1 files changed, 33 insertions, 0 deletions
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 53a2c6b9d5..5d782faa60 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -669,6 +669,9 @@ private:
     static std::atomic<bool> fFlushScheduled;
     std::atomic<bool> fAbortRescan;
     std::atomic<bool> fScanningWallet;
+    std::mutex mutexScanning;
+    friend class WalletRescanReserver;
+
 
     /**
      * Select a set of coins such that nValueRet >= nTargetValue and at least
@@ -1263,4 +1266,34 @@ CTxDestination GetDestinationForKey(const CPubKey& key, OutputType);
 /** Get all destinations (potentially) supported by the wallet for the given key. */
 std::vector<CTxDestination> GetAllDestinationsForKey(const CPubKey& key);
 
+/** RAII object to check and reserve a wallet rescan */
+class WalletRescanReserver
+{
+private:
+    CWalletRef m_wallet;
+    bool m_could_reserve;
+public:
+    explicit WalletRescanReserver(CWalletRef w) : m_wallet(w), m_could_reserve(false) {}
+
+    bool reserve()
+    {
+        assert(!m_could_reserve);
+        std::lock_guard<std::mutex> lock(m_wallet->mutexScanning);
+        if (m_wallet->fScanningWallet) {
+            return false;
+        }
+        m_wallet->fScanningWallet = true;
+        m_could_reserve = true;
+        return true;
+    }
+
+    ~WalletRescanReserver()
+    {
+        std::lock_guard<std::mutex> lock(m_wallet->mutexScanning);
+        if (m_could_reserve) {
+            m_wallet->fScanningWallet = false;
+        }
+    }
+};
+
 #endif // BITCOIN_WALLET_WALLET_H