Merge bitcoin/bitcoin#30425: kernel: De-globalize static validation variables

51fa26239af9bbfd44029aaf595cb4c6a8d4a75d refactor: Mark some static global vars as const (TheCharlatan)
39f9b80fba85d9818222c4d76e99ea1a804f5dda refactor: De-globalize last notified header index (TheCharlatan)
3443943f86678eb27d9895f3871fcf3945eb1c4f refactor: De-globalize validation benchmark timekeeping (TheCharlatan)

Pull request description:

  In future, users of the kernel library might run multiple chainstates in parallel, or create and destroy multiple chainstates over the lifetime of a process. Having static, mutable variables could lead to state inconsistencies in these scenarios.

  ---
  This pull request is part of the [libbitcoinkernel project](https://github.com/bitcoin/bitcoin/issues/27587).

ACKs for top commit:
  dergoegge:
    Code review ACK 51fa26239af9bbfd44029aaf595cb4c6a8d4a75d
  maflcko:
    ACK 51fa26239af9bbfd44029aaf595cb4c6a8d4a75d 🍚
  tdb3:
    code review ACK 51fa26239af9bbfd44029aaf595cb4c6a8d4a75d

Tree-SHA512: da91aa7ffa343325cabb8764ef03c8358845662cf0ba8a6cc1dd38e40e5462d88734f2b459c2de8e7a041551eda9143d92487842609f7f30636f61a0cd3c57ee

4 files changed, 58 insertions, 55 deletions

diff --git a/src/core_read.cpp b/src/core_read.cpp
index 114f92fc45..0ba271a8d2 100644
--- a/src/core_read.cpp
+++ b/src/core_read.cpp
@@ -245,7 +245,7 @@ bool ParseHashStr(const std::string& strHex, uint256& result)
 
 util::Result<int> SighashFromStr(const std::string& sighash)
 {
-    static std::map<std::string, int> map_sighash_values = {
+    static const std::map<std::string, int> map_sighash_values = {
         {std::string("DEFAULT"), int(SIGHASH_DEFAULT)},
         {std::string("ALL"), int(SIGHASH_ALL)},
         {std::string("ALL|ANYONECANPAY"), int(SIGHASH_ALL|SIGHASH_ANYONECANPAY)},
diff --git a/src/script/descriptor.cpp b/src/script/descriptor.cpp
index 0987db194c..ae9dba6a50 100644
--- a/src/script/descriptor.cpp
+++ b/src/script/descriptor.cpp
@@ -116,13 +116,13 @@ std::string DescriptorChecksum(const Span<const char>& span)
      * As a result, within-group-of-32 errors count as 1 symbol, as do cross-group errors that don't affect
      * the position within the groups.
      */
-    static std::string INPUT_CHARSET =
+    static const std::string INPUT_CHARSET =
         "0123456789()[],'/*abcdefgh@:$%{}"
         "IJKLMNOPQRSTUVWXYZ&+-.;<=>?!^_|~"
         "ijklmnopqrstuvwxyzABCDEFGH`#\"\\ ";
 
     /** The character set for the checksum itself (same as bech32). */
-    static std::string CHECKSUM_CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l";
+    static const std::string CHECKSUM_CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l";
 
     uint64_t c = 1;
     int cls = 0;
diff --git a/src/validation.cpp b/src/validation.cpp
index 988df3802a..72ff24d584 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -2399,15 +2399,6 @@ static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const Ch
 }
 
 
-static SteadyClock::duration time_check{};
-static SteadyClock::duration time_forks{};
-static SteadyClock::duration time_connect{};
-static SteadyClock::duration time_verify{};
-static SteadyClock::duration time_undo{};
-static SteadyClock::duration time_index{};
-static SteadyClock::duration time_total{};
-static int64_t num_blocks_total = 0;
-
 /** Apply the effects of this block (with given index) on the UTXO set represented by coins.
  *  Validity checks that depend on the UTXO set are also done; ConnectBlock()
  *  can fail if those validity checks fail (among other reasons). */
@@ -2452,7 +2443,7 @@ bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state,
     uint256 hashPrevBlock = pindex->pprev == nullptr ? uint256() : pindex->pprev->GetBlockHash();
     assert(hashPrevBlock == view.GetBestBlock());
 
-    num_blocks_total++;
+    m_chainman.num_blocks_total++;
 
