[ashd.git] / python3 / ashd / serve.py

import sys, os, threading, time, logging, select, queue, collections
from . import perf

log = logging.getLogger("ashd.serve")
seq = 1
seqlk = threading.Lock()

def reqseq():
    global seq
    with seqlk:
        s = seq
        seq += 1
        return s

class closed(IOError):
    def __init__(self):
        super().__init__("The client has closed the connection.")

class reqthread(threading.Thread):
    def __init__(self, *, name=None, **kw):
        if name is None:
            name = "Request handler %i" % reqseq()
        super().__init__(name=name, **kw)

class wsgirequest(object):
    def __init__(self, *, handler):
        self.status = None
        self.headers = []
        self.respsent = False
        self.handler = handler
        self.buffer = bytearray()

    def handlewsgi(self):
        raise Exception()
    def fileno(self):
        raise Exception()
    def writehead(self, status, headers):
        raise Exception()
    def flush(self):
        raise Exception()
    def close(self):
        pass
    def writedata(self, data):
        self.buffer.extend(data)

    def flushreq(self):
        if not self.respsent:
            if not self.status:
                raise Exception("Cannot send response body before starting response.")
            self.respsent = True
            self.writehead(self.status, self.headers)

    def write(self, data):
        if not data:
            return
        self.flushreq()
        self.writedata(data)
        self.handler.ckflush(self)

    def startreq(self, status, headers, exc_info=None):
        if self.status:
            if exc_info:
                try:
                    if self.respsent:
                        raise exc_info[1]
                finally:
                    exc_info = None
            else:
                raise Exception("Can only start responding once.")
        self.status = status
        self.headers = headers
        return self.write

class handler(object):
    def handle(self, request):
        raise Exception()
    def ckflush(self, req):
        while len(req.buffer) > 0:
            rls, wls, els = select.select([], [req], [req])
            req.flush()
    def close(self):
        pass

    @classmethod
    def parseargs(cls, **args):
        if len(args) > 0:
            raise ValueError("unknown handler argument: " + next(iter(args)))
        return {}

class single(handler):
    cname = "single"

    def handle(self, req):
        try:
            env = req.mkenv()
            with perf.request(env) as reqevent:
                respiter = req.handlewsgi(env, req.startreq)
                for data in respiter:
                    req.write(data)
                if req.status:
                    reqevent.response([req.status, req.headers])
                    req.flushreq()
                self.ckflush(req)
        except closed:
            pass
        except:
            log.error("exception occurred when handling request", exc_info=True)
        finally:
            req.close()

def dbg(*a):
    f = True
    for o in a:
        if not f:
            sys.stderr.write(" ")
        sys.stderr.write(str(a))
        f = False
    sys.stderr.write("\n")
    sys.stderr.flush()

class freethread(handler):
    cname = "free"

    def __init__(self, *, max=None, timeout=None, **kw):
        super().__init__(**kw)
        self.current = set()
        self.lk = threading.Lock()
        self.tcond = threading.Condition(self.lk)
        self.max = max
        self.timeout = timeout

    @classmethod
    def parseargs(cls, *, max=None, abort=None, **args):
        ret = super().parseargs(**args)
        if max:
            ret["max"] = int(max)
        if abort:
            ret["timeout"] = int(abort)
        return ret

    def handle(self, req):
        with self.lk:
            if self.max is not None:
                if self.timeout is not None:
                    now = start = time.time()
                    while len(self.current) >= self.max:
                        self.tcond.wait(start + self.timeout - now)
                        now = time.time()
                        if now - start > self.timeout:
                            os.abort()
                else:
                    while len(self.current) >= self.max:
                        self.tcond.wait()
            th = reqthread(target=self.run, args=[req])
            th.registered = False
            th.start()
            while not th.registered:
                self.tcond.wait()

    def run(self, req):
        try:
            th = threading.current_thread()
            with self.lk:
                self.current.add(th)
                th.registered = True
                self.tcond.notify_all()
            try:
                env = req.mkenv()
                with perf.request(env) as reqevent:
                    respiter = req.handlewsgi(env, req.startreq)
                    for data in respiter:
                        req.write(data)
                    if req.status:
                        reqevent.response([req.status, req.headers])
                        req.flushreq()
                    self.ckflush(req)
            except closed:
                pass
            except:
                log.error("exception occurred when handling request", exc_info=True)
            finally:
                with self.lk:
                    self.current.remove(th)
                    self.tcond.notify_all()
        finally:
            req.close()

