Hacktoberfest 2026: le issue che i maintainer hanno segnato per ottobre, aperte e adatte ai principianti. Sfoglia le issue Hacktoberfest

[EventHubs] PartitionClient publishes no thread safety contract for a concurrent Close

Aperta
  • Qualcosa non va?
#7,338 0 commenti 0 reazioni 0 assegnatari Vedi su GitHub

I maintainer di solito rispondono entro 1 giorno

Nessuno ha ancora preso questa issue.

Valutazione

Difficoltà
5/5
Tempo stimato
Più di una settimana
Idoneità per principianti
35/100
Tipo di issue
Bug
Chiarezza
Abbastanza chiara
Stato di attività
Tranquilla
Stack tecnologico
azure, cpp
Ambito
api, backend-api-design

Direzione di ricerca

Inizia dalla documentazione della classe PartitionClient in sdk/eventhubs/azure-messaging-eventhubs/inc/azure/messaging/eventhubs/partition_client.hpp:55-59, quindi esamina Close, ReceiveEvents e RebuildReceiver in sdk/eventhubs/azure-messaging-eventhubs/src/partition_client.cpp nelle posizioni indicate. Confronta la documentazione di ConsumerClient e il README di Event Hubs e consulta la linea guida dell’Azure SDK sulla thread-safety. Il lavoro è completo quando il contratto di concorrenza scelto è documentato e l’implementazione lo rispetta in modo coerente, senza la race condition segnalata né la finestra receiver-after-Close.

Scritto dal modello di indicizzazione a partire dal testo della issue.

Descrizione

Client Event Hubs

Summary

PartitionClient documents no thread safety contract. A Close that runs at the same time as ReceiveEvents on one instance is a data race on m_receiver, and it can leave an open receiver attached after Close returned.

Motivation

m_receiver is a value wrapper that holds a non-atomic std::shared_ptr (sdk/core/azure-core-amqp/inc/azure/core/amqp/internal/message_receiver.hpp:191). Close reads that pointer at sdk/eventhubs/azure-messaging-eventhubs/src/partition_client.cpp:272 and RebuildReceiver writes it at :303, with no synchronization, so concurrent calls are undefined behavior. There is also a window between the closed test at :412 and the assignment at :303: a Close that lands inside it lets the rebuild attach a new receiver after Close returned. ReceiveEvents also mutates m_lastReceivedOffset (:356) and m_pendingError (:396, :480) with no lock. The exposure predates PR #7337; on feat/link-reattach the recover loop rebuilds with no closed test at all. The Azure SDK for C++ guidelines state "DO be thread-safe. All public members of the client type must be safe to call from multiple threads concurrently", and this class does not meet that today. The class doc at sdk/eventhubs/azure-messaging-eventhubs/inc/azure/messaging/eventhubs/partition_client.hpp:55-59, the ConsumerClient doc, and the Event Hubs README say nothing about threads, so a caller has no stated contract to follow.

Proposal

Decide the contract first, then make the code match it. Two options are open. The first option documents PartitionClient as safe for one thread at a time and states that a caller must not call Close while ReceiveEvents runs. The second option meets the guideline: move the closed state into the receiver implementation as a latch, or swap the implementation pointer atomically, so Close and a rebuild cannot race. A mutex around the closed test and the rebuild does not work, because Close would block uninterruptibly while RebuildReceiver holds the lock across a network attach, and protecting the receiver reads at :492 and :511 would hold the lock across WaitForIncomingMessage for the full read deadline.

Found while reviewing #7337, which fixes the sequential case in #7334.

Lingua principale
C++
Stelle
206
Fork
177
Merge medio
2g 10h
PR unite (30g)
34

Preparare l'ambiente

Come iniziare

  1. Leggi tutta la issue e poi la guida ai contributi del progetto.
  2. Commenta sulla issue per dire che te ne occupi tu — evita che due persone facciano lo stesso lavoro.
  3. Fai un fork del repository e lavora su un branch.
  4. Apri una pull request che faccia riferimento al numero della issue.

Altre issue di Azure/azure-sdk-for-cpp

Tutte le issue di Azure/azure-sdk-for-cpp

Issue simili

Altre issue su C++

Ricevi le nuove issue nella tua casella

Un breve riepilogo di issue GitHub adatte ai principianti.