Wallet: Let the interval-flushing thread figure out the filename

src/wallet/wallet.cpp

@@ -3549,6 +3549,8 @@ bool CWallet::InitLoadWallet()
     return true;
 }
 
+std::atomic<bool> CWallet::fFlushThreadRunning(false);
+
 void CWallet::postInitProcess(boost::thread_group& threadGroup)
 {
     // Add wallet transactions that aren't already in a block to mempool
@@ -3556,7 +3558,9 @@ void CWallet::postInitProcess(boost::thread_group& threadGroup)
     ReacceptWalletTransactions();
 
     // Run a thread to flush wallet periodically
-    threadGroup.create_thread(boost::bind(&ThreadFlushWalletDB, boost::ref(this->strWalletFile)));
+    if (!CWallet::fFlushThreadRunning.exchange(true)) {
+        threadGroup.create_thread(ThreadFlushWalletDB);
+    }
 }
 
 bool CWallet::ParameterInteraction()

src/wallet/wallet.h

@@ -18,6 +18,7 @@
 #include "wallet/rpcwallet.h"
 
 #include <algorithm>
+#include <atomic>
 #include <map>
 #include <set>
 #include <stdexcept>
@@ -550,6 +551,8 @@ private:
 class CWallet : public CCryptoKeyStore, public CValidationInterface
 {
 private:
+    static std::atomic<bool> fFlushThreadRunning;
+
     /**
      * Select a set of coins such that nValueRet >= nTargetValue and at least
      * all coins from coinControl are selected; Never select unconfirmed coins

src/wallet/walletdb.cpp

@@ -768,7 +768,7 @@ DBErrors CWalletDB::ZapWalletTx(CWallet* pwallet, vector<CWalletTx>& vWtx)
     return DB_LOAD_OK;
 }
 
-void ThreadFlushWalletDB(const string& strFile)
+void ThreadFlushWalletDB()
 {
     // Make this thread recognisable as the wallet flushing thread
     RenameThread("bitcoin-wallet");
@@ -810,6 +810,7 @@ void ThreadFlushWalletDB(const string& strFile)
                 if (nRefCount == 0)
                 {
                     boost::this_thread::interruption_point();
+                    const std::string& strFile = pwalletMain->strWalletFile;
                     map<string, int>::iterator _mi = bitdb.mapFileUseCount.find(strFile);
                     if (_mi != bitdb.mapFileUseCount.end())
                     {

src/wallet/walletdb.h

@@ -182,6 +182,6 @@ private:
 
 };
 
-void ThreadFlushWalletDB(const std::string& strFile);
+void ThreadFlushWalletDB();
 
 #endif // BITCOIN_WALLET_WALLETDB_H