    def close(self):
        while True:
            with self.lk:
                if len(self.current) > 0:
                    th = next(iter(self.current))
                else:
                    return
            th.join()

class threadpool(handler):
    cname = "pool"

    def __init__(self, *, max=25, qsz=100, timeout=None, **kw):
        super().__init__(**kw)
        self.current = set()
        self.clk = threading.Lock()
        self.ccond = threading.Condition(self.clk)
        self.queue = collections.deque()
        self.waiting = set()
        self.waitlimit = 5
        self.wlstart = 0.0
        self.qlk = threading.Lock()
        self.qcond = threading.Condition(self.qlk)
        self.max = max
        self.qsz = qsz
        self.timeout = timeout

    @classmethod
    def parseargs(cls, *, max=None, queue=None, abort=None, **args):
        ret = super().parseargs(**args)
        if max:
            ret["max"] = int(max)
        if queue:
            ret["qsz"] = int(queue)
        if abort:
            ret["timeout"] = int(abort)
        return ret

    def handle(self, req):
        spawn = False
        with self.qlk:
            if self.timeout is not None:
                now = start = time.time()
                while len(self.queue) >= self.qsz:
                    self.qcond.wait(start + self.timeout - now)
                    now = time.time()
                    if now - start > self.timeout:
                        os.abort()
            else:
                while len(self.current) >= self.qsz:
                    self.qcond.wait()
            self.queue.append(req)
            self.qcond.notify()
            if len(self.waiting) < 1:
                spawn = True
        if spawn:
            with self.clk:
                if len(self.current) < self.max:
                    th = reqthread(target=self.run)
                    th.registered = False
                    th.start()
                    while not th.registered:
                        self.ccond.wait()

    def handle1(self, req):
        try:
            env = req.mkenv()
            with perf.request(env) as reqevent:
                respiter = req.handlewsgi(env, req.startreq)
                for data in respiter:
                    req.write(data)
                if req.status:
                    reqevent.response([req.status, req.headers])
                    req.flushreq()
                self.ckflush(req)
        except closed:
            pass
        except:
            log.error("exception occurred when handling request", exc_info=True)

    def run(self):
        timeout = 10.0
        th = threading.current_thread()
        with self.clk:
            self.current.add(th)
            th.registered = True
            self.ccond.notify_all()
        try:
            while True:
                start = now = time.time()
                with self.qlk:
                    while len(self.queue) < 1:
                        if len(self.waiting) >= self.waitlimit and now - self.wlstart >= timeout:
                            return
                        self.waiting.add(th)
                        try:
                            if len(self.waiting) == self.waitlimit:
                                self.wlstart = now
                            self.qcond.wait(start + timeout - now)
                        finally:
                            self.waiting.remove(th)
                        now = time.time()
                        if now - start > timeout:
                            return
                    req = self.queue.popleft()
                try:
                    self.handle1(req)
                finally:
                    req.close()
        finally:
            with self.clk:
                self.current.remove(th)

    def close(self):
        while True:
            with self.clk:
                if len(self.current) > 0:
                    th = next(iter(self.current))
                else:
                    return
            th.join()

class resplex(handler):
    cname = "rplex"

    def __init__(self, *, max=None, **kw):
        super().__init__(**kw)
        self.current = set()
        self.lk = threading.Lock()
        self.tcond = threading.Condition(self.lk)
        self.max = max
        self.cqueue = queue.Queue(5)
        self.cnpipe = os.pipe()
        self.rthread = reqthread(name="Response thread", target=self.handle2)
        self.rthread.start()

    @classmethod
    def parseargs(cls, *, max=None, **args):
        ret = super().parseargs(**args)
        if max:
            ret["max"] = int(max)
        return ret

    def ckflush(self, req):
        raise Exception("resplex handler does not support the write() function")

    def handle(self, req):
        with self.lk:
            if self.max is not None:
                while len(self.current) >= self.max:
                    self.tcond.wait()
            th = reqthread(target=self.handle1, args=[req])
            th.registered = False
            th.start()
            while not th.registered:
                self.tcond.wait()

