Merge bitcoin#15201: net: Add missing locking annotation for vNodes. …

…vNodes is guarded by cs_vNodes.

eea02be Add locking annotation for vNodes. vNodes is guarded by cs_vNodes. (practicalswift)

Pull request description:

  Add locking annotation for `vNodes`. `vNodes` is guarded by `cs_vNodes`.

Tree-SHA512: b1e18be22ba5b9dd153536380321b09b30a75a20575f975af9af94164f51982b32267ba0994e77c801513b59da05d923a974a9d2dfebdac48024c4bda98b53af

src/net.h

@@ -218,7 +218,18 @@ friend class CNode;
     CConnman(uint64_t seed0, uint64_t seed1);
     ~CConnman();
     bool Start(CScheduler& scheduler, const Options& options);
-    void Stop();
+
+    // TODO: Remove NO_THREAD_SAFETY_ANALYSIS. Lock cs_vNodes before reading the variable vNodes.
+    //
+    // When removing NO_THREAD_SAFETY_ANALYSIS be aware of the following lock order requirements:
+    // * CheckForStaleTipAndEvictPeers locks cs_main before indirectly calling GetExtraOutboundCount
+    //   which locks cs_vNodes.
+    // * ProcessMessage locks cs_main and g_cs_orphans before indirectly calling ForEachNode which
+    //   locks cs_vNodes.
+    //
+    // Thus the implicit locking order requirement is: (1) cs_main, (2) g_cs_orphans, (3) cs_vNodes.
+    void Stop() NO_THREAD_SAFETY_ANALYSIS;
+
     void Interrupt();
     bool GetNetworkActive() const { return fNetworkActive; };
     bool GetUseAddrmanOutgoing() const { return m_use_addrman_outgoing; };
@@ -572,7 +583,7 @@ friend class CNode;
     std::map<std::pair<Consensus::LLMQType, uint256>, std::set<uint256>> masternodeQuorumRelayMembers; // protected by cs_vPendingMasternodes
     std::set<uint256> masternodePendingProbes;
     mutable CCriticalSection cs_vPendingMasternodes;
-    std::vector<CNode*> vNodes;
+    std::vector<CNode*> vNodes GUARDED_BY(cs_vNodes);
     std::list<CNode*> vNodesDisconnected;
     std::unordered_map<SOCKET, CNode*> mapSocketToNode;
     mutable CCriticalSection cs_vNodes;