Change Details

This PR makes a number of improvements to the InvalidateBlock (`invalidateblock` RPC) and RewindBlockIndex functions, primarily around breaking up their long-term cs_main holding. In addition: * They're made safely interruptible (`bitcoind` can be shutdown, and no progress in either will be lost, though if incomplete, `invalidateblock` won't continue after restart and will need to be called again) * The validation queue is prevented from overflowing (meaning `invalidateblock` on a very old block will not drive bitcoind OOM) (see #14289). * `invalidateblock` won't bother to move transactions back into the mempool after 10 blocks (optimization). Partial Backport of Bitcoin Core PR15402 (commit 9ce9c37): https://github.com/bitcoin/bitcoin/pull/15402/commits/9ce9c37004440d6a329874dbf66b51666d497dcb //Prevent callback overruns in InvalidateBlock and RewindBlockIndex// Depends on D4802

This PR makes a number of improvements to the InvalidateBlock (`invalidateblock` RPC) and RewindBlockIndex functions, primarily around breaking up their long-term cs_main holding. In addition: * They're made safely interruptible (`bitcoind` can be shutdown, and no progress in either will be lost, though if incomplete, `invalidateblock` won't continue after restart and will need to be called again) * The validation queue is prevented from overflowing (meaning `invalidateblock` on a very old block will not drive bitcoind OOM) (see #14289). * `invalidateblock` won't bother to move transactions back into the mempool after 10 blocks (optimization). Partial Backport of Bitcoin Core PR15402 (commit 9ce9c37): https://github.com/bitcoin/bitcoin/pull/15402/commits/9ce9c37004440d6a329874dbf66b51666d497dcb //Prevent callback overruns in InvalidateBlock and RewindBlockIndex// Depends on D4942

This PR makes a number of improvements to the InvalidateBlock (`invalidateblock` RPC) and RewindBlockIndex functions, primarily around breaking up their long-term cs_main holding. In addition: * They're made safely interruptible (`bitcoind` can be shutdown, and no progress in either will be lost, though if incomplete, `invalidateblock` won't continue after restart and will need to be called again) * The validation queue is prevented from overflowing (meaning `invalidateblock` on a very old block will not drive bitcoind OOM) (see #14289). * `invalidateblock` won't bother to move transactions back into the mempool after 10 blocks (optimization). Partial Backport of Bitcoin Core PR15402 (commit 9ce9c37): https://github.com/bitcoin/bitcoin/pull/15402/commits/9ce9c37004440d6a329874dbf66b51666d497dcb //Prevent callback overruns in InvalidateBlock and RewindBlockIndex// Depends on D4802942