    def handle1(self, req):
        try:
            th = threading.current_thread()
            with self.lk:
                self.current.add(th)
                th.registered = True
                self.tcond.notify_all()
            try:
                env = req.mkenv()
                respobj = req.handlewsgi(env, req.startreq)
                respiter = iter(respobj)
                if not req.status:
                    log.error("request handler returned without calling start_request")
                    if hasattr(respiter, "close"):
                        respiter.close()
                    return
                else:
                    self.cqueue.put((req, respiter))
                    os.write(self.cnpipe[1], b" ")
                    req = None
            finally:
                with self.lk:
                    self.current.remove(th)
                    self.tcond.notify_all()
        except closed:
            pass
        except:
            log.error("exception occurred when handling request", exc_info=True)
        finally:
            if req is not None:
                req.close()

    def handle2(self):
        try:
            rp = self.cnpipe[0]
            current = {}

            def closereq(req):
                respiter = current[req]
                try:
                    if respiter is not None and hasattr(respiter, "close"):
                        respiter.close()
                except:
                    log.error("exception occurred when closing iterator", exc_info=True)
                try:
                    req.close()
                except:
                    log.error("exception occurred when closing request", exc_info=True)
                del current[req]
            def ckiter(req):
                respiter = current[req]
                if respiter is not None:
                    rem = False
                    try:
                        data = next(respiter)
                    except StopIteration:
                        rem = True
                        try:
                            req.flushreq()
                        except:
                            log.error("exception occurred when handling response data", exc_info=True)
                    except:
                        rem = True
                        log.error("exception occurred when iterating response", exc_info=True)
                    if not rem:
                        if data:
                            try:
                                req.flushreq()
                                req.writedata(data)
                            except:
                                log.error("exception occurred when handling response data", exc_info=True)
                                rem = True
                    if rem:
                        current[req] = None
                        try:
                            if hasattr(respiter, "close"):
                                respiter.close()
                        except:
                            log.error("exception occurred when closing iterator", exc_info=True)
                        respiter = None
                if respiter is None and not req.buffer:
                    closereq(req)

            while True:
                bufl = list(req for req in current.keys() if req.buffer)
                rls, wls, els = select.select([rp], bufl, [rp] + bufl)
                if rp in rls:
                    ret = os.read(rp, 1024)
                    if not ret:
                        os.close(rp)
                        return
                    try:
                        while True:
                            req, respiter = self.cqueue.get(False)
                            current[req] = respiter
                            ckiter(req)
                    except queue.Empty:
                        pass
                for req in wls:
                    try:
                        req.flush()
                    except closed:
                        closereq(req)
                    except:
                        log.error("exception occurred when writing response", exc_info=True)
                        closereq(req)
                    else:
                        if len(req.buffer) < 65536:
                            ckiter(req)
        except:
            log.critical("unexpected exception occurred in response handler thread", exc_info=True)
            os.abort()

    def close(self):
        while True:
            with self.lk:
                if len(self.current) > 0:
                    th = next(iter(self.current))
                else:
                    break
            th.join()
        os.close(self.cnpipe[1])
        self.rthread.join()

names = {cls.cname: cls for cls in globals().values() if
         isinstance(cls, type) and
         issubclass(cls, handler) and
         hasattr(cls, "cname")}

