非阻塞的Python套接字如何接收输入？

Question

如果我有这个代码与一个解锁套接字有关，称为sockrecv_data = sock.recv(1024)        if recv_data:            data.outb += recv_data        else:            print('closing connection to', data.addr)            sel.unregister(sock)            sock.close()究竟发生了什么？该语句与阻止和非阻止有何不同？如果程序不等待该语句完成，那么怎么会有价值呢？recv_data = sock.recv(1024)recv_data编辑：完整的服务器代码：import selectorsimport socketimport typeshost = "127.0.0.1"port = 65432def accept_wrapper(sock):    conn, addr = sock.accept()    print('accepted conneciton from', addr)    conn.setblocking(False)    data = types.SimpleNamespace(addr=addr, inb=b'', outb=b'')    events = selectors.EVENT_READ | selectors.EVENT_WRITE    sel.register(conn, events, data=data)def service_connection(key, mask):    sock = key.fileobj    data = key.data    if mask & selectors.EVENT_READ:        recv_data = sock.recv(1024)        if recv_data:            data.outb += recv_data        else:            print('closing connection to', data.addr)            sel.unregister(sock)            sock.close()    if mask & selectors.EVENT_WRITE:        if data.outb:            print('echoing', repr(data.outb), 'to', data.addr)            sent = sock.send(data.outb)            data.outb = data.outb[sent:]sel = selectors.DefaultSelector()lsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)lsock.bind((host, port))lsock.listen()print('listening on', (host, port))lsock.setblocking(False)sel.register(lsock, selectors.EVENT_READ, data=None)while True:    events = sel.select(timeout=None)    for key, mask in events:        if key.data is None:            # From the listening socket            accept_wrapper(key.fileobj)        else:            # Client Socket            service_connection(key, mask)

Answer 1

如果 是非阻塞的，则如果它以其他方式阻塞，它将引发。代码周围是否有 / 未显示？另一个选项用于确保在调用 之前读取要接收的数据。sockBlockingIOErrortryexceptselect.selectrecv

假设相应服务器的示例：

>>> from socket import *

>>> s=socket()

>>> s.connect(('localhost',5000))

>>> s.setblocking(0)

>>> s.recv(1024)

Traceback (most recent call last):

  File "<stdin>", line 1, in <module>

BlockingIOError: [WinError 10035] A non-blocking socket operation could not be completed immediately

编辑：

使用附加代码，仅在报告（数据准备读取）时调用，因此不应阻塞。它将返回数据或空字符串。后者表示套接字已关闭。recvsel.selectEVENT_READrecv