1 files changed, 42 insertions, 34 deletions

diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
index 643bb58d56..0b3cd08e22 100644
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -148,47 +148,53 @@ class LockImpl : public Chain::Lock, public UniqueLock<RecursiveMutex>
     using UniqueLock::UniqueLock;
 };
 
-class NotificationsHandlerImpl : public Handler, CValidationInterface
+class NotificationsProxy : public CValidationInterface
 {
 public:
-    explicit NotificationsHandlerImpl(Chain& chain, Chain::Notifications& notifications)
-        : m_chain(chain), m_notifications(&notifications)
-    {
-        RegisterValidationInterface(this);
-    }
-    ~NotificationsHandlerImpl() override { disconnect(); }
-    void disconnect() override
-    {
-        if (m_notifications) {
-            m_notifications = nullptr;
-            UnregisterValidationInterface(this);
-        }
-    }
+    explicit NotificationsProxy(std::shared_ptr<Chain::Notifications> notifications)
+        : m_notifications(std::move(notifications)) {}
+    virtual ~NotificationsProxy() = default;
     void TransactionAddedToMempool(const CTransactionRef& tx) override
     {
-        m_notifications->TransactionAddedToMempool(tx);
+        m_notifications->transactionAddedToMempool(tx);
     }
     void TransactionRemovedFromMempool(const CTransactionRef& tx) override
     {
-        m_notifications->TransactionRemovedFromMempool(tx);
+        m_notifications->transactionRemovedFromMempool(tx);
     }
-    void BlockConnected(const std::shared_ptr<const CBlock>& block,
-        const CBlockIndex* index,
-        const std::vector<CTransactionRef>& tx_conflicted) override
+    void BlockConnected(const std::shared_ptr<const CBlock>& block, const CBlockIndex* index) override
     {
-        m_notifications->BlockConnected(*block, tx_conflicted, index->nHeight);
+        m_notifications->blockConnected(*block, index->nHeight);
     }
     void BlockDisconnected(const std::shared_ptr<const CBlock>& block, const CBlockIndex* index) override
     {
-        m_notifications->BlockDisconnected(*block, index->nHeight);
+        m_notifications->blockDisconnected(*block, index->nHeight);
     }
     void UpdatedBlockTip(const CBlockIndex* index, const CBlockIndex* fork_index, bool is_ibd) override
     {
-        m_notifications->UpdatedBlockTip();
+        m_notifications->updatedBlockTip();
+    }
+    void ChainStateFlushed(const CBlockLocator& locator) override { m_notifications->chainStateFlushed(locator); }
+    std::shared_ptr<Chain::Notifications> m_notifications;
+};
+
+class NotificationsHandlerImpl : public Handler
+{
+public:
+    explicit NotificationsHandlerImpl(std::shared_ptr<Chain::Notifications> notifications)
+        : m_proxy(std::make_shared<NotificationsProxy>(std::move(notifications)))
+    {
+        RegisterSharedValidationInterface(m_proxy);
+    }
+    ~NotificationsHandlerImpl() override { disconnect(); }
+    void disconnect() override
+    {
+        if (m_proxy) {
+            UnregisterSharedValidationInterface(m_proxy);
+            m_proxy.reset();
+        }
     }
-    void ChainStateFlushed(const CBlockLocator& locator) override { m_notifications->ChainStateFlushed(locator); }
-    Chain& m_chain;
-    Chain::Notifications* m_notifications;
+    std::shared_ptr<NotificationsProxy> m_proxy;
 };
 
 class RpcHandlerImpl : public Handler
@@ -236,11 +242,10 @@ public:
     explicit ChainImpl(NodeContext& node) : m_node(node) {}
     std::unique_ptr<Chain::Lock> lock(bool try_lock) override
     {
-        auto result = MakeUnique<LockImpl>(::cs_main, "cs_main", __FILE__, __LINE__, try_lock);
-        if (try_lock && result && !*result) return {};
-        // std::move necessary on some compilers due to conversion from
-        // LockImpl to Lock pointer
-        return std::move(result);
+        auto lock = MakeUnique<LockImpl>(::cs_main, "cs_main", __FILE__, __LINE__, try_lock);
+        if (try_lock && lock && !*lock) return {};
+        std::unique_ptr<Chain::Lock> result = std::move(lock); // Temporary to avoid CWG 1579
+        return result;
     }
     bool findBlock(const uint256& hash, CBlock* block, int64_t* time, int64_t* time_max) override
     {
@@ -280,7 +285,10 @@ public:
         auto it = ::mempool.GetIter(txid);
         return it && (*it)->GetCountWithDescendants() > 1;
     }
-    bool broadcastTransaction(const CTransactionRef& tx, std::string& err_string, const CAmount& max_tx_fee, bool relay) override
+    bool broadcastTransaction(const CTransactionRef& tx,
+        const CAmount& max_tx_fee,
+        bool relay,
+        std::string& err_string) override
     {
         const TransactionError err = BroadcastTransaction(m_node, tx, err_string, max_tx_fee, relay, /*wait_callback*/ false);
         // Chain clients only care about failures to accept the tx to the mempool. Disregard non-mempool related failures.
@@ -342,9 +350,9 @@ public:
     {
         ::uiInterface.ShowProgress(title, progress, resume_possible);
     }
-    std::unique_ptr<Handler> handleNotifications(Notifications& notifications) override
+    std::unique_ptr<Handler> handleNotifications(std::shared_ptr<Notifications> notifications) override
     {
-        return MakeUnique<NotificationsHandlerImpl>(*this, notifications);
+        return MakeUnique<NotificationsHandlerImpl>(std::move(notifications));
     }
     void waitForNotificationsIfTipChanged(const uint256& old_tip) override
     {
@@ -368,7 +376,7 @@ public:
     {
         LOCK2(::cs_main, ::mempool.cs);
         for (const CTxMemPoolEntry& entry : ::mempool.mapTx) {
-            notifications.TransactionAddedToMempool(entry.GetSharedTx());
+            notifications.transactionAddedToMempool(entry.GetSharedTx());
         }
     }
     NodeContext& m_node;