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557b41a38cvalidation: make `IsInitialBlockDownload()` lock-free (Lőrinc)b9c0ab3b75chain: add `CChain::IsTipRecent` helper (Lőrinc)8d531c6210validation: invert `m_cached_finished_ibd` to `m_cached_is_ibd` (Lőrinc)8be54e3b19test: cover IBD exit conditions (Lőrinc) Pull request description: This PR is a follow-up to the stale #32885. ### Problem `ChainstateManager::IsInitialBlockDownload()` currently acquires `cs_main` internally, even though most existing call sites already hold the lock. This becomes relevant for proposals like #34054, which would call `IsInitialBlockDownload()` from the scheduler thread without holding `cs_main`, potentially introducing lock contention. ### Fix Make `ChainstateManager::IsInitialBlockDownload()` lock-free by caching its result in a single atomic `m_cached_is_ibd` (true while in IBD, latched to false on exit). Move the IBD exit checks out of `IsInitialBlockDownload()` (reader-side) into a new `ChainstateManager::UpdateIBDStatus()` (writer-side, called under cs_main). Call UpdateIBDStatus() at strategic points where IBD exit conditions may change, after active chain tip updates in `ConnectTip()`, `DisconnectTip()`, and `LoadChainTip()`, and after `ImportBlocks()` returns. With this, `IsInitialBlockDownload()` becomes a lock-free atomic read, avoiding internal `cs_main` acquisition on hot paths. ### Testing and Benchmarks This isn't strictly an optimization (though some usecases might benefit from it), so rather as a sanity check I ran a reindex-chainstate and an `AssumeUTXO` load (without background validation). <details> <summary>assumeutxo load | 910000 blocks | dbcache 4500 | i9-ssd | x86_64 | Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz | 16 cores | 62Gi RAM | xfs | SSD</summary> ``` COMMITS="595504a43209bead162da54a204df7d140a25f0e 63e822b637f67242e3689adedc0155b34100e651"; \ CC=gcc; CXX=g++; \ BASE_DIR="/mnt/my_storage"; DATA_DIR="$BASE_DIR/ShallowBitcoinData"; LOG_DIR="$BASE_DIR/logs"; UTXO_SNAPSHOT_PATH="$BASE_DIR/utxo-910000.dat"; \ (echo ""; for c in $COMMITS; do git fetch -q origin $c && git log -1 --pretty='%h %s' $c || exit 1; done; echo "") && \ for DBCACHE in 4500; do \ (echo "assumeutxo load | 910000 blocks | dbcache ${DBCACHE} | $(hostname) | $(uname -m) | $(lscpu | grep 'Model name' | head -1 | cut -d: -f2 | xargs) | $(nproc) cores | $(free -h | awk '/^Mem:/{print $2}') RAM | $(df -T $BASE_DIR | awk 'NR==2{print $2}') | $(lsblk -no ROTA $(df --output=source $BASE_DIR | tail -1) | grep -q 0 && echo SSD || echo HDD)";) &&\ hyperfine \ --sort command \ --runs 3 \ --export-json "$BASE_DIR/assumeutxo-$(sed -E 's/(\w{8})\w+ ?/\1-/g;s/-$//'<<<"$COMMITS")-$DBCACHE-$CC-$(date +%s).json" \ --parameter-list COMMIT ${COMMITS// /,} \ --prepare "killall -9 bitcoind 2>/dev/null; rm -rf $DATA_DIR/blocks $DATA_DIR/chainstate $DATA_DIR/chainstate_snapshot $DATA_DIR/debug.log; git clean -fxd; git reset --hard {COMMIT} && \ cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=RelWithDebInfo && ninja -C build bitcoind bitcoin-cli -j2 && \ ./build/bin/bitcoind -datadir=$DATA_DIR -stopatheight=1 -printtoconsole=0; sleep 20 && \ ./build/bin/bitcoind -datadir=$DATA_DIR -daemon -blocksonly -connect=0 -dbcache=$DBCACHE -printtoconsole=0; sleep 20" \ --conclude "build/bin/bitcoin-cli -datadir=$DATA_DIR stop || true; killall bitcoind || true; sleep 10; \ echo '{COMMIT} | dbcache=$DBCACHE | chainstate: $(find $DATA_DIR/chainstate_snapshot -type f 2>/dev/null | wc -l) files, $(du -sb $DATA_DIR/chainstate_snapshot 2>/dev/null | cut -f1) bytes' >> $DATA_DIR/debug.log; \ cp $DATA_DIR/debug.log $LOG_DIR/debug-assumeutxo-{COMMIT}-dbcache-$DBCACHE-$(date +%s).log" \ "COMPILER=$CC DBCACHE=$DBCACHE ./build/bin/bitcoin-cli -datadir=$DATA_DIR -rpcclienttimeout=0 loadtxoutset $UTXO_SNAPSHOT_PATH"; \ done595504a432Merge bitcoin/bitcoin#34236: Add sedited to trusted-keys 63e822b637 validation: make `IsInitialBlockDownload()` lock-free assumeutxo load | 910000 blocks | dbcache 4500 | i9-ssd | x86_64 | Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz | 16 cores | 62Gi RAM | xfs | SSD Benchmark 1: COMPILER=gcc DBCACHE=4500 ./build/bin/bitcoin-cli -datadir=/mnt/my_storage/ShallowBitcoinData -rpcclienttimeout=0 loadtxoutset /mnt/my_storage/utxo-910000.dat (COMMIT =595504a432) Time (mean ± σ): 418.452 s ± 0.461 s [User: 0.001 s, System: 0.001 s] Range (min … max): 418.070 s … 418.964 s 3 runs Benchmark 2: COMPILER=gcc DBCACHE=4500 ./build/bin/bitcoin-cli -datadir=/mnt/my_storage/ShallowBitcoinData -rpcclienttimeout=0 loadtxoutset /mnt/my_storage/utxo-910000.dat (COMMIT = 63e822b637f67242e3689adedc0155b34100e651) Time (mean ± σ): 415.994 s ± 0.294 s [User: 0.001 s, System: 0.001 s] Range (min … max): 415.788 s … 416.330 s 3 runs Relative speed comparison 1.01 ± 0.00 COMPILER=gcc DBCACHE=4500 ./build/bin/bitcoin-cli -datadir=/mnt/my_storage/ShallowBitcoinData -rpcclienttimeout=0 loadtxoutset /mnt/my_storage/utxo-910000.dat (COMMIT =595504a432) 1.00 COMPILER=gcc DBCACHE=4500 ./build/bin/bitcoin-cli -datadir=/mnt/my_storage/ShallowBitcoinData -rpcclienttimeout=0 loadtxoutset /mnt/my_storage/utxo-910000.dat (COMMIT = 63e822b637f67242e3689adedc0155b34100e651) ``` </details> <details> <summary>2026-01-12 | reindex-chainstate | 931139 blocks | dbcache 4500 | i9-ssd | x86_64 | Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz | 16 cores | 62Gi RAM | SSD</summary> ``` for DBCACHE in 4500; do \ COMMITS="595504a43209bead162da54a204df7d140a25f0e 63e822b637f67242e3689adedc0155b34100e651"; \ STOP=931139; CC=gcc; CXX=g++; \ BASE_DIR="/mnt/my_storage"; DATA_DIR="$BASE_DIR/BitcoinData"; LOG_DIR="$BASE_DIR/logs"; \ (echo ""; for c in $COMMITS; do git fetch -q origin $c && git log -1 --pretty='%h %s' $c || exit 1; done) && \ (echo "" && echo "$(date -I) | reindex-chainstate | ${STOP} blocks | dbcache ${DBCACHE} | $(hostname) | $(uname -m) | $(lscpu | grep 'Model name' | head -1 | cut -d: -f2 | xargs) | $(nproc) cores | $(free -h | awk '/^Mem:/{print $2}') RAM | SSD"; echo "") &&\ hyperfine \ --sort command \ --runs 1 \ --export-json "$BASE_DIR/rdx-$(sed -E 's/(\w{8})\w+ ?/\1-/g;s/-$//'<<<"$COMMITS")-$STOP-$DBCACHE-$CC.json" \ --parameter-list COMMIT ${COMMITS// /,} \ --prepare "killall -9 bitcoind 2>/dev/null; rm -f $DATA_DIR/debug.log; git clean -fxd; git reset --hard {COMMIT} && \ cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release -DENABLE_IPC=OFF && ninja -C build bitcoind -j1 && \ ./build/bin/bitcoind -datadir=$DATA_DIR -stopatheight=$STOP -dbcache=1000 -printtoconsole=0; sleep 20; rm -f $DATA_DIR/debug.log" \ --conclude "killall bitcoind || true; sleep 5; grep -q 'height=0' $DATA_DIR/debug.log && grep -q 'Disabling script verification at block #1' $DATA_DIR/debug.log && grep -q 'height=$STOP' $DATA_DIR/debug.log; \ cp $DATA_DIR/debug.log $LOG_DIR/debug-{COMMIT}-$(date +%s).log" \ "COMPILER=$CC ./build/bin/bitcoind -datadir=$DATA_DIR -stopatheight=$STOP -dbcache=$DBCACHE -reindex-chainstate -blocksonly -connect=0 -printtoconsole=0"; done595504a432Merge bitcoin/bitcoin#34236: Add sedited to trusted-keys 63e822b637 validation: make `IsInitialBlockDownload()` lock-free 2026-01-12 | reindex-chainstate | 931139 blocks | dbcache 4500 | i9-ssd | x86_64 | Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz | 16 cores | 62Gi RAM | SSD Benchmark 1: COMPILER=gcc ./build/bin/bitcoind -datadir=/mnt/my_storage/BitcoinData -stopatheight=931139 -dbcache=4500 -reindex-chainstate -blocksonly -connect=0 -printtoconsole=0 (COMMIT =595504a432) Time (abs ≡): 17187.310 s [User: 33104.415 s, System: 937.548 s] Benchmark 2: COMPILER=gcc ./build/bin/bitcoind -datadir=/mnt/my_storage/BitcoinData -stopatheight=931139 -dbcache=4500 -reindex-chainstate -blocksonly -connect=0 -printtoconsole=0 (COMMIT = 63e822b637f67242e3689adedc0155b34100e651) Time (abs ≡): 17240.300 s [User: 33164.803 s, System: 976.485 s] Relative speed comparison 1.00 COMPILER=gcc ./build/bin/bitcoind -datadir=/mnt/my_storage/BitcoinData -stopatheight=931139 -dbcache=4500 -reindex-chainstate -blocksonly -connect=0 -printtoconsole=0 (COMMIT =595504a432) 1.00 COMPILER=gcc ./build/bin/bitcoind -datadir=/mnt/my_storage/BitcoinData -stopatheight=931139 -dbcache=4500 -reindex-chainstate -blocksonly -connect=0 -printtoconsole=0 (COMMIT = 63e822b637f67242e3689adedc0155b34100e651) ``` </details> ACKs for top commit: sedited: ACK557b41a38csipa: utACK557b41a38cmzumsande: Code Review ACK557b41a38cTree-SHA512: 174015b9785846fc3375bd9d6e4ef91de47ffb659a94d645c49d333a33a32986d5c3cb2eb5a0a7245f96580ed6fea4ba5b7f93cac7e42e3b225f0a01538a2e5c