Bitcoin Core  22.99.0
P2P Digital Currency
versionbits.h
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1 // Copyright (c) 2016-2019 The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 
5 #ifndef BITCOIN_VERSIONBITS_H
6 #define BITCOIN_VERSIONBITS_H
7 
8 #include <chain.h>
9 #include <sync.h>
10 
11 #include <map>
12 
14 static const int32_t VERSIONBITS_LAST_OLD_BLOCK_VERSION = 4;
16 static const int32_t VERSIONBITS_TOP_BITS = 0x20000000UL;
18 static const int32_t VERSIONBITS_TOP_MASK = 0xE0000000UL;
20 static const int32_t VERSIONBITS_NUM_BITS = 29;
21 
27 enum class ThresholdState {
28  DEFINED, // First state that each softfork starts out as. The genesis block is by definition in this state for each deployment.
29  STARTED, // For blocks past the starttime.
30  LOCKED_IN, // For at least one retarget period after the first retarget period with STARTED blocks of which at least threshold have the associated bit set in nVersion, until min_activation_height is reached.
31  ACTIVE, // For all blocks after the LOCKED_IN retarget period (final state)
32  FAILED, // For all blocks once the first retarget period after the timeout time is hit, if LOCKED_IN wasn't already reached (final state)
33 };
34 
35 // A map that gives the state for blocks whose height is a multiple of Period().
36 // The map is indexed by the block's parent, however, so all keys in the map
37 // will either be nullptr or a block with (height + 1) % Period() == 0.
38 typedef std::map<const CBlockIndex*, ThresholdState> ThresholdConditionCache;
39 
41 struct BIP9Stats {
43  int period;
45  int threshold;
47  int elapsed;
49  int count;
51  bool possible;
52 };
53 
58 protected:
59  virtual bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const =0;
60  virtual int64_t BeginTime(const Consensus::Params& params) const =0;
61  virtual int64_t EndTime(const Consensus::Params& params) const =0;
62  virtual int MinActivationHeight(const Consensus::Params& params) const { return 0; }
63  virtual int Period(const Consensus::Params& params) const =0;
64  virtual int Threshold(const Consensus::Params& params) const =0;
65 
66 public:
68  BIP9Stats GetStateStatisticsFor(const CBlockIndex* pindex, const Consensus::Params& params) const;
71  ThresholdState GetStateFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const;
73  int GetStateSinceHeightFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const;
74 };
75 
79 {
80 private:
83 
84 public:
86  static BIP9Stats Statistics(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos);
87 
88  static uint32_t Mask(const Consensus::Params& params, Consensus::DeploymentPos pos);
89 
91  ThresholdState State(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos);
92 
94  int StateSinceHeight(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos);
95 
98  int32_t ComputeBlockVersion(const CBlockIndex* pindexPrev, const Consensus::Params& params);
99 
100  void Clear();
101 };
102 
103 #endif // BITCOIN_VERSIONBITS_H
ThresholdState::STARTED
@ STARTED
VERSIONBITS_TOP_MASK
static const int32_t VERSIONBITS_TOP_MASK
What bitmask determines whether versionbits is in use.
Definition: versionbits.h:18
ThresholdState::ACTIVE
@ ACTIVE
VersionBitsCache::State
ThresholdState State(const CBlockIndex *pindexPrev, const Consensus::Params &params, Consensus::DeploymentPos pos)
Get the BIP9 state for a given deployment for the block after pindexPrev.
Definition: versionbits.cpp:193
VersionBitsCache::ComputeBlockVersion
int32_t ComputeBlockVersion(const CBlockIndex *pindexPrev, const Consensus::Params &params)
Determine what nVersion a new block should use.
Definition: versionbits.cpp:215
Consensus::MAX_VERSION_BITS_DEPLOYMENTS
@ MAX_VERSION_BITS_DEPLOYMENTS
Definition: params.h:32
VersionBitsCache::Clear
void Clear()
Definition: versionbits.cpp:231
sync.h
AbstractThresholdConditionChecker::Threshold
virtual int Threshold(const Consensus::Params &params) const =0
AbstractThresholdConditionChecker::EndTime
virtual int64_t EndTime(const Consensus::Params &params) const =0
AbstractThresholdConditionChecker::GetStateFor
ThresholdState GetStateFor(const CBlockIndex *pindexPrev, const Consensus::Params &params, ThresholdConditionCache &cache) const
Returns the state for pindex A based on parent pindexPrev B.
