#!/usr/bin/env python3
import socketserver
-import plom_socket_io
import threading
-import time
+import queue
# Avoid "Address already in use" errors.
socketserver.TCPServer.allow_reuse_address = True
class Server(socketserver.ThreadingTCPServer):
- """Bind together threaded IO handling server and world state (counter)."""
+ """Bind together threaded IO handling server and message queue."""
- def __init__(self, counter, *args, **kwargs):
+ def __init__(self, queue, *args, **kwargs):
super().__init__(*args, **kwargs)
- self.counter = counter
+ self.queue_out = queue
self.daemon_threads = True # Else, server's threads have daemon=False.
-def fib(n):
- """Calculate n-th Fibonacci number."""
- if n in (1, 2):
- return 1
- else:
- return fib(n-1) + fib(n-2)
-
-
class IO_Handler(socketserver.BaseRequestHandler):
def handle(self):
- """Loop recv for input, send replies; also, send regular counter value.
+ """Move messages between network socket and main thread via queues.
+
+ On start, sets up new queue, sends it via self.server.queue_out to
+ main thread, and from then on receives messages to send back from the
+ main thread via that new queue.
- If input is 'QUIT', send reply 'BYE' and end loop / connection.
- Otherwise, use handle_message to interpret and enact commands.
+ At the same time, loops over socket's recv to get messages from the
+ outside via self.server.queue_out into the main thread. Ends connection
+ once a 'QUIT' message is received from socket, and then also kills its
+ own queue.
+
+ All messages to the main thread are tuples, with the first element a
+ meta command ('ADD_QUEUE' for queue creation, 'KILL_QUEUE' for queue
+ deletion, and 'COMMAND' for everything else), the second element a UUID
+ that uniquely identifies the thread (so that the main thread knows whom
+ to send replies back to), and optionally a third element for further
+ instructions.
"""
+ import plom_socket_io
+
def caught_send(socket, message):
"""Send message by socket, catch broken socket connection error."""
try:
except plom_socket_io.BrokenSocketConnection:
pass
- def send_counter_loop(socket, counter, kill):
- """Every 5 seconds, send state of counter[0] until kill[0] set."""
- while not kill[0]:
- caught_send(socket, 'COUNTER ' + str(counter[0]))
- time.sleep(5)
-
- def handle_message(message):
- """Evaluate message for tasks to perform, yield result.
-
- Accepts one command: FIB, followed by positive integers, all tokens
- separated by whitespace. Will calculate and return for each such
- integer n the n-th Fibonacci number. Uses multiprocessing to
- perform multiple such calculations in parallel. Yields a
- 'CALCULATING …' message before the calculation starts, and finally
- yields a message containing the results. (The 'CALCULATING …'
- message coming before the results message is currently the main
- reason this works as a generator function using yield.)
-
- When no command can be read into the message, just yields a 'NO
- COMMAND UNDERSTOOD:', followed by the message.
- """
- from multiprocessing import Pool
- tokens = message.split(' ')
- if tokens[0] == 'FIB':
- msg_fail_fib = 'MALFORMED FIB REQUEST'
- if len(tokens) < 2:
- yield msg_fail_fib
- return
- numbers = []
- for token in tokens[1:]:
- if token != '0' and token.isdigit():
- numbers += [int(token)]
- elif token == '':
- continue
- else:
- yield msg_fail_fib
- return
- yield 'CALCULATING …'
- reply = ''
- with Pool(len(numbers)) as p:
- results = p.map(fib, numbers)
- reply = ' '.join([str(r) for r in results])
- yield reply
- return
- yield 'NO COMMAND UNDERSTOOD: %s' % message
+ def send_queue_messages(socket, queue_in, thread_alive):
+ """Send messages via socket from queue_in while thread_alive[0]."""
