining with " + self.name)
self.stopped = Signal("stopped signal for " + self.name)
if PARENT_THREAD in kwargs:
del self.kwargs[PARENT_THREAD]
self.parent = kwargs[PARENT_THREAD]
else:
self.parent = Thread.current()
self.parent.add_child(self)
def __enter__(self):
return self
def __exit__(self, type, value, traceback):
if isinstance(type, BaseException):
self.please_stop.go()
# TODO: AFTER A WHILE START KILLING THREAD
self.join()
self.args = None
self.kwargs = None
def start(self):
try:
self.thread = start_new_thread(Thread._run, (self,))
return self
except Exception as e:
Log.error("Can not start thread", e)
def stop(self):
"""
SEND STOP SIGNAL, DO NOT BLOCK
"""
with self.child_locker:
children = copy(self.children)
for c in children:
DEBUG and c.name and Log.note("Stopping thread {{name|quote}}", name=c.name)
c.stop()
self.please_stop.go()
DEBUG and Log.note("Thread {{name|quote}} got request to stop", name=self.name)
def _run(self):
# if self.trace_func:
# sys.settrace(self.trace_func)
# self.trace_func = None
self.id = get_ident()
with RegisterThread(self):
try:
if self.target is not None:
a, k, self.args, self.kwargs = self.args, self.kwargs, None, None
self.end_of_thread.response = self.target(*a, **k)
except Exception as e:
e = Except.wrap(e)
with self.synch_lock:
self.end_of_thread.exception = e
with self.parent.child_locker:
emit_problem = self not in self.parent.children
if emit_problem:
# THREAD FAILURES ARE A PROBLEM ONLY IF NO ONE WILL BE JOINING WITH IT
try:
Log.error(
"Problem in thread {{name|quote}}", name=self.name, cause=e
)
except Exception:
sys.stderr.write(
str("ERROR in thread: " + self.name + " " + text(e) + "\n")
)
finally:
try:
with self.child_locker:
children = copy(self.children)
for c in children:
try:
DEBUG and Log.note("Stopping thread " + c.name + "\n")
c.stop()
except Exception as e:
Log.warning(
"Problem stopping thread {{thread}}",
thread=c.name,
cause=e,
)
for c in children:
try:
DEBUG and Log.note("Joining on thread " + c.name + "\n")
c.join()
except Exception as e:
Log.warning(
"Problem joining thread {{thread}}",
thread=c.name,
cause=e,
)
finally:
DEBUG and Log.note("Joined on thread " + c.name + "\n")
del self.target, self.args, self.kwargs
DEBUG and Log.note("thread {{name|quote}} stopping", name=self.name)
except Exception as e:
DEBUG and Log.warning(
"problem with thread {{name|quote}}", cause=e, name=self.name
)
finally:
(Till(seconds=60) | self.join_attempt).wait()
self.stopped.go()
DEBUG and Log.note("thread {{name|quote}} is done, wait for join", name=self.name)
if not self.join_attempt:
if self.end_of_thread.exception:
# THREAD FAILURES ARE A PROBLEM ONLY IF NO ONE WILL BE JOINING WITH IT
try:
Log.error(
"Problem in thread {{name|quote}}", name=self.name, cause=e
)
except Exception:
sys.stderr.write(
str("ERROR in thread: " + self.name + " " + text(e) + "\n")
)
elif self.end_of_thread.response != None:
Log.warning(
"Thread {{thread}} returned a response, but was not joined with {{parent}} after 10min",
thread=self.name,
parent=self.parent.name
)
else:
# IF THREAD ENDS OK, AND NOTHING RETURNED, THEN FORGET ABOUT IT
self.parent.remove_child(self)
def is_alive(self):
return not self.stopped
def join(self, till=None):
"""
RETURN THE RESULT {"response":r, "exception":e} OF THE THREAD EXECUTION (INCLUDING EXCEPTION, IF EXISTS)
"""
if self is Thread:
Log.error("Thread.join() is not a valid call, use t.join()")
with self.child_locker:
children = copy(self.children)
for c in children:
c.join(till=till)
DEBUG and Log.note(
"{{parent|quote}} waiting on thread {{child|quote}}",
parent=Thread.current().name,
child=self.name,
)
self.join_attempt.go()
(self.stopped | till).wait()
if self.stopped:
self.parent.remove_child(self)
if not self.end_of_thread.exception:
return self.end_of_thread.response
else:
Log.error(
"Thread {{name|quote}} did not end well",
name=self.name,
cause=self.end_of_thread.exception,
)
else:
raise Except(context=THREAD_TIMEOUT)
@staticmethod
def run(name, target, *args, **kwargs):
# ENSURE target HAS please_stop ARGUMENT
if get_function_name(target) == "wrapper":
pass # GIVE THE override DECORATOR A PASS
elif PLEASE_STOP not in target.__code__.co_varnames:
Log.error(
"function must have please_stop argument for signalling emergency shutdown"
)
Thread.num_threads += 1
output = Thread(name, target, *args, **kwargs)
output.start()
return output
@staticmethod
def current():
ident = get_ident()
with ALL_LOCK:
output = ALL.get(ident)
if output is None:
thread = BaseThread(ident)
thread.cprofiler = CProfiler()
thread.cprofiler.__enter__()
with ALL_LOCK:
ALL[ident] = thread
Log.warning(
"this thread is not known. Register this thread at earliest known entry point."
)
return thread
return output
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)
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()