Merge bitcoin#12287: Optimise lock behaviour for GuessVerificationProgress()

90ba2df Fix missing cs_main lock for GuessVerificationProgress() (Jonas Schnelli)

Pull request description:

  `GuessVerificationProgress()` needs `cs_main` due to accessing the `pindex->nChainTx`.
  This adds a `AssertLockHeld` in `GuessVerificationProgress()` and adds the missing locks in...
  * `LoadChainTip()`
  * `ScanForWalletTransactions()` (got missed in bitcoin#11281)
  * GUI, `ClientModel::getVerificationProgress()` <--- **this may have GUI performance impacts**, but could be relaxed later with a cache or something more efficient.

Tree-SHA512: 13302946571422375f32af8e396b9d2c1180f2693ea363aeba9e98c8266ddec64fe7862bfdcbb5a93a4b12165a61eec1e51e4e7d7a8515fa50879095dc163412

Author: jonasschnelli

src/qt/clientmodel.cpp

@@ -174,9 +174,9 @@ size_t ClientModel::getInstantSentLockCount() const
 double ClientModel::getVerificationProgress(const CBlockIndex *tipIn) const
 {
     CBlockIndex *tip = const_cast<CBlockIndex *>(tipIn);
+    LOCK(cs_main);
     if (!tip)
     {
-        LOCK(cs_main);
         tip = chainActive.Tip();
     }
     return GuessVerificationProgress(Params().TxData(), tip);

src/validation.cpp

@@ -4989,6 +4989,7 @@ bool DumpMempool(void)
 }
 
 //! Guess how far we are in the verification process at the given block index
+//! require cs_main if pindex has not been validated yet (because nChainTx might be unset)
 double GuessVerificationProgress(const ChainTxData& data, const CBlockIndex *pindex) {
     if (pindex == nullptr)
         return 0.0;

src/wallet/wallet.cpp

@@ -2065,20 +2065,15 @@ CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, CBlock
             dProgressStart = GuessVerificationProgress(chainParams.TxData(), pindex);
             dProgressTip = GuessVerificationProgress(chainParams.TxData(), tip);
         }
+        double gvp = dProgressStart;
         while (pindex && !fAbortRescan)
         {
             if (pindex->nHeight % 100 == 0 && dProgressTip - dProgressStart > 0.0) {
-                double gvp = 0;
-                {
-                    LOCK(cs_main);
-                    gvp = GuessVerificationProgress(chainParams.TxData(), pindex);
-                }
                 ShowProgress(_("Rescanning..."), std::max(1, std::min(99, (int)((gvp - dProgressStart) / (dProgressTip - dProgressStart) * 100))));
             }
             if (GetTime() >= nNow + 60) {
                 nNow = GetTime();
-                LOCK(cs_main);
-                LogPrintf("Still rescanning. At block %d. Progress=%f\n", pindex->nHeight, GuessVerificationProgress(chainParams.TxData(), pindex));
+                LogPrintf("Still rescanning. At block %d. Progress=%f\n", pindex->nHeight, gvp);
             }
 
             CBlock block;
@@ -2102,6 +2097,7 @@ CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, CBlock
             {
                 LOCK(cs_main);
                 pindex = chainActive.Next(pindex);
+                gvp = GuessVerificationProgress(chainParams.TxData(), pindex);
                 if (tip != chainActive.Tip()) {
                     tip = chainActive.Tip();
                     // in case the tip has changed, update progress max
@@ -2110,7 +2106,7 @@ CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, CBlock
             }
         }
         if (pindex && fAbortRescan) {
-            LogPrintf("Rescan aborted at block %d. Progress=%f\n", pindex->nHeight, GuessVerificationProgress(chainParams.TxData(), pindex));
+            LogPrintf("Rescan aborted at block %d. Progress=%f\n", pindex->nHeight, gvp);
         }
         ShowProgress(_("Rescanning..."), 100); // hide progress dialog in GUI
     }