+ while thread_alive[0]:
+ try:
+ msg = queue_in.get(timeout=1)
+ except queue.Empty:
+ continue
+ caught_send(socket, msg)
+ import uuid
print('CONNECTION FROM:', str(self.client_address))
- counter_loop_killer = [False]
- send_count = threading.Thread(target=send_counter_loop,
- kwargs={'counter': self.server.counter,
- 'socket': self.request,
- 'kill': counter_loop_killer})
- send_count.start()
+ connection_id = uuid.uuid4()
+ queue_in = queue.Queue()
+ self.server.queue_out.put(('ADD_QUEUE', connection_id, queue_in))
+ thread_alive = [True]
+ t = threading.Thread(target=send_queue_messages,
+ args=(self.request, queue_in, thread_alive))
+ t.start()
for message in plom_socket_io.recv(self.request):
if message is None:
- print('RECEIVED MALFORMED MESSAGE')
- caught_send(self.request, 'bad message')
+ caught_send(self.request, 'BAD MESSAGE')
elif 'QUIT' == message:
caught_send(self.request, 'BYE')
break
else:
- print('RECEIVED MESSAGE:', message)
- for reply in handle_message(message):
- caught_send(self.request, reply)
- counter_loop_killer = [True]
- print('CONNECTION CLOSED:', str(self.client_address))
+ self.server.queue_out.put(('COMMAND', connection_id, message))
+ self.server.queue_out.put(('KILL_QUEUE', connection_id))
+ thread_alive[0] = False
+ print('CONNECTION CLOSED FROM:', str(self.client_address))
self.request.close()
-def inc_loop(counter, interval):
- """Loop incrementing counter every interval seconds."""
+class Task:
+
+ def __init__(self, name, args=(), kwargs={}):
+ self.name = name
+ self.args = args
+ self.kwargs = kwargs
+ self.todo = 1
+
+
+class Thing:
+
+ def __init__(self, type_, position):
+ self.type = type_
+ self.position = position
+ self.task = Task('wait')
+
+ def task_wait(self):
+ pass
+
+ def task_move(self, direction):
+ if direction == 'UP':
+ self.position[0] -= 1
+ elif direction == 'DOWN':
+ self.position[0] += 1
+ elif direction == 'RIGHT':
+ self.position[1] += 1
+ elif direction == 'LEFT':
+ self.position[1] -= 1
+
+ def decide_task(self):
+ if self.position[1] > 1:
+ self.set_task('move', 'LEFT')
+ elif self.position[1] < 3:
+ self.set_task('move', 'RIGHT')
+ else:
+ self.set_task('wait')
+
+ def set_task(self, task, *args, **kwargs):
+ self.task = Task(task, args, kwargs)
+
+ def proceed(self, is_AI=True):
+ """Further the thing in its tasks.
+
+ Decrements .task.todo; if it thus falls to <= 0, enacts method whose
+ name is 'task_' + self.task.name and sets .task = None. If is_AI, calls
+ .decide_task to decide a self.task.
+ """
+ self.task.todo -= 1
+ if self.task.todo <= 0:
+ task= getattr(self, 'task_' + self.task.name)
+ task(*self.task.args, **self.task.kwargs)
+ self.task = None
+ if is_AI and self.task is None:
+ self.decide_task()
+
+
+class World:
+
+ def __init__(self):
+ self.turn = 0
+ self.map_size = (5, 5)
+ self.map_ = 'xxxxx\n'+\
+ 'x...x\n'+\
+ 'x.X.x\n'+\
+ 'x...x\n'+\
+ 'xxxxx'
+ self.things = [Thing('human', [3, 3]), Thing('monster', [1, 1])]
+ self.player_i = 0
+ self.player = self.things[self.player_i]
+
+
+def fib(n):
+ """Calculate n-th Fibonacci number. Very inefficiently."""
+ if n in (1, 2):
+ return 1
+ else:
+ return fib(n-1) + fib(n-2)
+
+
+class ArgumentError(Exception):
+ pass
+
+
+class CommandHandler:
+
+ def __init__(self, queues_out):
+ from multiprocessing import Pool
+ self.queues_out = queues_out
+ self.world = World()
+ # self.pool and self.pool_result are currently only needed by the FIB
+ # command and the demo of a parallelized game loop in cmd_inc_p.
+ self.pool = Pool()
+ self.pool_result = None
+
+ def send_to(self, connection_id, msg):
+ """Send msg to client of connection_id."""
+ self.queues_out[connection_id].put(msg)
+
+ def send_all(self, msg):
+ """Send msg to all clients."""
