From 735d9b5362aeca34c0e62006986fe9d82c24ca08 Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Wed, 8 Feb 2017 13:19:18 -0500
Subject: [PATCH] Use CScheduler for wallet flushing, remove
 ThreadFlushWalletDB

---
 src/init.cpp            |  2 +-
 src/wallet/wallet.cpp   |  9 +++++----
 src/wallet/wallet.h     |  6 +++---
 src/wallet/walletdb.cpp | 45 ++++++++++++++++++-----------------------
 src/wallet/walletdb.h   |  2 +-
 5 files changed, 30 insertions(+), 34 deletions(-)

diff --git a/src/init.cpp b/src/init.cpp
index a311ee7d8..280793c72 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1639,7 +1639,7 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
 
 #ifdef ENABLE_WALLET
     if (pwalletMain)
-        pwalletMain->postInitProcess(threadGroup);
+        pwalletMain->postInitProcess(scheduler);
 #endif
 
     return !fRequestShutdown;
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 02af1bf10..88dbb77ab 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -20,6 +20,7 @@
 #include "primitives/transaction.h"
 #include "script/script.h"
 #include "script/sign.h"
+#include "scheduler.h"
 #include "timedata.h"
 #include "txmempool.h"
 #include "util.h"
@@ -3754,17 +3755,17 @@ bool CWallet::InitLoadWallet()
     return true;
 }
 
-std::atomic<bool> CWallet::fFlushThreadRunning(false);
+std::atomic<bool> CWallet::fFlushScheduled(false);
 
-void CWallet::postInitProcess(boost::thread_group& threadGroup)
+void CWallet::postInitProcess(CScheduler& scheduler)
 {
     // Add wallet transactions that aren't already in a block to mempool
     // Do this here as mempool requires genesis block to be loaded
     ReacceptWalletTransactions();
 
     // Run a thread to flush wallet periodically
-    if (!CWallet::fFlushThreadRunning.exchange(true)) {
-        threadGroup.create_thread(ThreadFlushWalletDB);
+    if (!CWallet::fFlushScheduled.exchange(true)) {
+        scheduler.scheduleEvery(MaybeFlushWalletDB, 500);
     }
 }
 
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 65ad3e009..100793490 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -29,7 +29,6 @@
 #include <vector>
 
 #include <boost/shared_ptr.hpp>
-#include <boost/thread.hpp>
 
 extern CWallet* pwalletMain;
 
@@ -79,6 +78,7 @@ class CCoinControl;
 class COutput;
 class CReserveKey;
 class CScript;
+class CScheduler;
 class CTxMemPool;
 class CWalletTx;
 
@@ -593,7 +593,7 @@ private:
 class CWallet : public CCryptoKeyStore, public CValidationInterface
 {
 private:
-    static std::atomic<bool> fFlushThreadRunning;
+    static std::atomic<bool> fFlushScheduled;
 
     /**
      * Select a set of coins such that nValueRet >= nTargetValue and at least
@@ -1001,7 +1001,7 @@ public:
      * Wallet post-init setup
      * Gives the wallet a chance to register repetitive tasks and complete post-init tasks
      */
-    void postInitProcess(boost::thread_group& threadGroup);
+    void postInitProcess(CScheduler& scheduler);
 
     /* Wallets parameter interaction */
     static bool ParameterInteraction();
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index f894a365a..ae95fc4f2 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -777,38 +777,33 @@ DBErrors CWalletDB::ZapWalletTx(vector<CWalletTx>& vWtx)
     return DB_LOAD_OK;
 }
 
-void ThreadFlushWalletDB()
+void MaybeFlushWalletDB()
 {
-    // Make this thread recognisable as the wallet flushing thread
-    RenameThread("bitcoin-wallet");
-
-    static bool fOneThread;
-    if (fOneThread)
+    static std::atomic<bool> fOneThread;
+    if (fOneThread.exchange(true)) {
         return;
-    fOneThread = true;
-    if (!GetBoolArg("-flushwallet", DEFAULT_FLUSHWALLET))
+    }
+    if (!GetBoolArg("-flushwallet", DEFAULT_FLUSHWALLET)) {
         return;
+    }
 
-    unsigned int nLastSeen = CWalletDB::GetUpdateCounter();
-    unsigned int nLastFlushed = CWalletDB::GetUpdateCounter();
-    int64_t nLastWalletUpdate = GetTime();
-    while (true)
-    {
-        MilliSleep(500);
+    static unsigned int nLastSeen = CWalletDB::GetUpdateCounter();
+    static unsigned int nLastFlushed = CWalletDB::GetUpdateCounter();
+    static int64_t nLastWalletUpdate = GetTime();
 
-        if (nLastSeen != CWalletDB::GetUpdateCounter())
-        {
-            nLastSeen = CWalletDB::GetUpdateCounter();
-            nLastWalletUpdate = GetTime();
-        }
+    if (nLastSeen != CWalletDB::GetUpdateCounter())
+    {
+        nLastSeen = CWalletDB::GetUpdateCounter();
+        nLastWalletUpdate = GetTime();
+    }
 
-        if (nLastFlushed != CWalletDB::GetUpdateCounter() && GetTime() - nLastWalletUpdate >= 2)
-        {
-            const std::string& strFile = pwalletMain->strWalletFile;
-            if (CDB::PeriodicFlush(strFile))
-                nLastFlushed = CWalletDB::GetUpdateCounter();
-        }
+    if (nLastFlushed != CWalletDB::GetUpdateCounter() && GetTime() - nLastWalletUpdate >= 2)
+    {
+        const std::string& strFile = pwalletMain->strWalletFile;
+        if (CDB::PeriodicFlush(strFile))
+            nLastFlushed = CWalletDB::GetUpdateCounter();
     }
+    fOneThread = false;
 }
 
 //
diff --git a/src/wallet/walletdb.h b/src/wallet/walletdb.h
index 6b847cedb..85364c134 100644
--- a/src/wallet/walletdb.h
+++ b/src/wallet/walletdb.h
@@ -193,6 +193,6 @@ private:
     void operator=(const CWalletDB&);
 };
 
-void ThreadFlushWalletDB();
+void MaybeFlushWalletDB();
 
 #endif // BITCOIN_WALLET_WALLETDB_H