Call RewindBlockIndex without cs_main held

Author: sipa

src/init.cpp

@@ -1474,11 +1474,11 @@ bool AppInitMain(InitInterfaces& interfaces)
 
         uiInterface.InitMessage(_("Loading block index..."));
 
-        LOCK(cs_main);
-
         do {
             const int64_t load_block_index_start_time = GetTimeMillis();
+            bool is_coinsview_empty;
             try {
+                LOCK(cs_main);
                 UnloadBlockIndex();
                 pcoinsTip.reset();
                 pcoinsdbview.reset();
@@ -1550,7 +1550,7 @@ bool AppInitMain(InitInterfaces& interfaces)
                 // The on-disk coinsdb is now in a good state, create the cache
                 pcoinsTip.reset(new CCoinsViewCache(pcoinscatcher.get()));
 
-                bool is_coinsview_empty = fReset || fReindexChainState || pcoinsTip->GetBestBlock().IsNull();
+                is_coinsview_empty = fReset || fReindexChainState || pcoinsTip->GetBestBlock().IsNull();
                 if (!is_coinsview_empty) {
                     // LoadChainTip sets chainActive based on pcoinsTip's best block
                     if (!LoadChainTip(chainparams)) {
@@ -1559,18 +1559,25 @@ bool AppInitMain(InitInterfaces& interfaces)
                     }
                     assert(chainActive.Tip() != nullptr);
                 }
+            } catch (const std::exception& e) {
+                LogPrintf("%s\n", e.what());
+                strLoadError = _("Error opening block database");
+                break;
+            }
 
-                if (!fReset) {
-                    // Note that RewindBlockIndex MUST run even if we're about to -reindex-chainstate.
-                    // It both disconnects blocks based on chainActive, and drops block data in
-                    // mapBlockIndex based on lack of available witness data.
-                    uiInterface.InitMessage(_("Rewinding blocks..."));
-                    if (!RewindBlockIndex(chainparams)) {
-                        strLoadError = _("Unable to rewind the database to a pre-fork state. You will need to redownload the blockchain");
-                        break;
-                    }
+            if (!fReset) {
+                // Note that RewindBlockIndex MUST run even if we're about to -reindex-chainstate.
+                // It both disconnects blocks based on chainActive, and drops block data in
+                // mapBlockIndex based on lack of available witness data.
+                uiInterface.InitMessage(_("Rewinding blocks..."));
+                if (!RewindBlockIndex(chainparams)) {
+                    strLoadError = _("Unable to rewind the database to a pre-fork state. You will need to redownload the blockchain");
+                    break;
                 }
+            }
 
+            try {
+                LOCK(cs_main);
                 if (!is_coinsview_empty) {
                     uiInterface.InitMessage(_("Verifying blocks..."));
                     if (fHavePruned && gArgs.GetArg("-checkblocks", DEFAULT_CHECKBLOCKS) > MIN_BLOCKS_TO_KEEP) {