+ for connection_id in self.queues_out:
+ self.send_to(connection_id, msg)
+
+ def stringify_yx(self, tuple_):
+ """Transform tuple (y,x) into string 'Y:'+str(y)+',X:'+str(x)."""
+ return 'Y:' + str(tuple_[0]) + ',X:' + str(tuple_[1])
+
+ def proceed_to_next_player_turn(self, connection_id):
+ """Run game world turns until player can decide their next step.
+
+ Sends a 'TURN_FINISHED' message, then iterates through all non-player
+ things, on each step furthering them in their tasks (and letting them
+ decide new ones if they finish). The iteration order is: first all
+ things that come after the player in the world things list, then (after
+ incrementing the world turn) all that come before the player; then the
+ player's .proceed() is run, and if it does not finish his task, the
+ loop starts at the beginning. Once the player's task is finished, the
+ loop breaks, and client-relevant game data is sent.
+ """
+ self.send_all('TURN_FINISHED ' + str(self.world.turn))
+ while True:
+ for thing in self.world.things[self.world.player_i+1:]:
+ thing.proceed()
+ self.world.turn += 1
+ for thing in self.world.things[:self.world.player_i]:
+ thing.proceed()
+ self.world.player.proceed(is_AI=False)
+ if self.world.player.task is None:
+ break
+ self.send_all('NEW_TURN ' + str(self.world.turn))
+ self.send_all('MAP_SIZE ' + self.stringify_yx(self.world.map_size))
+ self.send_all('TERRAIN\n' + self.world.map_)
+ for thing in self.world.things:
+ self.send_all('THING TYPE:' + thing.type + ' '
+ + self.stringify_yx(thing.position))
+
+ def cmd_fib(self, tokens, connection_id):
+ """Reply with n-th Fibonacci numbers, n taken from tokens[1:].
+
+ Numbers are calculated in parallel as far as possible, using fib().
+ A 'CALCULATING …' message is sent to caller before the result.
+ """
+ if len(tokens) < 2:
+ raise ArgumentError('FIB NEEDS AT LEAST ONE ARGUMENT')
+ numbers = []
+ for token in tokens[1:]:
+ if token == '0' or not token.isdigit():
+ raise ArgumentError('FIB ARGUMENTS MUST BE INTEGERS > 0')
+ numbers += [int(token)]
+ self.send_to(connection_id, 'CALCULATING …')
+ results = self.pool.map(fib, numbers)
+ reply = ' '.join([str(r) for r in results])
+ self.send_to(connection_id, reply)
+
+ def cmd_inc_p(self, connection_id):
+ """Increment world.turn, send game turn data to everyone.
+
+ To simulate game processing waiting times, a one second delay between
+ TURN_FINISHED and NEW_TURN occurs; after NEW_TURN, some expensive
+ calculations are started as pool processes that need to be finished
+ until a further INC finishes the turn.
+
+ This is just a demo structure for how the game loop could work when
+ parallelized. One might imagine a two-step game turn, with a non-action
+ step determining actor tasks (the AI determinations would take the
+ place of the fib calculations here), and an action step wherein these
+ tasks are performed (where now sleep(1) is).
+ """
+ from time import sleep
+ if self.pool_result is not None:
+ self.pool_result.wait()
+ self.send_all('TURN_FINISHED ' + str(self.world.turn))
+ sleep(1)
+ self.world.turn += 1
+ self.send_all('NEW_TURN ' + str(self.world.turn))
+ self.send_all('MAP_SIZE ' + self.stringify_yx(self.world.map_size))
+ self.send_all('TERRAIN\n' + self.world.map_)
+ for thing in self.world.things:
+ self.send_all('THING TYPE:' + thing.type + ' '
+ + self.stringify_yx(thing.position))
+ self.pool_result = self.pool.map_async(fib, (35, 35))
+
+ def cmd_get_turn(self, connection_id):
+ """Send world.turn to caller."""
+ self.send_to(connection_id, str(self.world.turn))
+
+ def cmd_move(self, direction, connection_id):
+ """Set player task to 'move' with direction arg, finish player turn."""
