This creates a skeleton mining package that simply contains a few of the
definitions used by the mining and mempool code.
This is a step towards decoupling the mining code from the internals of
btcd and ultimately will house all of the code related to creating block
templates and CPU mining.
The main reason a skeleton package is being created before the full
blown package is ready is to avoid blocking mempool separation which
relies on these type definitions.
This introduces the concept of a new interface named TxSource which aims
to generically provide a concurrent safe source of transactions to be
considered for inclusion in a new block. This is a step towards
decoupling the mining code from the internals of btcd. Ultimately the
intent is to create a separate mining package.
The new TxSource interface relies on a new struct named miningTxDesc,
which describes each entry in the transaction source. Once this code is
refactored into a separate mining package, the mining prefix can simply
be dropped leaving the type exported as mining.TxDesc.
To go along with this, the existing TxDesc type in the mempool has been
renamed to mempoolTxDesc and changed to embed the new miningTxDesc type.
This allows the mempool to efficiently implement the MiningTxDescs
method needed to satisfy the TxSource interface.
This approach effectively separates the direct reliance of the mining
code on the mempool and its data structures. Even though the memory
pool will still be the default concrete implementation of the interface,
making it an interface offers much more flexibility in terms of testing
and even provides the potential to allow more than one source (perhaps
multiple independent relay networks, for example).
Finally, the memory pool and all of the mining code has been updated to
implement and use the new interface.
This introduces the concept of a mining policy struct which is used to
control block template generation instead of directly accessing the
config struct. This is a step toward decoupling the mining code from
the internals of btcd. Ultimately the intent is to create a separate
mining package.
Introduce an ECDSA signature verification into btcd in order to
mitigate a certain DoS attack and as a performance optimization.
The benefits of SigCache are two fold. Firstly, usage of SigCache
mitigates a DoS attack wherein an attacker causes a victim's client to
hang due to worst-case behavior triggered while processing attacker
crafted invalid transactions. A detailed description of the mitigated
DoS attack can be found here: https://bitslog.wordpress.com/2013/01/23/fixed-bitcoin-vulnerability-explanation-why-the-signature-cache-is-a-dos-protection/
Secondly, usage of the SigCache introduces a signature verification
optimization which speeds up the validation of transactions within a
block, if they've already been seen and verified within the mempool.
The server itself manages the sigCache instance. The blockManager and
txMempool respectively now receive pointers to the created sigCache
instance. All read (sig triplet existence) operations on the sigCache
will not block unless a separate goroutine is adding an entry (writing)
to the sigCache. GetBlockTemplate generation now also utilizes the
sigCache in order to avoid unnecessarily double checking signatures
when generating a template after previously accepting a txn to the
mempool. Consequently, the CPU miner now also employs the same
optimization.
The maximum number of entries for the sigCache has been introduced as a
config parameter in order to allow users to configure the amount of
memory consumed by this new additional caching.
This commit converts all block height references to int32 instead of
int64. The current target block production rate is 10 mins per block
which means it will take roughly 40,800 years to reach the maximum
height an int32 affords. Even if the target rate were lowered to one
block per minute, it would still take roughly another 4,080 years to
reach the maximum.
In the mean time, there is no reason to use a larger type which results
in higher memory and disk space usage. However, for now, in order to
avoid having to reserialize a bunch of database information, the heights
are still serialized to the database as 8-byte uint64s.
This is being mainly being done in preparation for further upcoming
infrastructure changes which will use the smaller and more efficient
4-byte serialization in the database as well.
Create GenerateCmd in btcjson v2. Update tests to check GenerateCmd.
Update chaincfg/params.go with a new bool in Params, GenerateSupported,
with true values in SimNetParams and RegressionNetParams and false in
the others.
Create new flag, discreteMining, in CPUMiner struct.
Add GenerateNBlocks function to cpuminer.go and handleGenerate
function to rpcserver.go.
Update documentation for the RPC calls.
This commit removes the error returns from the BlockHeader.BlockSha,
MsgBlock.BlockSha, and MsgTx.TxSha functions since they can never fail and
end up causing a lot of unneeded error checking throughout the code base.
It also updates all call sites for the change.
As pointed out in #189, according to the Go documentation, a ticker must
be stopped to release associated resources. This commit adds a defer call
to stop two tickers there were previously not being stopped as well as
changes two others that were being stopped over to use defer so it's more
consistent.
The other ticker in ScheduleShutdown is replaced and already calls Stop
before replacing it, so it has not been modified.
Closes#189.
ok @jrick
There are certain cases such as getblocktemplate which allow external
callers to be repsonsible for creating their own coinbase to replace the
generated one. By allowing the pay address to be nil in such cases, the
need to specify mining addresses via --miningaddr can be avoided thereby
leaving the payment address management up to the caller.
This commit implements a built-in concurrent CPU miner that can be enabled
with the combination of the --generate and --miningaddr options. The
--blockminsize, --blockmaxsize, and --blockprioritysize configuration
options wich already existed prior to this commit control the block
template generation and hence affect blocks mined via the new CPU miner.
The following is a quick overview of the changes and design:
- Starting btcd with --generate and no addresses specified via
--miningaddr will give an error and exit immediately
- Makes use of multiple worker goroutines which independently create block
templates, solve them, and submit the solved blocks
- The default number of worker threads are based on the number of
processor cores in the system and can be dynamically changed at
run-time
- There is a separate speed monitor goroutine used to collate periodic
updates from the workers to calculate overall hashing speed
- The current mining state, number of workers, and hashes per second can
be queried
- Updated sample-btcd.conf file has been updated to include the coin
generation (mining) settings
- Updated doc.go for the new command line options
In addition the old --getworkkey option is now deprecated in favor of the
new --miningaddr option. This was changed for a few reasons:
- There is no reason to have a separate list of keys for getwork and CPU
mining
- getwork is deprecated and will be going away in the future so that means
the --getworkkey flag will also be going away
- Having the work 'key' in the option can be confused with wanting a
private key while --miningaddr make it a little more clear it is an
address that is required
Closes#137.
Reviewed by @jrick.
