python - 多人游戏中的 Pygame 和套接字 : OverflowError

Question

我正在尝试使用 pygame 在 Python 中创建一个简单的多人游戏和 socket模块。它只是由两个圆圈组成，由两台不同计算机的 W、A、S、D 键控制。
起初我用 recv() 创建了一个客户端。在 pygame 循环的中间。它运行良好，但 recv()阻塞了循环，所以圆圈的运动并不顺畅，我不得不将速度增加到 6(在设置为 0.6 之前)才能获得正常速度。这是代码(我已经总结了一下):
客户端第一版

#import modules

def main(sock):
    pygame.init()
    
    #Display screen and set initial me_x and me_y

    vel = 0.6
   
    while True:
        keys_pressed = pygame.key.get_pressed()

        #Change me_x and me_y (with A, D, W, S keys)

        #Make sure me_x and me_y don't get off the screen

        screen.fill(color)
        
        if other_x and other_y:
            pygame.draw.circle(screen, colorMe, (other_x, other_y), radi)

        pygame.draw.circle(screen, colorOther, (int(me_x), int(me_y)), radi)

        pygame.display.flip()

        sock.send(int(me_x).to_bytes(3, byteorder = 'big') + int(me_y).to_bytes(3, byteorder = 'big'))

        otherPos = sock.recv(BUFSIZ)

        other_x = int.from_bytes(otherPos[:3], byteorder = 'big')
        other_y = int.from_bytes(otherPos[3:], byteorder = 'big')
        print(other_x, other_y)

#CONNECT TO TCP SOCKET

other_x = None
other_y = None

main(client_socket)

然后，我试着把 recv()在线程中停止阻塞循环:
客户端第二版

#import modules

def main(sock):
    pygame.init()
    
    #Display screen and set initial me_x and me_y

    vel = 0.6
   
    while True:
        for i in range(30):
            keys_pressed = pygame.key.get_pressed()

            #Change me_x and me_y (with A, D, W, S keys)

            #Make sure me_x and me_y don't get off the screen

            screen.fill(color)
            
            if other_x and other_y:
                pygame.draw.circle(screen, colorOther, (other_x, other_y), 15)

            pygame.draw.circle(screen, colorMe, (int(me_x), int(me_y)), 15)

            pygame.display.flip()

        msg = int(me_x).to_bytes(3, byteorder = 'big') + int(me_y).to_bytes(3, byteorder = 'big')
        sock.send(msg)

def recv_pos(sock):
    while True:
        other_pos = sock.recv(BUFSIZ)
        other_x = int.from_bytes(other_pos[:3], byteorder = 'big')
        other_y = int.from_bytes(other_pos[3:], byteorder = 'big')

        print(other_x, other_y)

#CONNECT TO TCP SOCKET

other_x = None
other_y = None

receive_thread = threading.Thread(target = recv_pos, args = (client_socket,))
receive_thread.daemon = True
receive_thread.start()

main(client_socket)

但是，当我在两台不同的计算机上启动客户端 2 的 2 个实例时，它给了我一个 OverflowError :

OverflowError: Python int too large to convert to C long

我添加了 for i in range(30):因为我认为服务器正在崩溃，因为同时发送的消息太多。输出是相同的:大约 3 秒后，程序崩溃并给出 OverflowError .
我添加了 print() recv() 之后的两个版本中的语句查看我收到的 x 和 y 的值。在第一个版本中，它们都在宽度和高度范围内。但是，在第 2 版中，收到的消息中有 1/5 是一个很大的数字，例如 124381473265。 .如果这个数字更大，它给出 OverflowError .我不明白为什么会这样:我在两个版本中都以相同的方式编码和解码消息，但是一个有效，另一个无效。
我不包括服务器代码，因为我认为没有必要。它只是在两个客户端之间传输消息而不修改它们。服务器不是错误，因为在第一个客户端版本中，消息被正确发送和接收。
任何帮助将不胜感激。如果您需要有关任何一点的更多信息，请告诉我。
提前致谢!

