test_selectors2.py 文件源码

def test_above_fd_setsize(self):
        # A scalable implementation should have no problem with more than
        # FD_SETSIZE file descriptors. Since we don't know the value, we just
        # try to set the soft RLIMIT_NOFILE to the hard RLIMIT_NOFILE ceiling.
        soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
        if hard == resource.RLIM_INFINITY:
            self.skipTest("RLIMIT_NOFILE is infinite")

        try:  # If we're on a *BSD system, the limit tag is different.
            _, bsd_hard = resource.getrlimit(resource.RLIMIT_OFILE)
            if bsd_hard == resource.RLIM_INFINITY:
                self.skipTest("RLIMIT_OFILE is infinite")
            if bsd_hard < hard:
                hard = bsd_hard

        # NOTE: AttributeError resource.RLIMIT_OFILE is not defined on Mac OS.
        except (OSError, resource.error, AttributeError):
            pass

        try:
            resource.setrlimit(resource.RLIMIT_NOFILE, (hard, hard))
            self.addCleanup(resource.setrlimit, resource.RLIMIT_NOFILE,
                            (soft, hard))
            limit_nofile = min(hard, 2 ** 16)
        except (OSError, ValueError):
            limit_nofile = soft

        # Guard against already allocated FDs
        limit_nofile -= 256
        limit_nofile = max(0, limit_nofile)

        s = self.make_selector()

        for i in range(limit_nofile // 2):
            rd, wr = self.make_socketpair()
            s.register(rd, selectors2.EVENT_READ)
            s.register(wr, selectors2.EVENT_WRITE)

        self.assertEqual(limit_nofile // 2, len(s.select()))