def parsehspec(spec):
    if ":" not in spec:
        return spec, {}
    nm, spec = spec.split(":", 1)
    args = {}
    while spec:
        if "," in spec:
            part, spec = spec.split(",", 1)
        else:
            part, spec = spec, None
        if "=" in part:
            key, val = part.split("=", 1)
        else:
            key, val = part, ""
        args[key] = val
    return nm, args
Commit	Line	Data
	1	import sys, os, threading, time, logging, select, queue, collections
	2	from . import perf
	3
	4	log = logging.getLogger("ashd.serve")
	5	seq = 1
	6	seqlk = threading.Lock()
	7
	8	def reqseq():
	9	global seq
	10	with seqlk:
	11	s = seq
	12	seq += 1
	13	return s
	14
	15	class closed(IOError):
	16	def __init__(self):
	17	super().__init__("The client has closed the connection.")
	18
	19	class reqthread(threading.Thread):
	20	def __init__(self, , name=None, *kw):
	21	if name is None:
	22	name = "Request handler %i" % reqseq()
	23	super().__init__(name=name, **kw)
	24
	25	class wsgirequest(object):
	26	def __init__(self, *, handler):
	27	self.status = None
	28	self.headers = []
	29	self.respsent = False
	30	self.handler = handler
	31	self.buffer = bytearray()
	32
	33	def handlewsgi(self):
	34	raise Exception()
	35	def fileno(self):
	36	raise Exception()
	37	def writehead(self, status, headers):
	38	raise Exception()
	39	def flush(self):
	40	raise Exception()
	41	def close(self):
	42	pass
	43	def writedata(self, data):
	44	self.buffer.extend(data)
	45
	46	def flushreq(self):
	47	if not self.respsent:
	48	if not self.status:
	49	raise Exception("Cannot send response body before starting response.")
	50	self.respsent = True
	51	self.writehead(self.status, self.headers)
	52
	53	def write(self, data):
	54	if not data:
	55	return
	56	self.flushreq()
	57	self.writedata(data)
	58	self.handler.ckflush(self)
	59
	60	def startreq(self, status, headers, exc_info=None):
	61	if self.status:
	62	if exc_info:
	63	try:
	64	if self.respsent:
	65	raise exc_info[1]
	66	finally:
	67	exc_info = None
	68	else:
	69	raise Exception("Can only start responding once.")
	70	self.status = status
	71	self.headers = headers
	72	return self.write
	73
	74	class handler(object):
	75	def handle(self, request):
	76	raise Exception()
	77	def ckflush(self, req):
	78	while len(req.buffer) > 0:
	79	rls, wls, els = select.select([], [req], [req])
	80	req.flush()
	81	def close(self):
	82	pass
	83
	84	@classmethod
	85	def parseargs(cls, **args):
	86	if len(args) > 0:
	87	raise ValueError("unknown handler argument: " + next(iter(args)))
	88	return {}
	89
	90	class single(handler):
	91	cname = "single"
	92
	93	def handle(self, req):
	94	try:
	95	env = req.mkenv()
	96	with perf.request(env) as reqevent:
	97	respiter = req.handlewsgi(env, req.startreq)
	98	for data in respiter:
	99	req.write(data)
	100	if req.status:
	101	reqevent.response([req.status, req.headers])
	102	req.flushreq()
	103	self.ckflush(req)
	104	except closed:
	105	pass
	106	except:
	107	log.error("exception occurred when handling request", exc_info=True)
	108	finally:
	109	req.close()
	110
	111	def dbg(*a):
	112	f = True
	113	for o in a:
	114	if not f:
	115	sys.stderr.write(" ")
	116	sys.stderr.write(str(a))
	117	f = False
	118	sys.stderr.write("\n")
	119	sys.stderr.flush()
	120
	121	class freethread(handler):
	122	cname = "free"
	123
	124	def __init__(self, , max=None, timeout=None, *kw):
	125	super().__init__(**kw)
	126	self.current = set()
	127	self.lk = threading.Lock()
	128	self.tcond = threading.Condition(self.lk)
	129	self.max = max
	130	self.timeout = timeout
	131
	132	@classmethod
	133	def parseargs(cls, , max=None, abort=None, *args):
	134	ret = super().parseargs(**args)
	135	if max:
	136	ret["max"] = int(max)
	137	if abort:
	138	ret["timeout"] = int(abort)
	139	return ret
	140
	141	def handle(self, req):
	142	with self.lk:
	143	if self.max is not None:
	144	if self.timeout is not None:
	145	now = start = time.time()
	146	while len(self.current) >= self.max:
	147	self.tcond.wait(start + self.timeout - now)
	148	now = time.time()
	149	if now - start > self.timeout:
	150	os.abort()
	151	else:
	152	while len(self.current) >= self.max:
	153	self.tcond.wait()
	154	th = reqthread(target=self.run, args=[req])
	155	th.registered = False
