diff options
Diffstat (limited to 'consensus/ethash/ethash.go')
| -rw-r--r-- | consensus/ethash/ethash.go | 46 |
1 files changed, 37 insertions, 9 deletions
diff --git a/consensus/ethash/ethash.go b/consensus/ethash/ethash.go index 19c94deb6..d98c3371c 100644 --- a/consensus/ethash/ethash.go +++ b/consensus/ethash/ethash.go @@ -29,6 +29,7 @@ import ( "runtime" "strconv" "sync" + "sync/atomic" "time" "unsafe" @@ -281,6 +282,7 @@ type dataset struct { mmap mmap.MMap // Memory map itself to unmap before releasing dataset []uint32 // The actual cache data content once sync.Once // Ensures the cache is generated only once + done uint32 // Atomic flag to determine generation status } // newDataset creates a new ethash mining dataset and returns it as a plain Go @@ -292,6 +294,9 @@ func newDataset(epoch uint64) interface{} { // generate ensures that the dataset content is generated before use. func (d *dataset) generate(dir string, limit int, test bool) { d.once.Do(func() { + // Mark the dataset generated after we're done. This is needed for remote + defer atomic.StoreUint32(&d.done, 1) + csize := cacheSize(d.epoch*epochLength + 1) dsize := datasetSize(d.epoch*epochLength + 1) seed := seedHash(d.epoch*epochLength + 1) @@ -306,6 +311,8 @@ func (d *dataset) generate(dir string, limit int, test bool) { d.dataset = make([]uint32, dsize/4) generateDataset(d.dataset, d.epoch, cache) + + return } // Disk storage is needed, this will get fancy var endian string @@ -348,6 +355,13 @@ func (d *dataset) generate(dir string, limit int, test bool) { }) } +// generated returns whether this particular dataset finished generating already +// or not (it may not have been started at all). This is useful for remote miners +// to default to verification caches instead of blocking on DAG generations. +func (d *dataset) generated() bool { + return atomic.LoadUint32(&d.done) == 1 +} + // finalizer closes any file handlers and memory maps open. func (d *dataset) finalizer() { if d.mmap != nil { @@ -589,20 +603,34 @@ func (ethash *Ethash) cache(block uint64) *cache { // dataset tries to retrieve a mining dataset for the specified block number // by first checking against a list of in-memory datasets, then against DAGs // stored on disk, and finally generating one if none can be found. -func (ethash *Ethash) dataset(block uint64) *dataset { +// +// If async is specified, not only the future but the current DAG is also +// generates on a background thread. +func (ethash *Ethash) dataset(block uint64, async bool) *dataset { + // Retrieve the requested ethash dataset epoch := block / epochLength currentI, futureI := ethash.datasets.get(epoch) current := currentI.(*dataset) - // Wait for generation finish. - current.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest) - - // If we need a new future dataset, now's a good time to regenerate it. - if futureI != nil { - future := futureI.(*dataset) - go future.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest) + // If async is specified, generate everything in a background thread + if async && !current.generated() { + go func() { + current.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest) + + if futureI != nil { + future := futureI.(*dataset) + future.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest) + } + }() + } else { + // Either blocking generation was requested, or already done + current.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest) + + if futureI != nil { + future := futureI.(*dataset) + go future.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest) + } } - return current } |