     // Special case for the genesis block, skipping connection of its transactions
     // (its coinbase is unspendable)
@@ -2494,11 +2485,11 @@ bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state,
     }
 
     const auto time_1{SteadyClock::now()};
-    time_check += time_1 - time_start;
+    m_chainman.time_check += time_1 - time_start;
     LogPrint(BCLog::BENCH, "    - Sanity checks: %.2fms [%.2fs (%.2fms/blk)]\n",
              Ticks<MillisecondsDouble>(time_1 - time_start),
-             Ticks<SecondsDouble>(time_check),
-             Ticks<MillisecondsDouble>(time_check) / num_blocks_total);
+             Ticks<SecondsDouble>(m_chainman.time_check),
+             Ticks<MillisecondsDouble>(m_chainman.time_check) / m_chainman.num_blocks_total);
 
     // Do not allow blocks that contain transactions which 'overwrite' older transactions,
     // unless those are already completely spent.
@@ -2596,11 +2587,11 @@ bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state,
     unsigned int flags{GetBlockScriptFlags(*pindex, m_chainman)};
 
     const auto time_2{SteadyClock::now()};
-    time_forks += time_2 - time_1;
+    m_chainman.time_forks += time_2 - time_1;
     LogPrint(BCLog::BENCH, "    - Fork checks: %.2fms [%.2fs (%.2fms/blk)]\n",
              Ticks<MillisecondsDouble>(time_2 - time_1),
-             Ticks<SecondsDouble>(time_forks),
-             Ticks<MillisecondsDouble>(time_forks) / num_blocks_total);
+             Ticks<SecondsDouble>(m_chainman.time_forks),
+             Ticks<MillisecondsDouble>(m_chainman.time_forks) / m_chainman.num_blocks_total);
 
     CBlockUndo blockundo;
 
@@ -2687,12 +2678,12 @@ bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state,
         UpdateCoins(tx, view, i == 0 ? undoDummy : blockundo.vtxundo.back(), pindex->nHeight);
     }
     const auto time_3{SteadyClock::now()};
-    time_connect += time_3 - time_2;
+    m_chainman.time_connect += time_3 - time_2;
     LogPrint(BCLog::BENCH, "      - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) [%.2fs (%.2fms/blk)]\n", (unsigned)block.vtx.size(),
              Ticks<MillisecondsDouble>(time_3 - time_2), Ticks<MillisecondsDouble>(time_3 - time_2) / block.vtx.size(),
              nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_3 - time_2) / (nInputs - 1),
-             Ticks<SecondsDouble>(time_connect),
-             Ticks<MillisecondsDouble>(time_connect) / num_blocks_total);
+             Ticks<SecondsDouble>(m_chainman.time_connect),
+             Ticks<MillisecondsDouble>(m_chainman.time_connect) / m_chainman.num_blocks_total);
 
     CAmount blockReward = nFees + GetBlockSubsidy(pindex->nHeight, params.GetConsensus());
     if (block.vtx[0]->GetValueOut() > blockReward) {
@@ -2705,12 +2696,12 @@ bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state,
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "block-validation-failed");
     }
     const auto time_4{SteadyClock::now()};
-    time_verify += time_4 - time_2;
+    m_chainman.time_verify += time_4 - time_2;
     LogPrint(BCLog::BENCH, "    - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs (%.2fms/blk)]\n", nInputs - 1,
              Ticks<MillisecondsDouble>(time_4 - time_2),
              nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_4 - time_2) / (nInputs - 1),
-             Ticks<SecondsDouble>(time_verify),
-             Ticks<MillisecondsDouble>(time_verify) / num_blocks_total);
+             Ticks<SecondsDouble>(m_chainman.time_verify),
+             Ticks<MillisecondsDouble>(m_chainman.time_verify) / m_chainman.num_blocks_total);
 
     if (fJustCheck)
         return true;
@@ -2720,11 +2711,11 @@ bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state,
     }
 
     const auto time_5{SteadyClock::now()};
-    time_undo += time_5 - time_4;
+    m_chainman.time_undo += time_5 - time_4;
     LogPrint(BCLog::BENCH, "    - Write undo data: %.2fms [%.2fs (%.2fms/blk)]\n",
              Ticks<MillisecondsDouble>(time_5 - time_4),
-             Ticks<SecondsDouble>(time_undo),
-             Ticks<MillisecondsDouble>(time_undo) / num_blocks_total);
+             Ticks<SecondsDouble>(m_chainman.time_undo),
+             Ticks<MillisecondsDouble>(m_chainman.time_undo) / m_chainman.num_blocks_total);
 