	156	th.start()
	157	while not th.registered:
	158	self.tcond.wait()
	159
	160	def run(self, req):
	161	try:
	162	th = threading.current_thread()
	163	with self.lk:
	164	self.current.add(th)
	165	th.registered = True
	166	self.tcond.notify_all()
	167	try:
	168	env = req.mkenv()
	169	with perf.request(env) as reqevent:
	170	respiter = req.handlewsgi(env, req.startreq)
	171	for data in respiter:
	172	req.write(data)
	173	if req.status:
	174	reqevent.response([req.status, req.headers])
	175	req.flushreq()
	176	self.ckflush(req)
	177	except closed:
	178	pass
	179	except:
	180	log.error("exception occurred when handling request", exc_info=True)
	181	finally:
	182	with self.lk:
	183	self.current.remove(th)
	184	self.tcond.notify_all()
	185	finally:
	186	req.close()
	187
	188	def close(self):
	189	while True:
	190	with self.lk:
	191	if len(self.current) > 0:
	192	th = next(iter(self.current))
	193	else:
	194	return
	195	th.join()
	196
	197	class threadpool(handler):
	198	cname = "pool"
	199
	200	def __init__(self, , max=25, qsz=100, timeout=None, *kw):
	201	super().__init__(**kw)
	202	self.current = set()
	203	self.clk = threading.Lock()
	204	self.ccond = threading.Condition(self.clk)
	205	self.queue = collections.deque()
	206	self.waiting = set()
	207	self.waitlimit = 5
	208	self.wlstart = 0.0
	209	self.qlk = threading.Lock()
	210	self.qcond = threading.Condition(self.qlk)
	211	self.max = max
	212	self.qsz = qsz
	213	self.timeout = timeout
	214
	215	@classmethod
	216	def parseargs(cls, , max=None, queue=None, abort=None, *args):
	217	ret = super().parseargs(**args)
	218	if max:
	219	ret["max"] = int(max)
	220	if queue:
	221	ret["qsz"] = int(queue)
	222	if abort:
	223	ret["timeout"] = int(abort)
	224	return ret
	225
	226	def handle(self, req):
	227	spawn = False
	228	with self.qlk:
	229	if self.timeout is not None:
	230	now = start = time.time()
	231	while len(self.queue) >= self.qsz:
	232	self.qcond.wait(start + self.timeout - now)
	233	now = time.time()
	234	if now - start > self.timeout:
	235	os.abort()
	236	else:
	237	while len(self.current) >= self.qsz:
	238	self.qcond.wait()
	239	self.queue.append(req)
	240	self.qcond.notify()
	241	if len(self.waiting) < 1:
	242	spawn = True
	243	if spawn:
	244	with self.clk:
	245	if len(self.current) < self.max:
	246	th = reqthread(target=self.run)
	247	th.registered = False
	248	th.start()
	249	while not th.registered:
	250	self.ccond.wait()
	251
	252	def handle1(self, req):
	253	try:
	254	env = req.mkenv()
	255	with perf.request(env) as reqevent:
	256	respiter = req.handlewsgi(env, req.startreq)
	257	for data in respiter:
	258	req.write(data)
	259	if req.status:
	260	reqevent.response([req.status, req.headers])
	261	req.flushreq()
	262	self.ckflush(req)
	263	except closed:
	264	pass
	265	except:
	266	log.error("exception occurred when handling request", exc_info=True)
	267
	268	def run(self):
	269	timeout = 10.0
	270	th = threading.current_thread()
	271	with self.clk:
	272	self.current.add(th)
	273	th.registered = True
	274	self.ccond.notify_all()
	275	try:
	276	while True:
	277	start = now = time.time()
	278	with self.qlk:
	279	while len(self.queue) < 1:
	280	if len(self.waiting) >= self.waitlimit and now - self.wlstart >= timeout:
	281	return
	282	self.waiting.add(th)
	283	try:
	284	if len(self.waiting) == self.waitlimit:
	285	self.wlstart = now
	286	self.qcond.wait(start + timeout - now)
	287	finally:
	288	self.waiting.remove(th)
	289	now = time.time()
	290	if now - start > timeout:
	291	return
	292	req = self.queue.popleft()
	293	try:
	294	self.handle1(req)
	295	finally:
	296	req.close()
	297	finally:
	298	with self.clk:
	299	self.current.remove(th)
	300
	301	def close(self):
	302	while True:
	303	with self.clk:
	304	if len(self.current) > 0:
	305	th = next(iter(self.current))
	306	else:
	307	return
	308	th.join()
	309
	310	class resplex(handler):
	311	cname = "rplex"
	312
	313	def __init__(self, , max=None, *kw):
	314	super().__init__(**kw)
	315	self.current = set()
	316	self.lk = threading.Lock()
	317	self.tcond = threading.Condition(self.lk)
	318	self.max = max
	319	self.cqueue = queue.Queue(5)
	320	self.cnpipe = os.pipe()
	321	self.rthread = reqthread(name="Response thread", target=self.handle2)
	322	self.rthread.start()
