Transactions are not allowed in the memory pool or selected for inclusion in a block until their lock times exceed chainActive.Tip()->GetMedianTimePast(). However blocks including transactions which are only mature under the old rules are still accepted; this is *not* the soft-fork required to actually rely on the new constraint in production.
Transactions that fail relative lock time checks will be rejected from the mempool and not included in generated blocks, making it easy to test the feature. However blocks including transactions containing "invalid" relative lock times will still be accepted; this is *not* the soft-fork required to actually enable relative lock times for production use.
The lock-time code currently uses CBlock::nTime as the cutoff point for time based locked transactions. This has the unfortunate outcome of creating a perverse incentive for miners to lie about the time of a block in order to collect more fees by including transactions that by wall clock determination have not yet matured. By using CBlockIndex::GetMedianTimePast from the prior block instead, the self-interested miner no longer gains from generating blocks with fraudulent timestamps. Users can compensate for this change by simply adding an hour (3600 seconds) to their time-based lock times.
If enforced, this would be a soft-fork change. This commit only adds the functionality on an unexecuted code path, without changing the behaviour of Bitcoin Core.
In summary, the sequence number of each input in a transaction is used to store an inverted relative locktime: a delta value which is added to the height or time of the block which included the output being spent to generate a per-input lock time from the sequence number. If enforced, this would make transaction replacement possible as replacing an input with a higher sequence number (lower relative lock time) would allow the new transaction to make it on the chain sooner.
This commit does not implement the transaction replacement logic. Nor does this commit make the relative lock time rules as consensus or policy rules. It merely adds new, but disabled functionality and unit tests for that functionality.
Under some circumstances it is possible for there to be a significant, discontinuous jump in a node's clock value. On mining nodes, this can result in block templates which are no longer valid due to time-based nLockTime constraints. UpdateTime() is modified so that it will never decrease a block's nLockTime, thereby preventing such invalidations.
When the internal miner is enabled at the start of a new node, there
is an near instant assert in TestBlockValidity because its attempting
to mine a block before the top checkpoint.
Also avoids a data race around vNodes.
Github-Pull: #6123
Rebased-From: bba7c24929
1bea2bb Rename ProcessBlock to ProcessNewBlock to indicate change of behaviour, and document it (Luke Dashjr)
d29a291 Rename RPC_TRANSACTION_* errors to RPC_VERIFY_* and use RPC_VERIFY_ERROR for submitblock (Luke Dashjr)
f877aaa Bugfix: submitblock: Use a temporary CValidationState to determine accurately the outcome of ProcessBlock, now that it no longer does the full block validity check (Luke Dashjr)
24e8896 Add CValidationInterface::BlockChecked notification (Luke Dashjr)
85c579e script: add a slew of includes all around and drop includes from script.h (Cory Fields)
db8eb54 script: move ToString and ValueString out of the header (Cory Fields)
e9ca428 script: add ToByteVector() for converting anything with begin/end (Cory Fields)
066e2a1 script: move CScriptID to standard.h and add a ctor for creating them from CScripts (Cory Fields)
This adds a -regetest-only undocumented (for regression testing only)
command-line option -blockversion=N to set block.nVersion.
Adds to the "has the rest of the network upgraded to a
block.nVersion we don't understand" code so it calls
-alertnotify when 51 of the last 100 blocks are up-version.
But it only alerts once, not with every subsequent new, upversion
block.
And adds a forknotify.py regression test to make sure it works.
Tested using forknotify.py:
Before adding CAlert::Notify, get:
Assertion failed: -alertnotify did not warn of up-version blocks
Before adding code to only alert once:
Assertion failed: -alertnotify excessive warning of up-version blocks
After final code in this pull:
Tests successful
7c70438 Get rid of the dummy CCoinsViewCache constructor arg (Pieter Wuille)
ed27e53 Add coins_tests with a large randomized CCoinViewCache test. (Pieter Wuille)
058b08c Do not keep fully spent but unwritten CCoins entries cached. (Pieter Wuille)
c9d1a81 Get rid of CCoinsView's SetCoins and SetBestBlock. (Pieter Wuille)
f28aec0 Use ModifyCoins instead of mutable GetCoins. (Pieter Wuille)
The efficient version of CCoinsViewCache::GetCoins only works for known-to-exist
cache entries, requiring a separate HaveCoins call beforehand. This is
inefficient as both perform a hashtable lookup.
Replace the non-mutable GetCoins with AccessCoins, which returns a potentially-NULL
pointer. This also decreases the overloading of GetCoins.
Also replace some copying (inefficient) GetCoins calls with equivalent AccessCoins,
decreasing the copying.
Split up util.cpp/h into:
- string utilities (hex, base32, base64): no internal dependencies, no dependency on boost (apart from foreach)
- money utilities (parsesmoney, formatmoney)
- time utilities (gettime*, sleep, format date):
- and the rest (logging, argument parsing, config file parsing)
The latter is basically the environment and OS handling,
and is stripped of all utility functions, so we may want to
rename it to something else than util.cpp/h for clarity (Matt suggested
osinterface).
Breaks dependency of sha256.cpp on all the things pulled in by util.
An user on IRC reported an issue where `getrawchangeaddress`
keeps returning a single address when the keypool is exhausted.
In my opinion this is strange behaviour.
- Change CReserveKey to fail when running out of keys in the keypool.
- Make `getrawchangeaddress` return RPC_WALLET_KEYPOOL_RAN_OUT when
unable to create an address.
- Add a Python RPC test for checking the keypool behaviour in combination
with encrypted wallets.
