Merge #13106: Simplify semantics of ChainStateFlushed callback

9cb6cdc Simplify semantics of ChainStateFlushed callback (Matt Corallo)
50b6533 scripted-diff: Rename SetBestChain callback ChainStateFlushed (Matt Corallo)

Pull request description:

  Previously, ChainStateFlushed would fire either if a full flush
  completed (which can happen due to memory limits, forced flush, or
  on its own DATABASE_WRITE_INTERVAL timer) *or* on a
  ChainStateFlushed-specific DATABASE_WRITE_INTERVAL timer. This is
  both less clear for clients (as there are no guarantees about a
  flush having actually happened prior to the call), and reults in
  extra flushes not clearly intended by the code. We drop the second
  case, providing a strong guarantee without removing the periodit
  timer-based flushing.

  This is a follow-up to discussion in #11857.

Tree-SHA512: 22ba3a0954d265d28413dbf87040790ca5b439820ee7bbadab14028295ec190de82ce5cd664426c82e58b706dc84278868026fa8d066702eb6e6962c9ace1f8e

1 files changed, 7 insertions, 11 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index 14257d78f..1b9e98275 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -2066,13 +2066,12 @@ bool static FlushStateToDisk(const CChainParams& chainparams, CValidationState &
     LOCK(cs_main);
     static int64_t nLastWrite = 0;
     static int64_t nLastFlush = 0;
-    static int64_t nLastSetChain = 0;
     std::set<int> setFilesToPrune;
-    bool fFlushForPrune = false;
-    bool fDoFullFlush = false;
-    int64_t nNow = 0;
+    bool full_flush_completed = false;
     try {
     {
+        bool fFlushForPrune = false;
+        bool fDoFullFlush = false;
         LOCK(cs_LastBlockFile);
         if (fPruneMode && (fCheckForPruning || nManualPruneHeight > 0) && !fReindex) {
             if (nManualPruneHeight > 0) {
@@ -2089,7 +2088,7 @@ bool static FlushStateToDisk(const CChainParams& chainparams, CValidationState &
                 }
             }
         }
-        nNow = GetTimeMicros();
+        int64_t nNow = GetTimeMicros();
         // Avoid writing/flushing immediately after startup.
         if (nLastWrite == 0) {
             nLastWrite = nNow;
@@ -2097,9 +2096,6 @@ bool static FlushStateToDisk(const CChainParams& chainparams, CValidationState &
         if (nLastFlush == 0) {
             nLastFlush = nNow;
         }
-        if (nLastSetChain == 0) {
-            nLastSetChain = nNow;
-        }
         int64_t nMempoolSizeMax = gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
         int64_t cacheSize = pcoinsTip->DynamicMemoryUsage();
         int64_t nTotalSpace = nCoinCacheUsage + std::max<int64_t>(nMempoolSizeMax - nMempoolUsage, 0);
@@ -2156,12 +2152,12 @@ bool static FlushStateToDisk(const CChainParams& chainparams, CValidationState &
             if (!pcoinsTip->Flush())
                 return AbortNode(state, "Failed to write to coin database");
             nLastFlush = nNow;
+            full_flush_completed = true;
         }
     }
-    if (fDoFullFlush || ((mode == FlushStateMode::ALWAYS || mode == FlushStateMode::PERIODIC) && nNow > nLastSetChain + (int64_t)DATABASE_WRITE_INTERVAL * 1000000)) {
+    if (full_flush_completed) {
         // Update best block in wallet (so we can detect restored wallets).
-        GetMainSignals().SetBestChain(chainActive.GetLocator());
-        nLastSetChain = nNow;
+        GetMainSignals().ChainStateFlushed(chainActive.GetLocator());
     }
     } catch (const std::runtime_error& e) {
         return AbortNode(state, std::string("System error while flushing: ") + e.what());