rfc: Synchronize validation interface registration

src/validationinterface.cpp

@@ -94,16 +94,22 @@ CMainSignals& GetMainSignals()
 }
 
 void RegisterValidationInterface(CValidationInterface* pwalletIn) {
-    ValidationInterfaceConnections& conns = g_signals.m_internals->m_connMainSignals[pwalletIn];
-    conns.UpdatedBlockTip = g_signals.m_internals->UpdatedBlockTip.connect(std::bind(&CValidationInterface::UpdatedBlockTip, pwalletIn, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3));
-    conns.TransactionAddedToMempool = g_signals.m_internals->TransactionAddedToMempool.connect(std::bind(&CValidationInterface::TransactionAddedToMempool, pwalletIn, std::placeholders::_1));
-    conns.BlockConnected = g_signals.m_internals->BlockConnected.connect(std::bind(&CValidationInterface::BlockConnected, pwalletIn, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3));
-    conns.BlockDisconnected = g_signals.m_internals->BlockDisconnected.connect(std::bind(&CValidationInterface::BlockDisconnected, pwalletIn, std::placeholders::_1));
-    conns.TransactionRemovedFromMempool = g_signals.m_internals->TransactionRemovedFromMempool.connect(std::bind(&CValidationInterface::TransactionRemovedFromMempool, pwalletIn, std::placeholders::_1));
-    conns.ChainStateFlushed = g_signals.m_internals->ChainStateFlushed.connect(std::bind(&CValidationInterface::ChainStateFlushed, pwalletIn, std::placeholders::_1));
-    conns.Broadcast = g_signals.m_internals->Broadcast.connect(std::bind(&CValidationInterface::ResendWalletTransactions, pwalletIn, std::placeholders::_1, std::placeholders::_2));
-    conns.BlockChecked = g_signals.m_internals->BlockChecked.connect(std::bind(&CValidationInterface::BlockChecked, pwalletIn, std::placeholders::_1, std::placeholders::_2));
-    conns.NewPoWValidBlock = g_signals.m_internals->NewPoWValidBlock.connect(std::bind(&CValidationInterface::NewPoWValidBlock, pwalletIn, std::placeholders::_1, std::placeholders::_2));
+    AssertLockNotHeld(cs_main);
+    std::promise<void> promise;
+    CallFunctionInValidationInterfaceQueue([&promise, pwalletIn] {
+        ValidationInterfaceConnections& conns = g_signals.m_internals->m_connMainSignals[pwalletIn];
+        conns.UpdatedBlockTip = g_signals.m_internals->UpdatedBlockTip.connect(std::bind(&CValidationInterface::UpdatedBlockTip, pwalletIn, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3));
+        conns.TransactionAddedToMempool = g_signals.m_internals->TransactionAddedToMempool.connect(std::bind(&CValidationInterface::TransactionAddedToMempool, pwalletIn, std::placeholders::_1));
+        conns.BlockConnected = g_signals.m_internals->BlockConnected.connect(std::bind(&CValidationInterface::BlockConnected, pwalletIn, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3));
+        conns.BlockDisconnected = g_signals.m_internals->BlockDisconnected.connect(std::bind(&CValidationInterface::BlockDisconnected, pwalletIn, std::placeholders::_1));
+        conns.TransactionRemovedFromMempool = g_signals.m_internals->TransactionRemovedFromMempool.connect(std::bind(&CValidationInterface::TransactionRemovedFromMempool, pwalletIn, std::placeholders::_1));
+        conns.ChainStateFlushed = g_signals.m_internals->ChainStateFlushed.connect(std::bind(&CValidationInterface::ChainStateFlushed, pwalletIn, std::placeholders::_1));
+        conns.Broadcast = g_signals.m_internals->Broadcast.connect(std::bind(&CValidationInterface::ResendWalletTransactions, pwalletIn, std::placeholders::_1, std::placeholders::_2));
+        conns.BlockChecked = g_signals.m_internals->BlockChecked.connect(std::bind(&CValidationInterface::BlockChecked, pwalletIn, std::placeholders::_1, std::placeholders::_2));
+        conns.NewPoWValidBlock = g_signals.m_internals->NewPoWValidBlock.connect(std::bind(&CValidationInterface::NewPoWValidBlock, pwalletIn, std::placeholders::_1, std::placeholders::_2));
+        promise.set_value();
+    });
+    promise.get_future().wait();
 }
 
 void UnregisterValidationInterface(CValidationInterface* pwalletIn) {

src/validationinterface.h

@@ -29,7 +29,7 @@ enum class MemPoolRemovalReason;
 // These functions dispatch to one or all registered wallets
 
 /** Register a wallet to receive updates from core */
-void RegisterValidationInterface(CValidationInterface* pwalletIn);
+void RegisterValidationInterface(CValidationInterface* pwalletIn) LOCKS_EXCLUDED(cs_main);
 /** Unregister a wallet from core */
 void UnregisterValidationInterface(CValidationInterface* pwalletIn);
 /** Unregister all wallets from core */

src/wallet/wallet.cpp

@@ -4293,6 +4293,7 @@ std::shared_ptr<CWallet> CWallet::CreateWalletFromFile(interfaces::Chain& chain,
     // Try to top up keypool. No-op if the wallet is locked.
     walletInstance->TopUpKeyPool();
 
+    {
     auto locked_chain = chain.lock();
     LOCK(walletInstance->cs_wallet);
 
@@ -4380,18 +4381,18 @@ std::shared_ptr<CWallet> CWallet::CreateWalletFromFile(interfaces::Chain& chain,
         }
     }
 
-    chain.loadWallet(interfaces::MakeWallet(walletInstance));
-
-    // Register with the validation interface. It's ok to do this after rescan since we're still holding locked_chain.
-    walletInstance->m_chain_notifications_handler = chain.handleNotifications(*walletInstance);
-
     walletInstance->SetBroadcastTransactions(gArgs.GetBoolArg("-walletbroadcast", DEFAULT_WALLETBROADCAST));
 
     {
         walletInstance->WalletLogPrintf("setKeyPool.size() = %u\n",      walletInstance->GetKeyPoolSize());
         walletInstance->WalletLogPrintf("mapWallet.size() = %u\n",       walletInstance->mapWallet.size());
         walletInstance->WalletLogPrintf("mapAddressBook.size() = %u\n",  walletInstance->mapAddressBook.size());
     }
+    }
+
+    chain.loadWallet(interfaces::MakeWallet(walletInstance));
+
+    walletInstance->m_chain_notifications_handler = chain.handleNotifications(*walletInstance);
 
     return walletInstance;
 }