Definition: versionbits.cpp:8
AnnotatedMixin< std::mutex >
VersionBitsCache::m_mutex
Mutex m_mutex
Definition: versionbits.h:81
VERSIONBITS_TOP_BITS
static const int32_t VERSIONBITS_TOP_BITS
What bits to set in version for versionbits blocks.
Definition: versionbits.h:16
ThresholdConditionCache
std::map< const CBlockIndex *, ThresholdState > ThresholdConditionCache
Definition: versionbits.h:38
AbstractThresholdConditionChecker::Period
virtual int Period(const Consensus::Params &params) const =0
VersionBitsCache::Statistics
static BIP9Stats Statistics(const CBlockIndex *pindexPrev, const Consensus::Params &params, Consensus::DeploymentPos pos)
Get the numerical statistics for a given deployment for the signalling period that includes the block...
Definition: versionbits.cpp:199
Consensus::Params
Parameters that influence chain consensus.
Definition: params.h:70
Consensus::DeploymentPos
DeploymentPos
Definition: params.h:28
AbstractThresholdConditionChecker::GetStateSinceHeightFor
int GetStateSinceHeightFor(const CBlockIndex *pindexPrev, const Consensus::Params &params, ThresholdConditionCache &cache) const
Returns the height since when the ThresholdState has started for pindex A based on parent pindexPrev ...
Definition: versionbits.cpp:130
AbstractThresholdConditionChecker::BeginTime
virtual int64_t BeginTime(const Consensus::Params &params) const =0
ThresholdState::DEFINED
@ DEFINED
VersionBitsCache::Mask
static uint32_t Mask(const Consensus::Params &params, Consensus::DeploymentPos pos)
Definition: versionbits.cpp:210
BIP9Stats::count
int count
Number of blocks with the version bit set since the beginning of the current period.
Definition: versionbits.h:49
BIP9Stats::threshold
int threshold
Number of blocks with the version bit set required to activate the softfork.
Definition: versionbits.h:45
AbstractThresholdConditionChecker
Abstract class that implements BIP9-style threshold logic, and caches results.
Definition: versionbits.h:57
chain.h
ThresholdState::FAILED
@ FAILED
AbstractThresholdConditionChecker::MinActivationHeight
virtual int MinActivationHeight(const Consensus::Params &params) const
Definition: versionbits.h:62
AbstractThresholdConditionChecker::GetStateStatisticsFor
BIP9Stats GetStateStatisticsFor(const CBlockIndex *pindex, const Consensus::Params &params) const
Returns the numerical statistics of an in-progress BIP9 softfork in the current period.
Definition: versionbits.cpp:101
BIP9Stats
Display status of an in-progress BIP9 softfork.
Definition: versionbits.h:41
VersionBitsCache::StateSinceHeight
int StateSinceHeight(const CBlockIndex *pindexPrev, const Consensus::Params &params, Consensus::DeploymentPos pos)
Get the block height at which the BIP9 deployment switched into the state for the block after pindexP...
Definition: versionbits.cpp:204
AbstractThresholdConditionChecker::Condition
virtual bool Condition(const CBlockIndex *pindex, const Consensus::Params &params) const =0
VERSIONBITS_NUM_BITS
static const int32_t VERSIONBITS_NUM_BITS
Total bits available for versionbits.
Definition: versionbits.h:20
BIP9Stats::elapsed
int elapsed
Number of blocks elapsed since the beginning of the current period.
Definition: versionbits.h:47
VersionBitsCache::GUARDED_BY
ThresholdConditionCache m_caches[Consensus::MAX_VERSION_BITS_DEPLOYMENTS] GUARDED_BY(m_mutex)
ThresholdState::LOCKED_IN
@ LOCKED_IN
BIP9Stats::possible
bool possible
False if there are not enough blocks left in this period to pass activation threshold.
Definition: versionbits.h:51
VERSIONBITS_LAST_OLD_BLOCK_VERSION
static const int32_t VERSIONBITS_LAST_OLD_BLOCK_VERSION
What block version to use for new blocks (pre versionbits)
Definition: versionbits.h:14
BIP9Stats::period
int period
Length of blocks of the BIP9 signalling period.
Definition: versionbits.h:43
ThresholdState
ThresholdState
BIP 9 defines a finite-state-machine to deploy a softfork in multiple stages.
Definition: versionbits.h:27
CBlockIndex
The block chain is a tree shaped structure starting with the genesis block at the root,...
Definition: chain.h:137
VersionBitsCache
BIP 9 allows multiple softforks to be deployed in parallel.
Definition: versionbits.h:78