Answer 1

将您的套接字代码放入线程中，或使用 select.select()用于非阻塞套接字读取。然后当数据报从服务器到达时，将自定义事件消息发布回主循环。

import pygame
import enum

class NetworkEvents( enum.IntEnum ):
    EVENT_HANGUP    = pygame.USEREVENT + 1
    EVENT_MESSAGE   = pygame.USEREVENT + 2

您的套接字读取代码也应该处理部分数据包、挂断和延迟。我认为您上面的错误是由于尝试解包部分(或某种垃圾)数据包引起的。通常人们使用 pickle模块来封装这些数据，但首先，我会使用简单的字符串数据进行预测试。更容易调试。然后，一旦传输代码全部完成并经过测试，如有必要，请更改为二进制。

我喜欢用 select()无论如何，在我的套接字代码中。它对套接字发生的事情提供了细粒度的控制。

这是一个简单的线程套接字对话处理程序。它实际上只支持 socket-hangup 和传入消息。但它可以很容易地扩展以处理更多的消息类型。

import threading
import pygame
import random
import enum
import socket
import select
import time

class ConversationHandlerThread( threading.Thread ):
    """ A thread that handles a conversation with a single remote server.
        Accepts commands of 'close', 'red', 'green' or 'blue', and posts messages
        to the main PyGame thread for processing """
    def __init__( self, server_address, server_port ):
        threading.Thread.__init__(self)
        self.server_address = server_address
        self.server_port    = server_port
        self.server_socket  = None
        self.data_buffer    = ''
        self.daemon         = True # exit with parent
        self.done           = False

    def stop( self ):
        self.done = True

    def connect( self ):
        self.server_socket = socket.socket( socket.AF_INET, socket.SOCK_STREAM )
        while True:
            try:
                self.server_socket.connect( ( self.server_address, self.server_port ) )
                print( "Connected to %s:%d" % ( self.server_address, self.server_port ) )
                break;
            except:
                print( "Failed to connect %s:%d" % ( self.server_address, self.server_port ) )
                time.sleep( 12 )
                print( "Retrying..." )

    def run( self ):
        """ Connects to Server, then Loops until the server hangs-up """
        self.connect()

        # Now we're connected, start reading commands
        read_events_on   = [ self.server_socket ]
        while ( not self.done ):
            # Wait for incoming data, or errors, or 0.3 seconds
            (read_list, write_list, except_list) = select.select( read_events_on, [], [], 0.5 )

            if ( len( read_list ) > 0 ):
                # New data arrived, read it
                incoming = self.server_socket.recv( 8192 )
                if ( len(incoming) == 0):
                    # Socket has closed
                    new_event = pygame.event.Event( NetworkEvents.EVENT_HANGUP, { "address" : self.server_address } )
                    pygame.event.post( new_event )
                    self.server_socket.close()
                    self.done = True
                else:
                    # Data has arrived
                    try:
                        new_str = incoming.decode('utf-8')
                        self.data_buffer += new_str
                    except:
                        pass # don't understand buffer

                    # Parse incoming message (trivial parser, not high quality) 
                    # commands are '\n' separated
                    if (self.data_buffer.find('\n') != -1 ):
                        for line in self.data_buffer.split('\n'):
                            line = line.strip()
                            # client disconnect command
                            if ( line == 'close' ):
                                new_event = pygame.event.Event( NetworkEvents.EVENT_HANGUP, { "address" : self.server_address } )
                                pygame.event.post( new_event )
                                self.server_socket.close()
                                self.done = True

                            # only make events for valid commands
                            elif ( line in ( 'red', 'green', 'blue' ) ):
                                new_event = pygame.event.Event( NetworkEvents.EVENT_MESSAGE, { "address" : self.server_address, "message" : line  } )
                                pygame.event.post( new_event )
                        self.data_buffer = ''  # all used-up

将所有这些复杂性放入线程的美妙之处在于，一旦开始，您就可以忘记它。

# Start the network-handler thread
thread1 = ConversationHandlerThread( '127.0.0.1', 5555 )
thread1.start()

在您的主循环中，像处理其他任何事件一样处理事件:

for event in pygame.event.get():
    if ( event.type == pygame.QUIT ):
        done = True

    elif ( event.type == NetworkEvents.EVENT_HANGUP ):
        print(" CLIENT DISCONNECTED %s " % ( str(event.address) ) )

    elif ( event.type == NetworkEvents.EVENT_MESSAGE ):
        print(" CLIENT MESSAGE FROM %s - %s " % ( str(event.address), event.message ) )
        if ( event.message == 'red' ):
            new_sprite = AlienSprite( RED )
            SPRITES.add( new_sprite )