feat(metrics): calculate the real pending tx (#983)

* calculate the real pending tx

* update

* move realPendingTx to miner

* update

* calculate the real pending tx by statsWithMinBaseFee

* update

* fix lint

* address comments

* add metrics to StatsWithMinBaseFee

* change read_lock to write_lock

core/txpool/legacypool/legacypool.go

@@ -95,14 +95,17 @@ var (
 	// that this number is pretty low, since txpool reorgs happen very frequently.
 	dropBetweenReorgHistogram = metrics.NewRegisteredHistogram("txpool/dropbetweenreorg", nil, metrics.NewExpDecaySample(1028, 0.015))
 
-	pendingGauge = metrics.NewRegisteredGauge("txpool/pending", nil)
-	queuedGauge  = metrics.NewRegisteredGauge("txpool/queued", nil)
-	localGauge   = metrics.NewRegisteredGauge("txpool/local", nil)
-	slotsGauge   = metrics.NewRegisteredGauge("txpool/slots", nil)
+	pendingGauge     = metrics.NewRegisteredGauge("txpool/pending", nil)
+	realPendingGauge = metrics.NewRegisteredGauge("txpool/real_pending", nil)
+	queuedGauge      = metrics.NewRegisteredGauge("txpool/queued", nil)
+	realQueuedGauge  = metrics.NewRegisteredGauge("txpool/real_queued", nil)
+	localGauge       = metrics.NewRegisteredGauge("txpool/local", nil)
+	slotsGauge       = metrics.NewRegisteredGauge("txpool/slots", nil)
 
 	reheapTimer = metrics.NewRegisteredTimer("txpool/reheap", nil)
 
-	txLifecycleTimer = metrics.NewRegisteredTimer("txpool/txfifecycle", nil)
+	txLifecycleTimer         = metrics.NewRegisteredTimer("txpool/txfifecycle", nil)
+	statsWithMinBaseFeeTimer = metrics.NewRegisteredTimer("txpool/stats_min_base_fee", nil)
 )
 
 // BlockChain defines the minimal set of methods needed to back a tx pool with
@@ -229,11 +232,13 @@ type LegacyPool struct {
 	queueTxEventCh  chan *types.Transaction
 	reorgDoneCh     chan chan struct{}
 	reorgShutdownCh chan struct{}  // requests shutdown of scheduleReorgLoop
-	reorgPauseCh    chan bool      // requests to pause scheduleReorgLoop
 	wg              sync.WaitGroup // tracks loop, scheduleReorgLoop
 	initDoneCh      chan struct{}  // is closed once the pool is initialized (for tests)
 
 	changesSinceReorg int // A counter for how many drops we've performed in-between reorg.
+
+	reorgPauseCh             chan bool // requests to pause scheduleReorgLoop
+	realTxActivityShutdownCh chan struct{}
 }
 
 type txpoolResetRequest struct {
@@ -261,8 +266,10 @@ func New(config Config, chain BlockChain) *LegacyPool {
 		queueTxEventCh:  make(chan *types.Transaction),
 		reorgDoneCh:     make(chan chan struct{}),
 		reorgShutdownCh: make(chan struct{}),
-		reorgPauseCh:    make(chan bool),
 		initDoneCh:      make(chan struct{}),
+
+		reorgPauseCh:             make(chan bool),
+		realTxActivityShutdownCh: make(chan struct{}),
 	}
 	pool.locals = newAccountSet(pool.signer)
 	for _, addr := range config.Locals {
@@ -332,6 +339,21 @@ func (pool *LegacyPool) Init(gasTip *big.Int, head *types.Header, reserve txpool
 	return nil
 }
 
+func (pool *LegacyPool) periodicallyCalculateRealTxActivity() {
+	defer pool.wg.Done()
+	ticker := time.NewTicker(time.Second)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ticker.C:
+			pool.StatsWithMinBaseFee(pool.chain.CurrentBlock().BaseFee)
+		case <-pool.realTxActivityShutdownCh:
+			log.Info("Real tx activity calculation stopped")
+			return
+		}
+	}
+}
+
 // loop is the transaction pool's main event loop, waiting for and reacting to
 // outside blockchain events as well as for various reporting and transaction
 // eviction events.
@@ -488,10 +510,12 @@ func (pool *LegacyPool) stats() (int, int) {
 // StatsWithMinBaseFee retrieves the current pool stats, namely the number of pending and the
 // number of queued (non-executable) transactions greater equal minBaseFee.
 func (pool *LegacyPool) StatsWithMinBaseFee(minBaseFee *big.Int) (int, int) {
-	pool.mu.RLock()
-	defer pool.mu.RUnlock()
-
-	return pool.statsWithMinBaseFee(minBaseFee)
+	statsStart := time.Now()
+	pool.mu.Lock()
+	pendingTxs, queuedTxs := pool.statsWithMinBaseFee(minBaseFee)
+	pool.mu.Unlock()
+	statsWithMinBaseFeeTimer.UpdateSince(statsStart)
+	return pendingTxs, queuedTxs
 }
 
 // statsWithMinBaseFee retrieves the current pool stats, namely the number of pending and the
@@ -506,6 +530,7 @@ func (pool *LegacyPool) statsWithMinBaseFee(minBaseFee *big.Int) (int, int) {
 			pending++
 		}
 	}
+	realPendingGauge.Update(int64(pending))
 
 	queued := 0
 	for _, list := range pool.queue {
@@ -516,6 +541,8 @@ func (pool *LegacyPool) statsWithMinBaseFee(minBaseFee *big.Int) (int, int) {
 			queued++
 		}
 	}
+	realQueuedGauge.Update(int64(queued))
+
 	return pending, queued
 }