4 files changed, 40 insertions, 17 deletions

diff --git a/src/interfaces/node.cpp b/src/interfaces/node.cpp
index 9e603a12cd..bd1b36fea5 100644
--- a/src/interfaces/node.cpp
+++ b/src/interfaces/node.cpp
@@ -27,6 +27,7 @@
 #include <sync.h>
 #include <txmempool.h>
 #include <ui_interface.h>
+#include <util/ref.h>
 #include <util/system.h>
 #include <util/translation.h>
 #include <validation.h>
@@ -80,14 +81,22 @@ public:
     bool appInitMain() override
     {
         m_context.chain = MakeChain(m_context);
-        return AppInitMain(m_context);
+        return AppInitMain(m_context_ref, m_context);
     }
     void appShutdown() override
     {
         Interrupt(m_context);
         Shutdown(m_context);
     }
-    void startShutdown() override { StartShutdown(); }
+    void startShutdown() override
+    {
+        StartShutdown();
+        // Stop RPC for clean shutdown if any of waitfor* commands is executed.
+        if (gArgs.GetBoolArg("-server", false)) {
+            InterruptRPC();
+            StopRPC();
+        }
+    }
     bool shutdownRequested() override { return ShutdownRequested(); }
     void mapPort(bool use_upnp) override
     {
@@ -186,6 +195,11 @@ public:
         LOCK(::cs_main);
         return ::ChainActive().Height();
     }
+    uint256 getBestBlockHash() override
+    {
+        const CBlockIndex* tip = WITH_LOCK(::cs_main, return ::ChainActive().Tip());
+        return tip ? tip->GetBlockHash() : Params().GenesisBlock().GetHash();
+    }
     int64_t getLastBlockTime() override
     {
         LOCK(::cs_main);
@@ -225,7 +239,7 @@ public:
     CFeeRate getDustRelayFee() override { return ::dustRelayFee; }
     UniValue executeRpc(const std::string& command, const UniValue& params, const std::string& uri) override
     {
-        JSONRPCRequest req;
+        JSONRPCRequest req(m_context_ref);
         req.params = params;
         req.strMethod = command;
         req.URI = uri;
@@ -308,21 +322,22 @@ public:
     }
     std::unique_ptr<Handler> handleNotifyBlockTip(NotifyBlockTipFn fn) override
     {
-        return MakeHandler(::uiInterface.NotifyBlockTip_connect([fn](bool initial_download, const CBlockIndex* block) {
-            fn(initial_download, block->nHeight, block->GetBlockTime(),
+        return MakeHandler(::uiInterface.NotifyBlockTip_connect([fn](SynchronizationState sync_state, const CBlockIndex* block) {
+            fn(sync_state, BlockTip{block->nHeight, block->GetBlockTime(), block->GetBlockHash()},
                 GuessVerificationProgress(Params().TxData(), block));
         }));
     }
     std::unique_ptr<Handler> handleNotifyHeaderTip(NotifyHeaderTipFn fn) override
     {
         return MakeHandler(
-            ::uiInterface.NotifyHeaderTip_connect([fn](bool initial_download, const CBlockIndex* block) {
-                fn(initial_download, block->nHeight, block->GetBlockTime(),
+            ::uiInterface.NotifyHeaderTip_connect([fn](SynchronizationState sync_state, const CBlockIndex* block) {
+                fn(sync_state, BlockTip{block->nHeight, block->GetBlockTime(), block->GetBlockHash()},
                     /* verification progress is unused when a header was received */ 0);
             }));
     }
     NodeContext* context() override { return &m_context; }
     NodeContext m_context;
+    util::Ref m_context_ref{m_context};
 };
 
 } // namespace
diff --git a/src/interfaces/node.h b/src/interfaces/node.h
index aef6b19458..0b7fb6736a 100644
--- a/src/interfaces/node.h
+++ b/src/interfaces/node.h
@@ -27,6 +27,7 @@ class Coin;
 class RPCTimerInterface;
 class UniValue;
 class proxyType;
+enum class SynchronizationState;
 enum class WalletCreationStatus;
 struct CNodeStateStats;
 struct NodeContext;
@@ -35,6 +36,7 @@ struct bilingual_str;
 namespace interfaces {
 class Handler;
 class Wallet;
+struct BlockTip;
 
 //! Top-level interface for a bitcoin node (bitcoind process).
 class Node
@@ -148,6 +150,9 @@ public:
     //! Get num blocks.
     virtual int getNumBlocks() = 0;
 
+    //! Get best block hash.
+    virtual uint256 getBestBlockHash() = 0;
+
     //! Get last block time.
     virtual int64_t getLastBlockTime() = 0;
 
@@ -249,12 +254,12 @@ public:
 
     //! Register handler for block tip messages.
     using NotifyBlockTipFn =
-        std::function<void(bool initial_download, int height, int64_t block_time, double verification_progress)>;
+        std::function<void(SynchronizationState, interfaces::BlockTip tip, double verification_progress)>;
     virtual std::unique_ptr<Handler> handleNotifyBlockTip(NotifyBlockTipFn fn) = 0;
 
     //! Register handler for header tip messages.
     using NotifyHeaderTipFn =
-        std::function<void(bool initial_download, int height, int64_t block_time, double verification_progress)>;
+        std::function<void(SynchronizationState, interfaces::BlockTip tip, double verification_progress)>;
     virtual std::unique_ptr<Handler> handleNotifyHeaderTip(NotifyHeaderTipFn fn) = 0;
 
     //! Return pointer to internal chain interface, useful for testing.
@@ -264,6 +269,13 @@ public:
 //! Return implementation of Node interface.
 std::unique_ptr<Node> MakeNode();
 
+//! Block tip (could be a header or not, depends on the subscribed signal).
+struct BlockTip {
+    int block_height;
+    int64_t block_time;
+    uint256 block_hash;
+};
+
 } // namespace interfaces
 
 #endif // BITCOIN_INTERFACES_NODE_H
diff --git a/src/interfaces/wallet.cpp b/src/interfaces/wallet.cpp
index 13b034936b..cec75030ad 100644
--- a/src/interfaces/wallet.cpp
+++ b/src/interfaces/wallet.cpp
@@ -351,14 +351,13 @@ public:
         }
         return result;
     }
-    bool tryGetBalances(WalletBalances& balances, int& num_blocks, bool force, int cached_num_blocks) override
+    bool tryGetBalances(WalletBalances& balances, uint256& block_hash) override
     {
         TRY_LOCK(m_wallet->cs_wallet, locked_wallet);
         if (!locked_wallet) {
             return false;
         }
-        num_blocks = m_wallet->GetLastBlockHeight();
-        if (!force && num_blocks == cached_num_blocks) return false;
+        block_hash = m_wallet->GetLastBlockHash();
         balances = getBalances();
         return true;
     }
diff --git a/src/interfaces/wallet.h b/src/interfaces/wallet.h
index f35335c69f..67569a3e55 100644
--- a/src/interfaces/wallet.h
+++ b/src/interfaces/wallet.h
@@ -202,11 +202,8 @@ public:
     //! Get balances.
     virtual WalletBalances getBalances() = 0;
 
-    //! Get balances if possible without waiting for chain and wallet locks.
-    virtual bool tryGetBalances(WalletBalances& balances,
-        int& num_blocks,
-        bool force,
-        int cached_num_blocks) = 0;
+    //! Get balances if possible without blocking.
+    virtual bool tryGetBalances(WalletBalances& balances, uint256& block_hash) = 0;
 
     //! Get balance.
     virtual CAmount getBalance() = 0;