     if (!pindex->IsValid(BLOCK_VALID_SCRIPTS)) {
         pindex->RaiseValidity(BLOCK_VALID_SCRIPTS);
@@ -2735,11 +2726,11 @@ bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state,
     view.SetBestBlock(pindex->GetBlockHash());
 
     const auto time_6{SteadyClock::now()};
-    time_index += time_6 - time_5;
+    m_chainman.time_index += time_6 - time_5;
     LogPrint(BCLog::BENCH, "    - Index writing: %.2fms [%.2fs (%.2fms/blk)]\n",
              Ticks<MillisecondsDouble>(time_6 - time_5),
-             Ticks<SecondsDouble>(time_index),
-             Ticks<MillisecondsDouble>(time_index) / num_blocks_total);
+             Ticks<SecondsDouble>(m_chainman.time_index),
+             Ticks<MillisecondsDouble>(m_chainman.time_index) / m_chainman.num_blocks_total);
 
     TRACE6(validation, block_connected,
         block_hash.data(),
@@ -3097,11 +3088,6 @@ bool Chainstate::DisconnectTip(BlockValidationState& state, DisconnectedBlockTra
     return true;
 }
 
-static SteadyClock::duration time_connect_total{};
-static SteadyClock::duration time_flush{};
-static SteadyClock::duration time_chainstate{};
-static SteadyClock::duration time_post_connect{};
-
 struct PerBlockConnectTrace {
     CBlockIndex* pindex = nullptr;
     std::shared_ptr<const CBlock> pblock;
@@ -3188,31 +3174,31 @@ bool Chainstate::ConnectTip(BlockValidationState& state, CBlockIndex* pindexNew,
             return false;
         }
         time_3 = SteadyClock::now();
-        time_connect_total += time_3 - time_2;
-        assert(num_blocks_total > 0);
+        m_chainman.time_connect_total += time_3 - time_2;
+        assert(m_chainman.num_blocks_total > 0);
         LogPrint(BCLog::BENCH, "  - Connect total: %.2fms [%.2fs (%.2fms/blk)]\n",
                  Ticks<MillisecondsDouble>(time_3 - time_2),
-                 Ticks<SecondsDouble>(time_connect_total),
-                 Ticks<MillisecondsDouble>(time_connect_total) / num_blocks_total);
+                 Ticks<SecondsDouble>(m_chainman.time_connect_total),
+                 Ticks<MillisecondsDouble>(m_chainman.time_connect_total) / m_chainman.num_blocks_total);
         bool flushed = view.Flush();
         assert(flushed);
     }
     const auto time_4{SteadyClock::now()};
-    time_flush += time_4 - time_3;
+    m_chainman.time_flush += time_4 - time_3;
     LogPrint(BCLog::BENCH, "  - Flush: %.2fms [%.2fs (%.2fms/blk)]\n",
              Ticks<MillisecondsDouble>(time_4 - time_3),
-             Ticks<SecondsDouble>(time_flush),
-             Ticks<MillisecondsDouble>(time_flush) / num_blocks_total);
+             Ticks<SecondsDouble>(m_chainman.time_flush),
+             Ticks<MillisecondsDouble>(m_chainman.time_flush) / m_chainman.num_blocks_total);
     // Write the chain state to disk, if necessary.
     if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) {
         return false;
     }
     const auto time_5{SteadyClock::now()};
-    time_chainstate += time_5 - time_4;
+    m_chainman.time_chainstate += time_5 - time_4;
     LogPrint(BCLog::BENCH, "  - Writing chainstate: %.2fms [%.2fs (%.2fms/blk)]\n",
              Ticks<MillisecondsDouble>(time_5 - time_4),
-             Ticks<SecondsDouble>(time_chainstate),
-             Ticks<MillisecondsDouble>(time_chainstate) / num_blocks_total);
+             Ticks<SecondsDouble>(m_chainman.time_chainstate),
+             Ticks<MillisecondsDouble>(m_chainman.time_chainstate) / m_chainman.num_blocks_total);
     // Remove conflicting transactions from the mempool.;
     if (m_mempool) {
         m_mempool->removeForBlock(blockConnecting.vtx, pindexNew->nHeight);
@@ -3223,16 +3209,16 @@ bool Chainstate::ConnectTip(BlockValidationState& state, CBlockIndex* pindexNew,
     UpdateTip(pindexNew);
 
