Revert "consensus/ethash: use atomic type (ethereum#27068)"

This reverts commit d218958.

consensus/ethash/algorithm.go

@@ -163,7 +163,7 @@ func generateCache(dest []uint32, epoch uint64, seed []byte) {
 	rows := int(size) / hashBytes
 
 	// Start a monitoring goroutine to report progress on low end devices
-	var progress atomic.Uint32
+	var progress uint32
 
 	done := make(chan struct{})
 	defer close(done)
@@ -174,7 +174,7 @@ func generateCache(dest []uint32, epoch uint64, seed []byte) {
 			case <-done:
 				return
 			case <-time.After(3 * time.Second):
-				logger.Info("Generating ethash verification cache", "percentage", progress.Load()*100/uint32(rows)/(cacheRounds+1), "elapsed", common.PrettyDuration(time.Since(start)))
+				logger.Info("Generating ethash verification cache", "percentage", atomic.LoadUint32(&progress)*100/uint32(rows)/(cacheRounds+1), "elapsed", common.PrettyDuration(time.Since(start)))
 			}
 		}
 	}()
@@ -185,7 +185,7 @@ func generateCache(dest []uint32, epoch uint64, seed []byte) {
 	keccak512(cache, seed)
 	for offset := uint64(hashBytes); offset < size; offset += hashBytes {
 		keccak512(cache[offset:], cache[offset-hashBytes:offset])
-		progress.Add(1)
+		atomic.AddUint32(&progress, 1)
 	}
 	// Use a low-round version of randmemohash
 	temp := make([]byte, hashBytes)
@@ -200,7 +200,7 @@ func generateCache(dest []uint32, epoch uint64, seed []byte) {
 			bitutil.XORBytes(temp, cache[srcOff:srcOff+hashBytes], cache[xorOff:xorOff+hashBytes])
 			keccak512(cache[dstOff:], temp)
 
-			progress.Add(1)
+			atomic.AddUint32(&progress, 1)
 		}
 	}
 	// Swap the byte order on big endian systems and return
@@ -299,7 +299,7 @@ func generateDataset(dest []uint32, epoch uint64, cache []uint32) {
 	var pend sync.WaitGroup
 	pend.Add(threads)
 
-	var progress atomic.Uint64
+	var progress uint64
 	for i := 0; i < threads; i++ {
 		go func(id int) {
 			defer pend.Done()
@@ -323,7 +323,7 @@ func generateDataset(dest []uint32, epoch uint64, cache []uint32) {
 				}
 				copy(dataset[index*hashBytes:], item)
 
-				if status := progress.Add(1); status%percent == 0 {
+				if status := atomic.AddUint64(&progress, 1); status%percent == 0 {
 					logger.Info("Generating DAG in progress", "percentage", (status*100)/(size/hashBytes), "elapsed", common.PrettyDuration(time.Since(start)))
 				}
 			}

consensus/ethash/ethash.go

@@ -308,12 +308,12 @@ func (c *cache) finalizer() {
 
 // dataset wraps an ethash dataset with some metadata to allow easier concurrent use.
 type dataset struct {
-	epoch   uint64      // Epoch for which this cache is relevant
-	dump    *os.File    // File descriptor of the memory mapped cache
-	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    atomic.Bool // Atomic flag to determine generation status
+	epoch   uint64    // Epoch for which this cache is relevant
+	dump    *os.File  // File descriptor of the memory mapped cache
+	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
@@ -326,7 +326,7 @@ func newDataset(epoch uint64) *dataset {
 func (d *dataset) generate(dir string, limit int, lock bool, test bool) {
 	d.once.Do(func() {
 		// Mark the dataset generated after we're done. This is needed for remote
-		defer d.done.Store(true)
+		defer atomic.StoreUint32(&d.done, 1)
 
 		csize := cacheSize(d.epoch*epochLength + 1)
 		dsize := datasetSize(d.epoch*epochLength + 1)
@@ -390,7 +390,7 @@ func (d *dataset) generate(dir string, limit int, lock bool, test bool) {
 // 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 d.done.Load()
+	return atomic.LoadUint32(&d.done) == 1
 }
 
 // finalizer closes any file handlers and memory maps open.