From 71de8a51dc614bea8f57771b126ad6959c2fe20e Mon Sep 17 00:00:00 2001
From: Stan Kladko <13399135+kladkogex@users.noreply.github.com>
Date: Fri, 21 Jun 2024 13:56:57 +0100
Subject: [PATCH] #1545 state locking

---
 libdevcore/LevelDB.cpp | 14 +++++---------
 libdevcore/LevelDB.h   | 11 +++++++----
 2 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/libdevcore/LevelDB.cpp b/libdevcore/LevelDB.cpp
index 7b65fe7b0..9a8660f21 100644
--- a/libdevcore/LevelDB.cpp
+++ b/libdevcore/LevelDB.cpp
@@ -30,10 +30,6 @@ namespace dev::db {
 
 unsigned c_maxOpenLeveldbFiles = 25;
 
-const size_t LevelDB::BATCH_CHUNK_SIZE = 10000;
-const size_t LevelDB::MAX_OLD_SNAPS_LIFETIME_MS = 10000;
-const size_t LevelDB::FORCE_CLOSE_TIME_MS = 3000;
-
 namespace {
 inline leveldb::Slice toLDBSlice( Slice _slice ) {
     return leveldb::Slice( _slice.data(), _slice.size() );
@@ -296,14 +292,14 @@ void LevelDB::reopenDataBaseIfNeeded() {
 
         auto startTimeMs = getCurrentTimeMs();
 
-        while (getCurrentTimeMs() <= startTimeMs + FORCE_CLOSE_TIME_MS) {
-            cleanOldSnapsUnsafe(FORCE_CLOSE_TIME_MS);
+        while (getCurrentTimeMs() <= startTimeMs + FORCE_SNAP_CLOSE_TIME_MS ) {
+            cleanUnusedOldSnapsUnsafe( FORCE_SNAP_CLOSE_TIME_MS );
         }
 
         if (oldSnaps.empty()) {
             // there are still open snaps. Close all of them not waiting for
             // eth_calls to complete by passing 0 as wait time
-            cleanOldSnapsUnsafe(0);
+            cleanUnusedOldSnapsUnsafe( 0 );
         }
 
         LDB_CHECK(oldSnaps.empty());
@@ -463,12 +459,12 @@ void LevelDB::createBlockSnap( uint64_t _blockId ) {
 
     // we clean unneeded old snaps that no-one used or that exist for more that max
     // lifetime we give for eth_calls to complete
-    cleanOldSnapsUnsafe( MAX_OLD_SNAPS_LIFETIME_MS );
+    cleanUnusedOldSnapsUnsafe( OLD_SNAP_LIFETIME_MS );
 }
 
 
 // this function should be called while holding database reopen lock
-void LevelDB::cleanOldSnapsUnsafe( uint64_t _maxSnapLifetimeMs ) {
+void LevelDB::cleanUnusedOldSnapsUnsafe( uint64_t _maxSnapLifetimeMs ) {
     std::unique_lock< std::shared_mutex > snapLock( m_snapMutex );
 
     //now we iterate over oldSnaps closing the ones that are not more in use
diff --git a/libdevcore/LevelDB.h b/libdevcore/LevelDB.h
index 6bfc32c34..082616901 100644
--- a/libdevcore/LevelDB.h
+++ b/libdevcore/LevelDB.h
@@ -120,9 +120,12 @@ class LevelDB : public DatabaseFace {
     std::shared_mutex m_snapMutex;
 
 
-    static const size_t BATCH_CHUNK_SIZE;
-    static const size_t MAX_OLD_SNAPS_LIFETIME_MS;
-    static const size_t FORCE_CLOSE_TIME_MS;
+    static constexpr size_t BATCH_CHUNK_SIZE = 10000;
+    // time after an existing old snap will be closed if no-one is using it
+    static const size_t OLD_SNAP_LIFETIME_MS = 10000;
+    // time after an existing old snap will be closed it is used in eth_call
+    // this will cause the eth_call to return an error
+    static const size_t FORCE_SNAP_CLOSE_TIME_MS = 3000;
 
     class SharedDBGuard {
         const LevelDB& m_levedlDB;
@@ -161,7 +164,7 @@ class LevelDB : public DatabaseFace {
     };
     void openDBInstanceUnsafe();
     void reopenDataBaseIfNeeded();
-    void cleanOldSnapsUnsafe( uint64_t _maxSnapLifetimeMs );
+    void cleanUnusedOldSnapsUnsafe( uint64_t _maxSnapLifetimeMs );
 };
 
 }  // namespace dev::db