+ if not direction in {'UP', 'DOWN', 'RIGHT', 'LEFT'}:
+ raise ArgumentError('MOVE ARGUMENT MUST BE ONE OF: '
+ 'UP, DOWN, RIGHT, LEFT')
+ self.world.player.set_task('move', direction=direction)
+ self.proceed_to_next_player_turn(connection_id)
+
+ def cmd_wait(self, connection_id):
+ """Set player task to 'wait', finish player turn."""
+ self.world.player.set_task('wait')
+ self.proceed_to_next_player_turn(connection_id)
+
+ def cmd_echo(self, tokens, input_, connection_id):
+ """Send message in input_ beyond tokens[0] to caller."""
+ msg = input_[len(tokens[0]) + 1:]
+ self.send_to(connection_id, msg)
+
+ def cmd_all(self, tokens, input_):
+ """Send message in input_ beyond tokens[0] to all clients."""
+ msg = input_[len(tokens[0]) + 1:]
+ self.send_all(msg)
+
+ def handle_input(self, input_, connection_id):
+ """Process input_ to command grammar, call command handler if found."""
+ tokens = [token for token in input_.split(' ') if len(token) > 0]
+ try:
+ if len(tokens) == 0:
+ self.send_to(connection_id, 'EMPTY COMMAND')
+ elif len(tokens) == 1 and tokens[0] == 'INC_P':
+ self.cmd_inc_p(connection_id)
+ elif len(tokens) == 1 and tokens[0] == 'GET_TURN':
+ self.cmd_get_turn(connection_id)
+ elif len(tokens) == 1 and tokens[0] == 'WAIT':
+ self.cmd_wait(connection_id)
+ elif len(tokens) == 2 and tokens[0] == 'MOVE':
+ self.cmd_move(tokens[1], connection_id)
+ elif len(tokens) >= 1 and tokens[0] == 'ECHO':
+ self.cmd_echo(tokens, input_, connection_id)
+ elif len(tokens) >= 1 and tokens[0] == 'ALL':
+ self.cmd_all(tokens, input_)
+ elif len(tokens) >= 1 and tokens[0] == 'FIB':
+ # TODO: Should this really block the whole loop?
+ self.cmd_fib(tokens, connection_id)
+ else:
+ self.send_to(connection_id, 'UNKNOWN COMMAND')
+ except ArgumentError as e:
+ self.send_to(connection_id, 'ARGUMENT ERROR: ' + str(e))
+
+
+def io_loop(q):
+ """Handle commands coming through queue q, send results back.
+
+ Commands from q are expected to be tuples, with the first element either
+ 'ADD_QUEUE', 'COMMAND', or 'KILL_QUEUE', the second element a UUID, and
+ an optional third element of arbitrary type. The UUID identifies a
+ receiver for replies.
+
+ An 'ADD_QUEUE' command should contain as third element a queue through
+ which to send messages back to the sender of the command. A 'KILL_QUEUE'
+ command removes the queue for that receiver from the list of queues through
+ which to send replies.
+
+ A 'COMMAND' command is specified in greater detail by a string that is the
+ tuple's third element. CommandHandler takes care of processing this and
+ sending out replies.
+ """
+ queues_out = {}
+ command_handler = CommandHandler(queues_out)
while True:
- time.sleep(interval)
- counter[0] += 1
+ x = q.get()
+ command_type = x[0]
+ connection_id = x[1]
+ content = None if len(x) == 2 else x[2]
+ if command_type == 'ADD_QUEUE':
+ queues_out[connection_id] = content
+ elif command_type == 'COMMAND':
+ command_handler.handle_input(content, connection_id)
+ elif command_type == 'KILL_QUEUE':
+ del queues_out[connection_id]
-counter = [0]
-b = threading.Thread(target=inc_loop, daemon=True, kwargs={'counter': counter,
- 'interval': 1})
-b.start()
-server = Server(counter, ('localhost', 5000), IO_Handler)
+q = queue.Queue()
+c = threading.Thread(target=io_loop, daemon=True, args=(q,))
+c.start()
+server = Server(q, ('localhost', 5000), IO_Handler)
try:
server.serve_forever()
except KeyboardInterrupt:
projects / plomrogue2-experiments / blobdiff