fix all cases with clocks

This commit is contained in:
holger krekel
2024-12-17 16:58:37 +01:00
parent a54f1390aa
commit b0a08cd1b2

View File

@@ -16,14 +16,23 @@ class Relay:
self.peers[newpeer.id] = newpeer
return self.peers.values()
def dump(self, title):
print(f"# {title}")
for peer_id, peer in self.peers.items():
pending = sum(len(x) for x in peer.from2mailbox.values())
members = ",".join(peer.members)
print(f"{peer_id} clock={peer.current_clock} members={members} pending={pending}")
print()
def receive_all(self, peers=None):
peers = peers if peers else self.peers.values()
peers = peers if peers is not None else list(self.peers.values())
for peer in peers:
# drain peer mailbox by reading messages from each sender separately
for from_peer in self.peers.values():
for msg in peer.from2mailbox.pop(from_peer, []):
msg.receive_imf(peer)
peer.current_clock = max(peer.current_clock, msg.clock) + 1
pending = peer.from2mailbox.pop(from_peer, [])
if from_peer.id != peer.id:
for msg in pending:
msg.receive(peer)
def assert_same_members(self):
peers = list(self.peers.values())
@@ -36,9 +45,9 @@ class Relay:
class Message:
def __init__(self, sender, **payload):
self.sender = sender
self.recipients = list(sender.members)
self.relay = sender.relay
self.payload = payload
self.recipients = set(sender.members)
sender.current_clock += self.inc
self.clock = sender.current_clock
def __repr__(self):
@@ -47,28 +56,59 @@ class Message:
def send(self):
for peer_id in self.sender.members:
peer = self.relay.peers[peer_id]
peer = self.sender.relay.peers[peer_id]
peer.from2mailbox.setdefault(self.sender, []).append(self)
class AddMemberMessage(Message):
def receive_imf(self, peer):
peer.members.add(self.payload["newmember"])
peer.members.update(self.recipients)
inc = 1
def __init__(self, sender, member):
sender.members.add(member)
super().__init__(sender, member=member)
def receive(self, peer):
if not peer.members:
peer.members = self.recipients.copy()
peer.current_clock = self.clock
return
peer.members.add(self.payload["member"])
if peer.current_clock < self.clock:
peer.members.update(self.recipients)
peer.current_clock = self.clock
class DelMemberMessage(Message):
def receive_imf(self, peer):
inc = 1
def send(self):
super().send()
self.sender.members.remove(self.payload["member"])
def receive(self, peer):
member = self.payload["member"]
if member in peer.members:
peer.members.remove(member)
if peer.current_clock <= self.clock:
peer.members.remove(member)
peer.current_clock = self.clock
class ChatMessage(Message):
def receive_imf(self, peer):
inc = 0
def receive(self, peer):
print(f"receive {peer.id} clock={peer.current_clock} msgclock={self.clock}")
if peer.current_clock < self.clock:
print(f"{peer.id} is outdated, using incoming memberslist")
peer.members = set(self.recipients)
peer.current_clock = self.clock
print(f"-> NEWCLOCK: {peer.current_clock}")
elif peer.current_clock == self.clock:
if peer.members != set(self.recipients):
print(f"{peer.id} has different members than incoming same-clock message")
peer.members = set(self.recipients)
peer.current_clock = self.clock + 1
class Peer:
@@ -95,24 +135,9 @@ class Peer:
assert not self.members
self.members.add(self.id)
for peer in peers:
self.send_add_member(peer.id)
AddMemberMessage(self, member=peer.id).send()
self.relay.receive_all()
def send_add_member(self, newmember):
assert isinstance(newmember, str)
self.members.add(newmember)
AddMemberMessage(self, newmember=newmember).send()
def send_del_member(self, member):
assert isinstance(member, str)
assert member in self.members
msg = DelMemberMessage(self, member=member)
msg.send()
self.members.remove(member)
def send_chatmessage(self):
ChatMessage(self).send()
### Tests
@@ -125,12 +150,12 @@ def test_add_and_remove(relay):
assert p0.members == p1.members == set([p0.id, p1.id])
# add members
p0.send_add_member(p2.id)
p0.send_add_member(p3.id)
AddMemberMessage(p0, member=p2.id).send()
AddMemberMessage(p0, member=p3.id).send()
relay.receive_all()
relay.assert_same_members()
p3.send_del_member(p0.id)
DelMemberMessage(p3, member=p0.id).send()
relay.receive_all()
relay.assert_same_members()
@@ -140,16 +165,14 @@ def test_concurrent_add(relay):
p0.immediate_create_group([p1])
# concurrent adding and then let base set send a chat message
p1.send_add_member(p2.id)
p0.send_add_member(p3.id)
# now p0 and p1 send a regular message
p0.send_chatmessage()
p1.send_chatmessage()
AddMemberMessage(p1, member=p2.id).send()
AddMemberMessage(p0, member=p3.id).send()
relay.receive_all()
relay.dump("after concurrent add")
# only now do p0 and p1 know of each others additions
# so p0 or p1 needs to send another message to get consistent membership
p0.send_chatmessage()
ChatMessage(p0).send()
relay.receive_all()
relay.assert_same_members()
@@ -159,17 +182,20 @@ def test_add_remove_and_stale_old_suddenly_sends(relay):
p0.immediate_create_group([p1, p2, p3])
# p3 is offline and a member get deleted
p0.send_del_member(p2.id)
# p3 is offline and p0 deletes p2
DelMemberMessage(p0, member=p2.id).send()
relay.receive_all([p0, p1, p2])
relay.dump("p0 has deleted p3")
# p3 sends a message with old memberlist and goes online
p3.send_chatmessage()
ChatMessage(p3).send()
relay.receive_all()
relay.dump("after p3 sent an old memberlist")
# p0 sends a message which should update all peers' members
p0.send_chatmessage()
ChatMessage(p0).send()
relay.receive_all()
relay.dump("final")
relay.assert_same_members()
assert p0.members == set([p0.id, p1.id, p3.id])