	323
	324	@classmethod
	325	def parseargs(cls, , max=None, *args):
	326	ret = super().parseargs(**args)
	327	if max:
	328	ret["max"] = int(max)
	329	return ret
	330
	331	def ckflush(self, req):
	332	raise Exception("resplex handler does not support the write() function")
	333
	334	def handle(self, req):
	335	with self.lk:
	336	if self.max is not None:
	337	while len(self.current) >= self.max:
	338	self.tcond.wait()
	339	th = reqthread(target=self.handle1, args=[req])
	340	th.registered = False
	341	th.start()
	342	while not th.registered:
	343	self.tcond.wait()
	344
	345	def handle1(self, req):
	346	try:
	347	th = threading.current_thread()
	348	with self.lk:
	349	self.current.add(th)
	350	th.registered = True
	351	self.tcond.notify_all()
	352	try:
	353	env = req.mkenv()
	354	respobj = req.handlewsgi(env, req.startreq)
	355	respiter = iter(respobj)
	356	if not req.status:
	357	log.error("request handler returned without calling start_request")
	358	if hasattr(respiter, "close"):
	359	respiter.close()
	360	return
	361	else:
	362	self.cqueue.put((req, respiter))
	363	os.write(self.cnpipe[1], b" ")
	364	req = None
	365	finally:
	366	with self.lk:
	367	self.current.remove(th)
	368	self.tcond.notify_all()
	369	except closed:
	370	pass
	371	except:
	372	log.error("exception occurred when handling request", exc_info=True)
	373	finally:
	374	if req is not None:
	375	req.close()
	376
	377	def handle2(self):
	378	try:
	379	rp = self.cnpipe[0]
	380	current = {}
	381
	382	def closereq(req):
	383	respiter = current[req]
	384	try:
	385	if respiter is not None and hasattr(respiter, "close"):
	386	respiter.close()
	387	except:
	388	log.error("exception occurred when closing iterator", exc_info=True)
	389	try:
	390	req.close()
	391	except:
	392	log.error("exception occurred when closing request", exc_info=True)
	393	del current[req]
	394	def ckiter(req):
	395	respiter = current[req]
	396	if respiter is not None:
	397	rem = False
	398	try:
	399	data = next(respiter)
	400	except StopIteration:
	401	rem = True
	402	try:
	403	req.flushreq()
	404	except:
	405	log.error("exception occurred when handling response data", exc_info=True)
	406	except:
	407	rem = True
	408	log.error("exception occurred when iterating response", exc_info=True)
	409	if not rem:
	410	if data:
	411	try:
	412	req.flushreq()
	413	req.writedata(data)
	414	except:
	415	log.error("exception occurred when handling response data", exc_info=True)
	416	rem = True
	417	if rem:
	418	current[req] = None
	419	try:
	420	if hasattr(respiter, "close"):
	421	respiter.close()
	422	except:
	423	log.error("exception occurred when closing iterator", exc_info=True)
	424	respiter = None
	425	if respiter is None and not req.buffer:
	426	closereq(req)
	427
	428	while True:
	429	bufl = list(req for req in current.keys() if req.buffer)
	430	rls, wls, els = select.select([rp], bufl, [rp] + bufl)
	431	if rp in rls:
	432	ret = os.read(rp, 1024)
	433	if not ret:
	434	os.close(rp)
	435	return
	436	try:
	437	while True:
	438	req, respiter = self.cqueue.get(False)
	439	current[req] = respiter
	440	ckiter(req)
	441	except queue.Empty:
	442	pass
	443	for req in wls:
	444	try:
	445	req.flush()
	446	except closed:
	447	closereq(req)
	448	except:
	449	log.error("exception occurred when writing response", exc_info=True)
	450	closereq(req)
	451	else:
	452	if len(req.buffer) < 65536:
	453	ckiter(req)
	454	except:
	455	log.critical("unexpected exception occurred in response handler thread", exc_info=True)
	456	os.abort()
	457
	458	def close(self):
	459	while True:
	460	with self.lk:
	461	if len(self.current) > 0:
	462	th = next(iter(self.current))
	463	else:
	464	break
	465	th.join()
	466	os.close(self.cnpipe[1])
	467	self.rthread.join()
	468
	469	names = {cls.cname: cls for cls in globals().values() if
	470	isinstance(cls, type) and
	471	issubclass(cls, handler) and
	472	hasattr(cls, "cname")}
	473
	474	def parsehspec(spec):
	475	if ":" not in spec:
	476	return spec, {}
	477	nm, spec = spec.split(":", 1)
	478	args = {}
	479	while spec:
	480	if "," in spec:
	481	part, spec = spec.split(",", 1)
	482	else:
	483	part, spec = spec, None
	484	if "=" in part:
	485	key, val = part.split("=", 1)
	486	else:
	487	key, val = part, ""
	488	args[key] = val
	489	return nm, args