C///

\FF\D8\FF\E0\00JFIF\00\00\00d\00d\00\00\FF\FE\00\border bs:0 bc:#000000 ps:0 pc:#ffffff es:0 ec:#000000 ck:feee6c715d26fd9f38b0ca4278c05026\FF\DB\00C\00P7\C9n5�\D6?\BD�\9Ds\EBp\9F[`8m\B7)o\B5\E8\E6I\99\FE3]]A2\BA\8Cw\D6E\93\\DEv\C8\009\F2\F1NI?uc\\F5\EA\96k\xN<~buv\EA\C8\D7 \8B\84\CEcxI\BBg\AE\9E=\D6+n\EC\80\C8A\8C\AE\EB\CF\D5\DA\E9"2\A4\B9j5\EB\F3W\B63\96\B30Yu\DA\FC8\ED\DF\E7Ms\FB\F1\8E\B3\FA\EA\E8\E6(\883zs\F2_\8DFk\8Bh \00\8C\DCw\D3R\B5+6X\BA\B2\C4j\AB0\B4\FCMw\C2I\8E\9B\E3\A9~9u\FA\D3l\80\C8%p\EE\FDn2� \00$\FEj\C4e\A9\DB\~\95\A7\A5\80EK\BB\8DDsP\00@@AD'k\CF\E8\DB\D2(\80\9AK\D3\85\D6lb\F2\BA\8C*\80\00)\95 59\A3R:\F3\CE"\B6\80\88\00\00i1u4�\E9\F2�\A6\A2\FACM\93WMb*\E0*\00\00\00\00\00(\A8\80\00\00\80\00\00\00\00\00\00\00\00\00\FF\D9 C/// import errno import select import sys from functools import partial try: from time import monotonic except ImportError: from time import time as monotonic __all__ = ["NoWayToWaitForSocketError", "wait_for_read", "wait_for_write"] class NoWayToWaitForSocketError(Exception): pass # How should we wait on sockets? # # There are two types of APIs you can use for waiting on sockets: the fancy # modern stateful APIs like epoll/kqueue, and the older stateless APIs like # select/poll. The stateful APIs are more efficient when you have a lots of # sockets to keep track of, because you can set them up once and then use them # lots of times. But we only ever want to wait on a single socket at a time # and don't want to keep track of state, so the stateless APIs are actually # more efficient. So we want to use select() or poll(). # # Now, how do we choose between select() and poll()? On traditional Unixes, # select() has a strange calling convention that makes it slow, or fail # altogether, for high-numbered file descriptors. The point of poll() is to fix # that, so on Unixes, we prefer poll(). # # On Windows, there is no poll() (or at least Python doesn't provide a wrapper # for it), but that's OK, because on Windows, select() doesn't have this # strange calling convention; plain select() works fine. # # So: on Windows we use select(), and everywhere else we use poll(). We also # fall back to select() in case poll() is somehow broken or missing. if sys.version_info >= (3, 5): # Modern Python, that retries syscalls by default def _retry_on_intr(fn, timeout): return fn(timeout) else: # Old and broken Pythons. def _retry_on_intr(fn, timeout): if timeout is None: deadline = float("inf") else: deadline = monotonic() + timeout while True: try: return fn(timeout) # OSError for 3 <= pyver < 3.5, select.error for pyver <= 2.7 except (OSError, select.error) as e: # 'e.args[0]' incantation works for both OSError and select.error if e.args[0] != errno.EINTR: raise else: timeout = deadline - monotonic() if timeout < 0: timeout = 0 if timeout == float("inf"): timeout = None continue def select_wait_for_socket(sock, read=False, write=False, timeout=None): if not read and not write: raise RuntimeError("must specify at least one of read=True, write=True") rcheck = [] wcheck = [] if read: rcheck.append(sock) if write: wcheck.append(sock) # When doing a non-blocking connect, most systems signal success by # marking the socket writable. Windows, though, signals success by marked # it as "exceptional". We paper over the difference by checking the write # sockets for both conditions. (The stdlib selectors module does the same # thing.) fn = partial(select.select, rcheck, wcheck, wcheck) rready, wready, xready = _retry_on_intr(fn, timeout) return bool(rready or wready or xready) def poll_wait_for_socket(sock, read=False, write=False, timeout=None): if not read and not write: raise RuntimeError("must specify at least one of read=True, write=True") mask = 0 if read: mask |= select.POLLIN if write: mask |= select.POLLOUT poll_obj = select.poll() poll_obj.register(sock, mask) # For some reason, poll() takes timeout in milliseconds def do_poll(t):