DRIVERS-3256 Fix PortPool uniqueness when used in multiple threads

[ShaneHarvey]

DRIVERS-3256 Make Singleton thread safe to fix PortPool uniqueness

Note I could not reproduce the error reported in the ticket but my theory is that Singleton was not thread safe so it was possible that 2 servers started in 2 threads could create 2 different PortPool instances and therefor both yield the same port. A lock fixes this problem.

Update: I was able to reproduce the bug locally by using python3.13t and increasing the number of servers:

$ curl -XPOST --data "{\"id\": \"rs0\", \"members\": [{}, {}, {}, {}, {}, {}]}" "http://localhost:8889/v1/replica_sets"
...
pymongo.errors.OperationFailure: Found two member configurations with same host field, members.0.host == members.1.host == localhost:1025, full error: {'ok': 0.0, 'errmsg': 'Found two member configurations with same host field, members.0.host == members.1.host == localhost:1025', 'code': 93, 'codeName': 'InvalidReplicaSetConfig'}

PortPool itself is also not thread safe so I had to utilize a lock there as well.

[blink1073]

LGTM!

[blink1073]

Actually, can you update the changelog readme and the version so I can tag and release?

[ShaneHarvey]

Update: I was able to reproduce the bug locally by using python3.13t and increasing the number of servers:

curl -XPOST --data "{\"id\": \"rs0\", \"members\": [{}, {}, {}, {}, {}, {}]}" "http://localhost:8889/v1/replica_sets"
Traceback (most recent call last):
  File "/Users/shane/git/mongo-orchestration/mongo_orchestration/apps/__init__.py", line 66, in wrap
    return f(*arg, **kwd)
  File "/Users/shane/git/mongo-orchestration/mongo_orchestration/apps/replica_sets.py", line 80, in rs_create
    result = _rs_create(data)
  File "/Users/shane/git/mongo-orchestration/mongo_orchestration/apps/replica_sets.py", line 37, in _rs_create
    rs_id = ReplicaSets().create(params)
  File "/Users/shane/git/mongo-orchestration/mongo_orchestration/replica_sets.py", line 657, in create
    repl = ReplicaSet(rs_params)
  File "/Users/shane/git/mongo-orchestration/mongo_orchestration/replica_sets.py", line 95, in __init__
    if not self.repl_init(config):
           ~~~~~~~~~~~~~~^^^^^^^^
  File "/Users/shane/git/mongo-orchestration/mongo_orchestration/replica_sets.py", line 209, in repl_init
    result = self.connection(init_server).admin.command("replSetInitiate", config)
...
pymongo.errors.OperationFailure: Found two member configurations with same host field, members.0.host == members.1.host == localhost:1025, full error: {'ok': 0.0, 'errmsg': 'Found two member configurations with same host field, members.0.host == members.1.host == localhost:1025', 'code': 93, 'codeName': 'InvalidReplicaSetConfig'}

Spoiler is this bugfix doesn't resolve the issue. PortPool itself is not thread safe so we have to introduce a lock there as well.

[ShaneHarvey]

Resolved the race:

$ curl -XPOST --data "{\"id\": \"rs0\", \"members\": [{}, {}, {}, {}, {}, {}, {}]}" "http://localhost:8889/v1/replica_sets"
{"id": "rs0", "auth_key": null, "members": [{"_id": 0, ...}

Also updated the readme and version to 0.11.1.

[blink1073]

LGTM, thanks!