@@ -4,7 +4,6 @@
import argparse
import json
import pprint
-import time
from lib import YnlFamily, Netlink, NlError
@@ -43,7 +42,10 @@ def main():
group.add_argument('--list-ops', action='store_true')
group.add_argument('--list-msgs', action='store_true')
- parser.add_argument('--sleep', dest='sleep', type=int)
+ parser.add_argument('--duration', dest='duration', type=int,
+ help='when subscribed, watch for DURATION seconds')
+ parser.add_argument('--sleep', dest='duration', type=int,
+ help='alias for duration')
parser.add_argument('--subscribe', dest='ntf', type=str)
parser.add_argument('--replace', dest='flags', action='append_const',
const=Netlink.NLM_F_REPLACE)
@@ -80,9 +82,6 @@ def main():
if args.ntf:
ynl.ntf_subscribe(args.ntf)
- if args.sleep:
- time.sleep(args.sleep)
-
if args.list_ops:
for op_name, op in ynl.ops.items():
print(op_name, " [", ", ".join(op.modes), "]")
@@ -106,8 +105,11 @@ def main():
exit(1)
if args.ntf:
- ynl.check_ntf()
- output(ynl.async_msg_queue)
+ try:
+ for msg in ynl.poll_ntf(duration=args.duration):
+ output(msg)
+ except KeyboardInterrupt:
+ pass
if __name__ == "__main__":
@@ -12,6 +12,9 @@ import sys
import yaml
import ipaddress
import uuid
+import queue
+import selectors
+import time
from .nlspec import SpecFamily
@@ -489,7 +492,7 @@ class YnlFamily(SpecFamily):
self.sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_GET_STRICT_CHK, 1)
self.async_msg_ids = set()
- self.async_msg_queue = []
+ self.async_msg_queue = queue.Queue()
for msg in self.msgs.values():
if msg.is_async:
@@ -903,7 +906,7 @@ class YnlFamily(SpecFamily):
msg['name'] = op['name']
msg['msg'] = attrs
- self.async_msg_queue.append(msg)
+ self.async_msg_queue.put(msg)
def check_ntf(self):
while True:
@@ -925,11 +928,30 @@ class YnlFamily(SpecFamily):
decoded = self.nlproto.decode(self, nl_msg, None)
if decoded.cmd() not in self.async_msg_ids:
- print("Unexpected msg id done while checking for ntf", decoded)
+ print("Unexpected msg id while checking for ntf", decoded)
continue
self.handle_ntf(decoded)
+ def poll_ntf(self, duration=None):
+ start_time = time.time()
+ selector = selectors.DefaultSelector()
+ selector.register(self.sock, selectors.EVENT_READ)
+
+ while True:
+ try:
+ yield self.async_msg_queue.get_nowait()
+ except queue.Empty:
+ if duration is not None:
+ timeout = start_time + duration - time.time()
+ if timeout <= 0:
+ return
+ else:
+ timeout = None
+ events = selector.select(timeout)
+ if events:
+ self.check_ntf()
+
def operation_do_attributes(self, name):
"""
For a given operation name, find and return a supported
The notification handling in ynl is currently very simple, using sleep() to wait a period of time and then handling all the buffered messages in a single batch. This patch adds async notification handling so that messages can be processed as they are received. This makes it possible to use ynl as a library that supplies notifications in a timely manner. - Add poll_ntf() to be a generator that yields 1 notification at a time and blocks until a notification is available. - Add a --duration parameter to the CLI, with --sleep as an alias. ./tools/net/ynl/cli.py \ --spec <SPEC> --subscribe <TOPIC> [ --duration <SECS> ] The cli will report any notifications for duration seconds and then exit. If duration is not specified, then it will poll forever, until interrupted. Here is an example python snippet that shows how to use ynl as a library for receiving notifications: ynl = YnlFamily(f"{dir}/rt_route.yaml") ynl.ntf_subscribe('rtnlgrp-ipv4-route') for event in ynl.poll_ntf(): handle(event) Signed-off-by: Donald Hunter <donald.hunter@gmail.com> --- tools/net/ynl/cli.py | 16 +++++++++------- tools/net/ynl/lib/ynl.py | 28 +++++++++++++++++++++++++--- 2 files changed, 34 insertions(+), 10 deletions(-)