Bitcoin Core  24.99.0
P2P Digital Currency
versionbits.h
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1 // Copyright (c) 2016-2022 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:
70  BIP9Stats GetStateStatisticsFor(const CBlockIndex* pindex, const Consensus::Params& params, std::vector<bool>* signalling_blocks = nullptr) const;
73  ThresholdState GetStateFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const;
75  int GetStateSinceHeightFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const;
76 };
77 
81 {
82 private:
85 
86 public:
90  static BIP9Stats Statistics(const CBlockIndex* pindex, const Consensus::Params& params, Consensus::DeploymentPos pos, std::vector<bool>* signalling_blocks = nullptr);
91 
92  static uint32_t Mask(const Consensus::Params& params, Consensus::DeploymentPos pos);
93 
96 
99 
102  int32_t ComputeBlockVersion(const CBlockIndex* pindexPrev, const Consensus::Params& params) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
103 
105 };
106 
107 #endif // BITCOIN_VERSIONBITS_H
Abstract class that implements BIP9-style threshold logic, and caches results.
Definition: versionbits.h:57
virtual bool Condition(const CBlockIndex *pindex, const Consensus::Params &params) const =0
virtual int Period(const Consensus::Params &params) const =0
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:9
virtual int64_t EndTime(const Consensus::Params &params) const =0
virtual int MinActivationHeight(const Consensus::Params &params) const
Definition: versionbits.h:62
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 ...
virtual int64_t BeginTime(const Consensus::Params &params) const =0
virtual int Threshold(const Consensus::Params &params) const =0
BIP9Stats GetStateStatisticsFor(const CBlockIndex *pindex, const Consensus::Params &params, std::vector< bool > *signalling_blocks=nullptr) const
Returns the numerical statistics of an in-progress BIP9 softfork in the period including pindex If pr...
The block chain is a tree shaped structure starting with the genesis block at the root,...
Definition: chain.h:151
BIP 9 allows multiple softforks to be deployed in parallel.
Definition: versionbits.h:81
int StateSinceHeight(const CBlockIndex *pindexPrev, const Consensus::Params &params, Consensus::DeploymentPos pos) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex)
Get the block height at which the BIP9 deployment switched into the state for the block after pindexP...
static BIP9Stats Statistics(const CBlockIndex *pindex, const Consensus::Params &params, Consensus::DeploymentPos pos, std::vector< bool > *signalling_blocks=nullptr)
Get the numerical statistics for a given deployment for the signalling period that includes pindex.
int32_t ComputeBlockVersion(const CBlockIndex *pindexPrev, const Consensus::Params &params) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex)
Determine what nVersion a new block should use.
static uint32_t Mask(const Consensus::Params &params, Consensus::DeploymentPos pos)
ThresholdState State(const CBlockIndex *pindexPrev, const Consensus::Params &params, Consensus::DeploymentPos pos) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex)
Get the BIP9 state for a given deployment for the block after pindexPrev.
ThresholdConditionCache m_caches[Consensus::MAX_VERSION_BITS_DEPLOYMENTS] GUARDED_BY(m_mutex)
void Clear() EXCLUSIVE_LOCKS_REQUIRED(!m_mutex)
DeploymentPos
Definition: params.h:31
@ MAX_VERSION_BITS_DEPLOYMENTS
Definition: params.h:35
Display status of an in-progress BIP9 softfork.
Definition: versionbits.h:41
int count
Number of blocks with the version bit set since the beginning of the current period.
Definition: versionbits.h:49
int elapsed
Number of blocks elapsed since the beginning of the current period.
Definition: versionbits.h:47
int threshold
Number of blocks with the version bit set required to activate the softfork.
Definition: versionbits.h:45
bool possible
False if there are not enough blocks left in this period to pass activation threshold.
Definition: versionbits.h:51
int period
Length of blocks of the BIP9 signalling period.
Definition: versionbits.h:43
Parameters that influence chain consensus.
Definition: params.h:73
#define EXCLUSIVE_LOCKS_REQUIRED(...)
Definition: threadsafety.h:49
std::map< const CBlockIndex *, ThresholdState > ThresholdConditionCache
Definition: versionbits.h:38
static const int32_t VERSIONBITS_NUM_BITS
Total bits available for versionbits.
Definition: versionbits.h:20
static const int32_t VERSIONBITS_TOP_BITS
What bits to set in version for versionbits blocks.
Definition: versionbits.h:16
static const int32_t VERSIONBITS_LAST_OLD_BLOCK_VERSION
What block version to use for new blocks (pre versionbits)
Definition: versionbits.h:14
static const int32_t VERSIONBITS_TOP_MASK
What bitmask determines whether versionbits is in use.
Definition: versionbits.h:18
ThresholdState
BIP 9 defines a finite-state-machine to deploy a softfork in multiple stages.
Definition: versionbits.h:27