Merge pull request #3401

012ca1c LoadWallet: acquire cs_wallet mutex before clearing setKeyPool (Wladimir J. van der Laan)
9569168 Document cs_wallet lock and add AssertLockHeld (Wladimir J. van der Laan)
19a5676 Use mutex pointer instead of name for AssertLockHeld (Wladimir J. van der Laan)

src/wallet.h

@@ -105,6 +105,11 @@ private:
     int64_t nLastResend;
 
 public:
+    /// Main wallet lock.
+    /// This lock protects all the fields added by CWallet
+    ///   except for:
+    ///      fFileBacked (immutable after instantiation)
+    ///      strWalletFile (immutable after instantiation)
     mutable CCriticalSection cs_wallet;
 
     bool fFileBacked;
@@ -154,10 +159,11 @@ public:
     int64_t nTimeFirstKey;
 
     // check whether we are allowed to upgrade (or already support) to the named feature
-    bool CanSupportFeature(enum WalletFeature wf) { return nWalletMaxVersion >= wf; }
+    bool CanSupportFeature(enum WalletFeature wf) { AssertLockHeld(cs_wallet); return nWalletMaxVersion >= wf; }
 
     void AvailableCoins(std::vector<COutput>& vCoins, bool fOnlyConfirmed=true, const CCoinControl *coinControl = NULL) const;
     bool SelectCoinsMinConf(int64_t nTargetValue, int nConfMine, int nConfTheirs, std::vector<COutput> vCoins, std::set<std::pair<const CWalletTx*,unsigned int> >& setCoinsRet, int64_t& nValueRet) const;
+
     bool IsLockedCoin(uint256 hash, unsigned int n) const;
     void LockCoin(COutPoint& output);
     void UnlockCoin(COutPoint& output);
@@ -174,7 +180,7 @@ public:
     // Load metadata (used by LoadWallet)
     bool LoadKeyMetadata(const CPubKey &pubkey, const CKeyMetadata &metadata);
 
-    bool LoadMinVersion(int nVersion) { nWalletVersion = nVersion; nWalletMaxVersion = std::max(nWalletMaxVersion, nVersion); return true; }
+    bool LoadMinVersion(int nVersion) { AssertLockHeld(cs_wallet); nWalletVersion = nVersion; nWalletMaxVersion = std::max(nWalletMaxVersion, nVersion); return true; }
 
     // Adds an encrypted key to the store, and saves it to disk.
     bool AddCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret);
@@ -323,6 +329,7 @@ public:
 
     unsigned int GetKeyPoolSize()
     {
+        AssertLockHeld(cs_wallet); // setKeyPool
         return setKeyPool.size();
     }
 
@@ -335,7 +342,7 @@ public:
     bool SetMaxVersion(int nVersion);
 
     // get the current wallet format (the oldest client version guaranteed to understand this wallet)
-    int GetVersion() { return nWalletVersion; }
+    int GetVersion() { AssertLockHeld(cs_wallet); return nWalletVersion; }
 
     /** Address book entry changed.
      * @note called with lock cs_wallet held.