     const auto time_6{SteadyClock::now()};
-    time_post_connect += time_6 - time_5;
-    time_total += time_6 - time_1;
+    m_chainman.time_post_connect += time_6 - time_5;
+    m_chainman.time_total += time_6 - time_1;
     LogPrint(BCLog::BENCH, "  - Connect postprocess: %.2fms [%.2fs (%.2fms/blk)]\n",
              Ticks<MillisecondsDouble>(time_6 - time_5),
-             Ticks<SecondsDouble>(time_post_connect),
-             Ticks<MillisecondsDouble>(time_post_connect) / num_blocks_total);
+             Ticks<SecondsDouble>(m_chainman.time_post_connect),
+             Ticks<MillisecondsDouble>(m_chainman.time_post_connect) / m_chainman.num_blocks_total);
     LogPrint(BCLog::BENCH, "- Connect block: %.2fms [%.2fs (%.2fms/blk)]\n",
              Ticks<MillisecondsDouble>(time_6 - time_1),
-             Ticks<SecondsDouble>(time_total),
-             Ticks<MillisecondsDouble>(time_total) / num_blocks_total);
+             Ticks<SecondsDouble>(m_chainman.time_total),
+             Ticks<MillisecondsDouble>(m_chainman.time_total) / m_chainman.num_blocks_total);
 
     // If we are the background validation chainstate, check to see if we are done
     // validating the snapshot (i.e. our tip has reached the snapshot's base block).
@@ -3423,16 +3409,15 @@ static bool NotifyHeaderTip(ChainstateManager& chainman) LOCKS_EXCLUDED(cs_main)
 {
     bool fNotify = false;
     bool fInitialBlockDownload = false;
-    static CBlockIndex* pindexHeaderOld = nullptr;
     CBlockIndex* pindexHeader = nullptr;
     {
         LOCK(cs_main);
         pindexHeader = chainman.m_best_header;
 
-        if (pindexHeader != pindexHeaderOld) {
+        if (pindexHeader != chainman.m_last_notified_header) {
             fNotify = true;
             fInitialBlockDownload = chainman.IsInitialBlockDownload();
-            pindexHeaderOld = pindexHeader;
+            chainman.m_last_notified_header = pindexHeader;
         }
     }
     // Send block tip changed notifications without cs_main
diff --git a/src/validation.h b/src/validation.h
index 9f99ba796b..ea4ec84242 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -949,6 +949,21 @@ private:
     //! A queue for script verifications that have to be performed by worker threads.
     CCheckQueue<CScriptCheck> m_script_check_queue;
 
+    //! Timers and counters used for benchmarking validation in both background
+    //! and active chainstates.
+    SteadyClock::duration GUARDED_BY(::cs_main) time_check{};
+    SteadyClock::duration GUARDED_BY(::cs_main) time_forks{};
+    SteadyClock::duration GUARDED_BY(::cs_main) time_connect{};
+    SteadyClock::duration GUARDED_BY(::cs_main) time_verify{};
+    SteadyClock::duration GUARDED_BY(::cs_main) time_undo{};
+    SteadyClock::duration GUARDED_BY(::cs_main) time_index{};
+    SteadyClock::duration GUARDED_BY(::cs_main) time_total{};
+    int64_t GUARDED_BY(::cs_main) num_blocks_total{0};
+    SteadyClock::duration GUARDED_BY(::cs_main) time_connect_total{};
+    SteadyClock::duration GUARDED_BY(::cs_main) time_flush{};
+    SteadyClock::duration GUARDED_BY(::cs_main) time_chainstate{};
+    SteadyClock::duration GUARDED_BY(::cs_main) time_post_connect{};
+
 public:
     using Options = kernel::ChainstateManagerOpts;
 
@@ -1048,6 +1063,9 @@ public:
     /** Best header we've seen so far (used for getheaders queries' starting points). */
     CBlockIndex* m_best_header GUARDED_BY(::cs_main){nullptr};
 
+    /** The last header for which a headerTip notification was issued. */
+    CBlockIndex* m_last_notified_header GUARDED_BY(::cs_main){nullptr};
+
     //! The total number of bytes available for us to use across all in-memory
     //! coins caches. This will be split somehow across chainstates.
     int64_t m_total_coinstip_cache{0};